Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 021859 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 300 PM EDT TUE JUN 2 2015 .SYNOPSIS...A MID LEVEL LOW PRESSURE TROUGH AND SURFACE COLD FRONT EXTENDING ALONG THE CENTRAL AND SOUTHERN APPALACHIANS WILL DRIFT SLOWLY EASTWARD THEN STALL OVER THE CAROLINAS THROUGH THE REST OF THE WORK WEEK... BRINGING UNSETTLED WEATHER. && .NEAR TERM /THROUGH TONIGHT/... AS OF 245 PM TUESDAY... TEMPERATURES STARTING TO RECOVER ACROSS THE AREA IN THE WAKE OF MORNING CONVECTION WITH SOUTHERN SITES STARTING TO CREEP INTO THE LOWER 80S. A SURGE OF LOW LEVEL MOISTURE NOW MOVING THROUGH THE CHARLOTTE METRO AREA WILL ADVECT NORTHWESTWARD AND NEW CONVECTION SHOULD BEGIN TO BREAK OUT ACROSS THE WESTERN PIEDMONT OVER THE NEXT COUPLE OF HOURS. FORECAST SOUNDINGS INDICATE THAT BULK SHEAR WILL BE BETWEEN 20-30 KTS FOR THE NEXT FEW HOURS BEFORE DROPPING OFF AGAIN CLOSER TO SUNSET. SPC ANALYSIS SHOWS ABOUT 1000 J/KG OF MIXED LAYER CAPE AVAILABLE TO NEW CONVECTION. WITH THE FREEZING LEVEL NEAR 12 KFT IN THE TRIAD THIS WOULD BE THE MOST LIKELY SPOT TO SEE SMALL HAIL BUT SKINNY CAPE THROUGH THE HAIL GROWTH ZONE MAKES THIS FAIRLY UNLIKELY BUT POSSIBLE. WIND THREAT IS NOT ALL THAT GREAT EITHER BUT DCAPE VALUES AROUND 700 IN THE SOUTHWEST SUGGEST THAT AT LEAST SOME SMALL WET MICROBURSTS WITH GUSTS IN THE 30-40 MPH RANGE ARE POSSIBLE. THAT LEAVES THE BIGGEST THREAT OF THE DAY TO BE HEAVY RAIN...ESPECIALLY IN THE SW WHERE ANTECEDENT CONDITIONS ARE FAIRLY WET AND 1 HR FLASH FLOOD GUIDANCE IS LOWER. OFF TO THE EAST THE SEA BREEZE IS PUSHING A BAND OF CONVECTION FURTHER INLAND WHICH WILL MOST LIKELY AFFECT EASTERN COUNTIES LATER THIS AFTERNOON/EVENING. SIMILAR CONDITIONS IN THIS AREA TO THE NW PIEDMONT (ONLY WITH A MUCH HIGHER FREEZING LEVER) ALSO SUGGEST THAT SOME STRONGER STORMS WILL BE POSSIBLE HERE AS WELL. NORTH CENTRAL AREAS OF THE CWA HAVE SEEN THE BIGGEST REDUCTION IN TEMPERATURE DUE TO EARLIER CONVECTION AND MAY TAKE SOME TIME TO RECOVER BUT THE SAME INSTABILITY/SHEAR NUMBERS HERE MAKE CONVECTION POSSIBLE LATER THIS AFTERNOON/EVENING AS WELL. TEMPERATURES THIS AFTERNOON IN THE UPPER 70S TO MID 80S. OVERNIGHT TONIGHT CHANCE FOR SHOWERS AND STORMS WILL LINGER THROUGH THE EVENING AS CONVECTING ALLOWING MODELS INDICATE MORE OF A PUSH FROM THE FRONTAL ZONE TO THE WEST. CEILINGS ARE ALSO EXPECTED TO DROP IN MOST LOCATIONS TO AT LEAST IFR IF NOT LIFR BETWEEN 9-12Z. LOWS IN THE MID 60S. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 245 PM TUESDAY... WEDNESDAY THE UPPER LEVEL LOW WILL MOVE MORE DIRECTLY OVERHEAD AND A SURFACE HIGH OVER NEW ENGLAND WILL HELP FLOW TO BECOME MORE NORTHEASTERLY ACROSS THE STATE. THIS WILL YIELD MUCH COOLER CONDITIONS AND A CREATE A SITUATION WHERE CEILINGS WILL NOT BE ABLE TO RECOVER TO MUCH MORE THAN MVFR LEVELS DURING THE DAY. LIFT GENERATED BY THE UPPER LOW WILL HELP TO KEEP STEADY PRECIP CHANCES THROUGH THE DAY OVER MUCH OF THE AREA BUT INSTABILITY WILL BE VERY WEAK AND SHEAR VALUES ONLY AROUND 10 KTS. HIGHS WILL ONLY MAKE IT TO THE LOWER 70S IN THE TRIAD WITH NEAR 80 DEGREES IN EASTERN COUNTIES. FRONT WILL CONTINUE TO MOVE EASTWARD WEDNESDAY NIGHT AND LOWS COULD MAKE IT INTO THE UPPER 50S IN THE TRIAD FOR THE FIRST TIME IN A WHILE. POINTS EAST WILL STILL SEE LOW TO MID 60S HOWEVER. CHANCES FOR LOW STRATUS WILL ONCE AGAIN BE FAVORABLE DURING THE OVERNIGHT HOURS WEDNESDAY NIGHT INTO THURSDAY WITH LINGERING CHANCES FOR RAIN CONTINUING INTO THURSDAY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY... WET WEATHER APPEARS LIKELY TO LINGER THROUGH THU... WITH THE SYNOPTIC CONFIGURATION SIMILAR TO WED WITH A NARROW STABLE SURFACE WEDGE OVER THE WRN PIEDMONT AND A BROAD FRONTAL ZONE OVER THE COASTAL PLAIN... ALTHOUGH THE MID LEVEL LOW TO OUR WEST WILL HAVE DRIFTED SLIGHTLY CLOSER... INTO THE FAR WRN CAROLINAS. MARGINAL TO MODERATE INSTABILITY IS EXPECTED (1000-2000 J/KG AREAWIDE ON THE NAM... SLIGHTLY LESS ON THE GFS) WITH SIMILAR WEAK DPVA ROTATING AROUND THE E/NE SIDE OF THE LOW... POSSIBLE UPPER DIVERGENCE (MAINLY NE)... PW AROUND 150% OF NORMAL... AND ONSHORE-DIRECTED LOW LEVEL FLOW FOCUSED ALONG THE FRONTAL ZONE. MODELS ARE GENERATING THE GREATEST AND MOST WIDESPREAD QPF OVER THE ERN AND NRN SECTIONS... NEAREST THE BOUNDARY... REASONABLE GIVEN THE POTENTIAL FOR SOME MID LEVEL DRYING TO WORK INTO SW SECTIONS. EXPECT ANOTHER ROUND OF SCATTERED (SW) TO NUMEROUS (ELSEWHERE) SHOWERS AND EMBEDDED STORMS... PEAKING IN THE AFTERNOON AND EVENING. THICKNESSES ARE EXPECTED TO BE 15-20 M BELOW NORMAL ESPECIALLY BENEATH THE WEDGE AXIS... AND FACTORING IN THE CLOUDS AND PRECIP... WILL KEEP HIGHS BELOW NORMAL... MID 70S TO AROUND 80. WITH LINGERING ELEVATED INSTABILITY AND ABOVE NORMAL PW PERSISTING OVERNIGHT... WILL TREND PRECIP CHANCES DOWN BUT NOT OUT THU NIGHT AS THE BY-NOW-WEAKENING UPPER LOW STARTS TO SHIFT OVERHEAD. LOWS IN THE LOW-MID 60S. TEMPS SHOULD REMAIN COOLER THAN CLIMO FRI... AS THE MID LEVEL LOW AND ASSOCIATED MID LEVEL TROUGH AND SURFACE FRONT ZONE ALL PUSH SLOWLY EAST AND OFFSHORE. LOW LEVEL MOISTURE WILL BE SLOW TO DISPERSE BASED ON THE WEAK LOW LEVEL FLOW... BUT ONCE THE OVERNIGHT/MORNING STRATUS BREAKS UP AND LIFTS... WE SHOULD SEE PARTIAL CLEARING AND SOME RECOVERY IN THICKNESSES. MARGINAL TO MODERATE INSTABILITY AND FAIRLY WEAK DEEP LAYER SHEAR ARE EXPECTED TO PERSIST... BUT OTHERWISE WE SHOULD SEE A BRIEF LULL IN FORCING FOR ASCENT BEHIND THE DEPARTING TROUGH. WILL KEEP NEAR-CLIMO 30-40% CHANCES MAINLY EAST. EXPECT HIGHS AROUND 80 TO THE LOWER 80S. MODELS ARE UNANIMOUS IN SHOWING LATE-DAY MOUNTAIN CONVECTION... WHICH MAY DROP SLOWLY SE INTO THE NW CWA LATE EVENING THROUGH THE OVERNIGHT HOURS FRI NIGHT BASED ON THE WEAK NW FLOW. WE`RE ALSO LIKELY TO SEE FRIDAY`S MIDWEST MCS ACTIVITY (OR ITS REMNANT MCV) DROP THROUGH THE WRN/CENTRAL OH VALLEY TOWARD THE SRN APPALACHIANS FRI EVENING AND OVERNIGHT... ALTHOUGH AT THIS PACE THIS FEATURE WOULD BE MORE LIKELY TO AFFECT US ON SAT. AT ANY RATE... WILL INDICATE A BETTER CHANCE OF SHOWERS AND ISOLATED STORMS OVER THE NW CWA OVERNIGHT WITH JUST A SLIGHT CHANCE ELSEWHERE. LOWS AGAIN IN THE LOWER-MID 60S. IF THE AFOREMENTIONED MCV COMES TO PASS AND MOVES AS MODELS SUGGEST... IT SHOULD MOVE THROUGH THE CAROLINAS ON SAT... POTENTIALLY RELOADING THE WEAK TROUGH AXIS BACK OVER THE CAROLINAS. BUT WITH THE OVERALL NOAM AND WRN ATLANTIC FLOW WEAKENING AND FLATTENING AT THESE LATITUDES FRI/SAT... IT`S DIFFICULT TO PINPOINT AND TRACK SPECIFIC FEATURES THIS FAR OUT. BY SUNDAY... THE GFS/ECMWF TAKE POTENT NRN STREAM ENERGY ESE THROUGH THE UPPER MIDWEST AND GREAT LAKES TO THE NORTHEAST SUN/MON... AMPLIFYING MID LEVEL TROUGHING OVER THE EASTERN STATES AND LIKELY INCREASING SHEAR ENOUGH OVER OUR AREA FOR AN INCREASED RISK OF STORMS MON INTO TUE. AFTER GENERALLY STABLE CONDITIONS SUNDAY (BEHIND THE POTENTIAL DEPARTING MCV BUT AHEAD OF THIS DIGGING TROUGH)... THE GFS DEPICTS RISING MUCAPE VALUES EACH DAY MON/TUE TO 1000-2500 J/KG. WILL RAMP UP LATE- DAY STORM CHANCES (SOME OF WHICH COULD BE STRONG) MON/TUE. TEMPS SHOULD REBOUND BACK TO NEAR NORMAL BY THAT TIME. -GIH && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 130 PM TUESDAY... 24 HOUR TAF PERIOD: UNSETTLED PATTERN WITH WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON. EARLIER CONVECTION HAS LEFT SEVERAL SMALL BOUNDARIES DRAPED ACROSS THE AREA THAT COULD HELP GENERATE CONVECTION LATER THIS AFTERNOON AS RAIN COOLED TEMPERATURES RECOVER AND ANOTHER SURGE OF MOISTURE MOVES IN FROM THE SOUTH. AS A RESULT...ALL TAF SITES WILL HAVE THE CHANCE FOR PERIODIC SHOWERS AND THUNDERSTORMS THIS AFTERNOON. STORMS COULD BECOME STRONGER TOWARDS EVENING WITH THE OCCASIONAL WIND GUST INTO THE 30-40 KT RANGE. OTHERWISE HEAVY RAIN WILL BE THE BIGGEST THREAT AND TEMPORARY RESTRICTIONS ON CEILING AND VISIBILITY. CONVECTION IS PROGGED TO CONTINUE INTO THE OVERNIGHT HOURS AND THERE IS A HIGH CONFIDENCE CHANCE OF SUB VFR CONDITIONS BEGINNING AFTER 6Z OR SO AND THEN A MEDIUM CONFIDENCE CHANCE THAT THESE COULD REMAIN AT LEAST AT MVFR LEVELS IF NOT LOWER THROUGH THE END OF THE TAF PERIOD. LONG TERM: AN UPPER LEVEL LOW MOVING OVER THE AREA FOLLOWED BY SEVERAL SHORT WAVES IN THE UPPER LEVEL PATTERN ADVECTING OVER THE AREA WILL KEEP CONDITIONS UNSETTLED FOR THE FORESEEABLE FUTURE WITH DAILY CHANCES FOR PRECIPITATION AND SUB-VFR CONDITIONS. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...ELLIS SHORT TERM...ELLIS LONG TERM...HARTFIELD AVIATION...ELLIS

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