Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 290002 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 701 PM EST FRI NOV 28 2014 .SYNOPSIS...HIGH PRESSURE WILL MOVE EAST ACROSS THE REGION THROUGH THE WEEKEND. A COLD FRONT CROSSES THE REGION FROM THE NORTHWEST LATE MONDAY AND MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 255 PM FRIDAY... TONIGHT...HIGH PRESSURE CENTERED OVER OUR AREA WILL MEAN FAIR WEATHER WITH CALM WIND. GFS AND ECWMF ARE NEARLY IDENTICAL IN THEIR DEPICTION OF LOW LEVEL THICKNESSES INCREASING RIGHT THROUGH THE WEEKEND...HOWEVER VALUES WILL STILL BE 10-30M BELOW NORMAL TONIGHT...SO LOOK FOR COLDER-THAN-NORMAL READINGS ONCE AGAIN TONIGHT. GUIDANCE IS IN GOOD AGREEMENT SHOWING LOWS GENERALLY IN THE UPPER 20S. IT`S WORTH NOTING THE MID AND HIGH CLOUDS CURRENTLY TO OUR NW...ARE PROGGED BY MODELS TO DRIFT SOUTH AND EAST TONIGHT. THESE CLOUDS WILL BE CLOSELY WATCHED GIVEN THEIR POTENTIAL IMPACTS ON TEMPS TONIGHT. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 255 PM FRIDAY... HIGH PRESSURE WILL MOVE OFFSHORE THROUGH THE PERIOD...WHILE A MID LEVEL RIDGE AMPLIFIES OVER THE SOUTHEAST. THE RESULT FOR OUR AREA WILL BE FAIR WEATHER WITH A WARMING TREND AS LOW LEVEL FLOW TURNS TO THE SOUTH AND THICKNESSES INCREASE. 850MB TEMP IS EXPECTED TO RECOVER TO 7-9 DEG C BY 00Z SUNDAY...WHICH IS FAIRLY CLOSE TO AVERAGE FOR THIS TIME OF YEAR. BUT SINCE IT WILL TAKE UNTIL LATE- DAY TO GET THERE...HIGHS WILL TOP OUT A FEW DEGREES BELOW NORMAL...GENERALLY RANGING FROM THE LOWER 50S NW TO MID 50S SE. LITTLE CHANGE IN THE PATTERN SATURDAY NIGHT WITH HIGH PRESSURE OFFSHORE AND THE MID LEVEL RIDGE CENTERED OVER THE GA COAST. CLEAR SKIES AND CALM WIND WILL SUPPORT EFFICIENT RADIATIONAL COOLING...SO STILL ANOTHER CHILLY NIGHT WITH LOWS IN THE LOW-MID 30S. ALSO WORTH NOTING THAT FORECAST SOUNDINGS AT SEVERAL COASTAL PLAIN SITES SUGGEST THE POTENTIAL FOR SOME FOG OR STRATUS EARLY SUNDAY MORNING GIVEN THE INCREASING LOW LEVEL MOISTURE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 255 PM FRIDAY... SUNDAY THROUGH MONDAY...MID LEVEL RIDGING CENTERED JUST SOUTH OF THE AREA AND RETURN FLOW AROUND OFFSHORE SURFACE HIGH PRESSURE WILL RESULT IN FAIR WEATHER FOR CENTRAL NC. IN ADDITION...TEMPS WILL UNDERGO A MODERATING TREND...WITH HIGHS ON SUNDAY IN THE LOW TO MID 60S AND WARMER STILL ON MONDAY...GENERALLY IN THE MID 60S TO NEAR 70 DEGREES. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE LOW/MID 40S. MONDAY NIGHT THROUGH TUESDAY NIGHT...A NORTHERN STREAM SHORT WAVE MOVING ALONG THE US/CANADIAN BORDER WILL SUPPRESS THE MID LEVEL RIDGE TO THE SOUTH AS IT PROPELS A SURFACE FRONT TOWARDS THE REGION DURING THIS TIME FRAME. THIS TRAILING COLD FRONT IS PROGGED TO CROSS THE AREA MONDAY NIGHT INTO TUESDAY...PROPELLED BY A 1040+ MB HIGH. FORCING IS NOT THAT IMPRESSIVE WITH THIS SYSTEM GIVEN THE PARENT LOW IS SO FAR NORTH OF THE AREA...BUT MODELS CONTINUE TO DEVELOP PRECIP BEHIND THE FRONT...WITHIN A DEVELOPING CAD AIR MASS. THERE ARE STILL SOME DIFFERENCES TO BE IRONED OUT...BUT THE GFS HAS BEEN PERSISTENT WITH INDICATING SOME FREEZING RAIN/DRIZZLE POTENTIAL ACROSS THE NORTHWEST PIEDMONT ON TUESDAY MORNING/AFTERNOON AS IT HAS THE MORE FAVORABLE SURFACE HIGH PLACEMENT (WHICH WOULD DELIVER AMPLE COLD AIR). THE ECMWF CONTINUES TO BE FURTHER NORTH WITH THE PLACEMENT OF THE HIGH AND THUS NOT AS COLD...SO THIS WILL HAVE TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL DAYS. REGARDLESS...IT DOES NOT APPEAR THAT WE WOULD SEE A LOT OF QPF WITH THIS SYSTEM. THE HIGH WILL THEN SHIFT QUICKLY OFFSHORE TUESDAY NIGHT...THUS ENDING/WEAKENING THE COLD AIR SUPPLY. TEMPS WILL ULTIMATELY DEPEND ON HOW THE CAD PLAYS OUT...BUT WILL CONTINUE TO TREND COLDER ON TUESDAY...WITH HIGHS RANGING FROM THE LOW 40S IN THE NORTHWEST PIEDMONT TO THE LOW 50S ACROSS THE SOUTHEAST (WHICH COULD VERY WELL END UP BEING TOO WARM...ESPECIALLY IN THE FAVORED DAMMING REGION). WEDNESDAY THROUGH FRIDAY...QUITE A BIT OF UNCERTAINTY THEN EXISTS FOR THE REMAINDER OF THE FORECAST PERIOD AS ANOTHER SYSTEM (POSSIBLY) APPROACHES FROM THE NORTHWEST. THE ECMWF IS MUCH MORE AMPLIFIED/PROGRESSIVE WITH ANOTHER SHORT WAVE/SURFACE FRONT SWINGING THROUGH THE AREA WEDNESDAY INTO THURSDAY...WHILE THE GFS IS MUCH LESS AMPLIFIED AND KEEPS THE NEXT SYSTEM TO OUR WEST UNTIL THE END OF THE WEEK. GIVEN THE DIFFERENCES...WILL KEEP ANY POPS LOW THROUGH THE TIME FRAME. TEMPS WILL BE TRICKY ON WEDNESDAY AS THEY WILL MAINLY BE DRIVEN BY ANY RESIDUAL CAD. MODELS SHOW THE CAD AIR MASS QUICKLY ERODING (BUT MODELS DO TEND TO ERODE IT TOO QUICKLY). OTHERWISE...NEAR SEASONAL TEMPS ARE EXPECTED FOR THE REMAINDER OF THE WEEK. && .AVIATION /00Z SATURDAY THROUGH TUESDAY/... AS OF 700 PM FRIDAY... VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS AS THE AREA REMAINS UNDER THE INFLUENCE OF HIGH PRESSURE. CURRENTLY CALM WINDS ACROSS WILL BECOME SOUTH TO SOUTHWESTERLY BY TOMORROW AFTERNOON AS THE SURFACE HIGH MOVES OFF THE CAROLINA COAST. THE CHANCE FOR SOME FOG OR STRATUS WILL INCREASE SUNDAY AND MONDAY MORNINGS AS SOUTHERLY FLOW INCREASES WITH THE HIGH SHIFTING OFFSHORE. OTHERWISE...THE NEXT CHANCE FOR PRECIP THAT MAY IMPACT FLIGHT CONDITIONS WILL BE ON MONDAY NIGHT INTO TUESDAY ASSOCIATED WITH THE NEXT COLD FRONT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...NP SHORT TERM...NP LONG TERM...KRD AVIATION...SEC/NP

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