[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 200631
SWODY2
SPC AC 200630

DAY 2 CONVECTIVE OUTLOOK RESENT 1
NWS STORM PREDICTION CENTER NORMAN OK
0130 AM CDT SAT MAY 20 2006

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY
INTO THE MIDDLE MS VALLEY AND CNTRL PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH
PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE PACIFIC
NW AND NRN ROCKIES...

...SYNOPSIS...

PATTERN WILL CHANGE LITTLE THROUGH SUNDAY WITH AN UPPER LOW
DOMINATING MUCH OF THE ERN HALF OF THE COUNTRY AND AN UPPER RIDGE
OVER THE ROCKIES. A SERIES OF SHORTWAVE TROUGHS EMANATING FROM ERN
PACIFIC UPPER LOW WILL LIFT NWD THROUGH CA AND THE PACIFIC NW. AT
THE SURFACE A FRONT WILL SETTLE SWD INTO THE TN VALLEY AND EXTEND
WNWWD THROUGH SRN MO...NRN OK AND NWWD INTO THE CNTRL HIGH PLAINS.

...SERN KS...NERN OK THROUGH THE LOWER MS AND WRN TN VALLEYS...

A RELATIVELY MOIST BOUNDARY LAYER WILL PERSIST NEAR FRONT FROM THE
TN AND MID MS VALLEYS INTO NRN OK AND PARTS OF THE CNTRL PLAINS.
WITH STEEP MID LEVEL LAPSE RATES IN PLACE...THE ATMOSPHERE SHOULD
BECOME MODERATELY UNSTABLE BY AFTERNOON. THE FRONT WILL LIKELY SERVE
AS A FOCUS FOR THUNDERSTORMS THIS PERIOD. A FEW STORMS MAY BE IN
PROGRESS EARLY SUNDAY IN WARM ADVECTION REGIME N OF FRONT OVER PART
OF THE LOWER MS VALLEY. THE NATURE OF CONVECTIVE EVOLUTION REMAINS A
BIT UNCERTAIN AT THIS TIME GIVEN EXPECTED LIMITED DEEP LAYER
FORCING. HOWEVER...SOME POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP
AND INTENSIFY IN VICINITY OF THE BOUNDARY AS CAP WEAKENS SUNDAY
AFTERNOON. OTHER STORMS MAY DEVELOP OVERNIGHT FROM THE SRN PLAINS
INTO THE LOWER MS VALLEY AS THE LOW LEVEL JET STRENGTHENS. ELY LOW
LEVEL FLOW NEAR THE FRONT VEERING TO WNWLY 25 TO 30 KT AT 6 KM
SUGGEST VERTICAL SHEAR WILL BE AT LEAST MARGINALLY FAVORABLE FOR
ORGANIZED STORMS. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL
BE THE MAIN THREATS.


...CNTRL HIGH PLAINS...

THIS AREA WILL BE IN CLOSER PROXIMITY TO UPPER RIDGE. HOWEVER...
STORMS MAY DEVELOP ALONG NWWD EXTENTION OF FRONT OVER THE CNTRL HIGH
PLAINS AS CAP WEAKENS SUNDAY AFTERNOON. DEWPOINTS IN THE 50S AND
STEEP LAPSE RATES SHOULD RESULT IN MLCAPE ON THE ORDER OF 1000 TO
1500 J/KG. MID LEVEL FLOW WILL NOT BE PARTICULARLY STRONG DUE TO
PROXIMITY OF UPPER RIDGE. HOWEVER...SELY LOW LEVEL FLOW VEERING TO
NWLY 20 KT AT 6 KM SHOULD RESULT IN DEEP LAYER SHEAR MARGINALLY
SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES. ISOLATED LARGE HAIL
AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS AS
ACTIVITY DEVELOPS SEWD THROUGH MID EVENING.

...PACIFIC NW AND NRN ROCKIES AREA...

EXTENT AND MAGNITUDE OF SEVERE THREAT IN THIS AREA WILL DEPEND ON
TIMING OF IMPULSES AND DEGREE OF CLOUD COVER. LOW LEVEL DEWPOINTS IN
THE UPPER 40S TO LOWER 50S WILL PERSIST WITHIN THE STEEP LAPSE RATE
ENVIRONMENT WITH MLCAPE ON THE ORDER OF 400 TO 800 J/KG BY
AFTERNOON. STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER
TERRAIN...POSSIBLY AIDED BY DEEP LAYER LARGER SCALE ASCENT
ASSOCIATED WITH NWD ADVANCING IMPULSES. STRONG MIDDLE AND UPPER SLY
FLOW WILL PERSIST OVER THIS REGION CONTRIBUTING TO FAVORABLE
VERTICAL SHEAR PROFILES FOR SUPERCELLS. THERMODYNAMIC ENVIRONMENT
SHOULD SUPPORT POTENTIAL FOR BOTH LARGE HAIL AND DAMAGING WIND
DURING THE AFTERNOON INTO THE EARLY EVENING.

..DIAL.. 05/20/2006