Lightning Strike in Delaware, August 11, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
230 PM EDT SAT AUG 11 2001

WE WILL BE ISSUING A FFA FOR MOST OF OUR CWA WITH THIS NEXT FCST PKG
FOR TNGT. GRANTED THE 2ND PERIOD MIGHT ALSO NEED A FFA BASED ON THE
LINGERING LOCN OF THE FNT...BUT DON/T WANT TO BOX MIDN SHIFT IN AND
THEY CAN REACCESS AFT TNGT/S ACTVTY.

UPSHOT OF ALL OF THIS IS BNDRY IS RMNG QUASI-STATINARY ACRS OUR CWA.
LCL FFA CHECKLIST IS 5 OF 6 AS PWATS ARE GREATER THAN 2
IN/THICKNESSES ARE GREATER THAN NML/AVN K INDEX FCST REACHES
40/INSTAB EXISTS THRU TNGT AND WE HAVE A WK SHRT WV TO ENHANCE PCPN
PTNL AS FNTL BNDRY DRIFTS BACK TO THE N. AVN FCSTG ENUF INSTAB
OVRNGT TO GIVE US THE PTNL TO HAVE CONVECTION GO THRU THE NGT WITH
THE APCHG SHRTWV. HIEST FCSTD K INDEX AND PACHG SHRTWV ACTUALLY MOVE
IN TWD MRNG. INCRG (ALBEIT NOT THAT STG) S-SWLY FLOW AT H8 ALSO APRS
TO CONVERGE OVR OUR CWA.  ONE MISSING INGRED IS A DECENT LLVL HODO
(WHICH ACTUALLY IPVS TWD SUN EVE)...BUT SLO MOVEMENT OF THE TSRAS
HAVE NEGATED THIS ONE LACKING FEAT SO FAR TDY.

THERE IS A CHC THAT THE ONGOING CONVECTION IN VA MIGHT SHUT HVY PCPN
FTHR TO THE N...ONE REASON FOR NOT INCLDG OUR NRNMST CTYS AND ALSO
REASON ITS A WATCH.  WOULD HAVE LIKED TO NOT INCLD BERKS AND THE
LEHIGH VLY ALSO...BUT THEY HAVE HAD HEAVY RAIN AND FLOODING ALRDY
AND FFG IN THE SRN PARTS OF BERKS/LEHIGH CTY WOULD BE PRETTY LO.

WILL GO LIKELY/CAT POPS WITH HVY PCPN WORDING FOR TNGT/SUN. IN
GENERAL GUID MINS LOOK OK FOR TNGT...MAX TEMPS A BIT TOASTY ON SUN.

DIF BTWN ETA (IMPLIED NGM MOS) AND AVN FOR HOW QUICKLY WE GET INTO
THE DRIER AIR ON MON. ATTM WE PLAN ON LEAVING POPS IN THE CHC CAT AS
H5 TROF IS STILL TO OUR W. WILL FOLLOW SAME TREND FOR TEMP FCST VS
GUID FOR SUN NGT AND MON.

ONE YEAR ANNIVERSARY OF HORRIFIC FLOODING IN SUSSEX COUNTY NJ.
THANKFULLY UA PAT IS NOT THE SAME AS THAT DAY TODAY.

MAR: ALL/S QUIET.

.PHI...FFA ALL ZONES INTO TNGT EXCEPT FOR PA54/55 AND NJ1/7/8.

TFG

DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>026-PAZ054-055-
060>062-067>071-120000-

SPECIAL WEATHER STATEMENT - HEAVY RAIN OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
955 AM EDT SAT AUG 11 2001

...VERY HEAVY RAIN LIKELY THROUGH TONIGHT...

THE FRONTAL BOUNDARY THAT BROKE THE BACK OF THE HEAT WAVE HAS
STALLED OVER THE REGION. WHILE THIS HAS ENDED THE OPPRESSIVE
HEAT...IT HAS NOT CLEARED THE HUMID AIR MASS THAT REMAINS DRAPED
OVER THE REGION. THE AIR MASS IS EXTREMELY HUMID AND UNSTABLE.
BREAKS ARE APPEARING IN THE OVERCAST OVER MARYLAND AND NORTHERN
VIRGINIA. THIS IS NOT GOOD NEWS BECAUSE IT INCREASES THE POTENTIAL
FOR STRONGER THUNDERSTORMS WITH EVEN HEAVIER RAIN THIS AFTERNOON.
THE GREATEST THREAT FOR THE HEAVIEST RAIN SHOULD BE FROM THE
PHILADELPHIA METROPOLITAN AREA AND CENTRAL NEW JERSEY SOUTHWARD INTO
THE DELMARVA REGION.

A LOW PRESSURE SYSTEM RIDING ALONG THE FRONTAL BOUNDARY IS EXPECTED
TO MOVE THROUGH THE REGION TONIGHT. WHILE THE RISK FOR SEVERE
THUNDERSTORMS APPEAR LOW FOR THIS AFTERNOON AND NIGHT...THE RISK FOR
TORRENTIAL DOWNPOURS IS HIGH. THUNDERSTORMS WITH HEAVY RAIN COULD
EASILY PRODUCE RAINFALL AMOUNTS OF AN INCH TO TWO WITHIN AN HOUR
WITH UP TO FOUR INCHES OF RAIN POSSIBLE IN ISOLATED AREAS. A SIMILAR
STORM THIS MORNING DROPPED BETWEEN 5 AND 6 INCHES OF RAIN ACROSS
EASTERN ATLANTIC COUNTY WITHIN A THREE HOUR PERIOD.

PRIOR TO THIS WEEKEND IT HAS BEEN EXTREMELY DRY AND THIS DOES BODE
WELL FOR THE LARGER STREAMS AND RIVERS. NEVERTHELESS...THE HEAVY
RAIN WILL CAUSE SOME POOR DRAINAGE AND LOW LYING AREA FLOODING AND
POSSIBLY CAUSE SOME SMALLER CREEKS TO EXCEED THEIR BANKS.

PLEASE BE WARY FOR CHANGING WEATHER CONDITIONS AND DO NOT CROSS
FLOODED OR BARRICADED ROADWAYS.

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

TFG