NORTHWEST UPPER WINDS HOLDING MOST INTENSE SOUTHERN HEAT AT BAY IN CHICAGO FOR NOW—BUT HEAT AND RISING HUMIDITIES COMING NEXT WEEK IF CURRENT FORECAST TRENDS VERIFY—COULD SEE TEMPS SURGING WELL INTO THE 90s, POTENTIALLY FLIRTING WITH 100° WED/THU; IN THE SHORT TERM: THE “NW” UPPER WINDS DUE TO LINGER THROUGH THE WEEKEND AND INTO MONDAY SETTING THE STAGE FOR SCATTERED WEEKEND T-STORM DEVELOPMENT
Warm summer temps are to continue in Chicago. But the northwest UPPER AIR FLOW currently in place—and expected to continue through the coming weekend—is to deliver cool temps aloft. Daytime warming beneath this cool air will destabilize the atmosphere, especially this weekend.
When meteorologists use the term “destabilize”, we refer to an atmosphere in which temps drop more quickly than usual with height. Such a set-up encourages air, once heated in the lower atmosphere, to become buoyant and begin to rise. We’ll see the impact of this instability in the formation of cottony summertime cumulus clouds as daytime temps rise in coming days. These clouds could “pop” an isolated shower or t-storm Friday–but our expectation is that the greater instability we anticipate Saturday and Sunday has the best chance of producing scattered t-storm development with these storms impacting as much as 40% of the area and especially numerous in the warmer hours of the day—i.e. the afternoon and evening hours.
It’s NEXT WEEK we continue to see signs the DOME OF HOT AIR which has been breaking records across the South and Southwest will expand northward into the Midwest.
If this process takes place as vigorously as is being modeled at present, temps could be headed into the mid to upper 90s–and could conceivably reach to within striking distance of 100-degrees.
That would be quite a development since there hasn’t been an official 100° temp in the city since July 6, 2012—for the past 11 years. There have only been 65 high temps at or above 100-deg over the 153 year term of official records in Chicago dating back to 1871.
JUST HOW HOT WE GET may hinge on t-storm development, which at the moment, looks likely to ebb (i.e. drop off) Wednesday and Thursday. That’s something we’ll be monitoring closely.
ALSO–The northwesterly upper steering winds will continue to transport some smoke into the Midwest aloft off the Canadian wildfires. Modeling is hinting the density of the smoke may pick up as we head up into the weekend.
Here are forecast panels off the National Weather Service’s “RAP” (for Rapid Update) model. This panel depicting smoke coverage predicted at 7am CDT Friday through 7pm Saturday smoke forecast indicating an increase in the density of the smoke plume which reaches Chicago aloft going into the coming weekend:
Meteorological “cascade effects” which result from a weather regime out of kilter in one area are evident from weather events that have made news in the country recently
It illustrates why there are valid concerns about weather anomalies enhanced by climate shifts, such as those underway across the planet. There are an array of upstream and downstream effects which come into being.
Here’s more on the TUESDAY NIGHT/WED MORNING TORRENTIAL RAINFALL which preliminary reports indicate may well have established a NEW KENTUCKY STATE RECORD for rainfall—and the continuing threat of t-storms capable of EXCESSIVE RAINFALL & SEVERE WEATHER PRODUCTION Thursday and Friday around the periphery of the huge dome of superheated air draped from coast to coast across the southern U.S.
Posted here are analyses of the Wednesday morning flooding downstate Illinois and Kentucky rains—but also the area OUTLOOKED Thursday and Friday FOR POTENTIALLY FLOODING RAINS by the National Weather Service’s Weather Prediction Center (WPC). WPC issues guidance on potential for excessive rainfall. Also included is the Thursday/Thursday night SEVERE WEATHER RISK AREA which has been produced by the National Weather Service’s STORM PREDICTION CENTER (SPC).
The storm complex responsible for the record western Kentucky deluge formed at the periphery of the record hot air dome draped across the southern U.S. The dome is MAMMOTH, as it extends from California east to Florida.
This is a GOES EAST color enhanced animation of the t-storm complex which formed on the periphery of the record hot air dome over the Southern U.S. unleashing nearly a foot of rain on western Kentucky—a rainfall which appears to have set a new Kentucky state record for the greatest recorded calendar day rain:
The drenching southern Illinois/western Kentucky & Tennessee rains were produced by a concentrated cluster of intense thunderstorms which you see animated on satellite imagery posted from the CIRA/RAMBB folks at Colorado State. This storm complex was embedded within the unusually strong July jet stream which is riding the northern periphery of the record-breaking hot air dome which has developed in recent weeks.
THERE’S A LINK BETWEEN THE T-STORM COMPLEX WHICH GENERATED THE RECORD KENTUCKY CLOUDBURST AND THE DEADLY EF-3 TORNADO WHICH RAKED A PORTION OF NORTH CAROLINA WEDNESDAY
Interestingly, it appears the outflow from the downstate Illnois/Kentucky/Tennessee storm complex which ended up generated the devastating EF3 tornado which struck in North Carolina just after noon EDT Wednesday:
The Current Warm Spell
We’ve been lucky in Chicago–spared, to date, the harshest impacts of the most extreme heat currently underway on three continents in the northern hemisphere, thanks in part to a northwest jet stream, sporadic heat tempering t-storms which have put in appearance here and close-by–at times with severe weather the Chicago area has experienced in the past week and possibly even the sun-dimming presence of smoke off an extraordinary and record breaking set of wildfires which has charred more of Canada than in any previous recorded fire season. Those fires continue to burn–the peak of the Canadian fire season is typically a month away.
It’s true–It’s SUMMER—and also true that summers are periods of hot weather. But what’s been happening this summer, most notably exceeding existing and established record high temps, almost on a daily basis and in disparate locations across the northern hemisphere simultaneously, puts us in rare meteorological/climatological territory. You don’t break this number–or the range of weather records–we’ve seen in recent days if this was just a typical summer hot spell.
Breaking records means this hasn’t been recorded before–and weather records go back more than a century with proxy records of climate that extend back thousands of years. This is out of the ordinary.
Flooding at the 17th-century monument in Agra city came as heavy floods swept away houses and bridges and resulted in deadly landslides. CONTINUE READING
Some of the sunniest regions on Earth are in the American Southwest and northeastern Africa. However a recent research article published in the Journal of the American Meteorological Society points to the Altiplano as the region that receives the highest solar radiation on Earth. Here is an interesting article on the subject
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