Drought Advancing

I said I would post an article on the drought and so I will.  For "official" measurements, visit www.crh.noaa.gov/iwx.  So far this May, most of the area has seen less than an inch of rain (excluding areas north of Route 6 and east of Defiance, with the epicenter of this rainfall deficit centered between Fort Wayne and Antwerp (including the two places).  In fact, it has been so dry that in the last 14-20 days, most areas have not seen rain, which is extremely rare in a spring month.  This has created a rainfall deficit of nearly 2-3 inches since the start of May, and an inch and a half rainfall deficit for the month of April.  Most of you probably have noticed that your yard does not look like it was May, but rather August.  WE really have a serious situation on our hands which will continue to impact our weather throughout the summer and into the fall.  My bet is that we end May with little more rainfall than we have right now, given the fact that most of the rainfall from the next two storm systems will bypass the area well to the north, I do not expect much if any rainfall when this heat wave comes to an end.  As I have talked about before in past blogposts, rainfall deficits lead to dry ground, and dry ground is able to heat up faster and to higher temperatures than wet ground.  Obviously, this is probably one of the most pronounced affects of the drought, with the sun causing warmer temperatures, which may lead to a hotter summer than originally forecast.  One less obvious effect of the drought, is the fact that it will lead to a positive feedback process (a process in which one variable "positively" influences another variable, leading to an enhancement in the process).  I am expecting that this drought will lead to more drought, due to the fact that quite a few storms that form during the summer depend on soil moisture for them to grow.  With less moisture for the storms to feed off of, there will be less rainfall, ultimately making the drought worse.  My theory on what is causing this drought is a combination of the extremely warm winter (even though we had near normal snowfall, the water did not stay in the ground very long because it never froze for more than a couple of days.), the "hot" weather we had in March, and a virtually rainless spring.  There are some other long-term factors, such as the changing positions of the ocean currents during the El Nino phase of the Southern Oscillation, and the changing ocean temperatures, but they likely have less effect than the other factors involved.  Due to the persistence in the heat this spring, I am expecting yet another hot summer across the area, as upper level ridges have seemed to dominate the weather across the East and Central U.S. for large portions of the spring.  This will all lead into next winter's weather, which could once again feature above normal temperatures, but below normal precipitation.  That is too far out to accurately predict so I will not say anything else.
As for this week's weather, temperatures will likely soar into the lower 90's across the area, especially in the aforementioned dry areas.  Even with strong mixing in the boundary layer, southeast winds will transport 60+ degree dew points into the area, giving the air quite a humid feel compared to recent days.  By tomorrow, the front that I mentioned in yesterday's post will cross into the area, causing temperatures to cool slightly (probably to near 88-89 with less humidity).  I am not expecting thunderstorm development with this front (even with the instability in place), due to the fact that the "cap" in the mid-levels is quite strong, which limit any thunderstorm development.  Second, much of the upper level lift will exist to far north of the area to even break the cap for the storms.  By Saturday, that same front will surge back northward, causing temperatures to jump to near 93, along with dew points approaching the mid to upper 60's, making for very humid weather.  On Sunday, temperatures will reach their highest, with some areas (especially areas near extreme eastern Indiana and western Ohio, including Antwerp and Fort Wayne) reaching from 96-98 from time to time.  This will also occur along with humid conditions, so don't be surprised if the National Weather Service issues a heat advisory.  During this same time period, low temperatures will become very warm, with lows in the upper 60's and lower 70's.

This chart shows how far behind in rainfall we are for the year to date