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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 200606
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
206 AM EDT MON MAY 20 2013

.SYNOPSIS...
UPPER LEVEL ENERGY WILL MOVE SLOWLY ACROSS THE REGION TONIGHT AND
MONDAY...RESULTING IN ROUNDS OF SHOWER AND THUNDERSTORM ACTIVITY.
THIS SYSTEM WILL THEN SHIFT OFF THE MID ATLANTIC COAST BY
TUESDAY. A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL
PLAINS ON MONDAY INTO THE GREAT LAKES BY THURSDAY. THIS SYSTEM
WILL PUSH A COLD FRONT THROUGH THE AREA ON FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT SUNDAY...

MOST SIGNIFICANT RAINS THIS EVENING FELL WEST OF INTERSTATE 77
WHERE UPWARDS OF 3 INCHES OF RAIN WAS OBSERVED OVER PARTS OF
GRAYSON...SMYTH AND TAZEWELL COUNTIES. HAD SEVERAL REPORTS OF
ROADS CLOSED FROM HIGH WATER FROM SALTVILLE TO RICHLANDS...AND ONE
REPORT OF LARGE HAIL...AROUND AN INCH IN DIAMETER...IN SALTVILLE.

SINCE SUNSET...RAIN INTENSITY AND COVERAGE HAS BEEN DECREASING.

UPPER TROUGH IS ALMOST DIRECTLY OVHD. YOU CAN SEE THIS IN THE
OVERALL ROTATION OF THE RADAR ECHOES FROM A REGIONAL PERSPECTIVE.
WITH UPPER TROUGH REMAINING OVHD DURING THE OVERNIGHT...SCATTERED
SHOWERS STILL POSSIBLE...BUT NOTHING NEAR THE MAGNITUDE NOR
COVERAGE DUE TO THE LOSS OF DAYTIME HEATING. UPSLOPE FLOW VCNTY OF
THE BLUE RIDGE ALSO LIKELY TO RESULT IN LOW STRATUS AND DRIZZLE.
WITH THE VERY MOIST CONDITIONS ACROSS THE AREA...BELIEVE THAT FOG
WILL BECOME WIDESPREAD ONCE AGAIN...AND DENSE IN A FEW AREAS. HIGH
DEWPOINTS WILL KEEP OVERNIGHT LOWS FOR MOST LOCATIONS IN THE LOW
60S...WITH A FEW UPPER 50S ACROSS THE MOUNTAINS.

THE BASE OF THE UPPER TROUGH IS EXPECTED TO BE OVER SOUTHSIDE
VIRGINIA BY MONDAY AFTERNOON...WITH NORTHWESTERLY FLOW ACROSS THE
MOUNTAINS AS WEAK UPPER RIDGING BUILDS IN FROM THE WEST. WILL SEE
ANOTHER ROUND OF SHOWER AND THUNDERSTORM ACTIVITY DEVELOP WITH
DAYTIME HEATING THAT WILL BE SPOTTY IN NATURE...BUT DO NOT EXPECT
THIS ACTIVITY TO BE AS WIDESPREAD AS TODAY...MORE CONFINED TO THE
PIEDMONTS ALTHOUGH WILL ALSO SEE DEVELOPMENT ALONG THE RIDGES.
EXPECT BETTER HEATING WITH THE DECREASED CLOUD COVER FOR MONDAY
AFTERNOON...WHICH WILL ALLOW HIGH TEMPERATURES TO REACH INTO THE
MID AND UPPER 70S.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 150 PM EDT SUNDAY...

SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL TAPER OFF MONDAY
NIGHT. THE GREATEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL OCCUR
IN THE PIEDMONT. AFTER MIDNIGHT CUT BACK POPS TO SLIGHT CHANCE IN
THE EAST. WITH A SOUTHWEST FLOW...IT WILL BE MILD MONDAY NIGHT WITH
READINGS FROM THE MID 50S IN THE MOUNTAINS TO THE LOWER 60S IN THE
SOUTHEAST.

MID-LVL RIDGE BUILDS OVERHEAD TUESDAY AFTER THE SHORTWAVE TROUGH
EXITS THE REGION. WITH DRIER AIR ALOFT AND ABSENCE OF ORGANIZED LIFT
TRANSLATES TO LESS COVERAGE OF CONVECTION. PLAYED THE HIGHEST POPS
ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS. HIGHS TUESDAY WILL RANGE
FROM THE UPPER 70S IN THE MOUNTAINS TO THE UPPER 80S IN THE
PIEDMONT. WARM AND MUGGY TUESDAY NIGHT EXPECTED WITH LOWS IN THE
60S.

WEAK UPPER AIR DISTURBANCES ROTATING AROUND THE WESTERN PERIPHERY OF
THE ATLANTIC SURFACE HIGH...WILL PROVIDE SOME LIFT FOR SHOWERS AND
THUNDERSTORMS ON WEDNESDAY. ISOLATED TO SCATTERED CONVECTION WILL
LINGER INTO WEDNESDAY NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 150 PM EDT SUNDAY...

AN UPPER LEVEL CLOSED LOW WILL SPIN AROUND THE UPPER MISSISSIPPI
VALLEY THROUGH AT LEAST FRIDAY. IN ADVANCE OF THIS SYSTEM...PLENTY
OF MOISTURE WILL ADVECT NORTHWARD INTO OUR REGION.

PIECES OF ENERGY WILL SPIRAL EASTWARD FROM THE MAIN SYSTEM AND
COMBINE WITH DAYTIME HEATING TO CREATE SHOWERS AND THUNDERSTORMS.
HPC CONTINUES TO FAVOR A SLOWER TIMING OF THE COLD FRONT. THE FRONT
IS EXPECTED TO EXIT OUR AREA FRIDAY EVENING INTO FRIDAY NIGHT. ECMWF
REMAINS FASTER THAN GFS WITH TIMING OF COLD FRONT. DO NOT BELIEVE
THE SFC LOW THAT DEVELOPS OFF THE SOUTHEAST ON GFS. HIGH PRESSURE
WILL RIDGE SOUTH FROM THE GREAT LAKES ON SATURDAY AND SLIDE EAST ON
SUNDAY.

COOLING TREND EXPECT FOR FRIDAY AND SATURDAY. HIGHS ON FRIDAY
WILL RANGE FROM AROUND 70 DEGREES IN THE WEST TO NEAR 80 DEGREES
IN THE SOUTHEAST. SATURDAY HIGHS ONLY REACH THE MID 60S ACROSS
THE MOUNTAINS TO THE LOWER 70S ACROSS THE PIEDMONT. HIGHS FOR
SUNDAY WILL WARM A COUPLE OF DEGREES FROM THE MID 60S IN THE WEST
TO THE MID 70S IN THE EAST.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
AS OF 200 AM EDT MONDAY...

LOCAL RADAR SHOWED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
EAST OF THE BLUE RIDGE EARLY THIS MORNING. LYH AND DAN MAY GET A
SHOWER WITH HEAVY RAIN BEFORE 09Z. EXPECT IFR TO LIFR STRATUS AND
FOG...ESPECIALLY EAST OF THE BLUE RIDGE THROUGH 14Z/10 AM THIS
MORNING.

CONDITIONS WILL BE SLOW TO IMPROVE...HOWEVER SURFACE AND LOW LEVEL
WINDS WILL GRADUALLY BECOME SOUTHWEST TODAY...ENDING THE UPSLOPE
FLOW. A SHORT WAVE SLOWLY CROSSING THE AREA TODAY WILL AGAIN
TRIGGER SHOWERS AND THUNDERSTORMS. ANY OF THE STRONGER STORMS WILL
HAVE VERY HEAVY RAIN...AS WELL AS IFR TO MVFR CEILINGS AND
VISIBILITIES.

THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY.
PATCHY FOG WITH MVFR VISIBILITIES IS LIKELY EACH NIGHT AND EACH
AFTERNOON AND EVENING THERE WILL BE A THREAT OF SCATTERED
THUNDERSTORMS.

NEXT FRONT APPROACHES ON THURSDAY WITH MORE SHOWERS/STORMS
DEVELOPING. HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE
EXPECTED ON FRIDAY BEHIND THE FRONT.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...NF
NEAR TERM...NF/PM
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/PM