Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 261658 CCA AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 100 PM EDT WED AUG 26 2015 .SYNOPSIS...A STALLED FRONT WILL PERSIST IN VICINITY OF THE CAROLINA COAST THROUGH THE DURATION OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1016 AM WEDNESDAY... AMPLIFIED FLOW REMAINS ACROSS THE CONUS TODAY... WITH TROUGHING IN THE EAST. FRONT REMAINS NEAR THE CAROLINA COAST... WITH A WEAK SURFACE WAVE OVER COASTAL SC. DEWPOINTS ARE IN THE 50S OVER THE WESTERN PART OF THE CWA... AND THE LOW TO MID 70S EAST OF I95 IN CLOSER PROXIMITY TO THE BOUNDARY. THE BEST CHANCE FOR SCATTERED SHOWERS AND STORMS REMAINS IN THIS MOISTER AIRMASS... WHERE CAPE IS PROGGED TO REACH 500-1000 J/KG. HIGHS MID TO UPPER 80S NW TO SE. SREF PROBABILITIES HINTING AT BETTER COVERAGE OF MVFR CEILINGS IN THE EAST BY EARLY THURSDAY MORNING. LOWS IN THE LOWER 60S NW TO UPPER 60S SE. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 330 AM WEDNESDAY... FOR THURSDAY MOST OF THE MODELS HAVE THE FRONTAL BOUNDARY PUSHED A BIT FURTHER EASTWARD THAN ON WEDNESDAY AND THUS HAVE CONFINED POPS TO MAINLY THE I-95 CORRIDOR FOR THURSDAY WITH THE MOST ACTIVITY OCCURRING WITH DAYTIME HEATING. THE GFS ONCE AGAIN HAS SOME SHOWER ACTIVITY EXPANDING BACK TO THE WEST BUT IT IS HARD TO GIVE THIS MUCH CREDENCE WITHOUT ANY REAL DISCERNIBLE SHORTWAVE ACTIVITY. IN ADDITION...AN UPPER LEVEL JET ENTRANCE REGION WILL BE OVER THE CWA WITH THE FAVORABLE RIGHT ENTRANCE REGION OVER THE EASTERN HALF OF THE CWA AND THE LESS FAVORABLE LEFT ENTRANCE REGION OVER THE TRIAD. COUPLE THIS WITH SURFACE HIGH PRESSURE TO THE NORTH AND VERY LITTLE ISENTROPIC LIFT AND THE RESULT IS A FORECAST SIMILAR TO THE LAST COUPLE OF DAYS WITH CONVECTIVE ACTIVITY IN THE EAST AND DRIER CONDITIONS TO THE WEST. HIGHS IN THE LOW TO MID 80S WITH THE HIGHEST TEMPS MOST LIKELY IN THE SOUTHWESTERN COUNTIES AS SOME LOWER THICKNESS VALUES WORK INTO THE EASTERN HALF OF THE CWA FROM THE NORTH. LOWS THURSDAY NIGHT IN THE MID TO UPPER 60S NORTH TO SOUTH. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 100 PM WEDNESDAY... RIDGING OVER THE SOUTHWEST ATLANTIC BEGINS TO RETROGRESS...PUSHING THE FRONTAL ZONE ALONG THE COAST WESTWARD TO THE NC COAST. THIS FRONT WILL BE BLOCKED BY SURFACE HIGH PRESSURE BUILDING DOWN THE ATLANTIC SEABOARD...AND IT WILL CONSEQUENTLY WRAP AROUND THE HIGH PRESSURE TO PRESENT A SURFACE PATTERN WITH AN APPEARANCE MUCH LIKE A DAMMING SCENARIO SANS COOLER AIR. THE HIGH PRESSURE HOLDS TIGHT THROUGH THE WEEKEND...WITH MINIMAL LIFT/FORCING THROUGH LATE SATURDAY...SO WILL MAINTAIN THE DRY FORECAST THROUGH LATER SATURDAY WITH HIGHS BOTH FRIDAY AND SATURDAY IN THE MID 80S. PRECIPITABLE WATER WILL BE ON A GRADUAL INCREASE DUE TO WEAK ATLANTIC AND GULF MOISTURE ADVECTION...REACHING 1.5 INCHES ON SUNDAY. MEANWHILE...AN UPPER IMPULSE IS PROGGED TO LIFT OUT OF THE LOWER MISSISSIPPI AND ACROSS WESTERN NORTH CAROLINA SUNDAY... PROVIDING SUPPORT FOR INCREASED CONVECTION IN THE WEST...WITH ACTIVITY SHIFTING TO THE EAST WITH LESS COVERAGE ON MONDAY AS THE SHORT WAVE LIFTS OUT. HIGHS WILL STILL REACH MID 80S EACH DAY...WITH UPPER 80S IN THE SOUTH. UNCERTAINTY INCREASES BY MIDWEEK AS ERIKA OR HER REMAINS WILL POTENTIALLY BE COMING INTO THE PICTURE. THE SOUTHWEST ATLANTIC UPPER RIDGE WILL DETERMINE WHERE THE SYSTEM TRACKS...AND WILL KEEP ITS IMPACT OUT OF THE EQUATION FOR NOW TO AVOID SEE-SAWING THE POPS EACH MODEL RUN. REGARDLESS...MOIST AND WARM AIRMASS WILL BE IN PLACE TUESDAY AND WEDNESDAY...WITH HIGHS WAY UP IN THE 80S...PROVIDING ENOUGH INSTABILITY FOR AT LEAST WIDELY SCATTERED DIURNAL CONVECTION. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 630 AM WEDNESDAY... 24 HOUR TAF PERIOD: SHOWER ACTIVITY CONTINUING ACROSS THE EASTERN COUNTIES MOVING NORTHWARD TOWARDS KRWI AS A WEAK SHORTWAVE LIFTS THROUGH THE AREA. THESE SHOWERS COULD REMAIN IN THE VICINITY OF KRWI FOR THE NEXT FEW HOURS. OTHERWISE SOME POCKETS OF LIFR CEILINGS HAVE DEVELOPED AROUND THE AREA AND KRWI WILL EXPERIENCE LESS THEN 500 FOOT CEILINGS PROBABLY THROUGH 12Z IF NOT LATER. VFR CONDITIONS ELSEWHERE WITH LITTLE THREAT OF RAIN FOR NOW. LATER IN THE DAY EXPECT ANOTHER ROUND OF CONVECTION IN THE EAST...WITH KRWI AND KFAY ONCE AGAIN THE MOST LIKELY AFFECTED HOWEVER IT IS POSSIBLE THAT SHORTWAVE ENERGY WILL HELP SOME ISOLATED SHOWER ACTIVITY FURTHER WEST IN THE VICINITY OF KRDU NEAR THE END OF THE TAF PERIOD. LONG TERM: WITH THE FRONTAL ZONE STALLING OUT OVER THE EASTERN HALF OF THE STATE...TERMINALS ALONG AND EAST OF ROUTE 1 WILL BE UNDER CONTINUED THREAT FOR DAILY SHOWERS AND THUNDERSTORMS...PARTICULARLY DURING AFTERNOON PEAK HEATING. TRIAD TERMINALS SHOULD REMAIN LARGELY VFR FOR MUCH OF THE WEEK BUT UNCERTAINTY INCREASES TOWARDS THE WEEKEND WHEN THE FRONTAL ZONE COULD RETROGRADE A LITTLE AS A WEAK LOW FORMS SOUTH OF THE AREA. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...30/ELLIS SHORT TERM...ELLIS LONG TERM...MLM AVIATION...ELLIS

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