SWODY2
SPC AC 291718
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1218 PM CDT SAT MAY 29 2010
VALID 301200Z - 311200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE TX PANHANDLE...NW
OK...AND A SMALL PART OF SCNTRL KS...
...SYNOPSIS...
THE WRN STATES UPPER TROUGH AND ASSOCIATED JET STREAK WILL TRANSLATE
INTO THE NRN PLAINS/UPPER MS VALLEY ON SUNDAY WITH A SUBSEQUENT
DEAMPLIFICATION OF THE DOWNSTREAM UPPER RIDGE. THE ATTENDANT COLD
FRONT WILL CONTINUE EWD THROUGH THE UPPER MS VALLEY AND GREAT LAKES
REGION WHILE THE TRAILING PORTIONS OF THE BOUNDARY SETTLE INTO NRN
OK AND ERN NM. MEANWHILE...A CUT-OFF UPPER LOW WILL PERSIST OVER
THE SERN STATES.
...ERN NM...TX PANHANDLE...NWRN OK AND KS...
UPGRADED A SMALL PORTION OF THE CNTRL TX PANHANDLE...NW 1/2 OF OK
AND SCNTRL KS TO A SLIGHT RISK/15 PERCENT SEVERE PROBABILITIES.
MODEST LOW-LEVEL MOISTURE CHARACTERIZED BY UPR 50S TO MID 60S
SURFACE DEW POINTS WILL CONTINUE IN THE PRE-FRONTAL WARM SECTOR
ACROSS KS...OK...TX PANHANDLE AND ERN NM. STRONG HEATING AND
PRESENCE OF 7-7.5 C/KM H7-H5 LAPSE RATES WILL RESULT IN 1500-2500
J/KG MLCAPES. AS CONVECTIVE INHIBITION WEAKENS VIA HEATING AND
SUSTAINED CONVERGENCE ALONG THE FRONT...HIGH CONFIDENCE WILL EXIST
FOR THE INITIATION OF ISOLATED TO WIDELY SCATTERED THUNDERSTORMS BY
LATE AFTERNOON FROM SCNTRL KS WWD ACROSS NWRN OK...NRN TX PANHANDLE
AND IN THE INCREASING UPSLOPE REGION OF ERN NM. GIVEN OVERALL WEAK
LARGER-SCALE FORCING...PARCELS WILL LIKELY NEED FRONTAL FORCING TO
REACH LFC...AND THE MAJORITY OF STORMS WILL PROBABLY BE SLIGHTLY
ELEVATED IMMEDIATELY AFTER INITIATING.
DESPITE THE FACT THAT THE MAJORITY OF THE STRONGER MID-LEVEL FLOW
WILL BE WELL N OF THE REGION...MAGNITUDE OF LAPSE RATES AND PRESENCE
OF MODEST FLOW ABOVE H5 MAY CONTRIBUTE TO STORM ORGANIZATION WITH
LARGE HAIL THE PRIMARY RISK. DAMAGING WIND GUSTS CANNOT BE RULED
OUT.
THUNDERSTORMS MAY CONTINUE INTO THE OVERNIGHT AS A WEAK SLY
LOW-LEVEL JET FEEDS UNSTABLE PARCELS INTO SRN FLANKS OF THE STORMS.
THE RESULTANT MCS WILL LIKELY DEVELOP ENE INTO NRN OK OR SRN KS
OVERNIGHT WITH AT LEAST ISOLATED RISKS FOR MARGINALLY SEVERE HAIL.
...UPPER MS VALLEY AND GREAT LAKES REGION...
DEWPOINTS GENERALLY IN THE LOW 60S F WILL ADVECT NWD THROUGH THE
PRE-FRONTAL WARM SECTOR...AND 1500-2000 J/KG MLCAPE WILL BECOME
POSSIBLE AS THE BOUNDARY LAYER WARMS. LOW LEVEL WINDS ARE FORECAST
TO VEER AHEAD OF FRONT AS IMPULSE EJECTS NEWD THROUGH MN IN POST
FRONTAL ZONE. THIS WILL LIMIT VERTICAL SHEAR IN WARM SECTOR...BUT
20-30 KT DEEP LAYER WINDS WILL EXIST IN VICINITY OF FRONT. UPPER JET
WILL LIFT NEWD THROUGH POST FRONTAL ZONE LEAVING SHORTWAVE RIDGING
DOWNSTREAM ACROSS WI. THIS SUGGESTS FRONTAL CIRCULATION WILL
PROBABLY BE SHALLOW...AND POINT FORECAST SOUNDINGS SHOW SUBSTANTIAL
DRY AIR IN THE 700-500 MB LAYER WHICH COULD POTENTIALLY ENHANCE DRY
ENTRAINMENT WITHIN DEVELOPING UPDRAFTS. A FEW MULTICELL STORMS COULD
STILL DEVELOP ALONG COLD FRONT DURING THE AFTERNOON AND SPREAD EWD
THROUGH THE UPPER GREAT LAKES AREA. ISOLATED STRONG TO DAMAGING WIND
GUSTS AND MARGINALLY SEVERE HAIL WILL BE POSSIBLE UNTIL MID EVENING.
...SERN STATES...
SCATTERED PULSE AND MULTICELL STORMS WILL REDEVELOP OVER THE SERN
STATES IN ASSOCIATION WITH WEAK CAP...MODERATE INSTABILITY AND
CUTOFF UPPER LOW. ISOLATED MARGINALLY SEVERE HAIL AND DOWNBURST
WINDS WILL BE POSSIBLE THROUGH THE EARLY EVENING.
..RACY.. 05/29/2010
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