SPC MD 259

MD 0259 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR FAR N-CNTRL KS…S-CNTRL NEB


MESOSCALE DISCUSSION 0259
NWS STORM PREDICTION CENTER NORMAN OK
1200 PM CST SAT MAR 09 2013

AREAS AFFECTED...FAR N-CNTRL KS...S-CNTRL NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 091800Z - 091930Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...SCATTERED THUNDERSTORM DEVELOPMENT IS FORECAST TO OCCUR
ACROSS FAR N-CNTRL KS AND S-CNTRL NEB THIS AFTERNOON. SOME OF THIS
ACTIVITY MAY POSE A THREAT FOR A COUPLE OF BRIEF TORNADOES...IN
ADDITION TO MARGINALLY SEVERE HAIL/DAMAGING WIND GUSTS. AREA IS
BEING MONITORED FOR A WW.

DISCUSSION...MIDDAY MESOANALYSIS SHOWS AN AREA OF SURFACE LOW
PRESSURE/TRIPLE POINT LOCATED NNE OF HLC...WITH A PACIFIC FRONT
EXTENDING SWD INTO WRN OK...ANOTHER COLD FRONT ARCING SWWD INTO SERN
CO...AND A STATIONARY FRONT EXTENDING NEWD ACROSS CNTRL INTO NERN
NEB. TEMPERATURES WITHIN A PRONOUNCED CLEAR SLOT HAVE WARMED INTO
THE 60S ALONG/IMMEDIATELY E OF THE TRIPLE POINT AND STATIONARY
FRONT...AND ARE JUXTAPOSED WITH A NARROW ZONE OF LOW 50S DEWPOINTS.
SURFACE HEATING HAS AIDED IN AN AXIS OF STEEPENING LOW-LEVEL LAPSE
RATES/ROBUST BOUNDARY LAYER DESTABILIZATION SPREADING NEWD FROM SWRN
KS INTO S-CNTRL NEB...AND IS PROMOTING THE DEVELOPMENT OF A
DEEPENING CUMULUS FIELD ACROSS THE AREA.

SCATTERED THUNDERSTORMS ARE EXPECTED TO EVOLVE OUT OF THE CUMULUS
FIELD DURING THE AFTERNOON AS THE SURFACE LOW AND STATIONARY FRONT
GRADUALLY SHIFT EWD. 500 MB TEMPERATURES AROUND -18C AND MIDLEVEL
LAPSE RATES FROM 6.5-7.0 C/KM...COLLOCATED WITH FAVORABLE ZONE OF
SURFACE HEATING WILL AID IN MLCAPE VALUES RANGING FROM 500-1000
J/KG. MODEL FORECAST SOUNDINGS ALSO SHOW 0-3 KM CAPE VALUES
INCREASING TO 100-200 J/KG BY MID-AFTERNOON. THE FAVORABLE LOW-LEVEL
BUOYANCY MAY AID IN A FEW BRIEF TORNADOES FOR SURFACE BASED STORMS
THAT CAN MAXIMIZE RESIDENCE TIME ALONG THE STATIONARY FRONT WHERE
LOW-LEVEL VORTICITY WILL BE MAXIMIZED. OTHERWISE...AN ISOLATED
THREAT FOR SEVERE HAIL/DAMAGING WIND GUSTS WILL EXIST ACROSS THE
NARROW WARM SECTOR AIRMASS.

..GARNER/EDWARDS.. 03/09/2013

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

ATTN...WFO...GID...LBF...GLD...

LAT...LON   39289990 39460013 40130021 40849980 41439897 41469801
            40759752 39929802 39309883 39289990

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0259.html