Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 040001
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
801 PM EDT TUE MAY 3 2016

.SYNOPSIS...
OUR WEATHER WILL REMAIN COOL AND UNSETTLED THROUGH THE END OF THE
WORKWEEK...WITH WEAK DISTURBANCES MOVING THROUGH THE REGION AND
BRINGING US A CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH
FRIDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 330 PM EDT TUESDAY...

EARLY CLOUDS GAVE WAY TO SOME SUN WHICH ALLOWED DIURNAL INSTABILITY TO
SET UP AN ENVIRONMENT CONDUCIVE FOR THUNDERSTORM DEVELOPMENT. THE
STORMS GOT STARTED WEST OF THE BLUE RIDGE AND HAVE NOW MOVED TO THE
EAST WHERE THERE IS BETTER INSTABILITY. WITH COOL TEMPERATURES ALOFT
AND PWATS OVER ONE INCH ACROSS THE PIEDMONT EXPECT LOCALLY HEAVY
RAIN AND SOME HAIL WITH AN ISOLATED SEVERE THREAT SOUTHSIDE/PIEDMONT...
WITH THE BEST SUPPORT FOR MORE WIDESPREAD SEVERE CONVECTION RESIDING
FURTHER TO THE SOUTH AND EAST OUTSIDE OF OUR AREA. EXPECT THE BULK
OF ACTIVITY TO BE EXITING THE REGION TO THE EAST EARLY THIS EVENING
BUT SOME SCATTERED SHOWERS/STORMS WILL BE FLOATING AROUND FURTHER
WEST AS WELL.

THE ACTIVITY WILL DWINDLE OVERNIGHT AS THE LINGERING COLD FRONTAL
BOUNDARY SINKS FURTHER TO THE SOUTH BUT AS A SHORT WAVE APPROACHES LATE
TONIGHT A RESURGENCE OF SCATTERED ACTIVITY IS EXPECTED FAR WEST OF THE
BLUE RIDGE. WEDNESDAY WILL REMAIN UNSETTLED WITH MORE SHORT WAVE ENERGY
ROTATING IN OUR DIRECTION. AS TEMPERATURES CONTINUE TO COOL ALOFT LAPSE
RATES SHOULD BE STEEP ENOUGH TO COMBINE WITH SOME DIURNAL INSTABILITY
TO GENERATE SOME SHOWERS/ISOLATED THUNDERSTORMS FROM LATE MORNING ON.
HIGHS ION WEDNESDAY WILL BE ON THE COOL SIDE WITH READINGS IN THE LOWER
70S EAST TO 60/65 WEST.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...

UPPER LEVEL PATTERN SUPPORTS DEVELOPMENT OF AN OMEGA BLOCK WITH
CUTOFF LOWS ON THE EAST AND WEST COASTS OF THE CONUS...A HIGH
AMPLITUDE RIDGE IN-BETWEEN.  PATTERN TRANSITION WILL TAKE PLACE
WEDNESDAY AND WEDNESDAY NIGHT AS A COLD UPPER LEVEL TROUGH SINKS
SOUTH FROM HUDSON BAY REGION THROUGH THE GREAT LAKES AND OHIO
VALLEY. THIS TROUGH WILL CUTOFF OVER THE MID ATLANTIC THURSDAY...AND
THEN STALL VCNTY OF THE MID-ATLANTIC COAST FOR FRIDAY.  SPOKES OF
VORTICITY WILL BE SPIRALING AROUND THE UPPER LOW...EACH VORT AXIS
PROVIDING DYNAMIC LIFT FOR SHOWERS.  AS SUCH...EXPECTING PERSISTENT
UNSETTLED WEATHER DURING THIS PERIOD OF THE FORECAST WITH
CONSIDERABLE CLOUDINESS AND THE THREAT OF SHOWERS. TEMPERATURES WILL
STRUGGLE PER ABUNDANT CLOUD COVER...SHOWERS...AND COLD POOL ALOFT.
FORECAST 85H TEMPS OF 0 TO +5 DEGREES C SUGGEST WE WILL BE
UNSEASONABLY COOL WITH SFC TEMPERATURES 10 TO 15 DEGREES BELOW
NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...

CUTOFF LOW VCNTY OF THE MID ATLANTIC COAST EARLY SATURDAY WILL BEGIN
TO WEAKEN AND DRIFT EAST THIS WEEKEND AS FLOW ALOFT SLOWLY EVOLVES
INTO A MORE PROGRESSIVE PATTERN FOR THE SECOND WEEK OF MAY. THE
WEEKEND WILL BE OUR TRANSITION BETWEEN THE TWO PATTERNS SO LOOK FOR
SATURDAY TO BE THE COOLER OF THE TWO DAYS. WARM AIR ADVECTION WILL
FINALLY WIN OUT BY SUNDAY WITH TEMPERATURES FAVORING THE WARMER SIDE
OF NORMAL FOR SUNDAY AND INTO THE FIRST PART OF NEXT WEEK.

MODELS STILL HANG ONTO SOME LINGERING CLOUDS SATURDAY...BUT THINK
SUBSIDENCE IN THE WAKE OF THE UPPER LOW SHOULD FAVOR MAINLY DRY
CONDITIONS. MODELS BRING ANOTHER FRONT INTO THE AREA FROM THE
NORTHWEST SUNDAY...THIS FEATURE STALLING SOUTH OF THE REGION SUNDAY
NIGHT BEFORE RETURNING AS A WARM FRONT MONDAY INTO TUESDAY. MOISTURE
CONVERGENCE ALONG THIS FRONT WILL RESULT IN A RISK FOR SHOWERS
DURING THE PERIOD...BUT NOT CONFIDENT ON TIMING OR AMOUNTS ATTM.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 750 PM EDT TUESDAY...

ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO GRADUALLY
DISSIPATE THIS EVENING. COVERAGE WILL BE TOO LIMITED TO INCLUDE
IN THE BODY OF THE TAFS. WINDS WERE OUT OF THE WEST TO NORTHWEST
ACROSS THE MOUNTAINS THIS EVENING. EXPECT STRIP OF MVFR
STRATOCUMULUS ON THE WEST SLOPES OF THE APPALACHIANS THROUGH
WEDNESDAY MORNING. HIGH CONFIDENCE THAT KBLF WILL LOWER TO MVFR BY
MIDNIGHT THEN REMAIN AROUND 2000 FT THROUGH SUNRISE. KLWB WAS ON
THE EASTERN EDGE OF THESE LOWER CLOUDS. MEDIUM CONFIDENCE THERE
WILL BE ENOUGH OF A BREAK IN THE CLOUD COVER AND ENOUGH LOW LEVEL
MOISTURE FOR LIFR FOG TO DEVELOP IN THE GREENBRIER RIVER VALLEY
AND AT KLWB OVERNIGHT.

ANY STRATUS AND FOG WILL DISSIPATE QUICKLY WEDNESDAY MORNING. A
SHORT WAVE TRACKING INTO THE MID ATLANTIC REGION LATE IN THE DAY
WILL BRING COLDER TEMPERATURES ALOFT...LEADING TO SCT-BKN VFR
STRATOCUMULUS IN THE AFTERNOON.

EXTENDED AVIATION DISCUSSION...

A CLOSED UPPER LOW WILL DEVELOP BY WEDNESDAY NIGHT AND WILL REMAIN
OVER THE MID ATLANTIC STATES FOR MUCH OF THE WEEK. CONDITIONS
SHOULD BE EXPECTED TO BE MVFR OR WORSE FOR MUCH OF THE REMAINDER
OF THE WEEK DUE TO PERIODIC SHOWERS AND ISOLATED THUNDERSTORMS
WHICH WILL RESULT IN LOWS CIGS....AND FOG. SATURDAY COULD BE A
DRY BREAK BETWEEN SYSTEMS BUT CONFIDENCE IS LOW.

&&

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

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...PM
LONG TERM...PM
AVIATION...AMS/JR



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