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 110703 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 305 AM EDT FRI JUL 11 2014 .SYNOPSIS...A WEAKENING SURFACE BOUNDARY WILL DRIFT TOWARD THE COAST TODAY. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 AM FRIDAY... A NEARLY SATURATED LOW LEVEL AIR MASS WILL SUPPORT THE DEVELOPMENT OF WIDESPREAD LOW CLOUDS ALONG WITH AREAS OF FOG...SOME OF WHICH MAY BE LOCALLY DENSE. EXPECT THE HIGHEST THREAT FOR FOG/LOCALLY DENSE TO OCCUR OVER THE PIEDMONT COUNTIES WHERE INTRUSION OF DRIER AIR HAS CLEARED OUT THE MID-HIGH LEVEL CLOUDINESS. BASICALLY ALONG AND EAST OF HIGHWAY 1 (WHERE BULK OF HEAVIEST SHOWERS/T-STORMS OCCURRED THURSDAY AFTERNOON-EVENING)...THICK LOW CLOUDS SHOULD PREVAIL WITH PATCHES OF FOG (VISIBILITY 1-3 MILES) EXPECTED. A MID LEVEL SHEAR AXIS AND ATTENDANT SURFACE BOUNDARY WAS ALIGNED SSW-NNE OVER THE EAST HALF OF OUR FORECAST AREA EARLY THIS MORNING. THIS FEATURE WILL DRIFT SLOWLY TO THE E-SE. BASED ON MODEL PROJECTION...THIS FEATURE SHOULD BE ALONG OR JUST EAST OF OUR EASTERN PERIPHERY EARLY THIS AFTERNOON. SIMILAR TO THURSDAY...THIS FEATURE WILL AID IN THE DEVELOPMENT OF SCATTERED CONVECTION. EXPECT GREATEST COVERAGE TO BE OVER OUR FAR E-SE COUNTIES WHILE COVERAGE SHOULD DROP OFF APPRECIABLY OVER THE PIEDMONT. IN THE PIEDMONT...PRESENCE OF DRIER MORE STABLE AIR ALOFT SHOULD INHIBIT CONVECTIVE DEVELOPMENT. STILL PLAN TO HOLD ONTO THE SLIGHT CHANCE ALONG AND IMMEDIATELY WEST OF THE HIGHWAY 1 CORRIDOR BUT SOME MODEL PROJECTIONS SUGGEST THAT THIS MAY BE TOO HIGH. PER MODEL SOUNDINGS AND RH CROSS SECTIONS...LOW CLOUDS MAY PERSIST THROUGH MUCH OF THE MORNING...AND POSSIBLY NOT BREAKING IN SOME AREAS UNTIL EARLY-MID AFTERNOON. THIS DELAY IN HEATING SHOULD RESULT IN HIGH TEMPS A COUPLE OF DEGREES SHY OF NORMAL. MAX TEMPS MOSTLY IN THE MID 80S WITH A FEW UPPER 80S SCATTERED ABOUT. TONIGHT...ANY CONVECTION OVER THE EASTERN SANDHILLS AND SOUTHERN COASTAL PLAIN SHOULD QUICKLY DISSIPATE WITH LOSS OF HEATING WITH JUST A STRAY SHOWER POSSIBLE UNTIL MIDNIGHT. AGAIN...MAY SEE AREAS OF LOW CLOUDS OR PATCHY FOG DEVELOP DURING THE OVERNIGHT. MIN TEMPS IN THE MID-UPPER 60S ACROSS THE PIEDMONT TO NEAR 70 IN THE SANDHILL AND COASTAL PLAIN. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 305 AM FRIDAY... WEAK HIGH PRESSURE WILL SETTLE INTO CENTRAL NC IN THE WAKE OF THE DEPARTING/DISSIPATING MID LEVEL SHEAR AXIS. WEAK-MODERATE W-NW FLOW WILL ADVECT A DRIER AIR MASS ALOFT. LIMITED MOISTURE AND LACK OF TRIGGERS ALOFT WILL INHIBIT CONVECTIVE DEVELOPMENT MOST LOCATIONS. EXCEPTION WILL BE THE FAR SE WHERE SCATTERED CONVECTION ALONG THE SEABREEZE MAY OCCUR LATE IN THE AFTERNOON-EARLY EVENING. ALSO...ANY CONVECTION THAT DEVELOPS ALONG THE BLUE RIDGE MAY THREATEN THE FAR NW PIEDMONT DURING THE LATE AFTERNOON-EARLY EVENING. DUE TO LIMITED MOISTURE AND WEAK INSTABILITY...HAVE OPTED TO KEEP POPS IN THIS REGION LESS THAN 20 PERCENT. MAY SEE ANOTHER ROUND OF FOG OR PATCHY LOW CLOUDS EARLY SATURDAY. CONSIDERING THE AMOUNT OF DRY AIR ALOFT...THE FOG/LOW CLOUDS WILL QUICKLY LIFT AND DISSIPATE WITHIN AN HOUR OR TWO OF SUNRISE. UNDER MOSTLY SUNNY SKIES...AFTERNOON TEMPS SHOULD RETURN TO NORMAL LEVELS OF UPPER 80S TO AROUND 90. MIN TEMPS SATURDAY NIGHT IN THE UPPER 60S/AROUND 70. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 315 PM THURSDAY... A DEEP VORTEX IS PROGGED TO MOVE SOUTH OUT OF CANADA AND EVENTUALLY ACROSS THE GREAT LAKES THROUGH THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN A DEEP TROUGH DEVELOPING OVER THE EASTERN HALF OF THE CONUS. THEREFORE...PRECIP CHANCES WILL BE ON THE INCREASE FOR NEXT WEEK...ESPECIALLY LATE TUESDAY INTO EARLY WEDNESDAY AS A FRONT APPROACHES THE AREA. ALSO...GIVEN THIS UNSEASONABLY STRONG TROUGH... THE MID LEVEL FLOW IS EXPECTED TO STRENGTHEN AND THEREFORE THE POSSIBILITY OF AN ORGANIZED SEVERE THREAT WILL EXIST AND THIS WILL BE MONITORED OVER THE NEXT SEVERAL DAYS. THEN THERE IS STILL A GOOD BIT OF UNCERTAINTY WITH REGARDS TO IF THIS FRONT WILL PUSH ALL THE WAY THROUGH THE AREA...BUT FOR NOW IT LOOKS LIKE THE FRONT WILL STALL SOMEWHERE ACROSS THE CAROLINAS. THUS...WILL SHOW A LITTLE DECREASE IN POPS FOR THE LATTER HALF OF THE WEEK...BUT WILL KEEP A CHANCE IN GIVEN THE UNCERTAINTY WITH REGARDS TO WHERE THE FRONT ENDS UP. HIGH TEMPS AHEAD OF THE FRONT ARE EXPECTED TO BE IN THE LOW TO MID 90S ON MONDAY AND POSSIBLY TUESDAY...ALTHOUGH DEPENDING ON THE TIMING OF THE PRECIP...TEMPS COULD BE SLIGHTLY LOWER ON TUESDAY. THEN SLIGHTLY COOLER TEMPS ARE EXPECTED WEDNESDAY AND THURSDAY GIVEN THE DEEP TROUGHING OVER THE EAST COAST AND THE POSSIBILITY THAT THE FRONT WILL PUSH THROUGH THE AREA. && AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 145 AM FRIDAY... A NEARLY SATURATED LOW LEVEL AIR MASS WILL SUPPORT THE DEVELOPMENT OF WIDESPREAD FOG AND LOW CLOUDS OVERNIGHT...AND INTO THE FIRST HALF OF THIS MORNING. THIS SHOULD LEAD TO WIDESPREAD IFR/LIFR CONDITIONS. IN ADDITION...COULD SEE A FEW SHOWERS DEVELOP ALONG A SLOW MOVING SURFACE FRONT OVER THE SANDHILLS AND COASTAL PLAIN OVERNIGHT INTO THE MID MORNING HOURS. BETWEEN 14Z AND 16Z...SHOULD SEE VISIBILITIES AND CEILINGS IMPROVE THOUGH STILL EXPECT MVFR CEILINGS TO OCCUR AT ALL TAF SITES. AFTER 16Z...AS DRIER AIR BECOMES MORE ESTABLISHED OVER THE WESTERN AND NORTHERN PIEDMONT...SHOULD SEE MVFR CEILINGS LIFT INTO A SCATTERED STRATOCUMULUS FIELD WITH BASES 2000-3000FT. ELSEWHERE...MVFR CEILINGS WILL PERSIST WITH CEILINGS 1500-2800FT EXPECTED. IN ADDITION WILL SEE AN INCREASE IN SHOWER AND THUNDERSTORM COVERAGE OVER THE COASTAL PLAIN THOUGH EXPECT MOST OF THE ACTIVITY TO OCCUR TO THE EAST-SE OF KFAY AND KRWI. FRIDAY NIGHT THROUGH SUNDAY...A WEAK AREA OF HIGH PRESSURE WILL BUILD THEN SETTLE INTO THE REGION. THIS WEATHER SYSTEM SHOULD MAINTAIN VFR CONDITIONS ACROSS CENTRAL NC. THE WEATHER PATTERN WILL GRADUALLY BECOME UNSETTLED EARLY NEXT WEEK AS A LOW PRESSURE SYSTEM APPROACHES FROM THE NORTHWEST. THIS SHOULD LEAD TO AN INCREASE IN LOW AND MID LEVEL MOISTURE...RESULTING IN EARLY MORNING FOG AND LOW CLOUDS. ALSO...EXPECT PERIODS OF MVFR CEILINGS AND VISIBILITY DUE TO SHOWERS AND THUNDERSTORMS IN THE AFTERNOON...ESPECIALLY TUESDAY AFTERNOON INTO TUESDAY NIGHT. && .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.