[MCD] SWOMCD

Mon Jul 17 22:42:57 UTC 2006

ACUS11 KWNS 172241
SWOMCD
SPC MCD 172241 COR
MIZ000-INZ000-WIZ000-ILZ000-IAZ000-MOZ000-180000-

MESOSCALE DISCUSSION 1541
NWS STORM PREDICTION CENTER NORMAN OK
0541 PM CDT MON JUL 17 2006

AREAS AFFECTED...CNTRL/ERN IA...SRN WI...NRN IL...LWR MI

CONCERNING...SEVERE THUNDERSTORM WATCH 606...607...

VALID 172241Z - 180000Z

CORRECTED SOUTHEAST LOWER MI TO SOUTHWEST LOWER MI

CONTINUE WWS 606-607.  AN ADDITIONAL WW MAY BE NEEDED WITHIN THE
NEXT HOUR OR TWO ACROSS NORTHERN ILLINOIS...INCLUDING THE CHICAGO
METROPOLITAN AREA...AND THE REMAINDER OF SOUTHWEST LOWER MICHIGAN.

STRONG HEATING ALONG PRE-FRONTAL THERMAL RIDGE AXIS EMANATING FROM
THE CENTRAL PLAINS HAS CONTRIBUTED TO AXIS OF EXTREME CONDITIONAL/
CONVECTIVE INSTABILITY AHEAD OF SURFACE FRONT ADVANCING SOUTHWARD
THROUGH THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES REGION. WITH
HIGH SURFACE DEW POINTS IN THE 70S...MIXED LAYER CAPE IS IN EXCESS
OF 4000 J/KG.  AT LEAST UNTIL INHIBITION INCREASES ONCE AGAIN AFTER
ONSET OF BOUNDARY LAYER COOLING LATER THIS EVENING... INCREASING
SEVERE CONVECTIVE DEVELOPMENT APPEARS LIKELY AS FRONTAL FORCING
DEVELOPS THROUGH INSTABILITY AXIS.  MEAN FLOW IS NOT PARTICULARLY
STRONG...BUT THERMODYNAMIC PROFILES WITH POTENTIAL FOR STRONG
EVAPORATIVE COOLING IN DOWNDRAFTS WILL BE FAVORABLE FOR A FEW
INTENSE DOWNBURSTS.  LOCALIZED VERY DAMAGING WINDS APPEAR
POSSIBLE...WITH A BROADER-SCALE STRONG/GUSTY WIND POTENTIAL
INCREASING AS A CONVECTIVE LINE GRADUALLY EVOLVES.  THE CHICAGO
METROPOLITAN AREA MAY BE IMPACTED BY 01-02Z...AND PERHAPS
SOUTHWESTERN LOWER MICHIGAN NOT LONG THEREAFTER.

..KERR.. 07/17/2006

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

ATTN...WFO...DTX...APX...IWX...GRR...GRB...LOT...ILX...MKX...DVN...ARX...DMX...EAX...

43428250 43198368 42988472 42168553 41458645 41138794
40529069 40499306 41389408 42379364 42889297 43319153
43798912 44218695 44418556 44948242 

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