Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 300521 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 121 AM EDT TUE JUN 30 2015 .SYNOPSIS...
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AN INCREASINGLY ACTIVE CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE REGION THROUGH THE END OF THE WORK WEEK.
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&& .NEAR TERM /TODAY AND TONIGHT/...
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AS OF 100 AM TUESDAY... SHORTWAVE ENERGY DIGGING SSE THROUGH IA/IL THIS MORNING WILL AMPLIFY CYCLONIC FLOW ALOFT /TROUGHING/ OVER THE MID-ATLANTIC AND CAROLINAS THIS AFT/EVE INTO TONIGHT. DPVA/HEIGHT FALLS ATTENDANT THE AFOREMENTIONED SHORTWAVE ENERGY TRACKING INTO THE TN VALLEY WILL BACK/STRENGTHEN LOW-LEVEL FLOW DOWNSTREAM OVER THE CAROLINAS THIS AFTERNOON. ENSUING MOISTURE RECOVERY WILL AID IN MARGINAL TO LOW-END MODERATE DESTABILIZATION ACROSS CENTRAL NC LATE THIS AFTERNOON. THE LATEST MODEL GUIDANCE CONTINUES TO SUGGEST A DISCONNECT BETWEEN PEAK HEATING AND THE BEST DPVA/HEIGHT FALLS ATTENDANT THE APPROACHING SHORTWAVE...RESULTING IN CONTINUED UNCERTAINTY WITH REGARD TO PRECIP CHANCES AND TIMING. WITH THE ABOVE IN MIND...EXPECT THE BEST POTENTIAL FOR CONVECTION BETWEEN 21-06Z...OR 21-03Z TRIAD TO 00-06Z TRIANGLE...WITH THE RELATIVE BEST CHANCE IN THE TRIAD/WESTERN PIEDMONT WHERE MID-AFTERNOON CONVECTION DEVELOPING IN THE MOUNTAINS IS APT TO PROPAGATE DOWNSTREAM INTO THE FOOTHILLS/NW PIEDMONT IN ADVANCE OF THE APPROACHING WAVE...IN CLOSER VICINITY TO PEAK HEATING. EXPECT HIGHS IN THE UPPER 80S TO LOWER 90S...LOWS IN THE UPPER 60S TO LOWER 70S...WARMEST S/SE. DEEP LAYER SHEAR AOA 30-35 KT AND 750-1500 J/KG MLCAPE WILL BE SUPPORTIVE OF MULTICELLULAR ORGANIZATION THIS AFT/EVE...PERHAPS BRIEF SUPERCELLULAR ORGANIZATION IN THE WESTERN PIEDMONT WHERE DEEP LAYER FORCING WILL BE BETTER JUXTAPOSED (RELATIVELY SPEAKING) WITH PEAK HEATING AND AN ISOLD POTENTIAL FOR DAMAGING WINDS WILL BE PRESENT GIVEN UNSEASONABLY STRONG MID-LEVEL FLOW AOA 35 KT (MOMENTUM TRANSPORT) AND STEEP LOW-LEVEL LAPSE RATES/MODERATE DCAPE (EVAP COOLING). OVERALL SEVERE POTENTIAL WILL BE TEMPERED BY THE AFOREMENTIONED DISCONNECT IN FORCING/PEAK HEATING...IN ADDITION TO MARGINAL INSTABILITY AND WEAK MID-LEVEL LAPSE RATES...THOUGH STEEPENING OF THE LATTER WILL BE POSSIBLE AFTER 00Z. -VINCENT
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&& .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
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AS OF 115 AM TUESDAY... AN UPPER LEVEL RIDGE CENTERED IN VICINITY OF THE 4-CORNERS REGION THIS MORNING WILL GRADUALLY SHIFT WESTWARD INTO THE GREAT BASIN WED/WED NIGHT...WITH NW FLOW ALOFT DEVELOPING OVER THE CENTRAL PLAINS AND CENTRAL MS RIVER VALLEY. BROAD CYCLONIC FLOW ALOFT WILL PERSIST OVER THE CAROLINAS/MID-ATLANTIC. CHANCES FOR CONVECTION IN CENTRAL NC WILL LARGELY BE TIED TO THE TIMING/MAGNITUDE OF UPPER LEVEL DISTURBANCES...UPSTREAM CONVECTION AND/OR MCV`S TRACKING DOWNSTREAM FROM THE MIDWEST/MS RIVER VALLEY INTO THE CAROLINAS...PRIMARILY WED EVE/NIGHT. SOME POTENTIAL FOR ISOLD CONVECTION WILL EXIST IN ASSOC/W MESOSCALE FEATURES SUCH AS THE SEABREEZE AND/OR PIEDMONT TROUGH DURING PEAK HEATING...THOUGH GUIDANCE SUGGESTS DIURNAL DESTABILIZATION WILL BE LIMITED/MARGINAL. GIVEN INHERENT UNCERTAINTY W/REGARD TO THE EVOLUTION OF UPSTREAM CONVECTION ALONG WITH ADDITIONAL UNCERTAINTY FROM POOR DIURNAL TIMING/MARGINAL THERMODYNAMICS...CONFIDENCE IN CONVECTIVE CHANCES/ COVERAGE IS LOW. WILL INDICATE A LOW CHANCE (~30%) OF SHOWERS/STORMS LATE WED AFT/EVE THROUGH WED NIGHT. HIGHS IN THE UPPER 80S TO LOWER 90S...LOWS UPPER 60S TO LOWER 70S. -VINCENT
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&& .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 230 PM MONDAY... THE UPPER PATTERN FEATURING A STRONG RIDGE IN THE WEST WITH A LONG WAVE TROF OVER THE EASTERN CONUS PERSISTS INTO THE WEEKEND. SURFACE PATTERN REFLECTS A SIMILARLY RESILIENT LEE TROF...HENCE TEMPERATURES WEDNESDAY THROUGH FRIDAY SHOW LITTLE VARIATION...RANGING FROM UPPER 80S ACROSS THE NORTH TO LOWER 90S SOUTH. MORNING LOWS WILL BE WITHIN A COUPLE OF DEGREES EITHER SIDE OF 70. WHILE MINOR PERTURBATIONS IN THE FLOW WILL SUPPORT WIDELY SCATTERED DIURNAL CONVECTION EACH AFTERNOON/EVENING...A STRONGER SHORT WAVE WILL GRAZE THE MID ATLANTIC AND ENHANCE THE CHANCE OF CONVECTION LATER THURSDAY INTO FRIDAY. UPPER PATTERN GRADUALLY DEAMPLIFIES OVER THE WEEKEND AND THE BERMUDA HIGH EDGES WESTWARD INTO THE SOUTHEAST ATLANTIC COAST. THE DEEPER WESTERLY DOWNSLOPE FLOW WILL STRENGTHEN SURFACE TROFFING AND NUDGE HIGH TEMPERATURES UPWARDS A BIT...MOSTLY LOW 90S NORTH TO MID 90S SOUTH EACH DAY. THE SURFACE TROFFING MIGHT ADD SOME LOCAL CONTRIBUTION TO LOW LEVEL CONVERGENCE AS A CONVECTIVE TRIGGER...BUT OTHERWISE THERE ARE NO STRONGER...READILY IDENTIFIABLE FEATURES THAT INSPIRE CONFIDENCE IN A FORECAST BEYOND NEAR-CLIMATOLOGICAL POPS THROUGH MONDAY. && .AVIATION /06Z TUESDAY THROUGH SUNDAY/...
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AS OF 115 AM TUESDAY... VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH EARLY/MID AFTERNOON...ASIDE FROM A POTENTIAL FOR SUB-VFR VISBYS ASSOCIATED WITH FOG AT THE RWI TERMINAL BETWEEN 08-11Z THIS MORNING. BY LATE AFTERNOON AND EVENING...EXPECT AN INCREASING POTENTIAL FOR CONVECTION...ESP AT THE INT/GSO TERMINALS 21-03Z. THOUGH CONFIDENCE IS LOWER AT THE FAY/RDU/RWI TERMINALS...CONVECTION WILL NONETHELESS REMAIN POSSIBLE...PRIMARILY 00-06Z WED. OUTLOOK: EXPECT A CONTINUED POTENTIAL FOR LATE AFTERNOON AND EVENING CONVECTION EACH DAY THIS WEEK IN ASSOCIATION WITH A PERSISTENT CYCLONIC FLOW ALOFT...AND PERHAPS EARLY MORNING FOG OR STRATUS AT THE FAY/RWI TERMINALS. -VINCENT
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&& ..RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...MLM AVIATION...VINCENT

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