New Forecast: Rain and Warmth on the way

I am very sorry for not posting any forecasts since I've been back, but I have been very busy and had other things to attend to.  Besides that, an interesting forecast period looks to be on the horizon, as a much warmer pattern will be building back into the United States.  The reason for the warmer pattern is because of yet another major trough to push into the Gulf of Alaska and the Western United States, causing a break down in the pattern over the United States, leading to a more zonal, fast flow aloft with embedded shortwaves.  In my opinion, this will eventually lead to the development of another staunch ridge in the Central plains after about a week or two's time.  In the mean time, I am expecting rain and thunderstorms to move back into the forecast by tonight and tomorrow.  If you've been outside on this beautiful warm spring day, you will have noticed high clouds moving into the region from the west.  This indicates that a storm system is approaching.  In fact, a large cluster of thunderstorms is approaching the area from Illinois.  This region of heavy rain and thunderstorms should move toward the area during the next several hours, with rain likely starting after midnight.  By tomorrow, rain and thunderstorms will continue through about noon before tapering off to mostly cloudy skies.  Temperatures will eventually rise into the lower 70's, but it sure won't be that nice of a day.  By Sunday, mostly sunny skies will prevail with temperatures possibly hitting 81-83 in the area, a very comfortable set up before more thunderstorms move into the area Sunday night, ahead of a cold front, which will eventually lead to a cooler air and an end to the warmth.

Forecast Update.

I can tell you this.  I have never, in my entire life, have seen such an incredible run of record-breaking warmth that we have just seen.  It was so incredible, it broke thousands of daily and all-time records across the United States.  Even here, after this run of warmth, we end up with a new all-time record high temperature for March, a new record for the number of consecutive record high days.  The old record was 7 days in a row of record high days in July of 1936, one of the hottest summers on record in the United States.  Not only that, but the average temperature over the last 10 days has been over 55 degrees (the average of the highs and lows).  Normal average temperatures for this time of year is 36 degrees.  This is nearly 20 degrees above normal, and will likely break many more records.  If temperatures continue to stay well above normal for the month of March, I expect that this will end up as the warmest March on record.  This March's average temperature is currently 53 degrees, which is incredible to say the least.  The old record is 48.6 set in 1910.  So for the forecast, I expect showers and even a few thunderstorms to continue impacting the area through the night and possibly into tomorrow morning.  Rainfall totals will generally range near a half inch, but greater rainfall totals will exist where thunderstorms train over certain areas.  Other than that, expect much cooler temperatures into the week, with temperatures into the lower 60's by Monday.  There will be another slight warm up, but not near as large as the one we've been in.  This could bring temperatures as high as the lower and mid 70's by Wednesday, but with the threat for rain and a few thunderstorms.  By Thursday, temperatures will cool but only into the mid 60's.  It is possible that this up and down pattern will continue, with well above normal warmth continuing well into April.  This will likely be the last blog post for a few days, until I will have a chance to access the Internet, since I will be in Florida until April 9th, so I will not be keeping you updated very much but I will try my best.  See ya everyone.

Records shattered everywhere.

After yesterday's high temperature of a "scorching" 83 degrees, we have made it six consecutive record high temperatures.  If today and Wednesday both break the record highs (which is highly likely), then it will be the longest streak of record high temperatures ever recorded at Fort Wayne.  The last time that we had this many consecutive record highs was in 1936!  Another thing, yesterday was our 7th consecutive day above 70 degrees.  This makes it the third longest streak of 70 degree weather ever recorded in March.  If the next several days make it above 70, we shall break the long standing record of 10 consecutive days of 70+ temperatures, which was set in 1910.  We owe the intensity and duration of this warmth to an incredibly strong upper level ridge of high pressure, which extends from the Gulf of Mexico to the Arctic Circle in Canada.  This has allowed warm, moist tropical air to flood the Central and Eastern portions of the country with record breaking warmth.  This tropical air has spread even well into Canada, with some places in Canada reaching the 70's, at a time of year when they are supposed to have an average high in the middle 30's!  Because of how far above normal we are during this "heat" wave, I expect that unless colder air filters into the area and drops the average temperature, we are well on our way to seeing the warmest March on record.  Besides these records that I have just listed, many other records were broken at Fort Wayne, with probably many more records to be broken over the next several days.  In fact, if cloud cover is not an issue, our high temperatures will be within striking distance of breaking March's all-time record high of 86.  Forecast highs for today and tomorrow are both near 85, and the temperatures happen to be warmer than this (which seems to be the trend), we may actually all-time record highs broken, especially at Fort Wayne.  Keep reading my blog for further updates.

Record-breaking Summer-like Warmth to Persist

After a "cooler" weekend, with highs only in the mid to upper 70's, and with scattered showers and thunderstorms.  In fact, compared to Thursday and Wednesday, these days were not near as far above average.  This is all about to change, as an incredible jet streak that has remained over the Pacific Ocean for the last week, is finally moving into the Western trough, which is the source of the stormy weather out west.  As the jet streak moves into the trough, it will cause an incredible deepening of the storm system, so deep in fact that the entire trough will break away from the jet stream in the form of a cut-off low.  Before this happens, the extreme deepening of the trough will cause the ridge over the east will amplify considerably, causing yet another surge of extremely warm air into the region.  In fact, this next surge of warm air will be even greater than the first surge back on last Wednesday, when temperatures first hit the lower 80's.  Tomorrow, I expect that after a relatively warm morning in the lower 60's, along with dense fog in areas, temperatures will warm considerably into the low and possibly even mid-80's, depending on the degree of cloud cover, which is all dependent on thunderstorm development in the afternoon tomorrow.  Either way, it is likely that temperatures will reach into the lower 80's, along with ample sunshine and warm southerly winds.  By Tuesday, temperatures have an even greater chance of hitting of the middle 80's, though mid level clouds could keep temperatures in check in the lower 80's.  GFSx model guidance suggests that the incredibly warm temperatures in the 80's will continue into Wednesday, with mid to upper 70's likely on Thursday as the chance of thunderstorms moves in.  By Friday, the closed-low will likely affect the region with widespread showers and thunderstorms, along with temperatures dropping into the upper 60's.  Here's where discrepancies come between model data.  The GFS is suggesting that the storm system will stall much longer in the Central Plains, which will keep warm air flowing into the region through Friday, keeping high temperatures in the middle 70's.  Amazingly, this is coming from a model that is very progressive, which means that normally it would have this system moving out a lot faster than it actually would.  If a progressive computer model is showing a much slower solution than all of the other computer models, more than likely it is the model that is likely to be the most accurate, especially in these types of situations.  Either way, I will keep a close eye on this, because it could mean a greater chance for severe weather come Friday or possibly Saturday.  Keep on checking this blog for further updates.

Short Term Forecast

Over the last few hours, the atmosphere has destabilized over the last few hours, with rather high instability building over parts of the area.  Current RUC analysis images from 3 p.m., show the axis of highest instability located in Northeast Indiana, along with parts of extreme western Ohio. (note: areas west of Defiance are relatively stable, and not near as warm as areas east of Defiance, due to morning rain and thunderstorms.)  CAPE values or instability values are over 3000 J/kg which indicates a strongly unstable environment, conducive for thunderstorms.  According to the latest satellite imagery, convection was developing over western Indiana, with a large cumulus field also located over the area.  Farther south, large areas of widespread severe thunderstorms were occurring in southern Indiana and along the Ohio River.  I expect over the next few hours that thunderstorms will begin to develop especially east of a line from South Bend to Indianapolis.  More organized thunderstorms will be present east of Defiance, due to stronger deep layer wind shear present, even though instability is not as high as around here.  With the rather moist environment that is also present, I expect that these thunderstorms will be capable of producing heavy rainfall, especially in areas where thunderstorms train (meaning that they move over the same areas over and over).  According to the Storm Prediction Center, large hail is the primary threat from any isolated severe thunderstorm, but it is possible that they also produce gusty winds.  The thunderstorm threat will gradually die out by about 11 or 12 tonight.  Tomorrow, a similar situation will occur, but with more available moisture.  In fact, according to computer models, these situations will be very similar each day until Sunday, when the ridge will be too strong to allow thunderstorms to develop.  The ridge will amplify considerably by Tuesday, with even warmer temperatures than what we've been seeing.  As for right now, we are not sure when this warmth will end, primarily due to the fact that computer models keep changing the story.  I will keep you informed about this record-breaking heat over the next several days.

Summer-like Conditions Overspreading the region.

During the overnight hours, due to the high degree of warmth located in the area, an unstable atmosphere has remained overnight, allowing for the development of scattered strong thunderstorms.  It does look like that over the next few hours, these storms will continue popping up, affecting many areas.  These storms will be capable of small hail, frequent lightning, and heavy rainfall.  Be on your guard this morning.  In other news, temperatures will once again soar to record levels by this afternoon, with high temperatures near 80 degrees.  Upper 70's and lower 80's look to be prevalent through at least the middle of next week.  Stay tuned for further updates.

Record Breaking Warmth Overspreading the Nation.

As I have said over the last several days, the wave of warmth overspreading the nation will be record-breaking in many aspects.  Even in our local area it will be unprecedented.  Temperatures will approach record highs for several days this week, and even well into next week.  For example, tomorrow, it is possible that temperatures reach the upper 70's and lower 80's in some areas (depending on how cold it gets tonight, especially if a weak frontal boundary sags farther south than what is expected).  This high is calculated based on using 850 millibar temperatures.  The idea behind it is that during a regular spring or summer day, the wind and solar heating will cause the entire boundary layer (the first several thousand feet from the surface) to mix out, allowing warm air aloft to mix to the surface.  I will show you how I did my math.  If you assume that the warm aloft is brought to surface by the Dry Adiabatic Lapse Rate (the rate at which the temperature of air changes as it is moved up or down.  On Earth, this lapse rate is approximately 10 degrees Celsius/kilometer), and if you can determine how far above the earth the 850 millibar layer is, you can find the surface temperature for that day.  Assuming that the 850 millibar temperature is 12 degrees Celsius and its height was 1530 meters (which is the conditions that will be existent tomorrow across the area), then you would add 15.3 degrees Celsius to 12 degrees ( first divide 1530 by 1000 , multiply that by 10 to get 15.3), yielding a high of 27.3 degrees Celsius or 81 degrees Fahrenheit.  You would not be able to use that number alone because we are above sea level by 200 meters or 720 feet, which would cause the actual high to be a couple of degrees cooler.  Since we are not that far above sea level, it will not make much a difference, considering the fact that even warmer air aloft could be transported to the surface, making this high temperature forecast true.  So after a high somewhere in the upper 70's on Wednesday, expect the development of scattered thunderstorms after midnight in northern areas, mainly in Michigan.  These storms will eventually develop southward, bringing the thunderstorm potential to most of the area by Thursday morning and afternoon.  This type of pattern will continue into Saturday, before large scale height rises in the upper atmosphere, cause an enormous ridge to develop that extends as far north as the Hudson Bay.  This will lead to a widespread surge of tropical moisture and warmth into the area, including temperatures into the upper 70's and lower 80's next week, along with very moist air.  Even most of the severe weather by the middle of next week will be concentrated in Oklahoma and Kansas, by the end of next week, severe weather may move into our area as a potent storm system affects the region.  Enjoy this warmth while it lasts, as this event is very rare and only happens every decade or so.

Important Update

I have been monitoring the latest trends in the storm system, and it looks like the severe threat could extend farther south than what was indicated this morning.  Upper level forcing is expected to move over the area in a few hours, causing the development of strong thunderstorms to our northwest over southwest lower Michigan and Northwest Indiana.  This thunderstorms will more than likely only sideswipe most areas that are south of Route 6, with a much more robust severe weather threat north of Route 6.  The main threats will be damaging winds and large hail, but tornadoes are also beginning to look like a possibility especially just north of the Michigan border.  Instability is on the increase west of us, and should soon develop in our area, as the area of clearing moves in.  Temperatures have warmed very nicely despite cloud cover.  As soon as clouds move out, I expect temperatures to jump several degrees, possibly just shy of 70.  Tonight, thunderstorms will impact the area after about 7 or 8 p.m.  These thunderstorms could be severe, but mainly north of Route 6.  Tomorrow will be a very nice day with temperatures in the upper 60's and lower 70's as upper level ridging builds into the region.  Light winds and a dry air mass will promote intense cooling Tuesday night, with temperatures falling into the mid 40's, instead of the mid 50's.  Despite this, temperatures on Wednesday will soar to near record levels, with most regions in the area hitting the middle 70's, under sunny skies.  By Wednesday Night, a stalling frontal boundary will approach the region, causing the development of scattered thunderstorms.  These storms probably will not be severe, but they could cause locally heavy rainfall in some areas, due to the highly moist air mass expected to arrive in the area.  Thursday, Friday, Saturday, upper level ridging will only get stronger, even with a series of shortwaves moving around it.  These individual shortwaves will initiate thunderstorms along the frontal boundary in Michigan, which will be a continual threat through Saturday.  These storms could also bring locally heavy rainfall.  At the same time, the rather moist and warm air mass will still remain across the area, keeping temperatures in the lower 70's and nighttime lows above 55.  Just to show how warm this air mass, I will tell you a little fact.  According to the National Weather Service, a nighttime low of 55 or warmer in mid-March has only occurred TWICE in Fort Wayne's 110 years of record keeping.  The forecast for the next week or so is showing at least five days could have lows above 55 degrees (mainly Wednesday, Thursday, Friday, Saturday, and Sunday.).  Next week, the ridge will amplify, causing an even greater surge of tropical air into the region.  In fact, it could get so warm by Monday and Tuesday, some areas could be seeing temperatures as high as 80 degrees!  Many March's in the last 30 years haven't even seen a 70 degree day.  Back in 2008, we were well below average and very snowy.  This  is how extreme the weather pattern has been.  The GFS is showing a quick end to the "heat wave" by the 24th of March, with a potential freeze. It is highly unlikely that this cold wave will last long at the end of March, especially given the current pattern.  Opposite the GFS, the ECMWF model is showing that the ridging will hold, allowing the warmth to continue.  I will continue to monitor this very nice late-spring weather in coming days, as we could see several temperature records broken!

Forecast Updated

The Experimental forecast page has been updated.  Come check it out for a brief long-range forecast and the forecast for this week.

Stormy at First, then Spring

I have good news and some bad news.  For the bad news, current data suggests the potential for thunderstorms tomorrow, mainly south of the Michigan/Indiana border.  If the thunderstorm threat persists longer into the day, then I highly doubt that temperatures will make it much past the lower 60's and upper 50's.  The initial waves of showers look to arrive in late afternoon for areas west of here such as Northern Illinois and possibly even Northwest Indiana, while the initial waves of showers for Indiana and Ohio will not arrive until about 10 p.m. to midnight.  A more solid line of convection will make its way to the Ohio Valley and lower Great Lakes by the early morning hours, with the NAM suggesting these showers and possibly thunderstorms will arrive by 4 or 5 a.m., and the GFS suggesting a much faster solution of arrival around 3 a.m.  Rainfall amounts will likely be near a half inch, with higher amounts of rainfall farther west near Chicago and Illinois.  After the initial warm front passes through the region, temperatures will warm quite nicely from the overnight lows of the mid to upper 40's, into the lower 60's.  If enough diurnal heating takes place tomorrow,  (aka. sunshine) then it is possible that any weak instability that forms do to the heating, will cause the scattered development of thunderstorms, with some taking on severe characteristics, especially with the wind profile that is suggested by the NAM.  This would be supportive of small hail, and a few damaging wind gusts.  Right now, this is only small possibility as the best lifting from the upper level system will have moved out of the region by the time that conditions would be conducive for severe weather.

GFS forecast of the 500 millibar closed low at 5 a.m. tomorrow morning

Conditions will then clear for Monday night, with temperatures dropping into the upper 40's.  Through most of the upcoming week, expect sunny conditions and very warm weather, with highs likely hitting the 70's for several days in a row.  There are some thunderstorm chances coming up, especially Wednesday night into Thursday and next Saturday night, but these rain chances will be rather small, and will not affect temperatures much.  In fact, the latest GFS is forecasting this warmth to last even into the next week, and it really isn't showing much of an end to the warmth even 16 days into the future!  According to the WFO IWX (Northern Indiana's National Weather Service office), they would be not surprised to see the lower 80's by the week after this week, that's how warm this pattern is going to be!  Enjoy!

Nice, Spring Weather Arriving

It may seem not to spring-like right now, with temperatures in the upper 30's and extremely dry air, but a major change is coming once again.  A rather large upper level ridge will anchor itself across the Central and Eastern United States by tomorrow.  Tomorrow, it is expected that southerly winds will bring in a much warmer air mass to the region, with temperatures rising from the mid 20's to the lower and mid 50's by Saturday afternoon.  On Sunday, strong warm air advection with the low levels ahead of a storm system ejecting out of the American Southwest will cause temperatures to jump into the lower and mid 60's, with possibly windy conditions.  By Sunday afternoon, clouds should cause skies to become partly cloudy and by evening mostly cloudy.  Sunday night lows will likely be in the lower 50's, as showers and thunderstorms move through the area, especially after 3 a.m.  Most shower and thunderstorm activity will move out of the area by mid to late morning.   After this, depending on the amount of cloud cover, temperatures should rise into the mid 60's by Monday afternoon.  On Tuesday, clear skies, warm southerly winds and a strong upper level ridge will allow temperatures to jump to near 70.  For the rest of next week, it looks as if temperatures will remain in the upper 60's and lower 70's, even through next weekend.  Stay tuned for further updates.

New Forecast

For anyone who wants a forecast, I have just updated the Experimental Forecast Page.  Right now, I do not have time to write a blog post explaining everything, but the forecast should answer most of your questions.  For a little bit of forecast information; I am becoming a bit concerned for yet another major severe weather outbreak across the Ohio Valley, Tennessee Valley, and even the lower Great Lakes by late this weekend and early next week.  The details are unclear right now, but I will continue to watch the situation.  Another bit of information is that it doesn't look like any major or sustained cold air will make it into the United States for the next several weeks.  If this is true, it might mean that we have just our last shot at winter, with the snow flurries this weekend.  Everybody its time to get out the summer clothes, because spring has just arrived!

Storm Threat Not Over

I am very sorry for not posting about the storm threat today, but I have been very busy.  The main line of storms is beginning to shift out of Northwest Ohio.  Behind this line of thunderstorms, temperatures will rise quickly into the mid and upper 50's, with a few places mainly south of Fort Wayne, reaching into the lower 60's.  This could generate enough instability ahead of the cold front, that a low-topped squall line could develop and race through areas SOUTH of Fort Wayne.  I do not think that any town north or northwest of Fort Wayne will see severe weather, so do not expect it.  Even areas northeast of Fort Wayne will probably have a hard time seeing any kind of strong thunderstorm.  There will be strong lifting and forcing which would replace the need for instability, which is why the Storm Prediction Center has said that the only way that we could get severe weather is if this low-topped squall line forms, which will bring strong, damaging winds and possibly some hail, maybe even a weak tornado.  Other than that, the cold front will pass through near early evening, with lapse rates becoming very high, allowing the transport of momentum of high wind aloft to the surface, combined with the strong surface pressure gradient, which will cause winds higher than 40 knots, which is near 50 mph.  This may mean that our wind advisory could be upgraded to a High Wind Warning, especially if gusts become over 55 mph.  Temperatures will rapidly drop into the lower 30's tonight, with snow showers possibly pivoting into the area with the comma head.  On Sunday, a shortwave will drop through bringing a greater chance for snow showers and much colder temperatures than what we have been seeing.  By next week, another warm up will be on the way, with possibly another heavy rain event/ or severe weather event by Thursday.  I will keep an eye on this over the next couple of days.

Incredibly Warm Day.

After a very cool and foggy start to the day (and after quite a bit of rain over a half an inch), skies have competely cleared and temperatures have soared into the upper 60's in most if not all areas south of Route 6.  Most areas north of Route 6 are still seeing temperatures in the fifties and cities such as Toledo haven't even hit 50 yet today!  Currently in Antwerp, the temperature is steady right near 69 degrees, with Fort Wayne at a very warm 68.  I can tell you this, these temperatures were a lot higher than what I was expecting earlier today.  I actually thought that temperatures may not even hit 60 when I woke up this morning, the warm advection behind the warm front was so incredible and the mixing was so incredible, that temperatures were many degrees warmer than MOS guidance and computer models.  It still does appear that thunderstorms will not form this afternoon, as the dry line is moving through right now, without initiating an convective development.  Even with the weak to moderate surface based instability, thunderstorms still have not had a chance to form.  After the cold front moves through, which will probably happen around 5 or 6 p.m., winds will continue to be strong for a little while longer before subsiding, as the upper level trough pivots through the area.  Most if not all wrap around precipitation will hit north of the area, with some showers around the Michigan.  As for the next couple of days, by Friday, another strong system will be located in the area, with heavy rain and severe weather all possible once again, including very warm temperatures.  I will have more updates tomorrow on this storm.

Forecast Update

It seems as if tomorrow's situation keeps changing every hour, so I will give you the latest consensus among the data.  It looks like the rain will probably start a bit later than what I said yesterday.  Yesterday, I mentioned that precipitation would probably start after 11 p.m., well now, it looks like rain will start around midnight.  In my opinion, I still think that precipitation will begin around the late evening hours, probably around 10 or 11 tonight.  It just all depends on how quickly the storm system moving into the plains occludes, because storm systems tend to accelerate until they occlude, which by that time, they tend to slow down considerably.  This will lead to timing issues with the onset of strong isentropic upglide, upper level forcing, the works... which will all eventually lead to the point at which the atmosphere above is saturated.  As was the trend in models, the storm looks to strengthen and accelerate for the next few hours, then occluding over the Northern Plains somewhere over southern Minnesota.  The storm looks to become fairly strong before becoming vertically stacked (this means that the storm system does not have a tilt to it when moving up from the earth's surface.  In a strengthening storm system, the surface low is located farthest east, while the 500 and 300 millibar lows and troughs, tend to be located north and west of the surface low.  When a low pressure system becomes vertically stacked, all of the upper level storm systems are located directly above the low, causing it to strengthen for a little while longer, but then weaken as it is source of development has been cut off.), which at the time that it is expected to become vertically stacked, the warm sector will be right over the area.  Tonight, no matter what time the rain arrives, it will become steadier and heavier with time, with embedded heavy thunderstorm development after 3 a.m.  By 7 a.m., scattered heavy thunderstorms will still be located in the area, leading to localized heavy rainfall amounts in some parts of the area.  After 9 a.m., most if not all thunderstorm development will cease, with rapidly clearing skies and strong southerly winds bringing in warm, moist air to the region.  Temperatures will soar into the lower and middle 60's across the area, with upper 50's at the Michigan border.  With increasing lapse rates, strong mixing will occur, bringing much higher winds aloft to the surface, increasing wind speeds as high as 40-50 mph.  Strong mixing could also cause the development of showers and thunderstorms in the warm sector ahead of the mesoscale dry line that is expected to pass through the area.  Right now, the highest chance for scattered thunderstorms after 2 p.m. is expected east of I-69, as the axis of highest instability and highest moisture, will move through the areas at the same time that low level convergence will be strongest.  Some models such as the GFS, are indicating that mixing will be so strong that dry air aloft will mix down to the surface, inhibiting significant convective development.  On the otherhand, the NAM has dew points well above what the GFS is forecasting, with dew points near 60, with temperatures near 65.  This would potential lead to thunderstorm development, but the NAM also has a very narrow opportunity for thunderstorm development, dry air mixing to the surface after 4 p.m., so thunderstorms may not ever form tomorrow afternoon, not in our area to the say the least.  My current thinking is that thunderstorms will form if the NAM is correct with the higher dew points in the area, especially if the left exit region of the jet streak ends up right over our area.  These thunderstorms could produce gusty winds and some small hail as they pass quickly through the area.  After they pass, the cold front will quickly pass through the area, with temperatures quickly dropping, but with strong winds continuing throughout the late afternoon.  Some showers and maybe a snow shower may pivot through the area by nightfall, with mostly cloudy skies and falling temperatures.  After this storm passes through, our attention will focus on the next potentially major storm system, which will further impact the area by Friday and Friday night.  Stay tuned for further updates.

A Few Changes

It was very nice day today, with highs approaching the mid 40's under sunny skies.  Winds did get quite strong today, with gusts as high 30 mph.  One of the few things I would like to change to my forecast is tonight's low temperatures.  It seems as if the winds will dying down earlier than what was expected, plus, the cold front currently moving through the area was producing more substantial cold air advection than what I was expecting last night.  So expect lows tonight to drop down to about 23-25 degrees, under clear skies, and relatively light winds.  By tomorrow, clouds will begin to move in from the west, with skies mostly cloudy by late afternoon.  Right now, it does look like precipitation will start a bit later than what was originally forecast.  Instead of around 9 or 10, it now looks around 11 p.m., so only a slight change in when the precipitation will begin.  Areas that are north of Defiance, will likely experience a very brief period of freezing rain before completely changing over to rain.  Do not expect much in the way of ice accretion though, unless you live in southern Michigan, which they might see some ice accumulation.  Throughout most of the night, rain and thunderstorms will prevail, with thunderstorms most likely occurring south of Route 6  There will be a rather large temperature gradient across the area during the morning hours, with temperatures in the low to mid 30's in southern Michigan, and temperatures in the mid and possibly upper 40's near and south of Fort Wayne.  One interesting thing that will happen on Wednesday during the morning and afternoon hours is that the atmosphere will quickly destabilize, with low level temperatures cooling very rapidly with height. With a strong cold front pushing through the area by mid-afternoon, I would expect scattered to widespread thunderstorm development along the cold front, with a few gusty thunderstorms possible also.  Highs now on Wednesday, could get as high as 65 degrees in the area, mainly south of U.S. 24, even though most areas will reach the upper 50's and lower 60's.  The one factor that would really limit a more sustained thunderstorm threat around here, is the fact that the axis of highest moisture could shift off to the east to quick for the cold front to interact with this moisture and produce stronger thunderstorms.  We would also be having more of a low topped supercell threat if large low level helicity values continue in our area, but models are indicating that most of the low level helicity will be moving out of the region before thunderstorm initiation occurs.  IF thunderstorms do form Wednesday afternoon, they will likely organize into a low-topped squall line, capable of producing brief heavy downpours, high winds, and hail.  If no organized thunderstorm threat develops, then expect as the cold front rushes through, for winds to rapidly increase, with winds over 50 mph possible.  By nightfall (and possible late afternoon), a few showers will pivot through the area as the back side of the system moves through the area.  Temperatures will cool into the low to mid 30's, with clearing skies.  By Thursday, temperatures will begin their warming trend once again, with highs back into the mid 40's.  On Friday, it looks as if yet another storm system will be in the making, with showers and thunderstorms possible once again.  According to current forecast soundings for Friday, our thunderstorm threat may be much more mature on Friday, but the limiting factor with Friday's thunderstorm is weak moisture return from the Gulf of Mexico.  This is because of another severe weather outbreak expected in the southern United States, which will limit moist flow northward.

Storm System Later this Week

After reviewing quite a bit of data, this upcoming week looks quite interesting.  I have been looking at the main synoptic models, which have been fairly consistent with their solutions.  For one thing the next couple of days look quite interesting, with strong winds on both Monday and Tuesday.  Tomorrow, a weakening low pressure system will bypass, dragging a cold front along with it through the area.  This will cause temperature lapse rates to steepen quickly, promoting strong mixing of the boundary layer (low levels of the atmosphere).  This will act to transport strong winds aloft to the surface.  Winds will be fairly strong tomorrow, with gusts as high as 35 miles per hour.  Monday afternoon, as the surface cold front drops through, temperatures will drop back into the 30's, and with clear skies Monday night, temperatures will likely drop into the upper 20's, before weak WAA (Warm Air Advection) at the 850 millibar level causes temperatures to rise by Tuesday morning.  On Tuesday, a thickening cloud layer will move into the region by mid afternoon, ahead of the next major storm system.  As the storm system moves closer, winds will become stronger and gusty, but not as strong as they were on Monday.  By Tuesday night, at about 9 or 10 p.m., rain and possibly sleet or freezing rain could begin to fall.  If the mid levels of the atmosphere above us are drier than currently forecast at the onset of precipitation, winter precipitation may be much more of a threat than what model output indicates now.  Right now, I am not too concerned with this, especially because of how strong the warm advection will be Tuesday night.  For right now, there is still the possibility that it could happen.  This will be a situation that I will continue to monitor in coming days.  Rain will continue for most of the night, with several embedded thunderstorms after 3 a.m.  Precipitation will quickly end by 9 a.m. in most locations on Wednesday, with areas north of Route 6, still seeing showers for a little while longer.  Due to the strength of this storm system, a strong temperature gradient will set up across the area from near the Michigan/Indiana state line to Lake Erie.  This will mean temperatures near and over 60 in Fort Wayne and areas farther south, while temperatures will hold in the lower to mid 40's north of Route 6 (a temperature change of 20 degrees in 30 miles of distance!).  As the warm front surges passed the area, I expect that most towns will hit 60 south of the Michigan border, with temperatures along the border in the lower 50's.  Strong mixing in the warm sector, will promote high winds, and could warrant a high wind warning for the area with winds over 45 mph possible!  This strong mixing could cause the atmosphere to become conditionally unstable by early afternoon, and with strong lift from the cold front and remaining low level moisture, there is the possibility of low topped supercells, especially with the strongly veering winds in the lower levels of the atmosphere.  Right now the threat is pretty low of any low topped supercells, but I cannot rule out scattered showers and thunderstorms developing during the early afternoon, especially under mostly sunny skies.  By Wednesday Night, temperatures will rapidly fall in the wake of the cold front, and the comma head of the storm system will pivot through the area, causing rain and a few snow showers, with some of these showers convective in nature, with locally moderate rainfall or snowfall.  After this system, temperatures will not fall that much, with highs easily reaching the mid 40's on Thursday.  By Friday, our next storm system will be in the making and hitting our area with rain once again, and another surge of very warm temperatures.

Another Forecast Update

Since I didn't really address the rain issue in the first post, I will address it now.  According to current radar and surface observations, convective bands of localized have developed and are moving north and eastward at slow rates.  These convective bands are a result of weak mid level instability, and a unique phenomena called slantwise convection.  Intstead of regular convection, which results from upward growth of large cumulus clouds, slantwise convection develops when air moves diagonally instead of directly upward.  Since this upward motion is not intense, lightning and thunder are rare with these bands of rain, but because of the how moist the atmosphere is, and how large scale this upward motion is, heavy rainfall can result from these bands of rain.  I believe this is exactly what is occurring right now, over most of our area.  Therefore, I believe that many areas will receive periods of rain for several hours, before changing over to snow (mainly north of Route 6).  South of Route 6, rain will not change over to snow until boundary layer temperatures cool just enough so that the warm layer is not as deep, which will result from intense synoptic scale lifting and cooling of dry air at the 850 millibar level, mixing with the warmer temperatures of the boundary layer, and causing a much more unstable situation.  This could also initiate even more bands of locally heavy rain.  For this reason rainfall totals will be anywhere in the range of a quarter to a half inch or possibly more.  By early tomorrow morning, most if not all precipitation will be snow in the area with around an inch of snow possible south of Route 6, and several inches north of Route 6.  Other than that, that is the only thing that has changed since my last blog post.

Important Forecast Update

I am very sorry for not posting since Tuesday, but I have been very busy.  As for this post, I need to update the forecast, as some very drastic changes have occurred.  One important thing is that the relatively weak storm system forecast a couple of days ago, has instead become a very strong low pressure system center over Missouri, with a central pressure of at least 990 millibars.  This system has formed in response to a rapidly strengthening jet streak currently situated over the area.  Because of the jet streak, intense lifting is occuring over a widespread area, but with the little moisture that is present, only a narrow band of precipitation has set up over the Midwest, with some areas located within the more intense lifting region experiencing rain changing over to snow.  Right now, the main band of precipitation over our area is mainly rain with some mixing of snow over lower Michigan.  This initial band of precipitation will shift out of the area, with maybe even some partial clearing south of Route 30, but other than that thick clouds will persist over the area.  Intense ascent and lifting due to the temperature gradient south of the area will cause bands of rain to redevelop in most of the area, with areas north and west of Route 6 experiencing rain mixing with snow, or completely changing to snow especially across southern Michigan.  My current thinking is that the jet streak will back build and intensify, causing more intense lifting, and eventually causing most if not all of our precipitation to change to snow after 2 a.m.  The only reason why rain instead of snow is falling currently is because of temperatures near the surface are several degrees above freezing.  Other than that, as soon as we can get temperatures in lowest three thousand feet to cool at least close to freezing, snow will begin to fall.  In some areas, this will occur faster, especially in lower Michigan, far Northern Ohio, and Indiana.  For areas south of Route 6, this changeover will not happen until after late night hours, possibly as late as midnight, especially south of Route 30.  The area that has the most uncertainty right now is the U.S. 24 corridor, as models have not shown any consistency, and have not made it clear where this storm system will move to.  My current thinking is that this system is going to move just south of the area, putting us in the zone of the most intense lifting and warm air advection, which will delay the transition from rain to snow over areas south of U.S. 6.  If the storm does happen to move farther south than indicated, rain will change to snow much more quickly, and bring much higher accumulations to the area.  In the region of Northwest Ohio and Northeast Indiana, the highest snowfall totals will be observed right near the state line, with somewhat higher snowfall totals located over southern Michigan, and somewhat lower totals over far Northwest Ohio and Indiana.  A general 2-4 inches will fall over far Northern Indiana and Northern Ohio (north of Route 6), with around an inch in areas south of Route 6, with much higher totals of 6-12 inches over Lower Michigan into Detroit.  This forecast is highly uncertain as storms like these seem to surprise meteorologists in what they do, so this will be situation that I will be watching.  There is the possibility that the storm shifts south, with more substantial cold air advection in the area, causing a earlier changeover to snow and more substantial snowfall amounts.  I still see this as a possibility, but then again we would still have to worry about warm boundary layer temperatures (the layer from the surface to about three thousand feet above the surface), which would melt the snow causing a cold rain.  One thing that would help the possibility of wintry precipitation is initially dry mid level air, which with intense lifting, would cause intense cooling in the middle and lower layers of the atmosphere.  This would cause the atmosphere to become marginally unstable, causing convection, with initial rain from the convection changing over to snow.  This is why I would also expect some areas to see thunder and lightning with any convective band of rain or even snow.  If this forecast changes, I will write another post to update it.

Experimental Forecast Page.

I have created an experimental forecast page on the blog.  Anybody can access it by clicking on the tab on the front page.  I will try my best to update it at least once a day, while in severe weather or winter weather situations it will be updated two or three times a day depending on how busy I am.  Sometimes if no changes are needed, I will update the forecast only every other day.  Generally I will post a five day forecast, but if I am crunched for time, usually a two or three day forecast will appear.  If you have any questions e-mail me at storm_reportsjoshua@yahoo.com.