Area Forecast Discussion
Issued by NWS Charleston, WV

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 271819 AFDRLX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 215 PM EDT WED APR 27 2016 .SYNOPSIS... FRONTED STALLED NORTHERN KY TO CENTRAL WEST VIRGINIA LIFTS BACK NORTH OVERNIGHT...THEN WAFFLES BACK/FORTH IN OUR VICINITY THROUGH FRIDAY...PROVIDING ROUNDS OF SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 18Z...STALLED SHALLOW SURFACE FRONT NEAR HTS-CRW TO N OF BKW. DIFFICULT POP AND QPF FORECAST TO SAY THE LEAST. NOT ENOUGH CONFIDENCE...AT 18Z...TO GO WITH ANY WIDESPREAD FLASH FLOOD WATCH OVERNIGHT. DO NOT EXPECT CONVECTION TO ALIGN WITH THE FLOW LIKE YESTERDAY...BUT STILL HAVE LOCALIZED PROBLEMS. SO IF THESE DOWNPOURS HIT THE WETTER AREAS FROM LAST NIGHT...COULD SEE FLOODING. WE WILL CONTINUE TO MONITOR FOR ANY POSSIBLE FFA FOR TONIGHT. WILL INSERT SOME HEAVY RAIN FOR OVERNIGHT...AS PRECIPITABLE WATER INCREASES TO AROUND 1.25 TO 1.5 INCHES...BEFORE TRENDING DOWN AGAIN LATE THURSDAY. THINKING SCATTERED CONVECTION DEVELOPS THIS AFTERNOON NEAR THE FRONT AND SOUTH. THEN THE MID LEVEL DISTURBANCE APPROACHES 00Z TO 06Z WITH STEERING FLOW AND LOW LEVEL FLOW BACKING AHEAD OF IT. 12Z MODEL SOLUTIONS SEEM A BIT SLOW...COMPARED TO THE 18Z RADAR...LIFTING THE DISTURBANCE NORTHEAST. SO MORE DEVELOPMENT OVERNIGHT FROM SOUTHWEST TO NORTHEAST...ESPECIALLY IN THE OHIO VALLEY COUNTIES. WILL BASE FORECAST ON THE FRONT LIFTING TOWARD THE ROUTE 50 CORRIDOR BY 12Z THURSDAY. AS A RESULT...WILL INCREASE MAX TEMPERATURE A BIT IN THE NORTH ON THURSDAY...BUT A SHARP GRADIENT AS YOU VENTURE FURTHER NORTH. HAVE POPS DECREASING IN THE MORNING AS THE MID LEVEL SUPPORT PULLS NORTH. MORE INSTABILITY DEVELOPS ON THURSDAY AFTERNOON...COMPARED TO TODAY...OVER CENTRAL AND SOUTHERN COUNTIES DESPITE THE LOWER PRECIPITABLE WATER. SO DIURNAL CONVECTION SHOULD REFIRE...WITH POSSIBLE SEVERE. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... STILL DEALING WITH TIMING DIFFERENCES REGARDING DRIER AIR INTRUDING INTO THE AREA FROM THE WEST ON THURSDAY. DIFFERENCES CONTINUE ON FRIDAY WITH TIMING OF COLDER AIR PUSHING INTO THE AREA. GFS AND CANADIAN ARE THE MOST AGGRESSIVE WITH THIS...WHILE THE NAM KEEPS THE WARMEST AIR OVER THE AREA. SREF AND ECMWF ARE IN BETWEEN. PRIME EXAMPLE IS THE MOS GUIDANCE HIGHS FOR HTS. NAM HAS 80 WHILE GFS HAS 67. BIG BUST POTENTIAL. WITH NO CLEAR EVIDENCE ON WHICH WAY TO LEAN... WILL KEEP A MIDDLE OF THE ROAD SOLUTION FOR BOTH THURSDAY AND FRIDAY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... UNSETTLED WEATHER IS EXPECTED THIS WEEKEND STARTING OUT DRY FRIDAY NIGHT BEFORE A WARM FRONT MOVES ACROSS THE REGION ON SATURDAY. MODELS DIFFER ON TIMING AND POSITION OF THIS NEXT SYSTEM. WITH THAT IN MIND, WENT WITH A BLEND OF THE MODELS FOR TIMING OF PRECIPITATION. INTRODUCED POPS FOR SATURDAY FROM SW TO NE WITH THE WARM FRONT. THE WARM FRONT LIFTS NORTH OF THE CWA ON SUNDAY WITH THE SFC LOW MOVING THROUGH THE AREA FROM WEST TO EAST DURING THE DAY ON SUNDAY AND MONDAY. THE LOW FINALLY EXITS TO THE EAST ON MONDAY NIGHT. SEASONAL TEMPERATURES WILL REMAIN THROUGHOUT THE FORECAST PERIOD. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... CONFIDENCE LOWERED TO LOW. HARD TO DETERMINE COVERAGE OF AFTERNOON CONVECTION FROM HTS-CRW-BKW ON SOUTH...THEN HARD TO TIME OVERNIGHT CONVECTION AND COVERAGE...AS IT LIFTS NORTH TOWARD PKB-CKB AND EKN. MODELS SEEM TO BE A BIT SLOW LIFTING NORTH...COMPARED TO 18Z RADAR. IN THE MEANTIME...HAVE DRY CONDITIONS WITH CEILINGS DIRUNALLY LIFTING THIS AFTERNOON OVER NORTHERN WEST VIRGINIA. PLUS WITH THE HIGHER DEW POINTS...WILL MOUNTAIN VALLEYS LIKE ELKINS SEE FOG FORM BEFORE THE OVERNIGHT CONVECTION REACHES THE MOUNTAINS. OVERALL...EXPECT LOW BASED CU AT MOSTLY 2 TO 3 THSD FT AGL SCATTERED TO BROKEN WITH LAYERS ABOVE. LOCAL IFR IN CONVECTION WITH VSBY BLO 3 MILES AND CEILINGS AOB 2 THSD FT. BASING FORECAST ON SURFACE FRONT LIFTING NORTH TO NEAR KUNI-KPKB- KCKB BY 12Z THURSDAY. LEFTOVER MORNING SHOWERS EXIT TO THE NORTH...BUT THEN INSTABILITY INCREASES BY 18Z THURSDAY...ESPECIALLY SOUTH OF PKB-CKB. SO TALLER CONVECTION EXPECTED THURSDAY AFTERNOON. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING THE ROUNDS OF CONVECTION COULD VARY. FOG MAY FORM IN MOUNTAIN VALLEYS BEFORE OVERNIGHT CONVECTION AREAS...WITH VSBY LOWER THAN FORECAST. 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. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY M M H H M M M M M M M H HTS CONSISTENCY M M M M M M M M M M M M BKW CONSISTENCY M M M M M M M M M M M M EKN CONSISTENCY M M M M M M M M M M H H PKB CONSISTENCY M M M M M M M M M M M M CKB CONSISTENCY M M M M M M M M M M H H AFTER 18Z THURSDAY... IFR POSSIBLE IN ROUNDS OF SHOWERS OR STORMS THURSDAY AFTERNOON INTO THURSDAY NIGHT. IFR AGAIN POSSIBLE SATURDAY NIGHT INTO SUNDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/TRM/MZ NEAR TERM...KTB SHORT TERM...RPY LONG TERM...JS AVIATION...KTB

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