[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 200755
SWOMCD
SPC MCD 200755 
IAZ000-200930-

MESOSCALE DISCUSSION 1577
NWS STORM PREDICTION CENTER NORMAN OK
0255 AM CDT THU JUL 20 2006

AREAS AFFECTED...NRN IA

CONCERNING...TORNADO WATCH 623...

VALID 200755Z - 200930Z

A MARGINAL SEVERE THREAT MAY CONTINUE WITH THE STRONGER
THUNDERSTORMS OVER NRN IA OVER THE NEXT HOUR. HOWEVER...THE SEVERE
THREAT SHOULD GRADUALLY DIMINISH AS THE TAIL END OF THE LINEAR MCS
EXITS NERN IA LATE TONIGHT.

SCATTERED STRONG THUNDERSTORMS ARE CURRENTLY ONGOING ALONG THE WRN
END OF A LARGE MCS ALONG AN AXIS OF LOW-LEVEL CONVERGENCE. THE
ACTIVITY IS ALONG AND JUST BEHIND A COLD FRONT ADVANCING SWD WITH
SFC DEWPOINTS SOUTH OF THE BOUNDARY IN THE 70S F. MODERATE
INSTABILITY IS PRESENT GENERALLY ABOVE 850 MB WITH MUCAPE VALUES IN
THE 1500 TO 2500 J/KG RANGE. THE THUNDERSTORMS ARE JUST BEHIND THE
FRONT AND AHEAD OF A 40 KT MID-LEVEL JET WHICH IS ENHANCING VERTICAL
SHEAR. THIS COMBINED WITH STEEP MID-LEVEL LAPSE RATES SHOULD RESULT
IN A MARGINAL SEVERE THREAT OVER THE NEXT HOUR. HAIL AND STRONG WIND
GUSTS WILL BE POSSIBLE WITH THE STRONGER CELLS BEFORE THE SEVERE
THREAT DIMINISHES.

..BROYLES.. 07/20/2006

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

ATTN...WFO...DVN...ARX...DMX...

42179209 42169389 42539452 43059448 43389393 43279186
42669144 

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