Mesoscale Discussion 1913

Issued

Aug 28, 2007, 3:24 PM CDT (20:24 UTC)

Expired

Aug 28, 2007, 4:30 PM CDT

In force

66 min

Issued by

the Storm Prediction Center

The La Crosse radar (KARX), 69 km from the middle of the area, began a volume at 20:21 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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• Severe Thunderstorm Watch 660Aug 28, 4:50 PM CDT
• Severe Thunderstorm Watch 661Aug 28, 5:30 PM CDT
• Severe Thunderstorm Watch 661Aug 28, 5:35 PM CDT

000 
ACUS11 KWNS 282024
SWOMCD
SPC MCD 282024 
MIZ000-WIZ000-IAZ000-MNZ000-282130-

MESOSCALE DISCUSSION 1913
NWS STORM PREDICTION CENTER NORMAN OK
0324 PM CDT TUE AUG 28 2007

AREAS AFFECTED...NRN IA/SERN MN/CENTRAL-NRN WI/PARTS OF U.P. OF MI

CONCERNING...SEVERE THUNDERSTORM WATCH 659...

VALID 282024Z - 282130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 659
CONTINUES.

REGIONAL RADARS INDICATED SEVERAL CLUSTERS OF TSTMS EXTENDING FROM
NORTH CENTRAL WI SWWD INTO SERN MN...WITH THE LEADING CLUSTER
LOCATED FROM ONEIDA TO NWRN MARATHON COUNTIES SHOWING SOME BOWING
STRUCTURE.  DEEP LAYER ASCENT ATTENDANT WITH MID LEVEL IMPULSE
TRACKING NEWD ACROSS NRN WI AND ALONG COLD FRONT MOVING SLOWLY EWD
INTO VERY UNSTABLE AIR MASS /MLCAPE 2000-3000 J/KG/ WILL SUPPORT
ADDITIONAL STRONG TO SEVERE TSTMS WITHIN WW.  40-50 KT OF EFFECTIVE
BULK SHEAR ORIENTED PARALLEL TO COLD FRONT SUGGEST LINEAR STRUCTURES
SHOULD BE PRIMARY CONVECTIVE MODE PRODUCING DAMAGING WINDS. 
HOWEVER...GIVEN STRONG SHEAR...SUPERCELLS WILL REMAIN POSSIBLE
ENHANCING THE HAIL THREAT...AND SOME THREAT FOR AN ISOLATED TORNADO.

SURFACE HEATING DOWNSTREAM INTO SRN PARTS OF THE U.P. OF MI AND
ACROSS FAR NERN WI INCLUDING DOOR COUNTY HAS AIDED IN WEAKENING THE
SBCIN WITH THE AIR MASS NOW MODERATELY UNSTABLE.  CURRENT RADAR
TRENDS WITH LEADING CLUSTER SUGGEST A DAMAGING WIND THREAT SHOULD
MOVE EAST OF WW 659 AROUND 22Z.  THUS...EITHER A NEW WW MAY BE
NEEDED OVER THESE AREAS...OR A LOCAL EXTENSION TO CURRENT WW OVER
NERN WI.

FARTHER SW...TSTMS SHOULD CONTINUE TO DEVELOP ACROSS NORTH CENTRAL
INTO NERN IA LATE THIS AFTERNOON ALONG COLD FRONT AS ASCENT WITH
NEXT UPSTREAM SHORT WAVE TROUGH SPREADS NEWD ACROSS NRN IA/SRN MN. 
THIS ACTIVITY WILL MOVE INTO SRN PART OF WW 659.  GIVEN SMALL
COVERAGE AREA FOR A SEVERE THREAT OVER NRN IA...A NEW WW IS NOT
ANTICIPATED TO THE S OF WW 659.

..PETERS.. 08/28/2007

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MQT...GRB...MKX...DLH...ARX...MPX...DMX...FSD...

42559372 42649474 43449488 44149487 44389335 44749255
45189207 45669137 45979038 46448801 46478663 45888596
44618739 43588978 42869132

Mesoscale Discussions in Wisconsin, 2007Mesoscale Discussions in Iowa, 2007Mesoscale Discussions in Minnesota, 2007Every mesoscale discussion in 2007

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.