DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 220055
SWODY1
SPC AC 220051

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0751 PM CDT TUE OCT 21 2008

VALID 220100Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PORTIONS OF THE
CNTRL AND SRN HIGH PLAINS...

...CNTRL/SRN PLAINS...

POTENT SHORT WAVE TROUGH DIGGING INTO THE CNTRL ROCKIES WILL
CONTINUE SEWD INTO THE CNTRL AND SRN HIGH PLAINS TONIGHT ON CYCLONIC
SIDE OF STRONG UPPER-LEVEL JET STREAK. IN THE LOW LEVELS...
ATTENDANT COLD FRONT EXTENDING FROM THE WRN DAKOTAS SSWWD INTO CNTRL
CO AS OF 00Z...WILL SURGE SEWD OVERNIGHT...LIKELY STRETCHING FROM
LOW PRESSURE OVER N-CNTRL KS INTO THE SRN TX PNHDL BY 22/12Z.

RUC OBJECTIVE FIELDS INDICATE THAT SFC-850 MB COLD FRONT IS
UNDERGOING CONSIDERABLE STRENGTHENING/FRONTOGENESIS WITH DEEP LAYER
ASCENT OVER THE CNTRL HIGH PLAINS BEING AUGMENTED BY STRONGLY
DIVERGENT FLOW ALOFT IN LEFT EXIT REGION OF DIGGING UPPER-LEVEL JET
STREAK. 00Z DDC SOUNDING INDICATES THE PRESENCE A RELATIVELY MOIST
LOW-LEVEL AIR MASS BENEATH A PLUME OF STEEP MIDLEVEL LAPSE RATES
WITH MLCAPE OF AROUND 1000 J/KG. HOWEVER...THE COOL BOUNDARY LAYER
CONDITIONS ARE RESULTING IN SOME REMAINING CAP FOR SURFACE-BASED
PARCELS.

THE PRIMARY FOCUS FOR STRONG TO SEVERE TSTM DEVELOPMENT OVERNIGHT
APPEARS TO BE ALONG OR IN IMMEDIATE WAKE OF COLD FRONT WHERE
MESOSCALE ASCENT WITHIN ANAFRONTAL AIRFLOW REGIME OVERCOMES
ABOVE-MENTIONED CAP. MARGINALLY SEVERE HAIL WILL BE THE MAIN
THREAT...THOUGH LOCALLY DAMAGING WINDS WILL BE POSSIBLE OWING TO
ADDITIVE EFFECTS OF GROWING STORM-SCALE COLD POOLS WITH
SYNOPTIC-SCALE ISALLOBARIC GRADIENT.

ELSEWHERE...A CLUSTER OF TSTMS HAS RECENTLY INTENSIFIED OVER NERN KS
IN WAKE OF MCV MOVING THROUGH THE LOWER MO VALLEY. LATEST
MESOANALYSIS INDICATES A WEAK WARM FRONT EXTENDING FROM LOW PRESSURE
OVER SERN CO ESEWD ACROSS SRN KS AND INTO FAR SWRN MO. LOW-LEVEL
WAA TO THE N OF THIS BOUNDARY APPEARS TO BE THE PRIMARY MECHANISM
FORCING THIS ELEVATED TSTM DEVELOPMENT. WHILE SOME HAIL IS POSSIBLE
WITH THE MORE INTENSE STORMS...LIMITED CONVECTIVE INSTABILITY
/ARISING FROM RELATIVE WEAKNESS IN MIDLEVEL LAPSE RATES/ IS EXPECTED
TO PRECLUDE A MORE ORGANIZED SEVERE THREAT.

..MEAD.. 10/22/2008

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