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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 240802
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
402 AM EDT THU JUL 24 2014

.SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL ENTER THE REGION TODAY AND SHIFT SOUTHEAST OF
THE AREA BY LATE TONIGHT. HIGH PRESSURE OVER THE MIDWEST WILL
BUILD ACROSS THE MID ATLANTIC THROUGH FRIDAY. OVER THE WEEKEND THE
PATTERN SETS UP FOR POTENTIAL UPPER DISTURBANCES MOVING INTO THE
REGION ON A NORTHWEST FLOW. A STRONG FRONT IS EXPECTED TO CROSS
THE AREA MONDAY.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --
AS OF 330 AM EDT THURSDAY...

A COUPLE OF SHORTWAVE TO DEAL WITH THROUGH THIS AFTERNOON. FIRST IS
OVER THE CENTRAL APPALACHIANS WITH MAIN BATCH OF SHRA AND ISOLATED
TSRA OCCURRING ALONG AND AHEAD OF IT. DESPITE INCREASING CIN AND
LIMITED INSTABILITY...HIGH THETA-E AND UPPER SUPPORT KEEPING SOME
STORMS ACROSS NW NC PIEDMONT INTO SOUTHSIDE VA. 4Z HRRR HANDLED THIS
PRETTY WELL...AND FOLLOWED SOME OF THIS INTO THE MORNING.

FRONTAL BOUNDARY LIES FROM NORTH OF CRW WEST TO SOUTH OF CVG AND
SOUTH TOWARD BNA THIS MORNING. SFC LOW ALONG THE FRONT OVER THE TN
VALLEY IS EXPECTED TO PUSH NORTHEAST INTO THE PIEDMONT OF VA BY MID
AFTERNOON AND SENDING THE FRONT WELL EAST OF THE MOUNTAINS BY THEN.
STILL UPPER SHORTWAVE THAT IS ACROSS IL THIS MORNING IS GOING TO
MOVE INTO THE MTNS THIS AFTERNOON AND WILL KEEP THREAT OF
SHOWERS/STORMS AROUND. BEST LIFT AND INSTABILITY THOUGH LOOKS TO
MOVE EAST OF THE MTNS THIS AFTERNOON. SPC HAS 5 PERCENT FOR DAMAGING
WINDS ACROSS MOST OF THE AREA TODAY. SOLAR INSOLATION MAY BE LIMITED
AS CLOUD COVER PER SAT TRENDS AND MODEL RH FORECASTS SUGGEST BKN-
OVC.

THE HIGHS TODAY WILL BE IMPACTED BY BOTH CLOUDS/CONVECTION BUT STILL
WARM WITH READINGS RANGING FROM THE MID 70S WEST TO MID 80S EAST.

TONIGHT...THE MAIN AXIS OF LIFT AND MOISTURE SHIFTS EAST OF AREA
WITH SKIES STARTING TO CLEAR IN THE WEST. WILL KEEP HIGH CHANCE
EARLY IN THE EAST THEN DRY IT OUT BY MIDNIGHT/EARLY OVERNIGHT...WHEN
MAIN TROUGH AXIS AT 5H SHIFTS ACROSS. LESS HUMID AIR WILL PUSH INTO
THE MOUNTAINS AT LEAST THOUGH PROXIMITY OF FRONT THAT STALLS OVER
ERN NC/SC MAY INHIBIT THE LOWER DEWPOINTS REACHING THE SE CWA
UNTIL FRIDAY. LOWS ARE GOING TO RANGE FROM THE MID 50S ACROSS THE
HIGHER MTNS TO MID 60S SOUTHEAST.

FRIDAY WILL BE DRY AND LESS HUMID WITH HIGH PRESSURE NOSING IN FROM
THE MID ATLANTIC TURNING WINDS AROUND MORE TO THE NE-E. HIGHS
RANGING FROM THE UPPER 70S MTNS TO LOWER 80S ROANOKE TO MID 80S EAST
CAN BE EXPECTED.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
AS OF 350 AM EDT THURSDAY...

FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT MONDAY. WILL HAVE TO MONITOR
THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL SHOWERS
AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...

STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.

DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.

ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 135 AM EDT THURSDAY...

AVIATION CONCERNS THIS MORNING WILL BE CONVECTION THAT IS MOVING
SLOWLY EAST NORTH OF ROA AND NW OF LYH...WITH MAINLY SHOWERS
FURTHER WEST. WILL HAVE VCSH IN THE TAFS FOR NOW THEN SHOULD BE A
BREAK AROUND DAWN-14Z. MODELS ARE DEVELOPING SHOWERS BY 09Z ACROSS
THE NC PIEDMONT AND PUSHING IT TO DAN. NOT SEEING THIS YET...BUT
CONFIDENCE IS MODERATE IN THIS HAPPENING PER DEEP MOISTURE
CONVERGENCE. AMENDMENTS AS NECESSARY WILL OCCUR IF STORMS LOOK TO
PUSH INTO THE TERMINALS.

ASIDE FROM CONVECTION WILL BE DEALING WITH PERIODS OF MVFR FOG DUE
TO HIGHER MOISTURE LEVELS IN PLACE. CLOUDINESS THOUGH SHOULD LIMIT
THE LOWER VSBYS.

STORMS WILL RE-DEVELOP LATE MORNING AS A COLD FRONT MOVES THROUGH
THE AREA. THE COVERAGE OF THE CONVECTION IS NOT EXPECTED TO BE
WIDESPREAD ENOUGH TO INCLUDE IN THE TAF SITES...BUT DID ADD A VCTS
AT ALL TAF SITES. THREAT FOR PRECIPITATION SHOULD END EARLY IN THE
AFTERNOON IN THE WEST AS THE FRONT EXITS THE FORECAST AREA BETWEEN
18Z THUR AND 00Z FRI...LEAVING VFR CONDITIONS.

EXTENDED AVIATION DISCUSSION...

AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. OVERALL EXPECT SUB VFR AT TIMES THURSDAY WITH SHRA/TSRA
AND MAYBE SOME FOG THU NIGHT...FOLLOWED BY VFR FRI- SAT OUTSIDE OF
ANY VALLEY FOG AT KLWB/KBCB EACH MORNING.

&&

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

&&

$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...PM/WP
LONG TERM...PM
AVIATION...WP