SWODY1
SPC AC 291946
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0246 PM CDT THU MAR 29 2012
VALID 292000Z - 301200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID MO
VALLEY...SRN PLAINS AND CNTRL PLAINS...
THE FIRST CHANGE TO THE OUTLOOK IS TO MOVE THE SLIGHT RISK IN NW OK
A BIT FURTHER TO THE EAST. THE GAGE OBSERVATION SHOWS A SW WIND WITH
DRYING TAKING PLACE. THE SECOND CHANGE IS TO MOVE THE THUNDER LINE
IN THE CNTRL HIGH PLAINS FURTHER TO THE EAST. OTHERWISE...THE
OUTLOOK LOOKS TO BE ON TRACK.
..BROYLES.. 03/29/2012
.PREV DISCUSSION... /ISSUED 1116 AM CDT THU MAR 29 2012/
...CENTRAL PLAINS/LOWER MO VALLEY...
WATER VAPOR IMAGERY SHOWS AN ELONGATED EWD MOVING SHORT WAVE TROUGH
EXTENDING FROM THE NRN HIGH PLAINS SSWWD INTO AZ. WITHIN THE
TROUGH...A STRONGER VORTICITY MAX OVER SERN WY IS EXPECTED TO
CONTINUE EWD INTO CENTRAL NEB BY THIS EVENING...WITH AN ASSOCIATED
BAND OF STRONGER MID/UPPER LEVEL WESTERLY WINDS TRANSLATING ACROSS
THE CENTRAL PLAINS. AT THE SURFACE...A LOW OVER N CENTRAL KS IS
FORECAST TO MOVE INTO NERN KS LATER THIS AFTERNOON AND PROGRESS
ACROSS NRN MO TOWARD SERN IA TONIGHT. A WARM FRONT CURRENTLY
EXTENDS ESEWD FROM THE LOW ACROSS SRN MO INTO THE TN VALLEY...WHILE
A DRY LINE TRAILS SWD INTO W TX. EXTENSIVE LOW CLOUDS NORTH OF THE
WARM FRONT OVER NRN PARTS OF KS AND MO /AND CONVECTION OVER NRN MO/
MAY LIMIT THE NWD MOVEMENT OF THE WARM FRONT THIS
AFTERNOON...ALTHOUGH RECENT SATELLITE TRENDS SUGGEST CLOUDS MAY
DIMINISH MORE QUICKLY OVER N CENTRAL/NERN KS AND ALLOW THE FRONT TO
LIFT TO NEAR THE NEB BORDER THIS AFTERNOON.
12Z AREA SOUNDINGS INDICATE STEEP MID LEVEL LAPSE RATES ASSOCIATED
WITH AN ELEVATED MIXED LAYER REMAINING OVER THE AREA. STRONG
DIURNAL HEATING SOUTH OF THE WARM FRONT WILL ENHANCE THE THERMAL
CONTRAST ACROSS THE BOUNDARY. SURFACE DEW POINTS IN THE LOW-MID 60S
ARE EXPECTED OVER ERN KS AND NWRN MO THIS AFTERNOON. CONTINUED
DESTABILIZATION WILL RESULT IN MLCAPE VALUES OF 2000-3000 J/KG IN
THE WARM SECTOR...WITH ELEVATED CAPE GRADUALLY DIMINISHING WITH NWD
EXTENT NORTH OF WARM FRONT. ELEVATED STORMS MAY PERSIST ACROSS
PARTS OF NRN MO THIS AFTERNOON IN ASSOCIATION WITH LOW LEVEL WARM
ADVECTION...WITH STRONGER CELLS CAPABLE OF PRODUCING MARGINALLY
SEVERE HAIL. HOWEVER...THE EML WILL LIKELY INHIBIT DEVELOPMENT OF
SURFACE-BASED STORMS NEAR THE SURFACE LOW AND IN THE WARM SECTOR
UNTIL LATER THIS AFTERNOON WHEN CONTINUED HEATING AND INCREASING
LARGE SCALE ASCENT REDUCE THE STRENGTH OF THE CAP. INITIAL STORMS
ARE EXPECTED TO FORM OVER PARTS OF SERN NEB/SWRN IA/NERN KS AND NWRN
MO LATE THIS AFTERNOON AND SPREAD EWD THROUGH THE EVENING. STRONG
CAPE AND SUFFICIENT DEEP LAYER SHEAR /30-40 KT IN THE LOWEST 6 KM/
WILL PROMOTE DEVELOPMENT OF ORGANIZED CONVECTIVE
STRUCTURES...INCLUDING SUPERCELLS...WITH POTENTIAL FOR STRONGER
STORMS TO PRODUCE VERY LARGE HAIL...DAMAGING WIND GUSTS...AND
ISOLATED TORNADOES. THE ACTIVITY IS EXPECTED TO SPREAD EWD ACROSS
PARTS OF IA AND NRN MO TONIGHT WITH THE SEVERE POTENTIAL SLOWLY
DIMINISHING AFTER 03-06Z.
...SRN KS INTO WRN OK...
SCATTERED STORMS MAY GRADUALLY DEVELOP SWWD ALONG THE DRY LINE
ACROSS S CENTRAL KS INTO WRN OK BY THIS EVENING AS WEAK LOW LEVEL
CONVERGENCE COUPLED WITH STRONG HEATING LOCALLY WEAKENS THE CAP.
ALTHOUGH WINDS ALOFT/VERTICAL SHEAR WEAKEN WITH SWD EXTENT AND
CONVECTIVE COVERAGE WILL BE MORE ISOLATED...STRONGER CELLS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND STRONG WIND GUSTS THROUGH THE
EVENING HOURS.
...SC...
STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON IN ADVANCE OF THE COLD
FRONT MOVING SWD FROM NC TOWARD SC. STRONG HEATING WILL CONTRIBUTE
TO A RELATIVELY DEEP MIXED LAYER WITH DCAPE VALUES APPROACHING 1000
J/KG. THE THERMODYNAMIC STRUCTURE SUGGESTS POTENTIAL FOR DOWNDRAFTS
TO BE ENHANCED WITH A THREAT FOR A FEW DOWNBURSTS...ALONG WITH
MARGINAL HAIL...THIS AFTERNOON INTO THE EVENING.
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