[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 141851
SWOMCD
SPC MCD 141847 
IAZ000-NEZ000-142015-

MESOSCALE DISCUSSION 2204
NWS STORM PREDICTION CENTER NORMAN OK
0147 PM CDT TUE SEP 14 2004

AREAS AFFECTED...CNTRL/ERN NEB INTO WRN/CNTRL IA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 141847Z - 142015Z

SURFACED-BASED TSTM DEVELOPMENT IS EXPECTED TO BECOME MORE LIKELY IN
THE NEXT 1 TO 2 HOURS AND A WW MAY BE REQUIRED.

LATEST MESOANALYSIS INDICATED A WEAK COLD FRONT FROM E-CNTRL MN SWWD
ACROSS NERN NEB TO AN AREA OF LOW PRESSURE OVER NWRN KS. A WARM
FRONT OR DIFFERENTIAL HEATING ZONE THEN EXTENDED FROM THIS LOW NEWD
ACROSS E-CNTRL NEB /NEAR OMA/ INTO CNTRL IA. SCATTERED ELEVATED
TSTMS HAVE PERSISTED THROUGH MUCH OF THE MORNING AND EARLY AFTERNOON
N OF THIS BOUNDARY OVER NERN NEB INTO NWRN IA WITHIN A ZONE OF
LOW-LEVEL WAA/ISENTROPIC ASCENT. STRONG DIABATIC HEATING HAS ALLOWED
AIRMASS ACROSS S-CNTRL AND SERN NEB INTO N-CNTRL/NERN KS TO WARM
THROUGH THE 80S INTO THE LOWER 90S AT SOME LOCATIONS. WHEN COUPLED
WITH DEWPOINTS IN THE 60S...ENVIRONMENT HAS BECOME MODERATELY
UNSTABLE WITH MLCAPES OF 1000-2000 J/KG.

CURRENT THINKING IS THAT CONTINUED HEATING/DESTABILIZATION SHOULD
ALLOW SOME OF ONGOING ELEVATED TSTMS TO BECOME PROGRESSIVELY ROOTED
IN BOUNDARY-LAYER OVER NEXT COUPLE OF HOURS. ADDITIONAL DEVELOPMENT
WILL ALSO BE POSSIBLE INVOF WARM FRONT OWING TO SUSTAINED
CONVERGENCE AND RESULTANT LOCAL CAP REMOVAL. MODESTLY STRONG
VERTICAL SHEAR OBSERVED ON CURRENT FAIRBURY NEB PROFILER AND RUC
FORECAST SOUNDINGS /I.E. 30-35 KTS THROUGH LOWEST 6 KM/ SUGGESTS THE
POTENTIAL UPDRAFT ROTATION WITH ANY SURFACE-BASED STORMS THAT BECOME
ESTABLISHED. THOUGH AN ISOLATED TORNADO WILL BE POSSIBLE SHORTLY
AFTER INITIATION /ESPECIALLY ALONG OR JUST N OF WARM FRONT/...LARGE
HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER
THREATS.

CONVECTIVE TRENDS ARE BEING MONITORED AND A WW MAY BE REQUIRED
BEFORE 2000 OR 2030Z.

..MEAD.. 09/14/2004

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

ATTN...WFO...DMX...FSD...OAX...GID...

40529945 41069910 42129696 42709409 42599288 41899236
41369324 40259857 

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