DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 140534
SWODY1
SPC AC 140531

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CDT MON OCT 14 2013

VALID 141200Z - 151200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR THE CNTRL PLAINS...

...SYNOPSIS...
EVENING RAOBS AND WV IMAGERY SHOW A LARGE UPPER WAVE LOCATED ACROSS
THE WRN CONUS WITH A SHORTWAVE IMPULSE ROUNDING ITS BASE OVER NRN
AZ. THIS IMPULSE IS FORECAST TO EJECT NEWD ACROSS THE SRN ROCKIES
THIS MORNING...AND THEN TRAVERSE OVER NEB THROUGH AFTERNOON. SURFACE
CYCLOGENESIS WILL TAKE PLACE OVER THE CNTRL HIGH PLAINS AHEAD OF THE
UPPER IMPULSE...WITH THE LOW MOVING INTO NRN NEB/FAR SRN SD BY
EVENING...AND THEN OCCLUDING TOWARD THE END OF THE PERIOD AS IT
ENTERS SWRN MN. A PSEUDO DRYLINE BOUNDARY WILL INITIALLY EXTEND SWD
FROM THE LOW WITHIN A SHARPENING LEE TROUGH OVER THE HIGH PLAINS.
THIS BOUNDARY WILL MIX EWD ACROSS WRN NEB/KS THROUGH MIDDAY BEFORE
BEING OVERTAKEN BY A COLD FRONT SURGING ESEWD DURING THE AFTERNOON
AND NIGHT.

...CNTRL PLAINS...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE ONGOING AT
THE START OF THE FORECAST PERIOD ACROSS THE CNTRL PLAINS...WHICH
WILL INITIALLY INHIBIT BOUNDARY LAYER DESTABILIZATION. HOWEVER...AS
A 60-70 KT MIDLEVEL JET STREAK SPREADS ACROSS THE REGION DURING THE
LATE MORNING...A DRY SLOT IS FORECAST TO YIELD SOME CLEARING...WHICH
WILL AID IN BOOSTING TEMPERATURES INTO THE 60S TO LOW 70S. THIS
HEATING COMBINED WITH AN AXIS OF MID TO UPPER 50S DEWPOINTS AND
COOLING MIDLEVEL TEMPERATURES WILL SUPPORT A NARROW CORRIDOR OF
MLCAPE AROUND 500 TO PERHAPS 1000 J/KG AHEAD OF THE SYNOPTIC
BOUNDARIES. SCATTERED SURFACE BASED THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG THE DRYLINE NEAR MIDDAY...WITH UPSCALE GROWTH INTO A
LINE OCCURRING ALONG THE SEWD SURGING COLD FRONT LATER IN THE
AFTERNOON AND EVENING.

UPPER-LEVEL SWLYS IN EXCESS OF 100 KT ATOP A 40+ KT SLY LLJ WILL
FAVOR LOW-TOPPED SUPERCELL DEVELOPMENT. THOUGH LOW-LEVEL SHEAR WILL
BE SUBSTANTIAL /0-1 KM SRH AOA 200 M2 S-2/...THE TORNADO THREAT IS
FORECAST TO BE LIMITED BY THE WEAK/NARROW ZONE OF BUOYANCY.
NEVERTHELESS...LONGER-LIVED CELLS WILL BE CAPABLE OF PRODUCING LARGE
HAIL AND DAMAGING WINDS. ADDITIONAL NEAR SURFACE BASED THUNDERSTORMS
WILL BE POSSIBLE CLOSE TO THE AREA OF SURFACE LOW PRESSURE OVER NRN
NEB. SHEAR PROFILES WILL FAVOR ROTATING STORMS OVER THIS AREA...BUT
MARGINAL SURFACE HEATING WILL LIMIT BOUNDARY LAYER DESTABILIZATION
AND RESULT IN A REDUCED SEVERE WEATHER THREAT. OTHERWISE...STORMS
FROM CNTRL NEB SWD INTO KS WILL QUICKLY ARC EWD BY LATE AFTERNOON AS
THE SURFACE CYCLONE BEGINS TO OCCLUDE. ACTIVITY WILL LIKELY WEAKEN
AFTER DARK OVER ERN NEB/KS AS THE BOUNDARY LAYER COOLS AND
STABILIZES...WITH SEVERE WEATHER POTENTIAL BECOMING INCREASINGLY
ISOLATED.

..GARNER/BROYLES.. 10/14/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.