National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
ACUS02 KWNS 191729
SWODY2
SPC AC 191728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS OK...SERN KS...EXTREME
NWRN AR...AND SWRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
SWRN TX TO THE UPPER GREAT LAKES...

...SOUTHERN PLAINS TO MID MS VALLEY...

SECONDARY MID LEVEL SPEED MAX...ON THE ORDER OF 60KT AT 500 MB...IS
EXPECTED TO EJECT ACROSS THE SRN ROCKIES INTO NRN OK BY 21/00Z.
WHILE LATE DAY1 CONVECTION MAY DISTURB LOW LEVEL WIND FIELDS ACROSS
PORTIONS OF SERN KS INTO MO...IT APPEARS LARGE SCALE INFLUENCE OF
APPROACHING SPEED MAX SHOULD SHARPEN SYNOPTIC FRONT ACROSS OK BY
PEAK HEATING.  THIS WILL BE THE PRIMARY FOCUS FOR RENEWED SEVERE
THUNDERSTORM DEVELOPMENT ACROSS THE MDT RISK REGION.

THUNDERSTORMS...A FEW SEVERE WITH A THREAT OF HAIL...MAY BE ONGOING
AT THE BEGINNING OF THE PERIOD ACROSS SERN KS/MO ALONG THE NOSE OF
VEERED LLJ.  THIS CONVECTION MAY TEMPORARILY DISPLACE THE SYNOPTIC
FRONT OR PERHAPS EVEN PRODUCE OUTFLOW THAT BECOMES A FOCUS FOR
AFTERNOON CONVECTIVE DEVELOPMENT.  STRONGEST BOUNDARY LAYER HEATING
IS EXPECTED ACROSS WEST TX INTO SWRN OK WHERE SFC TEMPERATURES
SHOULD SOAR INTO THE 90S.  ALONG/NORTH OF THE MAIN MID LEVEL JET
CORE MID LEVEL TEMPERATURES SHOULD COOL SUCH THAT DEEP CONVECTION
WILL EASILY DEVELOP ALONG AFOREMENTIONED CONVECTIVE OUTFLOW BOUNDARY
INTO MO AND SHARPENING COLD FRONT/DRYLINE FARTHER WEST.  IN
FACT...TSTMS MAY DEVELOP BY 20-21Z ACROSS OK WHERE SBCAPE IS
EXPECTED TO BE IN EXCESS OF 3000 J/KG.  FORECAST DEEP LAYER
SHEAR...IN EXCESS OF 50KT THROUGH 6KM...AND THE PROSPECT FOR A VERY
MOIST WARM SECTOR FAVOR NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID EVENING OF THE CONVECTIVE CYCLE.  VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS AND WITH TIME ONE OR MORE
MCS/S SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LLJ OVER OK.  AMPLE
MID LEVEL FLOW WILL EXTEND ALONG THE DRYLINE INTO THE EDWARDS
PLATEAU OF TX SUPPORTIVE OF ISOLATED SUPERCELL STRUCTURES CAPABLE OF
PRODUCING AT LEAST LARGE HAIL AND DAMAGING WINDS.


...UPPER MS VALLEY/GREAT LAKES...

LATEST MODEL GUIDANCE SUGGESTS A MID LEVEL SHORT WAVE TROUGH/SPEED
MAX WILL ROTATE NEWD ACROSS IA/IL INTO MN/WI DURING THE AFTERNOON
HOURS.  THIS FEATURE WILL SERVE TO INCREASE UVV ACROSS A FAIRLY
MOIST/UNSTABLE BOUNDARY LAYER SOUTH OF SHARP WARM FRONT THAT WILL
EXTEND FROM LOW NEAR THE ND/SD/MN BORDER...EWD INTO NRN WI AT PEAK
HEATING.  WHILE SHORT WAVE TROUGH WILL INFLUENCE/SUPPORT DEEP
CONVECTION...STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL
IN DESTABILIZATION ACROSS MN/WI AND SBCAPE COULD EASILY RISE TO NEAR
2000 J/KG.  DISCRETE SUPERCELL STRUCTURES MAY EVOLVE WITHIN THIS
AIRMASS AND WITH RELATIVELY LOW CLOUD BASES ISOLATED TORNADOES...IN
ADDITION TO LARGE HAIL MAY BE OBSERVED.

..DARROW.. 05/19/2013