Area Forecast Discussion
Issued by NWS Charleston, WV

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FXUS61 KRLX 280710
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
310 AM EDT THU MAY 28 2015

.SYNOPSIS...
WEAK UPPER LEVEL DISTURBANCES WILL HELP TRIGGER CONVECTION IN THE
VERY WARM AND HUMID AIR MASS INTO THIS WEEKEND.  A FRONT AND LOW
PRESSURE SYSTEM APPROACH THIS WEEKEND WITH INCREASED CONVECTION.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPPER LEVEL S/W TROUGH OVER THE EASTERN GREAT LAKES EARLY THIS
MORNING LIFTS NEWD THROUGH NY AND NE TODAY....LEAVING THE
ASSOCIATED SFC FRONT STALLED JUST TO THE N OF THE FCST AREA. A
WEAK UPPER LEVEL HIGH FORMING IN ITS WAKE DRIFTS E OF THE AREA
TONIGHT...ALLOWING AN EQUALLY WEAK UPPER LEVEL TROUGH OVER THE
SERN STATES THIS MORNING TO DRIFT NWD INTO THE FCST AREA LATE
TODAY AND TONIGHT...AS THE SFC FRONT STALLED JUST TO THE N REMAINS
THERE.

THIS FEATURE...TOGETHER WITH THE VERY WARM AND HUMID AIR IN
PLACE...WILL TRIGGER SCATTERED CONVECTION THIS AFTERNOON OVER SRN
PORTIONS OF THE FCST AREA AT FIRST. THE AREA OF CONVECTION AND
CELL MOVEMENT WILL DRIFT NWD LATER TODAY AND TONIGHT. GIVEN THE
DISTURBANCE...THE AIR MASS...AND THE FRONT JUST TO THE
N...CONVECTION MAY BE SLOW TO DIE OFF TONIGHT.

SLOW CELL MOVEMENT AND PW VALUES UPWARDS OF 1.75 IN COULD RESULT
IN LOCALIZED DOWNPOURS THAT LAST LONG ENOUGH TO CAUSE ACUTE POOR
DRAINAGE HIGH WATER.

MORNING CU KEPT TEMPERATURES FROM GETTING OUT OF THE GATE FOR A
TIME WED...AND HIGHS WERE MODEST. SOME MORNING CU THIS MORNING...
ALONG WITH A THICK CIRRUS CANOPY COMING OFF THE CONVECTION
ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE FROM THE S...MAY
AGAIN PLACE A LIMIT ON MAX TEMPERATURES TODAY. BLENDED IN MOSGUIDE
TO LOWER A BIT BUT STAYED ON HIGHER SIDE OF GUIDANCE. LOWS
TONIGHT WERE CLOSE TO GUIDANCE AND ACCEPTED.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
SHOWERS AND THUNDERSTORMS WILL CONTINUE FRIDAY IN THE WARM HUMID
ATMOSPHERE...AS UPPER DISTURBANCES MOVE NORTH THROUGH THE FLOW.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL DURING THE
PERIOD...PARTICULARLY ON SATURDAY AS SOUTHWESTERLY FLOW INCREASES
OUT AHEAD OF AN APPROACHING COLD FRONT. SHOWERS AND THUNDERSTORMS
WILL BE ON THE INCREASE OVER THE WEEKEND OUT AHEAD OF THIS
FRONT...WHICH WILL MOVE INTO THE CWA SATURDAY NIGHT OR EARLY
SUNDAY...BEFORE STALLING OUT ACROSS THE AREA. THUS...THERE LOOKS
TO BE NO END IN SIGHT TO THE WARM AND HUMID WEATHER.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE RIDGE AXIS SHIFTS JUST OFF THE E COAST OVER THE WEEKEND...OWING
TO DEEP MOIST S FLOW...WITH VARIOUS UPPER AIR IMPULSES TO FURTHER
AID IN CONVECTIVE POTENTIAL. GENERALLY HIGH CHANCE TO LIKELY POPS
ESPECIALLY LATE SUN AND MON. CONTINUED WARM AND MUGGY.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WILL STALL JUST NORTH OF THE AREA OVERNIGHT...AND
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH IT SHOULD ALSO STAY TO
THE NORTH. OTHERWISE AREAS OF VALLEY MIST MAY FORM OVERNIGHT BUT
DENSE FOG IS NOT LIKELY.  MVFR STRATOCU / MORNING CU IS LIKELY TO
FORM AND THEN MIX OUT BY LATE THU MORNING.

THE AREA REMAINS IN A VERY WARM AND VERY MOIST AIR MASS. SCATTERED
CONVECTION THIS AFTERNOON MAY FORM AS EARLY AS MIDDAY. ANY
CONVECTION AROUND THIS EVENING MAY PERSIST INTO THE OVERNIGHT
BEFORE DISSIPATING GIVEN VERY HIGH SFC DEW POINTS...AND THE FRONT
STILL CLOSE BY TO THE N.

SFC FLOW WILL BE LIGHT AND VARIABLE WHILE LIGHT W FLOW ALOFT
THROUGH THU BECOMES LIGHT AND VARIABLE THU NT.

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: VALLEY FOG MAY VARY FROM FORECAST OVERNIGHT.
ISOLATED CONVECTION MAY HIT TERMINALS THU AFTERNOON OR NT.

.AFTER 06Z FRIDAY... IFR IN MORE WIDESPREAD CONVECTION LATE
SATURDAY OR SATURDAY NIGHT AND AGAIN ON SUNDAY.


&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...30
AVIATION...TRM


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