Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 250636 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 135 AM EST SUN JAN 25 2015 .SYNOPSIS... HIGH PRESSURE WILL EXTEND NORTHEASTWARD FROM THE GULF COAST INTO THE CAROLINAS TODAY. A STRONG UPPER LEVEL DISTURBANCE AND SURFACE LOW PRESSURE WILL CROSS THE REGION MONDAY INTO MONDAY EVENING. A COLD FRONT WILL DROP THROUGH THE AREA LATE MONDAY NIGHT... THEN SETTLE TO OUR SOUTH THROUGH MID WEEK... AS HIGH PRESSURE BUILDS IN FROM THE WEST. ANOTHER LOW PRESSURE AREA AND COLD FRONT WILL CROSS THE REGION THURSDAY NIGHT INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 832 PM SATURDAY... STRONG SUBSIDENCE IN THE WAKE OF THE PRIMARY S/W TROUGH LIFTING UP THE MID-ATLANTIC COAST WILL QUICKLY COME TO AN END THIS EVENING AS THE NEXT SHORTWAVE TROUGH WILL TRAVERSE THE AREA OVER THE NEXT SEVERAL HOURS. MOISTURE IS LIMITED WITH THE WAVE...SO EXPECT ONLY SOME THIN HIGH CLOUDS TO SKIRT MOSTLY NORTHERN PORTIONS OF THE FORECAST AREA. LOW-LEVEL DRIER AIR FEED FROM THE WEST SHOULD PRECLUDE FOG DEVELOPMENT OVERNIGHT WITH SFC DEWPOINT DEPRESSIONS ~5F DEGREES. LOWS IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 235 PM SATURDAY... SUNDAY... AN INCREASING SOUTHWESTERLY FLOW AT ALL LEVELS OF THE ATMOSPHERE SUNDAY WILL LEAD TO A VERY MILD AFTERNOON. MOSTLY SUNNY SKIES ARE EXPECTED UNTIL MID TO LATE AFTERNOON. THIS IS WHEN HIGH LEVEL MOISTURE IS EXPECTED TO BEGIN OVERSPREADING OUR REGION. A RAPID INCREASE IN HIGH CLOUDINESS IS EXPECTED DUE TO THE APPROACHING MID/UPPER TROUGH THAT WILL BE DIVING SOUTHEAST FROM THE MID MISSISSIPPI VALLEY TOWARD THE CENTRAL APPALACHIANS DURING THE AFTERNOON. HIGHS SHOULD REACH INTO THE 50S THROUGHOUT CENTRAL NORTH CAROLINA... COOLEST IN THE NW WHERE CLOUDS WILL INCREASE EARLIER. SUNDAY NIGHT... THE OPERATIONAL MODELS HAVE TRENDED A BIT SOUTHWARD WITH THE TRACK OF THE MID/UPPER LEVEL VORTICITY MAXIMUM DIVING SOUTHEAST IN THE "ALBERTA CLIPPER" FASHION. USING THE ENSEMBLE APPROACH GIVEN SOME 50-100 MILE DIFFERENCES IN THE FORECAST TRACK WITHIN THE MODEL SUITE... A TRACK NEARLY BISECTING NORTH CAROLINA FROM NW TO SE WOULD BE AN AVERAGE RESULT. THE LATEST OPERATIONAL EUROPEAN IS A GOOD REPRESENTATIVE TO START WITH. THIS WOULD SUGGEST A SURFACE WAVE TRACK SOUTHEAST FROM SOUTHERN KENTUCKY INTO NC LATE SUNDAY NIGHT... WITH REDEVELOPMENT OFFSHORE OF CAPE HATTERAS MONDAY. FOR A WINTER P-TYPE THREAT... THE TYPICAL "CLIPPER LOW" TRACK WOULD MOST LIKELY HAVE TO TRACK 50-100 MILES TO THE SOUTH OF THE CURRENT FORECAST TRACK. THEREFORE... SUNDAY NIGHT... ANY LIGHT PRECIPITATION THAT DEVELOPS OVER OUR REGION IS EXPECTED TO BE LIQUID WITH HIGH CONFIDENCE. WE WILL STILL BE IN THE WARM SECTOR THROUGH SUNDAY NIGHT WHICH ALSO MEANS THAT TEMPERATURES TYPICALLY ARE A FEW DEGREES WARMER THAN FORECAST MOS GUIDANCE WITH PRE-FRONTAL WARM SECTOR EVENTS. EXPECT TO SEE THICKENING CLOUDINESS SUNDAY EVENING LEADING TO A CHANCE OF RAIN SHOWERS IN THE NORTHERN SECTIONS LATE SUNDAY NIGHT. LOWS ARE EXPECTED TO REMAIN WELL ABOVE FREEZING (IN THE 37-42 RANGE NW TO SE). WE WILL CARRY LOW END "CHANCE" POP IN THE NORTH FOR NOW WHICH IS 25-30 PERCENT FOR MEASURABLE RAIN (0.01). ANYTHING THAT FALLS THROUGH 12Z/MON WOULD BE RAIN AND WOULD BE LIGHT AND IN THE NW ZONES. MONDAY... THERE IS GOOD MODEL CONSENSUS ON THE TIMING OF THIS SHORT WAVE CLIPPER SYSTEM PIVOTING ACROSS THE AREA ON MONDAY. MOISTURE AND LIFT WILL BE QUITE LIMITED AND SUPPORTIVE OF ONLY LIGHT RAIN SHOWERS... AND MAINLY ACROSS THE NORTHERN TIER OF CENTRAL NC. RAINFALL AMOUNTS WILL BE LESS THAN A TENTH OF AN INCH. HIGHS SUNDAY WILL NOT SHOW MUCH INCLINATION TO RISE ACROSS THE NORTHERN TIER DUE TO CLOUDINESS AND LIGHT PRECIP...BUT SHOULD STILL REACH THE MID 40S DUE TO THE MILD...MID 30S...START TO THE DAY. HIGHS ACROSS THE SOUTH MAY REACH THE MID 50S WITH A SHORT PERIOD OF SOUTHWEST FLOW AND WARM AIR ADVECTION AHEAD OF THE SURFACE REFLECTION OF THE UPPER SHORTWAVE. THE COLD AIR SURGE BEHIND THE SYSTEM AS IT LIFTS NORTHEAST EARLY MONDAY NIGHT WILL OCCUR AFTER DEEPER MOISTURE HAS PULLED OUT...AND MODEL SOUNDINGS SHOW ONLY A COUPLE OF HOURS OF POTENTIAL SNOW SHOWERS MIXING WITH THE DEPARTING RAIN AS LEVELS ABOVE -12 DRY OUT. PRECIP WILL BE ENDING AROUND MIDNIGHT...WITH LOWS FALLING TO THE UPPER 20S NORTH TO AROUND FREEZING SOUTH. CLOUDINESS SHOULD REMAIN WIDESPREAD OVERNIGHT WITH THE APPROACH OF ANOTHER SHORT WAVE WITH LAGGING MID LEVEL MOISTURE IN THE FAST UPPER NORTHWEST FLOW. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 130 AM SUNDAY... TUE/TUE NIGHT: THE POLAR FRONT SHOULD HAVE SETTLED SOUTH OF NC... AS THE SURFACE LOW BOMBS OFF THE MIDATLANTIC COAST. SHEARED VORTICITY WILL CONTINUE TO STREAM SE AND EAST ACROSS THE CAROLINAS INTO THE BASE OF THE MEAN POLAR TROUGH. WE MAINTAIN A DECENT AMOUNT OF MOISTURE FROM 925 MB UP THROUGH 600 MB (WITH SOME VARIABILITY AMONG THE MODELS REGARDING SHALLOW DRY LAYERS THROUGH THIS DEPTH)... SO EXPECT TO RETAIN A GOOD AMOUNT OF CLOUD COVER THROUGH THE DAY... BUT ANY PRECIP IS APT TO BE QUITE PATCHY WITH ONLY TRACE AMOUNTS EXPECTED... AS LOW LEVEL FLOW TAKES ON A NORTHWESTERLY DOWNSLOPE COMPONENT. WILL LEAVE POPS UNDER 15%. DESPITE SOME LOW LEVEL MIXING... THICKNESSES DROP TO VALUES NEARLY 20 M BELOW NORMAL... SUGGESTING HIGHS FROM NEAR 40 NORTH TO THE UPPER 40S SOUTH WHEN FACTORING IN CLOUD COVER. THE COLUMN DRIES OUT TUE NIGHT AS HIGH PRESSURE SHIFTING OVER THE OH VALLEY ATTEMPTS TO PUSH OVER THE MOUNTAINS. WITH A SLACKENING MSLP GRADIENT AND LOWERING WIND SPEEDS UNDER CLEARING SKIES... EXPECT CHILLY LOWS WELL DOWN INTO THE 20S. WED-THU: THE MID LEVEL POLAR LOW OFF NEW ENGLAND LIFTS NORTHEAST WITH THE MEAN TROUGH FINALLY PUSHING EASTWARD OFF THE EAST COAST EARLY WED... LEAVING NC BENEATH WEAK MID LEVEL SHORTWAVE RIDGING. THIS WILL GENERATE MAINLY QUIET WEATHER AND A GRADUAL MODIFICATION OF TEMPS THROUGH MID WEEK AS SURFACE HIGH PRESSURE BUILDS ESE OVER THE CAROLINAS WED BEFORE PUSHING SOUTHWARD TO OVER FL AND OFF THE SE COAST THU. ANOTHER CLIPPER SHORTWAVE TROUGH MOVING THROUGH THE DAKOTAS AND UPPER MIDWEST WED NIGHT WILL CROSS THE SRN GREAT LAKES AND OH VALLEY REGION LATE THU... AND A SHOT OF WEAK MID LEVEL DPVA ACROSS NC ALONG WITH INCREASING UPPER LEVEL DIVERGENCE (IN THE LEFT EXIT REGION OF A STRENGTHENING UPPER JET ACROSS THE MID/LOWER MISS VALLEY INTO THE MIDSOUTH) AND ACCELERATING CYCLONIC LOW LEVEL FLOW INTO THE FORECAST AREA WILL LEAD TO INCREASING AND THICKENING CLOUDS WITH LOWERING BASES THU. EXPECT HIGHS WED MOSTLY IN THE MID-UPPER 40S WITH PLENTY OF SUNSHINE. LOWS IN THE MID-UPPER 20S WED NIGHT AND HIGHS THU IN THE UPPER 40S TO LOWER 50S... JUST A COUPLE OF DEGREES BELOW NORMAL. THU NIGHT-SAT: THE AFOREMENTIONED SHORTWAVE TROUGH COMING OUT OF THE OH VALLEY SWINGS THROUGH THE EASTERN STATES WHILE AMPLIFYING THU NIGHT THROUGH FRI NIGHT. THERE IS NOT MUCH MOISTURE RETURN AHEAD OF THE ASSOCIATED FRONT WITH PROJECTED PW VALUES JUST A BIT ABOVE NORMAL... SO DESPITE DECENT MID-LEVEL DPVA AND UPPER DIVERGENCE THU NIGHT/FRI MORNING... EXPECT ANY PRECIP TO BE BRIEF AND LIGHT... AND WILL KEEP POPS LOW. DRY WEATHER FOLLOWS FOR THE LATTER HALF OF FRI INTO FRI NIGHT... WITH INITIALLY BLUSTERY NW WINDS POST-FRONT WEAKENING FRI NIGHT. PLEASANT WEATHER SAT WITH BRIEF FLAT OR SHORTWAVE RIDGING BEHIND THE EXITING TROUGH WITH HIGH PRESSURE AGAIN NOSING INTO NC FROM THE GULF STATES. MODEL SOLUTIONS REALLY START TO DIVERGE HERE BUT WE MAY SEE YET ANOTHER CLIPPER WAVE DIVING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION SAT WITH SOME ADDITIONAL ENERGY EMANATING FROM THE CLOSED LOW OFF BAJA STREAKING EASTWARD INTO NC... MEANING INCREASING CLOUDS SAT. -GIH && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 1250 AM SUNDAY... 24 HOUR TAF PERIOD: HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE 24 HOUR TAF PERIOD AS SKIES THIS EVENING ARE CLEAR AND WINDS ARE LIGHT AND OUT OF THE WEST OR SOUTHWEST. WITH DRY AIR IN PLACE AT THE SURFACE...DEWPOINT DEPRESSIONS ARE LARGE ENOUGH THAT FOG SHOULD NOT BE AN ISSUE THIS MORNING. SOUNDINGS INDICATE THEIR COULD BE SOME OROGRAPHICALLY ENHANCED CIRRUS THIS MORNING THAT COULD AFFECT KINT AND KGSO ALONG WITH SOME HIGH CLOUDS ASSOCIATED WITH THE NEXT SYSTEM THAT WILL GRADUALLY MOVE IN FROM THE WEST LATER ON TODAY. THERE COULD BE A BRIEF PERIOD OF GUSTY WINDS AT KINT AND KGSO MAINLY BETWEEN 18Z SUNDAY AND 00Z MONDAY. LONG TERM: THE NEXT CLIPPER SYSTEM WILL BRUSH NORTHERN LOCALES ON MONDAY WITH PRECIPIATION EXPECT TO FALL AS RAIN. THIS MAY CAUSE SOME PERIODS OF SUB-VFR CONDITIONS MONDAY INTO TUESDAY MORNING. VFR CONDITIONS WILL RETURN FOR MIDWEEK WITH A WEAK SYSTEM FOR THURSDAY NIGHT POSSIBLY PRESENTING SOME ADVERSE CONDITIONS BUT CONFIDENCE IN THAT IS LOW AT THIS TIME. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...CBL SHORT TERM...BADGETT/MLM LONG TERM...HARTFIELD AVIATION...ELLIS

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