Area Forecast Discussion
Issued by NWS Charleston, WV

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 FXUS61 KRLX 140617 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 217 AM EDT SUN SEP 14 2014 .SYNOPSIS... DRY AIR MOVING IN AS HIGH PRESSURE BUILDS OVERNIGHT. WEAK MID/UPPER LEVEL DISTURBANCE PASSES MONDAY NIGHT...FOLLOWED BY ANOTHER ROUND OF HIGH PRESSURE THROUGH MIDWEEK. && .NEAR TERM /THROUGH TONIGHT/... 1030 PM UPDATE... FCST ON TRACK NOTWITHSTANDING THE PATCHY STRATOCU HANGING AROUND. THE DRIER AIR WAS WORKING IN FROM THE NW AND HAVING SOME EFFECT ON RAISING BASES AND SHOULD HELP TO DISSIPATE THE CLOUDS AND ALLOW THE RIVER VALLEY FOG TO FORM AS FCST...BUT THE STRONG FRONTAL INVERSION CATS A BIT OF UNCERTAINTY HERE. 745 PM UPDATE... DECREASED SKY AND TEMPERATURE VALUES A BIT OVERNIGHT. FCST OTHERWISE ON TRACK. PREV DISCN... SECONDARY WEAK COLD FRONT...ABOUT ALONG THE OHIO RIVER AS OF 17Z...WITH NOTHING MORE THAN A SHORT PERIOD OF SOME 10-20KT WINDS TO MARK ITS POSITION. DO HAVE DRIER AIR FILTERING IN BEHIND THE FRONT WITH LOW CLOUDS BEGINNING TO LIFT/SCATTER. INCLUDED SOME DRIZZLE ALONG WITH ISOLATED TO SCATTERED POPS MAINLY IN THE MOUNTAINS TO START...AND QUICKLY DIMINISHING BY THIS EVENING. WILL HAVE RELATIVELY DRY AIR IN PLACE TONIGHT...BUT WITH COOL TEMPS AND WARM RIVERS THINK THERE WILL BE AT LEAST SOME RIVER VALLEY FOG WITH CLOUDS SCATTERING OUT. HIGH PRESSURE PASSES BY TO THE NORTH TONIGHT AND SUNDAY. MODELS INDICATE SOME RETURN MOISTURE MAKING IT INTO SOUTHERN CWA. INCLUDED MORE CLOUDS THERE...BUT KEPT THE FORECAST DRY THROUGH THE NEAR TERM PERIOD. WITH THE LAST COOL SPELL...THE MET WAS THE OVERALL WINNER...SO BLENDED TOWARD THE MET ON BOTH HIGHS AND LOWS. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
HIGH PRESSURE REMAINS IN CONTROL MONDAY WITH NEAR NORMAL TEMPERATURES AND WEAK FLOW. AN H5 SHORTWAVE WILL APPROACH THE AREA FROM THE NORTHWEST MONDAY NIGHT. THE NAM MODEL HAS BEEN CONSISTENT WITH THE ASSOCIATED VORTICITY MAXIMA PASSING ACROSS THE NORTHERN HALF OF OUR CWA ON TUESDAY...WHILE THE REST OF THE MODELS SUITE HAVE THIS FEATURE PASSING FURTHER NORTH. PREFER THE NAM SOLUTION...BRINGING A COLD FRONT AS SEEN ON WIND AND QPF FIELDS. THE NAM SUGGESTS PWATS ABOUT 1.35 INCHES WITH THE FRONT WITH LITTLE OR NO SFC BASED CAPE AND DEEP LAYERED SHEAR OF 40-50 KNOTS. THESE PARAMETERS OCCURRING DURING THE NIGHT HOURS SUGGEST PCPN WILL OCCUR IN THE FORM OF RAIN SHOWERS AND NOT THUNDERSTORMS. THEREFORE...KEPT CHANCE POPS WITH THIS COLD FRONT MONDAY NIGHT...EXITING THE EASTERN MOUNTAINS BY MID TUESDAY. BROAD HIGH PRESSURE BUILDS FROM ACROSS THE GREAT LAKES REGION...OH VALLEY AND WV ON TUESDAY THROUGH THE END OF THE WEEK TO PROVIDE A COOLING TREND AND DRY CONDITIONS UNDER NORTHWEST TO NORTH FLOW. USED A BLEND OF VARIOUS GUIDANCE TO REFLECT THE COOLING TREND THROUGH THE PERIOD FOR HIGHS...WITH THE LOWEST BEING ON WEDNESDAY WITH AROUND 70 DEGREES LOWLANDS...RANGING TO THE MID 60S HIGHER ELEVATIONS. KEPT PREVIOUS LOW TEMPERATURES AS THEY LOOK REASONABLE COMPARED WITH LATEST GUIDANCE. COLDEST LOWS EXPECTED TUESDAY NIGHT WITH MID TO LOWER 40S NORTH AND NORTHEAST MOUNTAINS...RANGING TO THE LOWER 50S ELSEWHERE.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 500 MB RIDGE REMAINS OVER THE SRN ROCKIES AND SRN PLAINS THRU PERIOD WITH WEAK BOARD 500 MB TROF OVER THE MIDWEST AND OUR VICINITY. THIS LEAVES US IN A WEST AND NORTHWEST FLOW ALOFT...AND KEEPING THE DOOR SHUT FOR DEEP MOISTURE. FIGURING THE HIGH PRESSURE CENTER DOES NOT COME DIRECTLY OVER US BUT REMAINS JUST TO OUR NORTH. THIS ALLOWS A PROLONG PERIOD OF E AND SE FLOW. SO WILL KEEP MAXIMUM TEMPERATURES DOWN AND MORE CLOUDS ON OUR EASTERN SLOPES. WILL ACCEPT WPC GUIDANCE AND LEAVE DAY 7 DRY FOR NOW...BUT DISTURBANCE IN THE WESTERLIES MAY SINK DOWN FROM THE GREAT LAKES. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... PATCHY STRATOCU CONTINUES TO DEVELOP/MOVE AROUND THE REGION. IN ADDITION...LIGHT WINDS AND CLEAR SKIES IN MANY LOCATIONS HAS ALREADY RESULTED IN THE DEVELOPMENT OF IFR CONDITIONS IN RIVER VALLEY FOG. EXPECT THE VALLEY FOG WILL CONTINUE TO DEVELOP...WITH IFR CONDITIONS EXPECTED IN MANY VALLEY LOCATIONS BETWEEN 08Z AND 12Z. CONDITIONS OUTSIDE THESE VALLEYS SHOULD GENERALLY BE VFR OR MVFR...AT THE WORST. THE FOG AND ANY RESULTANT LOW CLOUDS WILL BURN OFF AROUND 13Z SUNDAY MORNING. STILL NOT EXPECTING MUCH MORNING CU...AND THE REST OF SUNDAY WILL TURN OUT VFR IN MANY LOCATIONS. AFT 03Z MONDAY...RIVER VALLEY FOG SHOULD ONCE AGAIN BEGIN TO DEVELOP. WINDS SHOULD PREVAIL THROUGH THE PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG MAY VARY OVERNIGHT INTO SUNDAY MORNING. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SUN 09/14/14 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY L L L L L L L L H H H H HTS CONSISTENCY M H L L L L L L H H H H BKW CONSISTENCY M M H H H H M H H H H H EKN CONSISTENCY H L L L L L L L H H H H PKB CONSISTENCY M L L L L L L L H H H H CKB CONSISTENCY M M L L L L L L H H H H AFTER 06Z MONDAY... IFR POSSIBLE IN VALLEY FOG MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/ARJ NEAR TERM...JSH SHORT TERM...ARJ LONG TERM...KTB AVIATION...JSH

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