Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 290736 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 135 AM EDT SAT AUG 29 2015 .SYNOPSIS...HIGH PRESSURE WILL EXTEND IN TO THE AREA FROM THE NORTH TODAY. AN UPPER LEVEL DISTURBANCE WILL MOVE NORTHWARD ALONG THE APPALACHIANS ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 333 AM SATURDAY... TODAY... A SURFACE RIDGE ACROSS CENTRAL NC SUPPORTED BY A WEAK S/W RIDGE ALOFT WILL INITIALLY PROVIDE CENTRAL NC WITH MOSTLY SUNNY SKIES TODAY THOUGH HIGH LEVEL CLOUDS WILL BE ON THE INCREASE AS AN AREA OF LOW PRESSURE OVER THE NORTHERN GULF BEGINS TO LIFT NEWD IN RESPONSE TO A S/W CROSSING THE GREAT LAKES. AT THIS TIME...DO NOT THINK THAT THE MID-HIGH LEVEL CLOUDS WILL BE THICK ENOUGH TO TOTALLY BLOCK OUT THE SUN...ESPECIALLY FROM RALEIGH AND POINTS EAST AND NORTH...BUT THIS WILL NEED TO BE MONITORED. THE BEST CHANCE FOR BROKEN/OVERCAST SKIES WILL BE ACROSS THE SOUTHERN PIEDMONT. AFTERNOON TEMPS SHOULD BE COMPARABLE TO HIGH TEMPS RECORDED FRIDAY...SOLIDLY IN THE MID AND POSSIBLY UPPER 80S. PRESENCE OF THE SFC RIDGE OVERHEAD WILL MAINTAIN A RELATIVELY DRY LOW LEVEL AIR MASS SO AFTERNOON DEWPOINTS IN THE 50S TO NEAR 60 LOOK ACHIEVABLE ONCE AGAIN...NOT BAD FOR LATE AUGUST. TONIGHT...MID-HIGH LEVEL CLOUDS WILL THICKEN IN RESPONSE TO THE APPROACH OF THE NORTHERN GULF S/W THOUGH LIFT TO GENERATE ANY SHOWERS APPEARS TO BE LACKING. WEAK (EMPHASIS ON WEAK) LOW LEVEL ISENTROPIC LIFT MAY GENERATE A SHOWER OR SPRINKLES AROUND DAYBREAK OVER THE FAR SOUTHERN PIEDMONT. THE INCREASING CLOUDINESS AND A MODIFYING AIR MASS WILL YIELD MIN TEMPS A FEW DEGREES WARMER THAN LOW TEMPS EXPECTED THIS MORNING. MIN TEMPS MID 60S NORTH TO THE UPPER 60S SOUTH. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 333 AM SATURDAY... HAVE TRENDED FORECAST THIS PERIOD A LITTLE WETTER...ESPECIALLY SUNDAY NIGHT ACROSS THE PIEDMONT AND SANDHILLS. ATMOSPHERE WILL CONTINUE TO MOISTEN AS NORTHERN GULF SYSTEM LIFTS NEWD ACROSS GA AND INTO THE SOUTHERN APPALACHIANS LATE IN THE DAY. THE APPROACH OF THIS SYSTEM WILL INDUCE A LOW LEVEL SELY FLOW...RESULTING IN AN UPSLOPE COMPONENT TO THE LOW LEVEL FLOW OVER THE SOUTHERN-WESTERN PIEDMONT. THE GFS SOLUTION IS A BIT MORE AGGRESSIVE WITH THIS SCENARIO COMPARED TO THE NAM WHILE THE 00Z ECMWF FAVORS THE GFS SOLUTION. INCREASING UPPER DIVERGENCE BY SUNDAY AFTERNOON IN CONJUNCTION WITH A SLIGHTLY UNSTABLE AND INCREASINGLY MOIST AIR MASS SHOULD SUPPORT THE DEVELOPMENT OF A FEW SHOWERS AND AN ISOLATED STORM...MAINLY ACROSS PORTIONS OF THE SOUTHERN PIEDMONT AND THE SANDHILLS. MAY SEE ADDITIONAL COVERAGE OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN DUE TO THE INLAND MOVING SEABREEZE. THUS...WILL INCREASE POPS BIT FROM THE PREVIOUS FORECAST...UP TO 40 PERCENT OVER THE SOUTH AND WEST SECTIONS BY LATE IN THE DAY/SUNDAY EVENING. DUE TO EXPECTED EXTENSIVE CLOUDINESS...HAVE ADJUSTED MAX TEMPS DOWN A BIT OVER THE WEST AND SW...WITH LITTLE CHANGE ELSEWHERE. IF CLOUDS ARE LOWER/THICKER THAN EXPECTED OR SHOWER COVERAGE MORE EXTENSIVE BY AFTERNOON...MAX TEMPS MAY END UP BEING 3-4 DEGREES COOLER THAN FORECAST EVERYWHERE. SUNDAY NIGHT...S/W LIFTS NEWD IMMEDIATELY WEST OF OUR REGION LATE IN THE NIGHT...MAXIMIZING UPPER DIVERGENCE. IN THE 850-700MB LAYER WEAK SPEED CONVERGENCE IN THE MOIST LAYER. THUS...SHOULD SEE A THREAT FOR A FEW SHOWERS THROUGHOUT THE NIGHT...MAINLY ACROSS THE PIEDMONT. MIN TEMPS MAINLY IN THE UPPER 60S TO NEAR 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 315 PM FRIDAY... FOR EARLY/MID NEXT WEEK...THE SUBTROPICAL RIDGE IS PROGGED TO EXPAND WESTWARD TOWARDS THE SOUTHEAST COAST. IN ADDITION ANOTHER UPPER LEVEL RIDGE WILL BUILD OVER THE UPPER MIDWEST/GREAT LAKES REGION. THE COMBINATION OF THESE TWO FEATURES SHOULD KEEP PRECIP CHANCES ON THE LOWER END. ALSO...LATEST INDICATIONS SHOW THAT THIS SETUP WOULD SUPPRESS TROPICAL STORM ERIKA...KEEPING IT PINNED CLOSER TO THE GULF COAST. ALTHOUGH THIS WILL HAVE TO BE MONITORED AS MODELS CONTINUE TO CHANGE AND THERE ARE SOME MODEL DIFFERENCES (WITH THE 00Z ECMWF NOT AS AGGRESSIVE WITH THE MIDWEST/GREAT LAKES RIDGE). REGARDLESS...WILL MAINTAIN THE CURRENT FORECAST THINKING...WITH NEAR CLIMATOLOGY (MAYBE SLIGHTLY ABOVE) POPS AND TEMPS. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 135 AM SATURDAY... THERE IS A HIGH PROBABILITY OF VFR CONDITIONS PERSISTING ACROSS CENTRAL NC THROUGH EARLY SUNDAY. HIGH PRESSURE CENTERED OVER THE NORTHERN MID ATLANTIC WILL EXTEND SOUTH INTO CENTRAL NC...CAUSING THE VFR CONDITIONS. A DECK OF HIGH CLOUDS WILL PREVAIL LATER TODAY AND TONIGHT WITH BASES ABOVE 10K FEET. SFC WINDS WILL BE GENERALLY LIGHT AND VARIABLE THOUGH KFAY AND KRWI SHOULD SEE A PREDOMINATE EAST-NE SFC WIND LATER THIS MORNING THROUGH EARLY AFTERNOON BETWEEN 7-10KTS. WHILE VFR CONDITIONS WILL LIKELY CONTINUE INTO EARLY NEXT WEEK...THERE WILL BE A THREAT FOR SCATTERED CONVECTION SUNDAY THROUGH MONDAY AS AN UPPER DISTURBANCE LIFTS NWD ACROSS THE CAROLINAS FROM THE DEEP SOUTH. MVFR CEILINGS/VISIBILITY COULD OCCUR IN VICINITY OF THE CONVECTION. THE AIR MASS WILL BECOME INCREASINGLY MOIST AND UNSTABLE TUESDAY AND WEDNESDAY...SUGGESTING A BETTER CHANCE FOR PERIODS OF MVFR/IFR CEILINGS DUE TO STRATUS IN THE OVERNIGHT-EARLY MORNING HOURS...AND SCATTERED CONVECTION. && .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.