Sunday, July 15, 2012

Increasing Heat on the Way Again

Here we go again.... after topping out at only 87 degrees on Friday, the mercury soared to 90 degrees once again on Saturday afternoon.  Call it what you will.  I think I will call it that start of a mini heat wave that will last a total of 4 days, and be over on Wednesday when the high is expected to be back in the 80's once again.  Here's how we get there.  Tonight some thunderstorms have formed in Wisconsin well north of Madison.   They are associated with a disturbance that is moving almost due south.  If they manage to hold together, the parts of the Stateline may be lucky enough to get a little rain late tonight, and maybe even a few rumbles of thunder.  I am skeptical about going overboard forecasting rainfall during the severe drought that in ongoing across extreme northern Illinois and southern Wisconsin.  The front will stall out to the north by morning, and start to retreat back towards the north as the heat starts to build into the mid west from the plains states.  It will be mostly sunny and hot on Sunday with a high around 94 degrees.  Sunday night will be mostly clear and warm with a low in the low 70's.  On Monday surface high pressure will be over eastern Tennessee while a strong upper high builds in closer to the Stateline.  It will be mostly sunny, very hot and more humid with a high around 97 degrees.  On Tuesday the core of the heat will be over Illinois, and the afternoon high will be around 99 degrees with some areas getting above 100 degrees.  With the humidity factored in the heat index will likely be between 100 and 105.  A cool front will be setting toward the southeast  stretching from Marquette, Michigan to Minneapolis to Sioux Falls, South Dakota around daybreak.  It will reach the Stateline late Tuesday night.  The hope is that there will be a good round of showers and thunderstorms as the front passes through the area.  Early forecasts do not produce that much rainfall, but could give our region around half an inch.  Keep in mind that the convective type of precipitation that falls during the mid summer tends to vary quite widely, and will not be evenly spread across the area.  Some areas may not receive any rainfall at all, and others may get some good downpours.  Some showers and thunderstorms may linger into Wednesday as the front moves south of Interstate 80 by the mid day hours, and continues southward for the rest of the day before stalling out as a stationary front stretching from southern Illinois,  across northeastern Missouri, northwestern Iowa, to northeast Montana.  The latter part of the week will be dominated by Canadian high pressure that ridges into Illinois.  High temperatures on Wednesday, Thursday, Friday, and Saturday will be in the mid to high 80's under partly cloudy skies.  There is a slight chance of showers and thunderstorms on Saturday.

No comments:

Post a Comment