Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KRAH 070526
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
125 AM EDT THU MAY 7 2015

.SYNOPSIS...THE LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY
EVOLVE INTO A SUBTROPICAL OR TROPICAL CYCLONE OVER THE NEXT 12 TO 24
HOURS AS IT DRIFTS SLOWLY NORTHWARD AND THEN NORTHWESTWARD TOWARDS
THE CAROLINAS THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM WEDNESDAY...

BENIGN CONDITIONS WILL PERSIST UNDER THE INFLUENCE OF A PRONOUNCED
UPPER LEVEL RIDGE IN PLACE ACROSS THE EASTERN UNITED STATES. BKN/
OVC CIRRUS WILL PERSIST AND GRADUALLY THICKEN BY SUNRISE...
HOWEVER...AS LIGHT SOUTHERLY FLOW ALOFT (~300 MB) ADVECTS
MOISTURE NORTHWARD FROM A CUT-OFF LOW CAUGHT WITHIN THE RIDGE
OFFSHORE THE SOUTHEAST COAST. ALTHOUGH MOISTENING ASSOCIATED WITH
DPVA AND STRENGTHENING ONSHORE /EASTERLY/ FLOW ATTENDANT THE
APPROACHING CUT-OFF LOW MAY BE SUFFICIENT FOR SPRINKLES OR LIGHT
MEASURABLE PRECIPITATION ALONG THE CAROLINA COAST BY SUNRISE THU
MORNING...NEITHER SPRINKLES NOR MEASURABLE PRECIPITATION ARE
EXPECTED IN FAR SOUTHEAST PORTIONS OF THE NWS RAH COASTAL PLAIN
(I.E. SAMPSON COUNTY). EXPECT LOWS RANGING FROM THE UPPER 50S
WEST/NW PIEDMONT TO NEAR 60F EAST/SE. -VINCENT

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 255 PM WEDNESDAY...

THURSDAY AND THURSDAY: THE LOW OFF THE SOUTHEAST U.S. COAST WILL
CONTINUE TO SLOWLY DRIFT NORTH TOWARD THE CAROLINA COAST
THURSDAY...WITH BOTH MODELS IN FAIRLY GOOD AGREEMENT ON THE
LOCATION...AND STARTING TO JOG WEST-NORTHWESTWARD THURSDAY NIGHT.
THE NORTHWEST PORTIONS OF THE AREA SHOULD STILL BE UNDER THE
INFLUENCE OF THE SURFACE HIGH...RIDGING IN FROM THE NORTHEAST. WITH
THE SYSTEM REMAINING OFFSHORE THURSDAY AND THURSDAY
NIGHT...IMPACTS...CLOUDY SKIES...SHOWERS AND STORMS...ARE STILL
EXPECTED TO BE MINIMAL AND MOSTLY CONFINED TO SOUTHEASTERN PORTIONS
OF THE FORECAST AREA. HAVE KEPT THE SLIGHT CHANCE TO CHANCE OF
SHOWERS AND STORMS IN THE FORECAST...HOWEVER THERE IS STILL A BIT OF
UNCERTAINTY REGARDING THE RAIN AND THUS CONFIDENCE IS NOT TERRIBLY
HIGH ON WHERE AND HOW MUCH RAIN WILL FALL. WITH THE ANTICIPATED
CLOUD COVER EXPECT HIGHEST HIGHS AND LOWEST LOWS IN THE NW...LOW 80S
AND UPPER 50S...AND THE LOWEST HIGHS AND HIGHEST LOWS IN THE
SOUTHEAST...MID 70S TO LOW 60S. WINDS WILL INCREASE EARLY THURSDAY
AS THE LOW APPROACHES...WITH THE STRONGEST WINDS IN THE SOUTH AND
SOUTHEAST. THE STRENGTH WILL DEPEND ON THE POSITION OF THE LOW...BUT
FOR NOW EXPECT 10-15 MPH WINDS IN THE SOUTHEAST THROUGH THURSDAY
NIGHT. -RAH

FRIDAY AND FRIDAY NIGHT: A 10008 MB LOW IS PROGGED TO BE ANCHORED
OFF THE COAST OF MYRTLE BEACH ON FRIDAY AND ALTHOUGH IT IS STILL
UNCLEAR IF IT IS TO BE A NAMED STORM OR NOT...THE PRESENTATION ON
THE GLOBAL MODELS LOOKS FAIRLY ORGANIZED. THE SYSTEM IS EXPECTED TO
BE LARGELY STATIONARY ON FRIDAY WITH SOME RETROGRADING BACK TO THE
SOUTHWEST POSSIBLE. THIS WILL KEEP IMPACTS TO MUCH OF THE AREA ON
FRIDAY FAIRLY MINIMAL. FORECAST SOUNDINGS ARE EXCEPTIONALLY DRY FOR
A QUOTE TROPICAL SYSTEM WITH PW VALUES FLUCTUATING AROUND 1.5
INCHES. EXPECT A FEW SETS OF BANDING SHOWERS TO MOVE THROUGH THE
SOUTHEASTERN AREAS BUT QPF SHOULD BE FAIRLY MINIMAL...WILL CURRENTLY
GO WITH A FORECAST OF LESS THAN A QUARTER OF AN INCH BUT SOME
LOCALIZED HEAVIER SHOWERS ARE PROBABLE. SOME INSTABILITY WILL BE
PRESENT DURING THE AFTERNOON HOURS AND A THUNDERSTORM WILL BE
POSSIBLE AS WELL BUT NO SEVERE WX IS EXPECTED AT THIS TIME.
NORTHEASTERLY WINDS SHOULD PREVAIL BUT WONT BE VERY STRONG WITH
GUSTS UP TO 15 KTS OR SO. WITH CLOUD COVER MOST DENSE IN THE
SOUTHEAST...EXPECT THE COOLEST HIGHS IN THE SOUTHEAST WITH UPPER 70S
PROBABLE WITH THE REST OF THE CWA IN THE LOW 80S.

FRIDAY NIGHT THE CHANCE FOR THUNDER WILL DIMINISH AFTER SUNSET BUT
SLIGHT CHANCES FOR CONTINUED SHOWERS WILL PREVAIL. LOWS AND
DEWPOINTS IN THE MID 60S SO SOME FOGGY PATCHES COULD BE POSSIBLE BY
MORNING. -ELLIS

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...

MUCH OF THE LONG TERM WILL BE DOMINATED BY THE SUBTROPICAL OR
TROPICAL SYSTEM THAT IS EXPECTED TO FORM OFF OF THE SOUTH CAROLINA
COAST. THIS SYSTEM WILL MEANDER ALONG THE SC AND NC COASTLINES
THROUGH AT LEAST MONDAY AND POSSIBLY INTO TUESDAY. MODEL FORECASTS
DIVERGE SIGNIFICANTLY BY SUNDAY AND CONFIDENCE IN THE LOCATION AND
INTENSITY OF THE SYSTEM BECOMES LOWER. NEAR THE END OF THE PERIOD A
COLD FRONT APPROACHES FROM THE WEST AND HELPS TO USHER THE TROPICAL
SYSTEM OUT TO SEA.

AS BEST AS DETAILS CAN BE IRONED OUT RIGHT NOW EXPECT THE MOST RAIN
TO BE IN THE SOUTH EASTERN COUNTIES BUT AT THIS TIME MOISTURE DOES
NOT LOOK HIGH ENOUGH TO PRODUCE SIGNIFICANT RAINFALL THAT WOULD
RESULT IN ANY KIND OF FLOODING. A WESTWARD SHIFT IN TRACK WOULD
RAISE THE POTENTIAL FOR SIGNIFICANT RAIN IN THE EASTERN COUNTIES
OVER THE WEEKEND AND INTO EARLY NEXT WEEK. FORECAST SOUNDINGS ARE
DEPICTING INSTABILITY DURING THE AFTERNOON HOURS EACH
AFTERNOON/EVENING BUT THE OVERNIGHT/MORNING HOURS SHOULD BE MOSTLY
CHARACTERIZED BY CONVECTIVE SHOWERS. SEVERE POTENTIAL LOOKS MINIMAL
AT THIS TIME AND WIND SHEAR VALUES ARE LOW ENOUGH THAT THE THREAT
FOR TROPICAL TORNADOES ALSO LOOKS MINIMAL AT THIS TIME. IN GENERAL
WINDS WILL BE OUT OF THE NORTHEAST AT AROUND 10 KTS GUSTING TO 15-20
KTS.

ON MONDAY NIGHT A COLD FRONT IS EXPECTED TO MOVE THROUGH FROM THE
WEST WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE WITH GOOD
INSTABILITY BUT ONLY ABOUT 20 KTS OF SHEAR SUGGESTIVE OF
MULTICELLULAR CONVECTION AT BEST. AFTER FRONTAL PASSAGE...WINDS WILL
BECOME NORTHWESTERLY AND DEWPOINTS ARE EXPECTED TO DROP BACK INTO
THE 50S. UNTIL THEN EXPECT HIGHS IN THE 80S WITH LOWS IN THE LOW TO
MID 60S. A RETURN TO DRY WEATHER AND SLIGHTLY COOLER TEMPS IS
EXPECTED ON WEDNESDAY.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 125 AM THURSDAY...

24-HOUR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO HOLD OVERNIGHT AND THROUGH THE DAYLIGHT
HOURS WITH MID/HIGH CLOUDS GRADUALLY THICKENING AND LOWERING BY THE
AFTERNOON. LIGHT AND VARIABLE OVERNIGHT WILL BECOME NELY BY DAYBREAK
OWING TO THE SLOW APPROACH OF THE OFFSHORE CYCLONE...INCREASING
THROUGHOUT TH DAY WITH GUSTS BETWEEN 15 TO 20KTS ACROSS CENTRAL
AND EASTERN TERMINALS. ANY SHOWERS SHOULD REMAIN CONFINED TO KFAY.
ASSOCIATED CYCLONIC ONSHORE FLOW WILL BEGIN TO ADVECT LOW-LEVEL
MARITIME MOISTURE INTO THE AREA LATE IN THE PERIOD(BETWEEN 00 TO
06Z)...WITH SUB-VFR CEILINGS SPREADING EAST TO WEST THROUGH DAYBREAK
FRIDAY.

LOOKING AHEAD: THE EVENTUAL SUBTROPICAL OR TROPICAL LOW WILL DRIFT
SLOWLY NORTHWARD ALONG THE SOUTHEAST U.S. COAST...STALLING AND
MEANDERING SOMEWHERE IN THE VICINITY OF SOUTH CAROLINA OR NORTH
CAROLINA LATE IN THE WEEK AND THROUGH THE WEEKEND. ALTHOUGH MODEL
AGREEMENT CONTINUES TO GET BETTER WITH THIS SYSTEM... THERE IS STILL
A LOT OF UNCERTAINTY WITH RESPECT TO THE PATH OF THIS SYSTEM...BUT
REGARDLESS...THIS SYSTEM COULD RESULT IN SOME ADVERSE AVIATION
IMPACTS IN WIDESPREAD SHOWERS AND THUNDERSTORMS...AND COULD PERSIST
THROUGH SUNDAY...ESPECIALLY ACROSS SOUTHERN AND EASTERN NC.
ADDITIONALLY...ENHANCED EASTERLY ONSHORE FLOW FROM THIS SYSTEM COULD
BRING AN INCREASE THREAT FOR MORNING STRATUS/FOG.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...RAH
LONG TERM...ELLIS
AVIATION...CBL



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.