[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 212000
SWODY1
SPC AC 211958

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CDT SUN MAY 21 2006

VALID 212000Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
PLAINS...OZARK PLATEAU...TN VALLEY AND SRN ATLANTIC SEABOARD...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL AND
NRN HIGH PLAINS...

...SRN ATLANTIC SEABOARD/SRN APPALACHIANS AND TN VALLEY...
WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL TROUGH OVER THE
ERN SEABOARD WITH AN MCS DEVELOPING ACROSS WRN SC. AT THE SFC...A
NEARLY STATIONARY FRONT IS LOCATED FROM TN EXTENDING EWD ACROSS NRN
SC. ALONG AND SOUTH OF THE BOUNDARY...SFC DEWPOINTS ARE IN THE 60S F
WITH A POCKET OF MODERATE INSTABILITY CURRENTLY LOCATED IN NRN SC
WHICH SHOULD SUSTAIN THE DEVELOPING MCS THIS AFTERNOON. IN
ADDITION...OBJECTIVE ANALYSIS SHOWS 0-6 KM SHEAR VALUES EXCEEDING 30
KT NEAR AND TO THE NORTH OF THE BOUNDARY. AS A RESULT..THE
ENVIRONMENT SHOULD BE SUPPORTIVE OF SUPERCELLS ESPECIALLY AS STORMS
ORGANIZE AND MOVE INTO THE STRONGER INSTABILITY IN THE COASTAL
PLAINS. STORM DEVELOPMENT WILL ALSO BE LIKELY FURTHER WEST ACROSS
THE TN VALLEY LATER THIS AFTERNOON AND EARLY THIS EVENING. THE
STRONGER CELLS SHOULD DEVELOP A POTENTIAL FOR LARGE HAIL AND
ISOLATED WIND DAMAGE ACROSS TN...FAR NRN MS AND FAR NRN AL WHERE
MLCAPE VALUES CURRENTLY RANGE FROM 1000-1500 J/KG AND MODERATE
VERTICAL SHEAR EXISTS. 

...CNTRL PLAINS AND OZARK PLATEAU...
WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SHORTWAVE
TROUGH AND PLUME OF MID-LEVEL MOISTURE OVER CNTRL KS. AT THE SFC...A
NEARLY STATIONARY FRONT IS LOCATED ACROSS ERN KS AND SRN MO. ALONG
AND SOUTH OF THE BOUNDARY...AN AXIS OF INSTABILITY EXISTS WITH
MLCAPE VALUES RANGING FROM 1500-2500 J/KG. IN ADDITION...REGIONAL
PROFILERS SHOW MODERATE VERTICAL SHEAR PROFILES ACROSS MUCH OF ERN
KS EXTENDING ESEWD ACROSS THE OZARK PLATEAU. AS A RESULT...THE
ENVIRONMENT SHOULD BE SUPPORTIVE OF SUPERCELLS AS STORMS INITIATE
AHEAD OF THE SHORTWAVE TROUGH ALONG THE BOUNDARY AND MOVE SEWD INTO
THE INSTABILITY AXIS LATE THIS AFTERNOON. STEEP MID-LEVEL LAPSE
RATES WILL BE FAVORABLE FOR LARGE HAIL. THE WIND DAMAGE POTENTIAL
SHOULD ALSO INCREASE AS LOW-LEVEL LAPSE RATES STEEPEN AND THE STORMS
INCREASE IN COVERAGE BY EARLY EVENING.

...CNTRL AND NRN HIGH PLAINS...
WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL RIDGE IN PLACE
ACROSS THE HIGH PLAINS. SCATTERED THUNDERSTORMS ARE DEVELOPING UNDER
THE RIDGE ALONG AND EAST OF A LEE SFC TROUGH. DEWPOINTS ARE IN THE
50S F WITH AN AXIS OF MODERATE INSTABILITY EXTENDING NNWWD FROM WRN
KS ACROSS WRN NEB...FAR NE CO AND ERN WY. IN ADDITION TO THE
INSTABILITY...REGIONAL PROFILERS SHOW SUFFICIENT VERTICAL SHEAR FOR
SUPERCELLS. AS STORMS INCREASE IN COVERAGE AND MOVE EWD INTO THE
INSTABILITY AXIS...THE SEVERE POTENTIAL SHOULD INCREASE. STEEP LAPSE
RATES SHOULD FAVOR LARGE HAIL AND ISOLATED WIND DAMAGE AS THE
PRIMARY SEVERE THREAT.

FURTHER NORTHWEST ACROSS THE NRN ROCKIES...SCATTERED THUNDERSTORMS
SHOULD DEVELOP THIS AFTERNOON AND MOVE NEWD ACROSS THE REGION.
ALTHOUGH OBJECTIVE ANALYSIS SHOWS MODERATE VERTICAL SHEAR PROFILES 
AND STEEP LAPSE RATES IN PLACE ACROSS MOST OF THE
REGION...INSTABILITY IS WEAKER FROM CNTRL MT EXTENDING WWD ACROSS
ID. THIS WEAKNESS IN INSTABILITY SHOULD KEEP ANY SEVERE THREAT
MARGINAL LATE THIS AFTERNOON AND EARLY THIS EVENING.

..BROYLES.. 05/21/2006