Severe Thunderstorm Warning 56, NWS Baltimore/Washington

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1005 AM EDT SAT MAY 13 2000

WK BKDOOR BNDRY RUNS FM N OF NHK TO DCA TO FDK AT 14Z. 06Z ETA AND RUC
MV THIS BNDY N OF THE AREA DURING THE AFT IN RESPONSE TO INCREASING SW
FLO AHD OF THE CDFNT.

OVRNGT CONVECTION MANAGED TO CLIP FAR WRN ALLEGANY CO MD THIS MRNG WITH
A REPORT OF PEA SIZE HAIL FM FROSTBURG. HWVR...THAT CNVCTN HAS WEAKENED
AND HAS MVD INTO PA. THE REMAINING OUTFLOW BNDRY TRAILING SWD INTO WV
WL MV E DURING THE AFTRN.

LAPS AND MAPS DATA INDICATES ATMS IS VERY UNSTABLE S OF THE BKDOOR FNT
WITH MORE STABLE AIR ACRS THE NE ZNS N OF THE BNDRY. AS THE BKDOOR FNT
MVS BACK TO THE N THIS AFTRN...THE NE ZNS SHUD DESTABILIZE. 06Z ETA IS
FCSTG CAPES OF 2000...LIS -6 TO -10...DWPTS IN THE 70S...AND MODERATELY
STEEP LAPSE RATES THIS AFTRN OVR MUCH OF THE AREA. IN ADDTN...PCP WATER
IS WELL OVR 1 INCH. CAP IN PLACE THIS MRNG SHUD BREAK THIS AFTRN AS WE
HEAT UP. THE APPROACH OF THE CDFNT WL RESULT IN CNVCTN. CNVCTN WL
EITHER FIRE JUST AHD OF THE CDFNT OR ALONG THE OLD OUTFLOW BNDRY
HEADING EWD.  IN ADDTN...SOME CNVCTN MAY FIRE WELL AHD OF THESE 2
BNDRYS ALG THE WMFNT OVR THE NE ZNS BY MID AFTRN.

BIGGEST THREAT FM CNVCTN WL BE LARGE HAIL...WITH DAMAGING STRAIGHT LINE
WINDS BEING THE 2ND BIGGEST THREAT. LACK OF ANY GOOD DIRECTIONAL SHEAR
SHUD CUT DOWN ON THE TORNADO THREAT.

CURRENT ZNS HANDLE SVR THREAT FINE. WL KEEP THE 50 POPS IN THE CHO AREA
BUT BUMP POPS UP TO 60 ELSEWHERE. 12Z IAD SOUNDING FCSTG MAX TEMPS IN
THE UPR 90S S OF THE BKDOOR FNT. THINK DVLPMT OF CLDS WL KEEP US FM
REACHING TEMPS THAT HI BUT WILL BUMP MAX TEMPS UP INTO THE LWR 90S E OF
THE MTNS. EXCEPTION TO THIS WL BE THE BWI AREA WHERE WE WL GO UPR 80S
DUE TO PRESENCE OF BKDOOR FNT.

WND FCST FOR TNGT REQUIRES THE USE OF BREEZY SO INSERTED THAT INTO
LATER PERIODS. OTHERWISE...NO CHGS TO 2ND OR 3RD PD.

ZNS BY 1030AM. SPS CONCERNING SVR WX THREAT BY 1100AM.

.LWX...NONE.