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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 200806
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
406 AM EDT THU JUN 20 2013

.SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE WILL SHIFT OVER THE NORTHEAST COAST TODAY AND WEDGE
SOUTHWEST INTO OUR REGION INTO FRIDAY. UNSTABLE AIR OVER THE
MOUNTAINS WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND STORMS
MAINLY IN THE AFTERNOON THROUGH FRIDAY.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 400 AM EDT THURSDAY...
THE SE FLOW HAS KEPT A FEW SHOWERS LOCKED ACROSS THE MTNS IN NC
EARLY THIS MORNING WHICH HAVE NOW FADED. THERE IS SOME AREAS OF
FOG BUT THE STRATOCU ACROSS THE AREA HAS KEPT DENSE FOG ISOLATED.

THIS SE FLOW WILL HANG AROUND TODAY WITH BEST THETA-E RIDGING ACROSS
THE SW. FIGURING OUT WHERE THE SHOWERS AND STORMS REFIRE IS TRICKY
BUT MODELS HAVE BEEN LEANING TOWARD THE SW VA/NW NC AREA MORESO THAN
ANY OTHER AREA. HOWEVER...THEY HAVE NOT INITIALIZED THAT WELL WITH
WHAT WE ARE GETTING THIS MORNING AS THEY ARE OVERDOING QPF TOO FAR
NORTH.

OUT OF THE MODEL SOLUTIONS...THE 00Z CMC SEEMS THE BEST FIT FOR WHAT
IS HAPPENING...AND WILL LEAN TOWARD ITS SOLUTION...AGAIN PUTTING
40ISH POPS OVER THE NC MTNS THIS AFTERNOON WITH LOWER CHANCES ALONG
THE BLUE RIDGE INTO VA AND WEST INTO WV. THINK THE PIEDMONT WILL
STAY UNDER MORE INFLUENCE OF HIGH PRESSURE KEEPING THE SHOWER
CHANCES LESS THAN 15 PERCENT.

CLOUDS WILL STAY LOCKED IN A LITTLE LONGER ACROSS THE BLUE RIDGE AND
EITHER SIDE THIS MORNING AS INDICATED BY THE NAM/CMC CLOUD COVER
PRODUCT. WITH THE HEATING OF THE EARLY SUMMER SUN...STILL SHOULD BE
SEEING MORE BREAKS. HEIGHTS BUILD ALOFT AND HUMIDITY STAYS ELEVATED
SO HIGH TEMPS WILL BE SIMILAR TO YESTERDAY WITH MID TO UPPER 70S
MTNS...CLOSER TO AROUND 80 FAR SW VA WITH LOWER 80S EAST.

TONIGHT...THE SHOWERS SHOULD LINGER INTO THE NIGHT OVER THE NC MTNS
WITH RESIDUAL OUTFLOW AND HIGHER THETA-E STAYING LOCKED IN ACROSS
THE MTN EMPIRE. WILL SEE SHOWERS FADE AFTER MIDNIGHT.

LOWS WILL BE RANGING FROM THE UPPER 50S TO LOWER 60S.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
AS OF 235 AM EDT THURSDAY...

OVERALL ONSHORE FLOW WILL BE MAINTAINED THROUGH THE PERIOD WITH
SURFACE HIGH PRESSURE OFF THE MID ATLANTIC COAST RIDGING SW INTO THE
REGION AND SLOWLY STRENGTHENING AS UPPER HEIGHTS BUILD. WEAK LOW
PRESSURE OFF THE OUTER BANKS SHOULD ALSO ACT TO ENHANCE THE LOW
LEVEL EASTERLY FETCH...WITH A DRIER NE FLOW OUT EAST TURNING MORE
SE HEADING WEST INTO THE WESTERN SLOPES. HOWEVER LATEST MODEL
SOUNDINGS CONTINUE TO INDICATE JUST ENOUGH MOISTURE BELOW 7H TO
PERHAPS POP A FEW SHRA/TSRA FAR WEST...ESPCLY I-77 CORRIDOR FRIDAY
AFTERNOON WHERE THE HIGHER 85H THETA-E WILL EXIST. THUS BUMPED UP
POPS A LITTLE FRIDAY BUT NO MORE THAN LOW CHANCE AT THIS POINT...
WITH LITTLE CHANCE ELSW GIVEN LESS MOISTURE AND CAP ALOFT. ANY
CONVECTION SHOULD FADE WITH LOSS OF HEATING PER LITTLE UPPER SUPPORT
MAKING FOR A MAINLY CLEAR FRIDAY OVERNIGHT. TREND CONTINUES SATURDAY
WITH A BIT STRONGER EAST/SE FLOW ACROSS THE WEST WHERE MOISTURE WILL
BE LESS THAN FRIDAY AS STRONG RIDGING ALOFT WILL PREVAIL. HOWEVER
CANT TOTALLY RULE OUT ISOLATED SHRA PER HEATING SO KEEPING A 20ISH
POP GOING MAINLY FAR SW/NW COUNTIES...AND BASICALLY DRY ELSW INTO
SAT NIGHT.

TEMPS AGAIN SHOULD BE WARMING TO AOA SEASONAL LEVELS BY SAT GIVEN
SLIGHT WARMING ALOFT AND HEATING OF DRY AIR ESPCLY EAST...WITH
A GOOD DIURNAL RANGE IN RATHER COMFORTABLE HIGHS/LOWS THRU SAT NIGHT.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 PM EDT WEDNESDAY...

GRADUAL UPTICK OF BOTH TEMPERATURE AND DEWPOINT EXPECTED EARLY
NEXT WEEK. MODELS ARE IN AGREEMENT THE SUBTROPICAL RIDGE WILL
STRENGTHEN AND RETROGRADE TO THE WEST...BUT DIFFER IN HANDLING
DAY-TO-DAY DETAILS AS FAR AS EMBEDDED SHORT WAVE ENERGY.
AS SUCH...CONFIDENCE IS REASONABLY GOOD FOR RAISING TEMPERATURES
DURING THE PERIOD...BUT BELOW AVERAGE FOR PROBABILITY OF RAINFALL.
MODELS DIFFER IN THE HANDLING OF THE DISTURBED WEATHER ALONG THE
CAROLINA COAST...THE GFS DRAWING IT WESTWARD AND NORTHWARD.
GIVEN THAT RISING HEIGHTS ARE ANTICIPATED DURING THIS PERIOD AND
CONCERNS THAT THE CONVECTIVE PARAMETRIZATION OF THE GFS MAY BE TOO
AGGRESSIVE...THE PREFERENCE IS FOR AN ECMWF-LIKE SCENARIO THAT
MAINTAINS MOST OF THE PRECIPITATION ALONG THE SOUTHEAST COAST.
EVEN SIDING WITH THE ECMWF...AT SOME POINT WE WARM AND MOISTEN
ENOUGH TO SUPPORT DAILY THREAT OF SCATTERED DIURNAL DEEP
CONVECTION OVER THE MTNS ANYWAY...SO FEEL SCATTERED AFTN/EVE
SHRA/TSRA BECOME WARRANTED FOR MONDAY AND BEYOND IN SPITE OF THE
MODEL DIFFERENCES.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 1233 AM EDT THURSDAY...

LEFTOVER AREAS OF STRATO-CU CONTINUE ALONG THE MOUNTAINS ATTM AND
EXPECT CIGS TO LOWER INTO MVFR LEVELS AT TIMES OVER THE NEXT FEW
HOURS. HOWEVER ONSET OF FOG/STRATUS ALREADY ONGOING ESPCLY IN
SPOTS THAT SAW HEAVY RAINFALL EARLIER...MAINLY KROA/KBCB...AND
EXPECT OTHER LOCATIONS THAT SEE LESS STRATO-CU TO FOG IN BY
DAYBREAK. THUS CONFIDENCE REMAINS HIGH ON SUB VFR AT MOST SITES.
MVFR/IFR CIGS WITH IFR/LIFR VSBYS ARE LIKELY IN FAVORED LOCATIONS
AND AT LEAST BRIEFLY ELSW BY DAWN THURSDAY.

FOR THURSDAY INTO THE WEEKEND...CONTINUED DIURNAL
CONVECTION...ESPECIALLY ALONG THE APPALACHIANS...WITH LOCALLY
BRIEF MVFR-IFR CIGS/VSBYS IN TSRA. AREAS OF MVFR-IFR VSBYS
BR...LOCALLY IFR FG...ALSO POSSIBLE DURING THE MORNING HOURS. OTRW
OVERALL VFR DURING THE DAYTIME HOURS BEFORE/AFTER ANY RIDGE
ORIENTED CONVECTION DEVELOPS WHICH LOOKS QUITE ISOLATED OVER THE
WEEKEND AT THIS POINT.

DUE TO A PROBLEM WITH THE VISIBILITY SENSOR AT KDAN AND APPARENT
COMMS ISSUE IN TRANSMITTING THE OBSERVATION...WILL INCLUDE AMD NOT
SKED WITHIN THE KDAN TAF UNTIL THESE ISSUES ARE CORRECTED ON
THURSDAY.

&&

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

&&

$$
SYNOPSIS...KK/WP
NEAR TERM...WP
SHORT TERM...JH
LONG TERM...PM
AVIATION...JH/KK/RCS