Severe Thunderstorm Warning 12, NWS Wakefield, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD, VA
425 PM EDT FRI APR 19 2002

WEATHER IN THE SHORT-TERM WILL BE MESOSCALE DRIVEN...WITH THE BROKEN
LINE OF CONVECTION BECOMING MORE WIDESPREAD AS IT APPROACHES CENTRAL
VA. HEAVIEST CELLS ARE CURRENTLY IN THE RICHMOND REGION. MAX
SURFACE-BASED CAPES WILL CONTINUE IN THE RANGE OF 2500-3000 J/KG FOR
MOST...WITH LIS NEAR -8C. WIND PROFILE ALOFT CONTINUES TO BE
RELATIVELY WEAK...THOUGH WITH THE STORM MOTION ESE AROUND 10-15KTS
(APPROXIMATE TO MID LEVEL OR STEERING FLOW IN THIS CASE) THE STORMS
ARE MAKING MORE PROGRESS THAN THEY WERE THIS TIME YDAY.

AGAIN...DESPITE WEAK WIND FIELDS ALOFT ISOLATED SEVERE STORMS (WET
MICROBURSTS) ARE POSSIBLE GIVEN THE DRY AIR NUDING IN AT MID LEVELS
(REF WV AND VSBL SATELLITE IMAGES).

IN TERMS OF PROBS...HAVE CONTINUED WITH THE HIGHEST POPS ACROSS
CENTRAL VA (RICHMOND AND THE TRI CITIES) PER THE LATEST RADAR
TRENDS. HAVE TAPERED PROBABILITIES TO THE SE...ESPECIALLY NEAR THE
COAST (SCATTERED COVERAGE)...AS AGAIN EXPECT ACTIVITY TO DIMINISH
AS WITH THE DAYTIME HEATING AFTER SUNSET.

SAT...AVN/ETA RUNS SIMILAR IN DROPPING THE FRONT INTO FAR SRN VA BY
LATE IN THE DAY. BY THAT TIME...IT WILL HAVE BECOME MORE W-E
ORIENTED AND (THUS) PARALLEL TO THE 850-500 MB FLOW. WHILE THE
DYNAMICS (850/500 MB OMEGA AND QVECTOR CONVERGENCE) REMAIN RATHER
MINIMAL...WILL BUMP POPS UP TO 60% BASED ON THE FAVORABLE
THERMODYNAMICAL PROFILE ALONG WITH THE MORE DEFINITIVE CONVERGENCE
WITH THE FRONT.

SAT NIGHT...FRONT/SHALLOW COLD WEDGE SLIDES FARTHER S TO NEAR
NC/SC BORDER (LIKELY TO BE AIDED BY THE NOCTURNAL COOLING). WILL
MAINTAIN A CHANCE OF SHOWERS/TSTS EARLY...THEN MENTION DRIZZLE LATE
WITH THE HIGH DEGREE OF MOISTURE ALONG WITH INCREASED STABILITY (AND
WIND SHEAR) IN THE LOWER LAYERS.

SUN...HAVE CONTINUED WITH THE CHANCE OF LIGHT RAIN/DRIZZLE WITH WEAK
OVERRUNNING FORCING N OF THE FRONT (WHICH WILL BE RETREATING N AS A
WARM FRONT).

SUN NIGHT...WARM FRONT LIFTS N BACK TO VA/NC BORDER. DEEPER
ISENTROPIC ASCENT/WARM FRONTAL DYANMICS WILL RESULT IN ANOTHER
CHANCE FOR RAIN ACROSS THE AREA...MAINLY SHOWERS/CHANCE OF TSTMS
ACROSS FAR SRN VA AND NRN NORTH CAROLINA CLOSER TO THE WARM SECTOR.

MONDAY...CONTINUED WITH SHOWER CHANCES THROUGH THE MORNING OVER WRN
ZONES BEFORE THE COLD FRONT MOVES THROUGH...WITH THE CHANCES ALL DAY
E TOWARD THE ERN SHORE (WITH A MENTION OF TSTMS IN THE WARM SECTOR).

EXTENDED...COOLER ON TUE/WED BEHIND THE FRONT WITH THE NEXT CHANCE
OF RAIN ON THU AHEAD OF THE NEXT COLD FRONT.

MARINE FCST...NO FLAGS CONTINUE.

FCSTID = 13
SBY   64  74  48  58 /  50  60  50  30
OXB   64  73  47  57 /  40  60  50  30
ECG   66  82  56  62 /  40  60  50  40
ORF   66  82  56  62 /  40  60  50  40
PHF   65  80  53  62 /  50  60  50  30
AKQ   66  82  55  62 /  50  60  50  40
RIC   63  80  54  62 /  60  60  50  40
FVX   63  82  55  62 /  60  60  50  40

.AKQ...
MD...NONE.
NC...NONE.
VA...NONE.

HURLEY

MDZ021>025-NCZ012>017-030>032-102-VAZ049-060>100-191815-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE WAKEFIELD VA
1113 AM EDT FRI APR 19 2002

...ISOLATED SEVERE THUNDERSTORMS POSSIBLE AGAIN THIS AFTERNOON AND
EVENING...

* THREAT AREA...SOUTH CENTRAL AND SOUTHEAST VIRGINIA...FAR NORTHEAST
  NORTH CAROLINA...AND THE LOWER EASTERN SHORE.

* TIME OF SEVERE WEATHER THREAT...BETWEEN 3 AND 9 PM.

* SYNOPSIS...CONTINUED HOT AND HUMID CONDITIONS...ALONG WITH A
  WEAK FRONTAL BOUNDARY IN PLACE ACROSS THE REGION...WILL TRIGGER
  SCATTERED SHOWERS AND  THUNDERSTORMS ONCE AGAIN THIS AFTERNOON.
  A FEW OF THESE STORMS MAY REACH SEVERE LIMITS.

* SPOTTER ACTIVATION...SKYWARN SPOTTER ACTIVATION MAY BE NEEDED
  LATER THIS AFTERNOON AND EVENING.

* SEVERE WEATHER THREAT INCLUDES THE FOLLOWING...

  WIND GUSTS TO 60 MPH...
  HAIL UP TO THREE QUARTER INCH IN DIAMETER...

  IN ADDITION...HEAVY RAINFALL FROM THESE THUNDERSTORMS MAY RESULT
  IN LOCALIZED FLASH FLOODING...MAINLY IN URBAN AREAS AND IN LOW
  LYING LOCATIONS NEAR RIVERS AND STREAMS.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES. YOU CAN ALSO CHECK OUT OUR WEB SITE AT
HTTP://WEATHER.NOAA.GOV/AKQ.

HURLEY