SPC MD 1263

MD 1263 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR CNTRL/ERN NEB…N-CNTRL/NERN KS…FAR WRN IA


MESOSCALE DISCUSSION 1263
NWS STORM PREDICTION CENTER NORMAN OK
0428 AM CDT THU JUN 27 2013

AREAS AFFECTED...CNTRL/ERN NEB...N-CNTRL/NERN KS...FAR WRN IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 270928Z - 271030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTM COVERAGE IS EXPECTED TO INCREASE OVER THE NEXT COUPLE
HRS ACROSS CNTRL AND NERN NEB ALONG THE NOSE OF A LLJ...AND COULD
EXPAND E-SEWD WITH TIME. THE ENVIRONMENT WILL BE SUPPORTIVE FOR
ISOLATED LARGE HAIL AND PERHAPS A FEW STRONG-SVR WIND GUSTS.
CONVECTIVE TRENDS WILL BE MONITORED FOR A POSSIBLE WW.

DISCUSSION...RADAR MOSAIC LOOP SHOWS INCREASING ELEVATED TSTMS
ACROSS NERN AND CNTRL NEB WITHIN THE PAST 1-2 HRS...FORMING WITHIN A
WAA REGIME ORIENTED ENE-WSW ALONG THE NOSE OF A 30-40 KT LLJ /AS
SAMPLED BY LNX VWP DATA/. STEEP MIDLEVEL LAPSE RATES WITHIN A MOIST
AIR MASS ARE YIELDING MUCAPE VALUES ABOVE 1500 J/KG. THIS...ALONG
WITH MODERATELY STRONG BULK SHEAR WITHIN THE CLOUD-BEARING
LAYER...WILL SUPPORT THE POTENTIAL FOR SOME ORGANIZED CONVECTION
CAPABLE OF PRODUCING LARGE HAIL. DESPITE THIS ACTIVITY LIKELY BEING
ELEVATED...MODIFIED 27/00Z OBSERVED AND MODEL FORECAST SOUNDINGS
SUGGEST THE DEPTH OF THE NEAR-SFC STABLE LAYER IS SHALLOW...AND
COULD SUPPORT STRONG TO POSSIBLY SVR WIND GUSTS IF A COLD POOL CAN
MATERIALIZE. CURRENT THINKING IS THAT TSTMS WILL CONTINUE TO
INCREASE IN COVERAGE/INTENSITY OVER THE NEXT 2-3 HRS AND EVENTUALLY
SPREAD E-SEWD INTO ERN NEB...NERN KS...AND POSSIBLY FAR WRN IA. THE
POTENTIAL FOR A WW WILL BE DEPENDENT ON INDICATIONS OF AN ORGANIZED
WIND/HAIL THREAT DEVELOPING...AND TRENDS WILL CONTINUE TO BE
MONITORED FOR THIS POSSIBILITY.

..ROGERS/HART.. 06/27/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...EAX...FSD...OAX...TOP...GID...LBF...

LAT...LON   42149609 41659577 40509554 39799601 39669647 39499789
            40009883 40769986 41479979 42539860 42759828 42599676
            42149609

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md1263.html