SWODY1
SPC AC 281616
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1016 AM CST TUE FEB 28 2012
VALID 281630Z - 291200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL
PLAINS INTO THE MID MS VALLEY...
WATER VAPOR LOOPS SHOW AN IMPRESSIVE SHORTWAVE TROUGH OVER THE FOUR
CORNERS REGION. THIS FEATURE WILL EJECT QUICKLY NORTHEASTWARD INTO
THE CENTRAL HIGH PLAINS BY EVENING...AND INTO THE UPPER MS VALLEY BY
29/12Z. MEANWHILE...AN INCREASINGLY STRONG SOUTHERLY LOW LEVEL JET
WILL AFFECT THE SOUTHERN PLAINS AND LOWER MS VALLEY...DRAWING GULF
MOISTURE RAPIDLY NORTHWARD. THE CONDITIONS WILL BECOME FAVORABLE
FOR MULTIPLE AREAS OF POTENTIAL SEVERE WEATHER DURING THIS FORECAST
PERIOD.
...NEB/KS AFTERNOON AND EVENING...
CONDITIONS ACROSS NEB/KS ARE STARTING COLD AND DRY...WITH
TEMPERATURES ONLY IN THE 30S/40S. HOWEVER...RAPID MODIFICATION OF
THE LOW LEVEL AIR MASS IS EXPECTED THIS AFTERNOON AS SOUTHERLY LOW
LEVEL WINDS AND WARMING TEMPERATURES ABOVE THE SURFACE HELP TO ERODE
THE CLOUDS AND TRANSPORT MOISTURE INTO REGION. BY LATE
AFTERNOON...DEWPOINTS NEAR 50F ARE EXPECTED INTO SOUTHERN NEB ALONG
WITH AT LEAST MARGINAL CAPE. STRONG DYNAMIC FORCING WILL ARRIVE
ACROSS WESTERN NEB AND NORTHWEST KS BEFORE DARK...SETTING THE STAGE
FOR SCATTERED LOW-TOPPED THUNDERSTORMS. STRONG WIND FIELDS AND
STEEP LAPSE RATES SUGGEST A RISK OF A FEW STRONG/SEVERE STORMS
CAPABLE OF HAIL AND DAMAGING WINDS. EASTWARD EXTENT OF THESE STORMS
IS UNCERTAIN DUE TO DECREASING INSTABILITY ACROSS EASTERN NEB/IA.
HOWEVER...STRENGTH OF UPPER SYSTEM SUGGESTS AT LEAST SOME THREAT OF
MAINTAINING THE SEVERE THREAT AT LEAST TO THE MO RIVER.
...KS/OK/MO THIS EVENING...
MID LEVEL CAPPING IS LIKELY TO LIMIT CONVECTIVE DEVELOPMENT ACROSS
THE SOUTHERN PLAINS UNTIL AFTER DARK...WHEN THE SURFACE COLD FRONT
BEGINS TO SAG SOUTHEASTWARD INTO THE DEEPER MOISTURE PROFILES OVER
CENTRAL KS/OK. MULTIPLE MODEL SOLUTIONS SUGGEST THUNDERSTORMS WILL
FORM FIRST IN CENTRAL KS AND BUILD SOUTHWARD ALONG THE FRONT INTO
OK...THEN SPREAD EASTWARD INTO PARTS OF MO/AR DURING THE EVENING.
FAVORABLE WIND FIELDS AND STEEPENING LAPSE RATES WILL SUPPORT A RISK
OF SEVERE STORMS CAPABLE OF HAIL AND DAMAGING WINDS. IF DISCRETE
STORMS CAN FORM AHEAD OF THE FRONT...LOW LEVEL HODOGRAPHS ALSO
SUPPORT A RISK OF TORNADIC SUPERCELLS.
...MID MS VALLEY OVERNIGHT...
THE INCREASING CONVECTION OVER OK/KS DURING THE EVENING IS EXPECTED
TO CONGEAL ACROSS SOUTHERN MO AND NORTHERN AR AFTER MIDNIGHT. WHILE
THERE IS CONSIDERABLE DIVERSITY BETWEEN MODEL SOLUTIONS REGARDING
HOW THIS CONVECTION EVOLVES...WIND FIELDS WILL BECOME VERY STRONG
OVERNIGHT AND FAVORABLE FOR DAMAGING WINDS AND TORNADOES. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING ALONG THE MS RIVER VALLEY...
INCREASING THE RISK OF BUOYANT SURFACE-BASED PARCELS AS FAR NORTH AS
SOUTHEAST MO/SOUTHERN IL BY 12Z.
..HART/COHEN/MOSIER.. 02/28/2012
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