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. --
244 FXUS62 KRAH 050226 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 925 PM EST THU FEB 4 2016 .SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL MOVE OFFSHORE OVERNIGHT...AS A STRONG UPPER TROUGH SWINGS ACROSS THE REGION. COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY INTO THE WEEKEND. AN ARCTIC COLD FRONT WILL ARRIVE EARLY NEXT WEEK.
-- End Changed Discussion --
&& .NEAR TERM /OVERNIGHT/...
-- Changed Discussion --
AS OF 925 PM THURSDAY... STILL APPEARS A GOOD CHANCE FOR RAIN SHOWERS OVER THE PIEDMONT OVERNIGHT TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS BEFORE THE PRECIP ENDS AROUND DAYBREAK. LATEST MODEL GUIDANCE AND TRENDS HAVE SCATTERED RAIN SHOWERS EXPANDING BACK INTO THE WESTERN PIEDMONT SHORTLY AFTER MIDNIGHT AS A RATHER POTENT S/W ROUNDS THE BASE OF THE AMPLIFYING UPPER TROUGH TO OUR WEST. THIS S/W WILL HELP TO INDUCE AN AREA OF LOW PRESSURE AT THE SFC TO DEVELOP/DEEPEN OFF THE SC/NC COAST OVERNIGHT. MEANWHILE 925-850MB TROUGH WILL CROSS THE REGION...WITH CAA EXPECTED TO COMMENCE OVER THE PIEDMONT OVERNIGHT. WHILE THE GSO 00Z SOUNDING WAS QUITE DRY IN THE FAVORED ICE NUCLEATION GROWTH REGION...MODELS STILL DEPICT A 2-4 HOUR WINDOW WHERE THIS REGION MOISTENS ENOUGH TO GENERATE SNOW ALOFT. LOOP OF INFRARED SATELLITE IMAGERY DOES DEPICT COOLER CLOUD TOPS EXPANDING BACK INTO THE WESTERN PIEDMONT. WHERE THE HEAVIER PRECIP RATES OCCUR AFTER 06Z...SHOULD SEE THE RAIN MIX WITH SNOW...AND COULD EVENTUALLY SEE THE ENTIRE COLUMN BECOME COLD ENOUGH TO SUPPORT A PRECIP TYPE OF MOSTLY LIGHT WET SNOW. THIS SCENARIO...IF IT WERE TO OCCUR...WOULD BE MOST LIKELY IN VICINITY OF AND NORTH OF I-85...FROM ASHEBORO-BURLINGTON UP TO THE HENDERSON AREA. TIMING FAVORS 3-6 AM IN THE WESTERN PIEDMONT FOR CHANGE OVER TO OCCUR... AND 5-8 AM IN THE EASTERN-NE PIEDMONT. STILL NOT EXPECTING THE WINTRY MIX TO CAUSE ANY TRAVEL PROBLEMS AS ANTECEDENT CONDITIONS ARE TOO WARM...LIKELY CAUSING ANY SNOW THAT FALLS TO MELT ON IMPACT. WHERE BRIEF HEAVIER BURST OF SNOW OCCURS...COULD SEE A DUSTING ACCUMULATE ON GRASSY SURFACES INITIALLY THEN MELT AWAY WITHIN AN HOUR OR TWO. ALL-IN-ALL THIS SHOULD A LOW/NO IMPACT EVENT. MAIN ADJUSTMENT TO THE NEAR TERM WAS TO BRING THE WINTRY MIX A LITTLE FARTHER SOUTH INTO SECTIONS OF THE SOUTHERN PIEDMONT OVERNIGHT DUE TO DECENT LIFT...CLOSE PROXIMITY OF DEEPER MOISTURE...AND SLIGHTLY FASTER ARRIVAL OF THE COLDER AIR. WORTH NOTING THAT SOME MODEL GUIDANCE SUGGEST THAT THE ATMOSPHERE ALOFT OVER RALEIGH AND AREAS TO THE EAST DRIES OUT PRIOR TO THE ARRIVAL OF THE COLDER...LIMITING THE POTENTIAL FOR ICE NUCLEATION ALOFT. THUS THE AREA POTENTIALLY RECEIVING A WINTRY MIX COULD END UP BEING A NARROW CORRIDOR BETWEEN THE TRIANGLE AND THE TRIAD.
-- End Changed Discussion --
&& .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 320 PM THURSDAY... THE DEEP UPPER TROUGH AND VORT MAX WILL BE DEPARTING TO THE NORTHEAST...LEAVING NC UNDER STRONG SUBSIDENCE AND CLEARING SKIES. LOW-LEVEL THICKNESSES AROUND 1290M IN THE MORNING AND WEAKENING COLD ADVECTION THROUGHOUT THE DAY SHOULD YIELD HIGHS MOSTLY IN THE MID 40S. GUSTY NORTHERLY WINDS EARLY WILL SUBSIDE BY FRIDAY AFTERNOON. 1032MB HIGH PRESSURE WILL THEN CONTINUE TO BUILD IN OVERNIGHT AND SETTLE ALMOST OVERHEAD BY SATURDAY MORNING. THICKNESS CLIMATOLOGY FOR 1290M SUGGESTS MID 20S FOR A LARGE PART OF THE AREA. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 250 PM THURSDAY... SATURDAY THROUGH SUNDAY...PRECIP MAY RETURN TO THE REGION BY SATURDAY NIGHT INTO SUNDAY AS A DEEP UPPER LEVEL TROUGH DIGS INTO THE SOUTHEAST CONUS AND INDUCES A LOW PRESSURE SYSTEM THAT WILL MOVE UP THE COAST. MODELS CONTINUE TO SLOWLY CONVERGE TOWARDS A SOLUTION...THUS CONFIDENCE IS SLOWLY INCREASING. HOWEVER...THERE ARE STILL SOME MINOR DIFFERENCES IN THE TIMING/TRACK OF THE SURFACE LOW...WHICH HAS IMPLICATIONS ON HOW FAR INLAND THE PRECIP WILL MAKE IT. THERE ARE SOME INDICATIONS THAT PRECIP MAY STAY CONFINED TO THE COAST AND NOT IMPACT OUR AREA. HOWEVER...THERE IS STILL ENOUGH SUPPORT TO KEEP AT LEAST SLIGHT CHANCE POPS IN THE EASTERN PORTIONS OF THE FORECAST AREA. THUS... WILL SHOW PRECIP SPREADING INTO THE EASTERN PORTIONS OF THE FORECAST AREA SATURDAY NIGHT AND PERSIST THROUGH SUNDAY. MONDAY THROUGH THURSDAY...ANOTHER EVEN DEEPER UPPER LEVEL TROUGH WILL DIG DOWN INTO THE EASTERN CONUS DURING THE REMAINDER OF THE PERIOD. THIS WILL BRING DOWN SOME ARCTIC AIR OUT OF CANADA...WITH THE AREA SEEING HIGHS IN THE 30S AND 40S AND LOWS IN THE 20S. CONFIDENCE IS VERY LOW WITH RESPECT TO HOW THIS WILL ULTIMATELY EVOLVE...THEREFORE WILL NOT PUT A LOT OF DETAIL IN THE PRECIP FORECAST. HOWEVER...THE BEST TIME FRAME FOR PRECIP DURING THIS PERIOD LOOKS TO MONDAY AS A FRONT DROPS INTO THE REGION. PRECIP SHOULD START OUT AS RAIN...BUT AS THICKNESS VALUES FALL MONDAY NIGHT...A TRANSITION TO RAIN/SNOW OR ALL SNOW IS EXPECTED. BEYOND THE MONDAY NIGHT TIME FRAME...THE DEEP TROUGH WILL REMAIN OVER THE REGION UNTIL MID WEEK WITH SEVERAL WAVES MOVING DOWN IN THE NORTHWEST FLOW. IT IS HARD TO ACCURATELY TIME THESE WAVES...BUT GIVEN THE ARCTIC AIR THAT WILL BE IN PLACE...LIGHT SNOW WOULD BE POSSIBLE. STAY TUNED. REGARDLESS OF ANY PRECIP...TEMPS WILL BE COLD...WITH HIGHS STAYING IN THE 30S AND 40S FOR A FEW DAYS...WITH OVERNIGHT LOWS IN THE 20S AND POSSIBLY TEENS. THE TROUGH IS PROGGED TO EXIT THE EAST COAST BY MID TO LATE WEEK... THUS ENDING OUR PRECIP CHANCES. IN ADDITION...TEMPS WILL BEGIN TO MODERATE SOME. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 725 PM THURSDAY... 24 HOUR TAF PERIOD: ADVERSE AVIATION CONDITIONS ARE EXPECTED TO CONTINUE ACROSS EASTERN PORTIONS OF CENTRAL NC THIS EVENING INTO FRIDAY MORNING... POSSIBLY SPREADING WESTWARD TO KGSO AND KINT FOR A BRIEF PERIOD OF TIME DURING THE EARLY MORNING HOURS OF FRIDAY... AS A PLUME OF MOISTURE STREAMS ALONG THE SOUTHEAST COAST IN ADVANCE OF A POTENT UPPER TROUGH. GENERALLY IFR/LOW END MVFR CONDITIONS AT KRDU/KFAY/KRWI ARE EXPECTED THIS EVENING THROUGH AROUND DAYBREAK FRIDAY... WITH POSSIBLY A BRIEF PERIOD OF LIFR CONDITIONS AT KFAY/KRWI. A STRONG UPPER TROUGH WILL SWING ACROSS THE AREA TONIGHT...WHILE A LOW PRESSURE DEEPENS OFF THE CAROLINA COAST. THIS WILL LEAD TO NORTHERLY WINDS INCREASING TO 10-14KT AND POSSIBLY GUSTING TO 20-25KT...WITH A PERIOD OF RAIN MIXING OR CHANGING TO ALL SNOW POSSIBLE AFTER 06Z...MAINLY FROM KGSO/KINT EAST TO KRDU... BEFORE DRY AIR ALOFT QUICKLY RUSHES IN AND BRINGS VFR CONDITIONS FOR FRIDAY SHORTLY AFTER DAYBREAK. BREEZY NORTH-NORTHWESTERLY WINDS WILL CONTINUE FOR FRIDAY MORNING INTO THE AFTERNOON. WINDS WILL BEGIN TO DECREASE MID TO LATE FRIDAY AFTERNOON AS THE UPPER TROUGH AND ASSOCIATED SURFACE LOW LIFT OFF TO THE NORTH AND EAST OF THE REGION. OUTLOOK: VFR CONDITIONS WILL DOMINATE INTO EARLY NEXT WEEK AS CHILLY HIGH PRESSURE BUILDS IN FROM THE WEST FRIDAY THROUGH MONDAY... ALTHOUGH ANOTHER STRONG UPPER LEVEL DISTURBANCE MAY BRING A CHANCE OF SUB-VFR CONDITIONS LATE IN THE PERIOD... MAINLY SUNDAY INTO EARLY MONDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMITH NEAR TERM...WSS SHORT TERM...SMITH LONG TERM...KRD AVIATION...BSD/SMITH

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.