John Jensen K9WXX of McHenry County Weather is an avid and passionate weather geek who post watches, warnings and advisories on our blog and Facebook
Established: 2013
Coverage Area:
McHenry County, IL
Wednesday, May 30, 2012
Test Message 11:00:54.3925745
THIS IS THE WEEKLY TEST OF THE WXWARN1 ALERT SYSTEM THIS IS ONLY A TEST
Monday, May 28, 2012
Watch County Notification 20:55:41.7458758
THE NATIONAL WEATHER SERVICE HAS CANCELLED SEVERE THUNDERSTORM
WATCH 311 FOR THE FOLLOWING AREAS
IN ILLINOIS THIS CANCELS 11 COUNTIES
IN NORTH CENTRAL ILLINOIS
DE KALB LA SALLE LEE
IN NORTHEAST ILLINOIS
COOK DUPAGE GRUNDY
KANE KENDALL LAKE IL
MCHENRY WILL
THIS INCLUDES THE CITIES OF...AURORA...CHICAGO...DEKALB...DIXON...
JOLIET...MORRIS...OSWEGO...OTTAWA...WAUKEGAN...
WHEATON AND WOODSTOCK.
WATCH 311 FOR THE FOLLOWING AREAS
IN ILLINOIS THIS CANCELS 11 COUNTIES
IN NORTH CENTRAL ILLINOIS
DE KALB LA SALLE LEE
IN NORTHEAST ILLINOIS
COOK DUPAGE GRUNDY
KANE KENDALL LAKE IL
MCHENRY WILL
THIS INCLUDES THE CITIES OF...AURORA...CHICAGO...DEKALB...DIXON...
JOLIET...MORRIS...OSWEGO...OTTAWA...WAUKEGAN...
WHEATON AND WOODSTOCK.
Watch County Notification 18:05:59.6450741
THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
311 IN EFFECT UNTIL 11 PM CDT THIS EVENING FOR THE FOLLOWING
AREAS
IN ILLINOIS THIS WATCH INCLUDES 14 COUNTIES
IN NORTH CENTRAL ILLINOIS
BOONE DE KALB LA SALLE
LEE OGLE WINNEBAGO
IN NORTHEAST ILLINOIS
COOK DUPAGE GRUNDY
KANE KENDALL LAKE IL
MCHENRY WILL
THIS INCLUDES THE CITIES OF...AURORA...BELVIDERE...CHICAGO...
DEKALB...DIXON...JOLIET...MORRIS...OREGON...OSWEGO...OTTAWA...
ROCKFORD...WAUKEGAN...WHEATON AND WOODSTOCK.
311 IN EFFECT UNTIL 11 PM CDT THIS EVENING FOR THE FOLLOWING
AREAS
IN ILLINOIS THIS WATCH INCLUDES 14 COUNTIES
IN NORTH CENTRAL ILLINOIS
BOONE DE KALB LA SALLE
LEE OGLE WINNEBAGO
IN NORTHEAST ILLINOIS
COOK DUPAGE GRUNDY
KANE KENDALL LAKE IL
MCHENRY WILL
THIS INCLUDES THE CITIES OF...AURORA...BELVIDERE...CHICAGO...
DEKALB...DIXON...JOLIET...MORRIS...OREGON...OSWEGO...OTTAWA...
ROCKFORD...WAUKEGAN...WHEATON AND WOODSTOCK.
Special Weather Statement 17:08:09.6107211
...SPECIAL WEATHER STATEMENT...
AT 504 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
RAPIDLY DEVELOPING THUNDERSTORM NEAR LAKEWOOD...MOVING NORTHEAST AT
40 MPH.
ONE HALF INCH DIAMETER HAIL...WINDS GREATER THAN 40 MPH...OCCASIONAL
CLOUD TO GROUND LIGHTNING...ARE POSSIBLE WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
BULL VALLEY... LAKE IN THE HILLS... LAKEWOOD...
ALGONQUIN... WOODSTOCK... PRAIRIE GROVE...
HOLIDAY HILLS... OAKWOOD HILLS... MCHENRY...
THE FOLLOWING LOCATIONS MAY ALSO BE IMPACTED...
CHAIN O LAKES STATE PARK...COLLEGE OF LAKE COUNTY...ILLINOIS BEACH
STATE PARK...LAKE COUNTY ILLINOIS FAIRGROUNDS...MCHENRY COUNTY
COLLEGE...AND MCHENRY COUNTY FAIRGROUNDS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.
LAT...LON 4250 8780 4249 8779 4239 8780 4234 8782
4215 8826 4215 8834 4228 8847 4250 8822
TIME...MOT...LOC 2207Z 234DEG 36KT 4227 8829
AT 504 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
RAPIDLY DEVELOPING THUNDERSTORM NEAR LAKEWOOD...MOVING NORTHEAST AT
40 MPH.
ONE HALF INCH DIAMETER HAIL...WINDS GREATER THAN 40 MPH...OCCASIONAL
CLOUD TO GROUND LIGHTNING...ARE POSSIBLE WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
BULL VALLEY... LAKE IN THE HILLS... LAKEWOOD...
ALGONQUIN... WOODSTOCK... PRAIRIE GROVE...
HOLIDAY HILLS... OAKWOOD HILLS... MCHENRY...
THE FOLLOWING LOCATIONS MAY ALSO BE IMPACTED...
CHAIN O LAKES STATE PARK...COLLEGE OF LAKE COUNTY...ILLINOIS BEACH
STATE PARK...LAKE COUNTY ILLINOIS FAIRGROUNDS...MCHENRY COUNTY
COLLEGE...AND MCHENRY COUNTY FAIRGROUNDS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.
LAT...LON 4250 8780 4249 8779 4239 8780 4234 8782
4215 8826 4215 8834 4228 8847 4250 8822
TIME...MOT...LOC 2207Z 234DEG 36KT 4227 8829
Mesoscale Discussion 17:02:24.6073056
AREAS AFFECTED...EXTREME ERN IA THROUGH NRN IL
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 282159Z - 282330Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...STORMS DEVELOPING FROM ERN IA INTO NRN IL WILL POSE A
THREAT FOR ISOLATED DAMAGING WIND AND LARGE HAIL THIS EVENING. WW
ISSUANCE WILL ULTIMATELY DEPEND ON CONVECTIVE TRENDS...AND IF STORMS
CONTINUE TO INCREASE IN COVERAGE AND INTENSITY...A SEVERE TSTM WATCH
MAY BE NEEDED.
DISCUSSION...RECENT TRENDS HAVE BEEN FOR STORMS TO INCREASE IN
COVERAGE WITHIN ZONE OF FRONTAL CONVERGENCE FROM ERN IA...EXTREME
NWRN IL AND CNTRL WI. DOWNSTREAM THE WARM SECTOR IS MODERATELY
UNSTABLE OVER NRN IL WITH 2000-2500 J/KG MLCAPE AND 7.5 C/KM 700-500
MB LAPSE RATES. LOW LEVEL WINDS HAVE VEERED AHEAD OF THE FRONT WHICH
IS SERVING TO LIMIT CONVERGENCE TO SOME DEGREE. ALOFT A WEAK IMPULSE
WAS INDICATED ON THE RAPID REFRESH ANALYSIS LIFTING NEWD THROUGH IA.
NEVERTHELESS...BOUNDARY LAYER TEMPERATURES HAVE CLIMBED TO AROUND 90
CONTRIBUTING TO A RELATIVELY WEAK CAP...AND STORMS MAY CONTINUE
DEVELOPING AS THE FRONT ADVANCES INTO NRN IL. WHILE SHEAR IN THE
WARM SECTOR IS WEAK...STRONGER FLOW ALOFT HAS OVERTAKEN THE FRONTAL
ZONE RESULTING IN 35-40 KT UNIDIRECTIONAL EFFECTIVE DEEP LAYER
SHEAR. BOTH MULTICELL LINE SEGMENTS AND POSSIBLY SOME SUPERCELL
MODES MAY OCCUR.
..DIAL/HART.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...DVN...
LAT...LON 41509100 42408990 42278799 40858926 40519187 41509100
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 282159Z - 282330Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...STORMS DEVELOPING FROM ERN IA INTO NRN IL WILL POSE A
THREAT FOR ISOLATED DAMAGING WIND AND LARGE HAIL THIS EVENING. WW
ISSUANCE WILL ULTIMATELY DEPEND ON CONVECTIVE TRENDS...AND IF STORMS
CONTINUE TO INCREASE IN COVERAGE AND INTENSITY...A SEVERE TSTM WATCH
MAY BE NEEDED.
DISCUSSION...RECENT TRENDS HAVE BEEN FOR STORMS TO INCREASE IN
COVERAGE WITHIN ZONE OF FRONTAL CONVERGENCE FROM ERN IA...EXTREME
NWRN IL AND CNTRL WI. DOWNSTREAM THE WARM SECTOR IS MODERATELY
UNSTABLE OVER NRN IL WITH 2000-2500 J/KG MLCAPE AND 7.5 C/KM 700-500
MB LAPSE RATES. LOW LEVEL WINDS HAVE VEERED AHEAD OF THE FRONT WHICH
IS SERVING TO LIMIT CONVERGENCE TO SOME DEGREE. ALOFT A WEAK IMPULSE
WAS INDICATED ON THE RAPID REFRESH ANALYSIS LIFTING NEWD THROUGH IA.
NEVERTHELESS...BOUNDARY LAYER TEMPERATURES HAVE CLIMBED TO AROUND 90
CONTRIBUTING TO A RELATIVELY WEAK CAP...AND STORMS MAY CONTINUE
DEVELOPING AS THE FRONT ADVANCES INTO NRN IL. WHILE SHEAR IN THE
WARM SECTOR IS WEAK...STRONGER FLOW ALOFT HAS OVERTAKEN THE FRONTAL
ZONE RESULTING IN 35-40 KT UNIDIRECTIONAL EFFECTIVE DEEP LAYER
SHEAR. BOTH MULTICELL LINE SEGMENTS AND POSSIBLY SOME SUPERCELL
MODES MAY OCCUR.
..DIAL/HART.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...DVN...
LAT...LON 41509100 42408990 42278799 40858926 40519187 41509100
Mesoscale Discussion 16:30:03.5880897
AREAS AFFECTED...MN....WI...MI
CONCERNING...SEVERE THUNDERSTORM WATCH 308...309...
VALID 282058Z - 282230Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
308...309...CONTINUES.
SUMMARY...SCATTERED STRONG TO OCCASIONALLY SEVERE STORMS CONTINUE
ACROSS WATCHES 308 AND 309. CONVECTION DOES APPEAR TO TAKING ON MORE
LINEAR CHARACTER AND EXPECT WIND AND HAIL POTENTIAL TO CONTINUE IN
PORTIONS OF BOTH WATCHES INTO THE EVENING.
DISCUSSION...CONVECTION ACROSS WI HAS STRUGGLED TO ATTAIN MORE VIGOR
THIS AFTERNOON BUT A FEW STORMS HAVE INTENSIFIED RECENTLY AND WIND
AND HAIL SHOULD CONTINUE TO BE A THREAT. FARTHER WEST...IN WATCH
309...RECENT TRENDS SUGGEST STORMS NEAR LAKE SUPERIOR AND ACROSS
CNTRL MN HAVE WEAKENED SOMEWHAT. HOWEVER...LARGE SCALE FORCING AND
SHEAR WILL CONTINUE TO SUPPORT PERSISTENCE. SOME OF THIS ACTIVITY
MAY SPREAD INTO THE WRN PORTIONS OF WATCH 308 DURING THE EVENING
WITH SOME CHANCE FOR HAIL AND WIND CONTINUING.
..CARBIN.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...APX...MQT...GRB...LOT...MKX...DVN...DLH...ARX...
MPX...
LAT...LON 46518632 46658534 45738605 43578723 42448705 42459048
42559106 43519062 44389033 44489496 45029529 45759514
45779437 46419407 46469316 46739311 46759244 47019055
46579072 46298985 46228904 46428895 46518632
CONCERNING...SEVERE THUNDERSTORM WATCH 308...309...
VALID 282058Z - 282230Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
308...309...CONTINUES.
SUMMARY...SCATTERED STRONG TO OCCASIONALLY SEVERE STORMS CONTINUE
ACROSS WATCHES 308 AND 309. CONVECTION DOES APPEAR TO TAKING ON MORE
LINEAR CHARACTER AND EXPECT WIND AND HAIL POTENTIAL TO CONTINUE IN
PORTIONS OF BOTH WATCHES INTO THE EVENING.
DISCUSSION...CONVECTION ACROSS WI HAS STRUGGLED TO ATTAIN MORE VIGOR
THIS AFTERNOON BUT A FEW STORMS HAVE INTENSIFIED RECENTLY AND WIND
AND HAIL SHOULD CONTINUE TO BE A THREAT. FARTHER WEST...IN WATCH
309...RECENT TRENDS SUGGEST STORMS NEAR LAKE SUPERIOR AND ACROSS
CNTRL MN HAVE WEAKENED SOMEWHAT. HOWEVER...LARGE SCALE FORCING AND
SHEAR WILL CONTINUE TO SUPPORT PERSISTENCE. SOME OF THIS ACTIVITY
MAY SPREAD INTO THE WRN PORTIONS OF WATCH 308 DURING THE EVENING
WITH SOME CHANCE FOR HAIL AND WIND CONTINUING.
..CARBIN.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...APX...MQT...GRB...LOT...MKX...DVN...DLH...ARX...
MPX...
LAT...LON 46518632 46658534 45738605 43578723 42448705 42459048
42559106 43519062 44389033 44489496 45029529 45759514
45779437 46419407 46469316 46739311 46759244 47019055
46579072 46298985 46228904 46428895 46518632
Mesoscale Discussion 12:01:50.4287689
AREAS AFFECTED...IA..WI...IL
CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY
VALID 281700Z - 281800Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...STRONG TO SEVERE TSTMS ARE EXPECTED TO DEVELOP AHEAD OF A
COLD FRONT MOVING INTO AREAS OF EXTREME ERN IA...MUCH OF WI...AND
NRN IL THROUGH THE AFTERNOON. A WATCH IS POSSIBLE ACROSS SOME OR
MOST OF THESE AREAS WITHIN THE NEXT HOUR OR TWO.
DISCUSSION...STRONG ASCENT ACCOMPANYING THE SHORT WAVE TROUGH MOVING
INTO ERN MN AND IA WILL LIKELY AID CONVECTIVE DEVELOPMENT ALONG AND
AHEAD OF A COLD FRONT CURRENTLY SITUATED FROM WRN WI SWWD INTO NERN
IA. AIRMASS AHEAD OF THE FRONT CONTINUES TO DESTABILIZE WITH HEATING
OF THE DAY AND SURFACE-BASED CAPE IS CURRENTLY NEARING 1000 J/KG IN
SOME LOCATIONS. A WIDE ARRAY OF MODEL GUIDANCE INDICATES A
REMARKABLY CONSISTENT SIGNAL FOR THE DEVELOPMENT AND INCREASING
COVERAGE OF DEEP CONVECTION...ESPECIALLY ACROSS NRN AND ERN
WI...THROUGH THIS AFTERNOON. THIS MODEL SIGNAL IS LIKELY A RESULT OF
FAVORABLE LARGE SCALE FORCING FOR ASCENT MOVING INTO THE REGION AND
A LACK OF STRONGER INHIBITION THAN WHAT HAS BEEN IN PLACE IN RECENT
DAYS.
AMBIENT DEEP-LAYER SHEAR OF 40KT WITHIN THE SERN FLANK OF THE LARGE
UPPER LOW TO THE WEST WILL SUPPORT INCREASING STORM ORGANIZATION
WITH SUPERCELLS AND BOWING LINE SEGMENTS POTENTIALLY EVOLVING WITH
TIME. LARGE HAIL AND LOCALLY DAMAGING WINDS MAY ACCOMPANY THE
STRONGER STORMS LATER TODAY.
..CARBIN.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GRB...LOT...MKX...DVN...DLH...ARX...
LAT...LON 44159089 44949062 45459001 45808920 45568804 44598754
43768771 42898837 42078983 42279097 43049146 44159089
CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY
VALID 281700Z - 281800Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...STRONG TO SEVERE TSTMS ARE EXPECTED TO DEVELOP AHEAD OF A
COLD FRONT MOVING INTO AREAS OF EXTREME ERN IA...MUCH OF WI...AND
NRN IL THROUGH THE AFTERNOON. A WATCH IS POSSIBLE ACROSS SOME OR
MOST OF THESE AREAS WITHIN THE NEXT HOUR OR TWO.
DISCUSSION...STRONG ASCENT ACCOMPANYING THE SHORT WAVE TROUGH MOVING
INTO ERN MN AND IA WILL LIKELY AID CONVECTIVE DEVELOPMENT ALONG AND
AHEAD OF A COLD FRONT CURRENTLY SITUATED FROM WRN WI SWWD INTO NERN
IA. AIRMASS AHEAD OF THE FRONT CONTINUES TO DESTABILIZE WITH HEATING
OF THE DAY AND SURFACE-BASED CAPE IS CURRENTLY NEARING 1000 J/KG IN
SOME LOCATIONS. A WIDE ARRAY OF MODEL GUIDANCE INDICATES A
REMARKABLY CONSISTENT SIGNAL FOR THE DEVELOPMENT AND INCREASING
COVERAGE OF DEEP CONVECTION...ESPECIALLY ACROSS NRN AND ERN
WI...THROUGH THIS AFTERNOON. THIS MODEL SIGNAL IS LIKELY A RESULT OF
FAVORABLE LARGE SCALE FORCING FOR ASCENT MOVING INTO THE REGION AND
A LACK OF STRONGER INHIBITION THAN WHAT HAS BEEN IN PLACE IN RECENT
DAYS.
AMBIENT DEEP-LAYER SHEAR OF 40KT WITHIN THE SERN FLANK OF THE LARGE
UPPER LOW TO THE WEST WILL SUPPORT INCREASING STORM ORGANIZATION
WITH SUPERCELLS AND BOWING LINE SEGMENTS POTENTIALLY EVOLVING WITH
TIME. LARGE HAIL AND LOCALLY DAMAGING WINDS MAY ACCOMPANY THE
STRONGER STORMS LATER TODAY.
..CARBIN.. 05/28/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GRB...LOT...MKX...DVN...DLH...ARX...
LAT...LON 44159089 44949062 45459001 45808920 45568804 44598754
43768771 42898837 42078983 42279097 43049146 44159089
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