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 251702 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1153 AM EST SUN JAN 25 2015 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE WILL GIVE WAY TO A STRONG UPPER LEVEL DISTURBANCE THAT IS EXPECTED TO PUSH SOUTHEAST ACROSS NORTH CAROLINA MONDAY INTO MONDAY EVENING. THE ASSOCIATED SURFACE COLD FRONT WILL PUSH THROUGH MONDAY NIGHT. THIS WILL BE FOLLOWED BY COLD HIGH PRESSURE TUESDAY AND WEDNESDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 1050 AM SUNDAY... THE OROGRAPHIC ENHANCED CIRRUS EVENT OVER NORTHERN NORTH CAROLINA HAS ESSENTIALLY ENDED. THE LATEST SATELLITE DATA INDICATED A SHIFT NORTHWARD AND DECREASE IN FAVORABLE CONDITIONS FOR ADDITIONAL MOUNTAIN WAVE CLOUDS EAST OF THE BLUE RIDGE. THIS SETS THE STAGE FOR A SUNNY AFTERNOON THROUGHOUT THE REGION. THERE SHOULD BE SOME CIRRUS LATE AFTERNOON AS THE NEXT SYSTEM APPROACHES THE MOUNTAINS FROM THE W-NW LATE IN THE DAY AND TONIGHT. HIGHS SHOULD EASILY REACH INTO THE MID 50S WITH LIGHT SW WIND. THERE IS A CHANCE OF RAIN LATE TONIGHT WITH THE AFOREMENTIONED APPROACH OF THE VORT MAX FROM THE NW. MILD SW FLOW AND THICKENING CLOUDS WILL KEEP TEMPERATURES WELL ABOVE FREEZING.
-- End Changed Discussion --
&& .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... AS OF 255 AM SUNDAY... A CLIPPER SYSTEM WILL MOVE INTO THE AREA WITH THE SURFACE LOW TRACKING SOMEWHERE IN THE VICINITY OF NC. MODELS DISAGREE SLIGHTLY WITH THE SOUTHWARD EXTENT OF THE TRACK BUT IN GENERAL THE FIRST WAVE MOVES INTO NC MONDAY MORNING. SOME UPPER LEVEL DYNAMICS ASSOCIATED WITH THE LEFT EXIT REGION OF AN UPPER JET WILL HELP PROVIDE SOME LIFT ABOVE 500 MB BUT BELOW THAT...THE SURFACE LOW WILL BE JUST STARTING TO DEEPEN. THEREFORE LACK OF STRONG DYNAMICS AND SATURATION IN THE LOW LEVELS WILL HELP KEEP PRECIPITATION AMOUNTS AT BAY. IN GENERAL...THE BEST CHANCES FOR RAIN WILL BE ACROSS THE NORTH. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT A LIQUID RAIN EVENT DURING THE DAY ON MONDAY. RAINFALL TOTALS WILL GENERALLY BE LESS THAN A TENTH OF AN INCH. HIGHS TEMPERATURES WILL BE TRICKY DUE TO TRACK OF THE LOW BUT EXPECT UPPER 40S NORTH TO LOW TO MID 50S SOUTH AS A GOOD STARTING POINT. LATER IN THE AFTERNOON THE LOW WILL EVENTUALLY REACH THE COAST AND REALLY START TO DEEPEN AND START TO IMPORT A LOT MORE MOISTURE OFF OF THE SOUTHWEST ATLANTIC. BY THIS TIME HOWEVER...LOW WILL BE FAR ENOUGH EAST FOR US TO HAVE TO WORRY ABOUT HEAVY RAIN THREAT HERE IN CENTRAL NC. THE ATTENTION AT THIS TIME WILL THEN TURN TO A SECONDARY WAVE ON THE HEELS OF THE FIRST WAVE DIVING DOWN THROUGH THE UPPER LEVEL LONGWAVE TROUGH. AT THIS TIME A COOLING AND DRYING TREND WILL HAVE INITIATED BUT THERE STILL COULD BE ENOUGH SATURATION FOR SOME PRECIPIATION. BY 00Z TUESDAY WETBULB TEMPERATURES WILL START TO REACH THE FREEZING MARK IN THE TRIAD...AND DOWN TO RALEIGH BY 06Z TUESDAY. IF SOME LINGERING MOISTURE IS LEFT...THERE COULD BE ENOUGH LIFT IN THE SECONDARY WAVE TO PRODUCE A QUICK RAIN OR SNOW SHOWER. THAT BEING SAID...FORECAST SOUNDINGS DRY OUT RATHER QUICKLY IN THE SNOW GROWTH ZONE...SO THE LIKELIHOOD OF THIS IS NOT VERY HIGH BUT IT IS POSSIBLE...ESPECIALLY FURTHER NORTH AND WEST. OTHERWISE EXPECT MOST PRECIPITATION TO BE LIGHT AND ALL LIQUID. OVERNIGHT MONDAY NIGHT INTO TUESDAY...TEMPERATURES ARE EXPECTED TO DROP TO OR BELOW FREEZING IN THE NORTHERN HALF OF THE CWA. WITH VERY COLD TEMPERATURES AND RAIN ENDING EARLIER IN THE DAY...THE QUESTION OF POSSIBLE BLACK ICE IS A LOGICAL ONE FOR EARLY TUESDAY MORNING. A COUPLE OF THINGS ARE STACKING UP AGAINST THIS AT THIS POINT. FIRST...WINDS WILL REMAIN NEAR 10 KNOTS AFTER THE PRECIPITATION ENDS...WHICH WAS ALREADY LIGHT AMOUNTS TO BEGIN WITH...SO IT IS ENTIRELY POSSIBLE THAT ROADS COULD BE DRY BEFORE TEMPERATURES DROP BELOW FREEZING. EVEN IF THEY ARE NOT...VERY WARM SOIL TEMPERATURES AND HIGHS EARLIER IN THE DAY NEAR 50 DEGREES WOULD BE HARD TO SUPPORT THE DEVELOPMENT OF ANY ICE. CANT RULE OUT A FEW ICY PATCHES BUT OVERALL THIS IS NOT EXPECTED TO BE A PROBLEM. LOWS MONDAY NIGHT IN THE LOW 30S. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 130 AM SUNDAY... TUE/TUE NIGHT: THE POLAR FRONT SHOULD HAVE SETTLED SOUTH OF NC... AS THE SURFACE LOW BOMBS OFF THE MIDATLANTIC COAST. SHEARED VORTICITY WILL CONTINUE TO STREAM SE AND EAST ACROSS THE CAROLINAS INTO THE BASE OF THE MEAN POLAR TROUGH. WE MAINTAIN A DECENT AMOUNT OF MOISTURE FROM 925 MB UP THROUGH 600 MB (WITH SOME VARIABILITY AMONG THE MODELS REGARDING SHALLOW DRY LAYERS THROUGH THIS DEPTH)... SO EXPECT TO RETAIN A GOOD AMOUNT OF CLOUD COVER THROUGH THE DAY... BUT ANY PRECIP IS APT TO BE QUITE PATCHY WITH ONLY TRACE AMOUNTS EXPECTED... AS LOW LEVEL FLOW TAKES ON A NORTHWESTERLY DOWNSLOPE COMPONENT. WILL LEAVE POPS UNDER 15%. DESPITE SOME LOW LEVEL MIXING... THICKNESSES DROP TO VALUES NEARLY 20 M BELOW NORMAL... SUGGESTING HIGHS FROM NEAR 40 NORTH TO THE UPPER 40S SOUTH WHEN FACTORING IN CLOUD COVER. THE COLUMN DRIES OUT TUE NIGHT AS HIGH PRESSURE SHIFTING OVER THE OH VALLEY ATTEMPTS TO PUSH OVER THE MOUNTAINS. WITH A SLACKENING MSLP GRADIENT AND LOWERING WIND SPEEDS UNDER CLEARING SKIES... EXPECT CHILLY LOWS WELL DOWN INTO THE 20S. WED-THU: THE MID LEVEL POLAR LOW OFF NEW ENGLAND LIFTS NORTHEAST WITH THE MEAN TROUGH FINALLY PUSHING EASTWARD OFF THE EAST COAST EARLY WED... LEAVING NC BENEATH WEAK MID LEVEL SHORTWAVE RIDGING. THIS WILL GENERATE MAINLY QUIET WEATHER AND A GRADUAL MODIFICATION OF TEMPS THROUGH MID WEEK AS SURFACE HIGH PRESSURE BUILDS ESE OVER THE CAROLINAS WED BEFORE PUSHING SOUTHWARD TO OVER FL AND OFF THE SE COAST THU. ANOTHER CLIPPER SHORTWAVE TROUGH MOVING THROUGH THE DAKOTAS AND UPPER MIDWEST WED NIGHT WILL CROSS THE SRN GREAT LAKES AND OH VALLEY REGION LATE THU... AND A SHOT OF WEAK MID LEVEL DPVA ACROSS NC ALONG WITH INCREASING UPPER LEVEL DIVERGENCE (IN THE LEFT EXIT REGION OF A STRENGTHENING UPPER JET ACROSS THE MID/LOWER MISS VALLEY INTO THE MIDSOUTH) AND ACCELERATING CYCLONIC LOW LEVEL FLOW INTO THE FORECAST AREA WILL LEAD TO INCREASING AND THICKENING CLOUDS WITH LOWERING BASES THU. EXPECT HIGHS WED MOSTLY IN THE MID-UPPER 40S WITH PLENTY OF SUNSHINE. LOWS IN THE MID-UPPER 20S WED NIGHT AND HIGHS THU IN THE UPPER 40S TO LOWER 50S... JUST A COUPLE OF DEGREES BELOW NORMAL. THU NIGHT-SAT: THE AFOREMENTIONED SHORTWAVE TROUGH COMING OUT OF THE OH VALLEY SWINGS THROUGH THE EASTERN STATES WHILE AMPLIFYING THU NIGHT THROUGH FRI NIGHT. THERE IS NOT MUCH MOISTURE RETURN AHEAD OF THE ASSOCIATED FRONT WITH PROJECTED PW VALUES JUST A BIT ABOVE NORMAL... SO DESPITE DECENT MID-LEVEL DPVA AND UPPER DIVERGENCE THU NIGHT/FRI MORNING... EXPECT ANY PRECIP TO BE BRIEF AND LIGHT... AND WILL KEEP POPS LOW. DRY WEATHER FOLLOWS FOR THE LATTER HALF OF FRI INTO FRI NIGHT... WITH INITIALLY BLUSTERY NW WINDS POST-FRONT WEAKENING FRI NIGHT. PLEASANT WEATHER SAT WITH BRIEF FLAT OR SHORTWAVE RIDGING BEHIND THE EXITING TROUGH WITH HIGH PRESSURE AGAIN NOSING INTO NC FROM THE GULF STATES. MODEL SOLUTIONS REALLY START TO DIVERGE HERE BUT WE MAY SEE YET ANOTHER CLIPPER WAVE DIVING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION SAT WITH SOME ADDITIONAL ENERGY EMANATING FROM THE CLOSED LOW OFF BAJA STREAKING EASTWARD INTO NC... MEANING INCREASING CLOUDS SAT. -GIH && .AVIATION /18Z SUNDAY THROUGH THURSDAY/... AS OF 1153 AM SUNDAY... VFR CONDITIONS ARE EXPECTED THIS AFTERNOON WITH AN INCREASE IN HIGH CLOUDS FROM THE WEST AGAIN LATER. LIGHT WINDS EXPECTED. MVFR CIGS ARE EXPECTED LATER TONIGHT INTO MONDAY FOR A GOOD PART OF THE AREA WITH A CHANCE OF RAIN SHOWERS. A QUICK RETURN TO VFR CONDITIONS BEHIND THE COLD FRONT IS EXPECTED MONDAY NIGHT. LONG TERM: VFR CONDITIONS ARE FORECAST TUE AND WED. GUSTY NW WINDS TO 22-25KT ARE EXPECTED TUESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...BADGETT SHORT TERM...ELLIS LONG TERM...HARTFIELD AVIATION...BADGETT

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