Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 180711 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 310 AM EDT FRI APR 18 2014 .SYNOPSIS...STRONG HIGH PRESSURE CENTERED OVER NEW ENGLAND WILL EXTEND SOUTH THROUGH THE CAROLINAS TODAY. MEANWHILE...LOW PRESSURE WILL DEVELOP OVER THE NORTHEASTERN GULF OF MEXICO...DRIFT ACROSS THE BIG BEND OF FL TONIGHT...THEN MEANDER ALONG THE SOUTHEAST US COAST THROUGH THE WEEKEND. && .NEAR TERM /THROUGH SATURDAY NIGHT/... AS OF 256 AM FRIDAY... SURFACE HIGH PRESSURE WILL EXTEND DOWN THE EAST COAST DURING THE DAY FRIDAY. A SHORTWAVE IN THE SOUTHERN STREAM WILL MOVE EASTWARD ALONG THE GULF COAST... CLOSING OFF LATE IN THE DAY... AS A SURFACE LOW DEVELOPS IN THE VICINITY OF THE FL PANHANDLE. SIGNIFICANT UPPER LEVEL CLOUDINESS... ALREADY VISIBLE ON SATELLITE IMAGERY JUST TO OUR SOUTHWEST... WILL KEEP HIGH TEMPERATURES SUPPRESSED IN TO THE MID 50S TO LOW 60S. PRECIPITATION WILL BEGIN TO TRY TO SPREAD IN TO THE AREA FROM THE SOUTH BY AROUND 00Z SATURDAY... HOWEVER IT MAY TAKE THE SEVERAL HOURS TO SATURATE THE DRY LOW LEVELS... AND THE DEEPER ISENTROPIC LIFT WILL ARRIVE AFTER 06Z SATURDAY. WITH THICK CLOUD COVER AND PRECIPITATION... TEMPERATURES WILL NOT FALL OFF MUCH AND LOWS WILL BE IN THE MID TO UPPER 40S. STACKED LOW PRESSURE WILL CONTINUE TO TRACK SLOWLY EASTWARD OVER NORTHERN FL ON SATURDAY... BEFORE EXITING THE EAST COAST SATURDAY EVENING. CONTINUED BELOW NORMAL TEMPERATURES IN THE MID 50S.. WITH NORTHEAST FLOW... CLOUD COVER... AND PRECIPITATION. EXPECTING A GOOD SOAKING THROUGH THE DAY SATURDAY... WITH TOTAL QPF OF ABOUT 0.75-1.5 INCHES... GREATEST IN THE SOUTHEAST. PRECIPITATION WILL END GENERALLY FROM WEST TO EAST AS THE SYSTEM BEGINS TO PULL AWAY FROM THE COAST... AND ISENTROPIC LIFT DIMINISHES IN THE WEST AFTER 12Z... AND IN THE COASTAL PLAIN AFTER 00Z. LOWS IN THE MID AND UPPER 40S. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AS OF 255 AM FRIDAY... THE SOUTHERN STREAM COASTAL GYRE WILL DRIFT ONLY SLOWLY EAST AND AWAY FROM THE COAST OF THE CAROLINAS SUNDAY. CONTINUED OVERCAST - LOW ONES IN THE COASTAL PLAIN AND MORE MID LEVEL ONES OVER THE WESTERN PIEDMONT - WITH NORTHEASTERLY LOW LEVEL FLOW IN ASSOCIATION WITH RENEWED POLAR HIGH PRESSURE EXTENDING SOUTH FROM NEW ENGLAND...WILL RESULT IN COOLER TEMPERATURES THAN EARLIER ANTICIPATED. TEMPERATURES WILL LIKELY DISPLAY AN ATYPICAL DISTRIBUTION...WITH WARMER TEMPERATURES IN THE MIDDLE 60S IN THE SOUTHERN AND WESTERN PIEDMONT AS CLEARING OCCURS DURING THE MID- AFTERNOON...AND 50S FOR MOST OF THE DAY...WITH PERIODS OF LINGERING LIGHT RAIN EARLY...IN THE COASTAL PLAIN. CLEARING WILL THEN OVERSPREAD ALL OF CENTRAL NC BEHIND THE DEPARTING LOW SUN NIGHT-MON...WITH THE EXCEPTION OF BRIEF LOW OVERCAST...IN CONTINUED NE LOW LEVEL FLOW...MON MORNING. THE MUCH ANTICIPATED - AND NOW WELL-DELAYED - WARM-UP WILL FINALLY ARRIVE MON...WHEN THE HIGH OVER NEW ENGLAND SUCCUMBS TO WARMTH BUILDING OVER THE PLAINS AND MS VALLEY. HIGHS MON IN THE UPPER 60S TO LOWER 70S. LOWS 50 TO 55. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
AS OF 305 AM FRIDAY... THE NORTHERN STREAM...HELD AT BAY ACROSS THE NORTHERN TIER OF STATES DURING THROUGH THE SHORT TERM...WILL BUCKLE/AMPLIFY SOUTHEASTWARD FROM THE UPPER MIDWEST TO THE NE QUARTER OF THE NATION THROUGH EARLY- MID NEXT WEEK. THE SHARPENING TROUGH ALOFT WILL SEND AN ASSOCIATED SURFACE COLD FRONT THROUGH THE MIDDLE ATLANTIC AND CAROLINAS TUE AFTERNOON-EVENING...AT WHICH TIME SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS...FUELED BY DESTABILIZING SURFACE TEMPERATURES IN THE UPPER 70S (TO AROUND 80) AND DEWPOINTS AROUND 60 DEGREES...ARE EXPECTED. COOLER BUT GENERALLY CLEAR CONDITIONS WILL FOLLOW IN BRIEF SURFACE RIDGING FROM THE OH VALLEY/GREAT LAKES WED. FRONTOGENESIS WILL THEN OCCUR FROM THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS WED NIGHT-THU...LEADING TO A WARMER SOUTHWEST LOW LEVEL FLOW BENEATH A BUILDING RIDGE ALOFT OVER THE SOUTHEASTERN US...LATE WEEK.
-- End Changed Discussion --
&& .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 210 AM FRIDAY... POLAR HIGH PRESSURE CENTERED OVER NEW ENGLAND WILL EXTEND SOUTH AND MAINTAIN VFR CONDITIONS FOR MOST OF THE TAF PERIOD...WITH TWO EXCEPTIONS. THE FIRST WILL BE THE AREA IFR STRATUS CEILINGS OVER NE NC THIS MORNING...WHICH IS FORECAST TO ADVECT/DEVELOP WESTWARD INTO THE KRWI AND KRDU VICINITIES...WITH A LOWER PROBABILITY SOUTH AT KFAY AND WEST AT TRIAD TERMINALS...IN THE 09-13Z TIME FRAME. AN ADDITIONAL PLUME OF MOISTURE AT THE BASE OF A LINGERING SUBSIDENCE INVERSION AROUND 4000 FT...WILL MOVE INLAND FROM SE NC AND RESULT IN SCT TO BKN (VFR) STRATOCUMULUS CLOUD BASES AT KFAY THIS MORNING. THE SECOND POTENTIAL FOR SUB-VFR CONDITIONS WILL BE AT THE VERY END OF THE 06Z TAF PERIOD...AND MORE LIKELY JUST BEYOND...AS CLOUDS THICKEN AND LOWER AND RESULT IN THE DEVELOPMENT OF LIGHT RAIN - AND EVENTUALLY MVFR-IFR CEILINGS - TO THE NORTH OF AN AREA OF LOW PRESSURE FORECAST TO DEVELOP FROM THE NE GULF OF MEXICO TO THE SOUTHEAST US COAST. OTHERWISE...5-10 KT ENE SURFACE WINDS THIS MORNING WILL BACK TO A MORE NE COMPONENT TODAY. OUTLOOK: MOISTURE ASSOCIATED WITH THE AFOREMENTIONED DEVELOPING LOW PRESSURE AREA WILL CONTINUE TO SPREAD NORTH LATE TONIGHT AND EARLY SATURDAY...AND CONSEQUENTLY RESULT IN THE DEVELOPMENT OF RAIN THROUGHOUT CENTRAL NC DURING THAT TIME. HOWEVER...CEILINGS WILL BE PROGRESSIVELY HIGHER FROM SOUTHEAST TO NORTHWEST...SUCH THAT IFR- MVFR ONES WILL BE LIKELY AT SOUTHEASTERN TERMINALS...TRENDING HIGHER TO THE WEST AT KRDU AND TRIAD TERMINALS...THE LATTER OF WHICH MAY REMAIN VFR DESPITE PERIODS OF LIGHT RAIN. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MWS NEAR TERM...SEC SHORT TERM...MWS LONG TERM...MWS AVIATION...MWS

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