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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 221924
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
324 PM EDT WED MAY 22 2013

.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
AS OF 300 PM EDT WEDNESDAY...

SCATTERED STRONG TO SEVERE THUNDERSTORMS DEVELOPING THIS AFTERNOON
MAINLY ACROSS THE MOUNTAINS IN THE WARM AND UNSTABLE AIR. THE
MAIN THREATS FOR THIS AFTERNOON INTO TONIGHT ARE HEAVY
RAIN...WINDS (DCAPES ARD 1000 IN REGION) AND HAIL (WITH WBZ ARD
10KFT). CAPES OF 1 TO 3 J/KG AS SEEN ON THE SPC MESO ANAL WERE
FORECASTED BY MODIFIED SOUNDINGS THIS MORNING. LEANED POPS TONIGHT
TOWARDS RNK WRFARW WHICH PLACED THIS AFTERNOONS CONVECTION QUITE
WELL. NAM...GFS AND ECWMF CONTINUE SHOWERS AND THUNDERSTORMS INTO
TONIGHT ESPECIALLY IN THE WEST. EXPECT AREAS OF FOG OVERNIGHT
WHERE RAIN FALLS THIS AFTERNOON INTO TONIGHT. PLAYED LOW
TEMPERATURES TONIGHT FROM MID 50S IN THE NORTHWEST TO THE MID 60S
IN THE SOUTHEAST.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 300 PM EDT WEDNESDAY...

ECMWF/GFS BLEND FOLLOWED THIS PERIOD...AS TIMING LOOKS GOOD FOR THE
FRONT ARRIVING IN THE AREA THURSDAY MORNING AND EXITING BY THURSDAY
EVENING IN THE EAST. MAIN FORCING WILL BE WEAKENING BUT ENOUGH LOW
LVL CONVERGENCE AND DECENT FLOW ALOFT TO MAINTAIN A BROKEN LINE OF
SHOWERS AND STORMS INTO THE MTNS THURSDAY MORNING SHIFTING EAST TO
THE PIEDMONT BY MIDDAY. DRY SLOT WORKS INTO THE SOUTHWEST AROUND
LATE EVENING WITH STRONG SHORTWAVE FOLLOWING INTO WV/VA BY FRIDAY
MORNING. THIS WILL ENHANCE THE SHOWER ACTIVITY IN THE WV MTNS
ALTHOUGH AIRMASS OVERALL WILL BE DRYING OUT.

SVR THREAT THURSDAY WILL BE EAST WHERE SOME SUN MAY OCCUR EARLY
ENOUGH TO DESTABILIZE THE AIRMASS. NOT OUTLOOKED THOUGH BUT CANNOT
RULE OUT AN ISOLATED WIND GUST OVER 50 MPH OR HAIL.

THE CHANGE IN AIRMASS WILL BE NOTICEABLE FRIDAY AS DEWPOINTS DROP
INTO THE 30S AND 8H TEMPS DROP TO NEAR ZERO. NOT SEEING MUCH CLOUD
COVER AFTER LATE MORNING SO SUNSHINE MAY WORK TO BALANCE OUT THE
CAA. STILL LEANING TOWARD THE ECMWF MOS WITH LOWER TO MID 60S
MOUNTAINS TO LOWER TO MID 70S EAST. DOWNSLOPE MAY ENHANCE THE
HEATING AS WELL...AND COULD BE SEVERAL DEGREES WARMER BUT BREEZY
CONDITIONS AT TIMES HINDERS WARM UPS.

NOT OF THE QUESTION TO SEE SOME SMALL HAIL PRODUCING SHOWERS ACROSS
THE ALLEGHANY HIGHLANDS FRIDAY AS THE UPPER TROUGH AXIS MOVES
ACROSS...BUT AGAIN APPEARS GFS/ECMWF DRY IT OUT TOO MUCH.

FRIDAY NIGHT STAYS BREEZY AS TEMPS DROP INTO THE 30S/40S. NOT SEEING
FROST/FREEZE ISSUES AT THIS POINT GIVEN WINDS BUT A FEW HIGHER
ELEVATIONS LIKE HOT SPRINGS COULD SLIP TOWARD 32F SAT MORNING.

SATURDAY WILL BE FALL LIKE WITH MOSTLY SUNNY SKIES AND NW BREEZE.
HIGHS WILL RANGE FROM THE MID 60S MOUNTAINS TO LOWER 70S EAST.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 1245 PM EDT WEDNESDAY

EXPECT COOL TROUGH TO LINGER INTO SUNDAY BEFORE LIFTING EAST.
MEANWHILE A STRONG TROUGH DIGS INTO THE PACIFIC NORTHWEST BY MONDAY
WITH INCREASING HEIGHTS ARRIVING OVER OUR AREA NEXT WEEK. THE
WEATHER PATTERN WILL BE MAINLY DRY SAT NIGHT-MONDAY...BUT AS WE CAN
SEE WITH A WESTERLY FLOW ALOFT THE CHANCE THAT CONVECTION THAT FIRES
ALONG A WARM FRONT OVER THE OHIO/MID MISSISSIPPI VALLEY COULD SHIFT
EAST AND AFFECT OUR MOUNTAINS.

WILL LEAN TOWARD AN ECMWF/WPC BLEND SOLUTION. THIS WILL KEEP THE
CHANCE POPS IN THE AREA BY MONDAY AFTERNOON THROUGH TUESDAY. THE
WARM FRONT LIFTS NORTH TOWARD THE GREAT LAKES BY MIDWEEK WITH
HEIGHTS CONTINUING TO BUILD. AT THE SFC...HIGH PRESSURE WILL BE
SITUATED ACROSS THE MID ATLANTIC COAST THEN SHIFT OFF THE COAST
MIDWEEK. DEWPOINTS WILL BE INCREASING AGAIN BY NEXT WEEK WITH TEMPS
WARMING BACK TO NORMAL OR JUST ABOVE.
-- End Changed Discussion --

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 140 PM EDT WEDNESDAY...

SCATTERED MVFR/IFR CONVECTION DEVELOPING IN THE WARM UNSTABLE AIR
ACROSS CWA THIS AFTERNOON. THE BEST CHANCE OF THUNDERSTORMS WILL
OCCUR ACROSS WESTERN TAF SITES OF BLF/LWB/RNK. RNKWRF ARW SHOWED
GOOD COVERAGE OF STORM ACROSS THE MOUNTAINS THIS AFTERNOON INTO
TONIGHT. ECMWF/GFS GENERALLY CONSISTENT ON A LINE OF STRONG
THUNDERSTORMS MOVING INTO FAR SW VA FROM KY/TN IN THE 00Z-04Z TIME
FRAME...THEN GENERALLY DISSIPATING AS MOVE EAST. FOR THE EAST...
THERE IS POTENTIAL TSRA DEVELOPMENT ACROSS THE NC
PIEDMONT...LIFTING NORTHWARD TOWARD LYH/DAN/EVEN ROA BY LATE
AFTERNOON INTO THIS EVENING.

S-SW WINDS 5-10KTS THROUGH TAF VALID PERIOD...WITH LOW END GUSTS
ACROSS THE PIEDMONT. AREAS OF FOG WILL DEVELOP TONIGHT INTO
WEDNESDAY MORNING WHERE RAIN FALLS THIS AFTERNOON INTO THIS
EVENING.

MEDIUM TO HIGH CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...KK/RAB