Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 280019 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 719 PM EST THU NOV 27 2014 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE OVER THE REGION WILL SHIFT EAST AND AWAY FROM THE AREA THIS EVENING. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST TONIGHT THROUGH EARLY SATURDAY... BEFORE PUSHING EAST OFF THE COAST LATE SATURDAY THROUGH SUNDAY. && .NEAR TERM /THROUGH FRIDAY NIGHT/... AS OF 215 PM THURSDAY... THROUGH TONIGHT: THE NORTHERN TWO-THIRDS OF THE CENTRAL NC HAVE HAD A VARIABLY CLOUDY... SOMEWHAT CHILLY... AND OCCASIONALLY SHOWERY THANKSGIVING DAY SO FAR... THANKS TO PASSAGE OF A COUPLE OF SHORTWAVE TROUGHS... THE SECOND OF WHICH IS NOW TRACKING EASTWARD INTO THE WRN CAROLINAS. MESOANALYSES AND RAP SOUNDINGS SHOW MINOR AMOUNTS OF CAPE... DUE TO FAIRLY STEEP 850-500 MB LAPSE RATES OF 6.5- 7.5 C/KM... AUGMENTING THE DYNAMIC FORCING FOR ASCENT. WILL MAINTAIN SCATTERED SHOWERS OVER THE AREA FOR ANOTHER FEW HOURS... ENDING LAST IN THE NE CWA BY VERY EARLY EVENING. AS THE SHORTWAVE TROUGH HEADS TO OUR EAST... A DRYING AND STABILIZING COLUMN WILL ENSUE FROM WEST TO EAST... YIELDING CLEARING SKIES AREAWIDE DURING THE EARLY-MID EVENING. CLEAR SKIES AND DIMINISHING WINDS ARE EXPECTED OVERNIGHT WITH RISING HEIGHTS... DOWNSLOPE-DIRECTED LOW LEVEL FLOW... AND HIGH PRESSURE BEGINNING TO BUILD IN FROM THE WEST. BASED ON LOCAL RESEARCH USING HISTORIC MIN TEMPS... LOW LEVEL THICKNESSES DROPPING TO AROUND 1280 M WOULD SUGGEST LOWS IN THE LOWER 20S... HOWEVER WITH THE MSLP GRADIENT STAYING UP ENOUGH TO ALLOW FOR A SLIGHT NW BREEZE OVERNIGHT LIMITING RADIATIONAL COOLING SOMEWHAT... WILL STICK WITH LOWS IN THE MID-UPPER 20S... CONSISTENT WITH STATISTICAL GUIDANCE. FOR FRI/FRI NIGHT: A QUIET DAY AND NIGHT WITH HIGH PRESSURE BUILDING OVERHEAD AND STRONGLY SUBSIDING MID LEVELS. EXPECT LOTS OF SUNSHINE DURING THE DAY. THE THERMAL TROUGH LIFTS OUT DURING THE LATTER HALF OF THE DAY... AND THICKNESSES ACCORDINGLY REBOUND CONSIDERABLY (ALTHOUGH THIS 1000-850 MB LAYER GRABS SOME OF THE WARMER AIR ABOVE THE SUBSIDENCE INVERSION). USING A LOW LEVEL DRY ADIABATIC PROFILE TO 925 MB INDICATES HIGHS OF 42-46... A SLIGHT LEAN TO THE COOL SIDE OF GUIDANCE AND IN LINE WITH EARLIER FORECAST HIGHS. THE SURFACE RIDGE SHOULD BE OVERHEAD EARLY FRI NIGHT BUT SHIFTING EASTWARD LATE... SO WINDS SHOULD BE FAIRLY LIGHT WITH GENERALLY CLEAR SKIES... ALTHOUGH WE`LL SEE INCREASING HIGH CLOUDS LATE AS MINOR WAVES TRACK ESE INTO NC WITHIN THE FAST STEERING FLOW ALOFT. STILL EXPECT LOWS IN THE MID-UPPER 20S. -GIH && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 245 PM THURSDAY... HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY ON SATURDAY... ALLOWING RETURN FLOW TO FIRMLY SET UP OVER THE REGION FOR THE WEEKEND. IN ADDITION...MID LEVEL RIDGING WILL BUILD NORTH AND EAST ACROSS THE AREA. ALL OF THIS WILL LEAD TO FAIR WEATHER AND A WARMING TREND...WITH HIGHS EXPECTED TO BE IN THE LOW TO MID 50S ON SATURDAY AND THEN LOW TO MID 60S BY SUNDAY. OVERNIGHT LOWS WILL ALSO MODERATE THROUGH THE PERIOD...WITH MOSTLY MID/UPPER 30S SATURDAY NIGHT AND THEN MID/UPPER 40S SUNDAY NIGHT. && .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 /00Z FRIDAY THROUGH TUESDAY/...
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AS OF 719 PM THURSDAY... SCATTERED SHOWER ACTIVITY FROM THIS AFTERNOON HAS STEADILY DIMINISHED AFTER SUNSET. DRY WEATHER WITH VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS. WINDS WILL CONTINUE TO BE LIGHT AND FROM THE NORTHWEST AT 5-10 KTS AS HIGH PRESSURE BUILDS INTO THE SOUTHEAST STATES. LOOKING BEYOND 18Z FRI... VFR CONDITIONS ARE EXPECTED TO DOMINATE THROUGH MON... ALTHOUGH AREAS OF MVFR OR IFR FOG ARE POSSIBLE EARLY SUN MORNING AND EARLY MON MORNING. HIGH PRESSURE WILL SHIFT EASTWARD OVER THE REGION THROUGH SAT... THEN MOVE EAST AND OFFSHORE SAT NIGHT/SUN. A COLD FRONT WILL MOVE IN FROM THE NORTH LATE MON OR MON NIGHT... BRINGING A GOOD CHANCE OF MVFR/IFR CONDITIONS MON NIGHT/TUE AND PATCHY LIGHT RAIN. -GIH
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&& .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...KRD LONG TERM...KRD AVIATION...SEC/HARTFIELD

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