[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 312144
SWOMCD
SPC MCD 312143 
IAZ000-NEZ000-SDZ000-312245-

MESOSCALE DISCUSSION 1808
NWS STORM PREDICTION CENTER NORMAN OK
0443 PM CDT SAT JUL 31 2004

AREAS AFFECTED...SERN SD...NERN NEB...NWRN IA

CONCERNING...TORNADO WATCH 676...

VALID 312143Z - 312245Z

...WATCH MAY BE REQUIRED ACROSS PORTIONS OF SERN SD...NERN
NEB...NWRN IA SHORTLY...

STRONG BOUNDARY LAYER HEATING APPEARS TO BE COMPENSATING FOR
APPARENT WEAKNESS IN LOW LEVEL CONVERGENCE ALONG THE SD/NEB BORDER
WHERE CONVECTION CONTINUES TO DEEPEN.  THIS ACTIVITY IS RELATIVELY
HIGH BASED WITHIN STEEP LAPSE RATE ENVIRONMENT...BUT MAY GRADUALLY
LOWER AS UPDRAFTS ENCOUNTER INCREASINGLY MOIST ENVIRONMENT WHERE SFC
DEW POINTS ARE HOLDING IN THE UPPER 60S TO NEAR 70F.  LARGE SCALE
WARM ADVECTION REGIME APPEARS CONDUCIVE FOR ACTIVITY TO PROPAGATE
SEWD ONCE UPDRAFTS BECOME ESTABLISHED. STRONG INSTABILITY FAVORS AT
LEAST LARGE HAIL AND WIND...AND PERHAPS A TORNADO.  WW IS BEING
CONSIDERED.

..DARROW.. 07/31/2004

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

ATTN...WFO...DMX...FSD...OAX...LBF...

43679741 43069538 41769572 41639744 42579874 43329847 

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