Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Graphics & Text | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 280800 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 300 AM EST FRI NOV 28 2014 .SYNOPSIS...HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST TODAY...AND SETTLE OVERHEAD TONIGHT AND SATURDAY. THE HIGH WILL DRIFT OFFSHORE BY SUNDAY RESULTING IN A WARM SOUTHWEST FLOW OVER OUR AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY... TODAY...LOW LEVEL CAA AS HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY/LOWER GREAT LAKES SLOWLY DRIFTS SEWD. 850MB THERMAL TROUGH OVER THE REGION EVENTUALLY LIFTS NORTH-NE AWAY FROM OUR REGION LATE IN THE DAY. LOW LEVEL THICKNESSES SUGGEST MAX TEMPS A SOLID 10-15 SATURDAY AND SATURDAY NIGHT...AIR MASS MODIFICATION GETS UNDERWAY AS SURFACE HIGH DRIFTS EAST AND 850MB FLOW BECOMES SWLY. THICKNESSES RESPOND BY RECOVERING INTO THE 1330-1334M RANGE...SLIGHTLY BELOW NORMAL. ASIDE FROM BRIEF PERIODS OF MID-LEVEL CLOUDINESS...EXPECT MOSTLY SUNNY SKIES SATURDAY AND CLEAR SKIES SATURDAY NIGHT. HIGH TEMPS LOW-MID 50S WHILE MIN TEMPS SATURDAY NIGHT IN THE LOW-MID 30S. DEGREES BELOW NORMAL. THIS YIELDS MAX TEMPS IN THE LOW-MID 40S...FAIRLY COMPARABLE TO MOS GUIDANCE NUMBERS. NW FLOW ALOFT HAS SUFFICIENT STRENGTH/PROPER ORIENTATION TO SUPPORT THE FORMATION OF OROGRAPHICALLY INDUCED CLOUDINESS. WATER VAPOR IMAGERY DOES DEPICT ADEQUATE MOISTURE UPSTREAM. HOWEVER MODEL RH CROSS SECTIONS DO NOT SUGGEST MUCH IN THE MANNER OF CLOUDS IN THE MID-UPPER LEVELS LATER THIS MORNING THROUGH THE AFTERNOON. FOR NOW...WILL ADJUST SKY COVERAGE TO GO MORE PESSIMISTIC (PARTLY CLOUDY VERSUS SUNNY). IF VEIL OF CLOUDS THICKER THAN CURRENTLY ANTICIPATED...THIS MAY LIMIT SUNSHINE ENOUGH TO CAUSE MAX TEMPS TO BE 3-4 DEGREES COLDER THAN CURRENTLY FORECAST. TONIGHT...LOW LEVELS WILL REMAIN DRY AND COOL AS SURFACE HIGH WILL BE OVERHEAD. ALOFT...PATCHY CLOUDINESS MAY DRIFT OVERHEAD AS A SERIES OF WEAK PERTURBATIONS CROSS THE REGION. GFS MORE AGGRESSIVE WITH THE CLOUDINESS VERSUS THE NAM/CANADIAN/ECMWF. WILL TREND SKY COVERAGE TO PARTLY CLOUDY. CHILLY WITH MIN TEMPS IN THE MID-UPPER 20S. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 300 AM FRIDAY... SATURDAY AND SATURDAY NIGHT...AIR MASS MODIFICATION GETS UNDERWAY AS SURFACE HIGH DRIFTS EAST AND 850MB FLOW BECOMES SWLY. THICKNESSES RESPOND BY RECOVERING INTO THE 1330-1334M RANGE...SLIGHTLY BELOW NORMAL. ASIDE FROM BRIEF PERIODS OF MID-LEVEL CLOUDINESS...EXPECT MOSTLY SUNNY SKIES SATURDAY AND CLEAR SKIES SATURDAY NIGHT. HIGH TEMPS LOW-MID 50S WHILE MIN TEMPS SATURDAY NIGHT IN THE LOW-MID 30S. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 245 PM THURSDAY... 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 EARLY NEXT WEEK. THIS TRAILING COLD FRONT IS STILL PROGGED TO CROSS THE AREA MONDAY NIGHT INTO TUESDAY. FORCING IS NOT THAT IMPRESSIVE WITH THIS SYSTEM GIVEN THE PARENT LOW IS SO FAR NORTH OF THE AREA. HOWEVER...GIVEN SOME CONVERGENCE AND MOISTURE POOLING ALONG THE BOUNDARY...WILL MAINTAIN SLIGHT CHANCE POPS IN THE FORECAST. HIGHS WILL WARM UP NICELY WITHIN THE DEEP SOUTHWESTERLY FLOW AHEAD OF THE FRONT...WITH MID TO UPPER 60S (NEAR 70 DEGREES ACROSS THE SOUTHEAST) EXPECTED. TEMPS WILL BE COOLER BEHIND THE FRONT ON TUESDAY...WITH HIGHS GENERALLY IN THE UPPER 40S TO MID/UPPER 50S (COOLEST IN THE NORTHWEST WHERE SOME CAD MAY DEVELOP). QUITE A BIT OF UNCERTAINTY THEN PERSISTS 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 SWINGING THROUGH THE AREA WEDNESDAY INTO THURSDAY...WILL THE GFS IS MUCH LESS AMPLIFIED (WITH ZONAL FLOW ACTUALLY OVER THE MID ATLANTIC REGION). GIVEN THE DIFFERENCES...WILL KEEP ANY POPS LOW...WITH SEASONAL HIGHS/LOWS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 1250 AM FRIDAY... HIGH PRESSURE BUILDING INTO THEN SETTLING OVER THE CAROLINAS THROUGH SATURDAY WILL PROVIDE VFR CONDITIONS. THE HIGH WILL DRIFT OFFSHORE SATURDAY NIGHT INTO SUNDAY. THE RESULTANT SLY FLOW WILL ADVECT LOW LEVEL MOISTURE...INCREASING THE PROBABILITY FOR PATCHES OF MVFR/IFR FOG SUNDAY MORNING AND AGAIN MONDAY MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND CROSS THE REGION MONDAY NIGHT. THIS WEATHER SYSTEM WILL INCREASE THE THREAT FOR MVFR CEILINGS AND AREAS OF RAIN MONDAY NIGHT INTO TUESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...KRD AVIATION...WSS

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