SPC MD 799

MD 0799 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR SOUTHWEST/SOUTH-CENTRAL NEB


MESOSCALE DISCUSSION 0799
NWS STORM PREDICTION CENTER NORMAN OK
0650 PM CDT SAT MAY 25 2013

AREAS AFFECTED...SOUTHWEST/SOUTH-CENTRAL NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 252350Z - 260115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...MONITORING FOR AN INCREASING SEVERE THREAT ACROSS PARTS OF
SOUTHWEST/SOUTH-CENTRAL NEB THROUGH THE EARLY/MIDDLE PART OF THIS
EVENING. SUCH A THREAT COULD INCLUDE BOUTS OF SEVERE HAIL/LOCALLY
DAMAGING WINDS AND PERHAPS EVEN A LOW TORNADO RISK.

DISCUSSION...A LOOSELY ORGANIZED COMPLEX /POSSIBLY WITH SOME
TRANSITORY SUPERCELL CHARACTERISTICS/ IS CENTERED ALONG THE NEB/KS
BORDER VICINITY WEST OF MCCOOK AS OF 2330Z...WITH SOME NORTHEASTWARD
EXPANSION EVIDENT OVER THE PAST HOUR. TOWERING CU IS NOTED IN
VISIBLE SATELLITE IMAGERY FARTHER EAST-NORTHEASTWARD ALONG THE I-80
CORRIDOR IN VICINITY OF THE LEXINGTON-KEARNEY NEB AREAS...WHICH
APPEARS TO COINCIDE WITH THE RESIDUAL INFLUENCE OF EXTENSIVE
OVERNIGHT/MORNING CONVECTION. IT SEEMS PLAUSIBLE THAT THE FAR
NORTHWEST KS/SOUTHWEST NEB STORMS MAY PERSIST/CONTINUE TO DEVELOP
EAST-NORTHEAST INTO ADDITIONAL PARTS OF
SOUTHWEST/WEST-CENTRAL/SOUTH-CENTRAL NEB THIS EVENING...FURTHER
AIDED BY A PROBABLE SOUTHERLY LOW LEVEL JET INCREASE OVER THE NEXT
SEVERAL HOURS.

RELATIVELY WEAK CONVECTIVE INHIBITION EXISTS INTO CENTRAL NEB
COINCIDENT WITH AN ESTIMATED CORRIDOR OF 2000-2500 J/KG MLCAPE.
MIDDLE/UPPER TROPOSPHERIC WESTERLY WINDS ARE RELATIVELY WEAK...BUT
VEERING WIND PROFILES ARE LIKELY RESULTING IN AROUND 30-40 KT OF
EFFECTIVE BULK SHEAR...WHICH WILL SUPPORT SUSTAINED MULTICELLS/SOME
SUPERCELLS. SHOULD STORM DEVELOPMENT CONTINUE/OCCUR
EAST-NORTHEASTWARD THIS EVENING...BOUTS OF SEVERE HAIL/LOCALLY
DAMAGING WINDS WILL BE POSSIBLE. A CONDITIONAL TORNADO RISK CANNOT
BE ENTIRELY DISCOUNTED THROUGH EARLY/MID EVENING GIVEN THE EXPECTED
LOW LEVEL JET INCREASE AND PROXIMITY OF THE AFOREMENTIONED RESIDUAL
OUTFLOW/EFFECTIVE WARM FRONT.

..GUYER/THOMPSON.. 05/25/2013

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

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

LAT...LON   40490132 41160071 41509887 41149816 40329802 40029962
            40360009 40490132

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