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.