Despite drought conditions gusty thunderstorms continue

When we think of drought we usually think of the dry and hot weather and lack of rainfall.  This has been the case for most of the summer but despite the current drought conditions, thunderstorms have moved through the area with some force behind them.  The Chicago National Weather Service examined the thunderstorms we've experienced so far this year paying particular attention to the wind gusts.  Here's what they found:

WHILE THE SEVERE WEATHER SEASON WAS QUIET AT ITS NORMAL PEAK TIME OF SPRING AND EARLY SUMMER ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...IT HAS BECOME MORE ACTIVE SINCE THE TAIL END OF JUNE. NEARLY 80 PERCENT OF THE PRELIMINARY SEVERE WEATHER REPORTS ACROSS THE NWS CHICAGO COUNTY WARNING AREA THIS METEOROLOGICAL SUMMER /JUNE-AUGUST/ HAVE BEEN CONVECTIVE WIND DAMAGE AND/OR OBSERVED GUSTS. THERE HAVE BEEN APPROXIMATELY 225 PRELIMINARY REPORTS OF EITHER WIND DAMAGE OR SEVERE CRITERIA WIND GUSTS /58 MPH OR STRONGER/ RELAYED TO NWS CHICAGO SINCE JUNE 1ST.

SOME OF THE SEVERE WINDS HAVE BEEN EXTREMELY LOCALIZED IN THE FORM OF MICROBURSTS...WHILE OTHERS HAVE BEEN WIDESPREAD WIND EVENTS SUCH AS WHAT TRANSPIRED THIS PAST SATURDAY AUGUST 4TH. THUS IT IS CHALLENGING TO TRY AND QUANTIFY THE NUMBER OF THESE GUSTY THUNDERSTORMS VERSUS A NORMAL AND HAVE IT BE REPRESENTATIVE EVERYWHERE. LOOKING AT PEAK CONVECTIVE GUSTS AT TWO INDIVIDUAL AREA AIRPORTS CAN SHED SOME LIGHT HOWEVER.
            Rockford:  Summer 2012        1996-2011 Summer Average

Days with gusts >= 40 mph  6                   3
Days with gusts >=58 mph   1                 <1>

*Through August 6th

REGULARLY CAPABLE OF LONG-LASTING WIND EVENTS.
ROCKFORD HAD FOUR DAYS WITH 40 MPH CONVECTIVELY INDUCED GUSTS IN JULY ALONE...TYING IT WITH JUNE 1998...JULY 2003...AND JUNE 2008 FOR THE MOST IN ANY ONE SUMMER MONTH.

THE MORE FREQUENT GUSTY STORMS CAN BE...AT LEAST IN PART...ATTRIBUTED TO THE PERSISTENT HOT AND DRY CONDITIONS.  THE ONGOING VAST DROUGHT HAS LIKELY HELPED KEEP THE BOUNDARY LAYER DRIER THAN NORMAL THROUGH SIGNIFICANTLY LESS EVAPOTRANSPIRATION FROM WHAT WOULD TYPICALLY BE MOISTURE-LADEN CROPS...WHICH IS WHY THE DEW POINTS HAVE NOT BEEN FREQUENTLY IN THE 70S. DRIER NEAR-SURFACE AIR ALLOWS FOR DEEPER MIXING OF THE LOWER ATMOSPHERE AND OVERALL HIGHER CLOUD BASES. THUNDERSTORMS THAT ARE ABLE TO DEVELOP OR MOVE INTO SUCH AN ENVIRONMENT CAN HAVE A HIGHER LIKELIHOOD OF PRODUCING STRONG WINDS AS THEIR DOWNDRAFTS READILY ACCELERATE TO THE GROUND. IN ADDITION...THE PERSISTENT UPPER LEVEL RIDGE AND ASSOCIATED STAGNANT HEAT ACROSS THE MIDSECTION OF THE COUNTRY HAS ALLOWED FOR SCENARIOS IN WHICH THE UPPER PARTS OF THE ATMOSPHERE ACROSS THE REGION REMAIN WELL-MIXED...THROUGH WHAT METEOROLOGISTS CALL AN ELEVATED MIXED LAYER.  STORM GROWTH AND ASSOCIATED WIND STRENGTH CAN DEPEND HEAVILY ON THIS. THE HEAT DOME HAS ALSO ALLOWED FOR THE OCCASIONAL RING-OF-FIRE WEATHER PATTERN ON ITS PERIPHERY...WITH ORGANIZED STORM COMPLEXES