Area Forecast Discussion
Issued by NWS Wilmington, OH

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 KILN 211802 AFDILN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 202 PM EDT THU AUG 21 2014 .SYNOPSIS... A WARM FRONT WILL GRADUALLY LIFT NORTHEAST INTO THE GREAT LAKES THROUGH SATURDAY...THEN CONTINUE TO WAVER ACROSS THE REGION THROUGH THE BEGINNING OF NEXT WEEK. DISTURBANCES IN NORTHWEST FLOW ALOFT WILL INTERACT WITH A VERY WARM AND MOIST AIRMASS TO PRODUCE SHOWERS AND THUNDERSTORMS AT TIMES THROUGH THE PERIOD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
SHOWERS AND EMBEDDED THUNDERSTORMS CONTINUE TO TRACK ACROSS THE FORECAST AREA. EXPECT ACTIVITY TO COME TO AN END DURING THE MID TO LATE AFTERNOON. THERE IS A NORTHWEST-SOUTHEAST ORIENTED BOUNDARY ACROSS INDIANA WITH A VERY UNSTABLE AIRMASS TO THE WEST OF THAT. THIS HAS LED TO AN AGITATED CUMULUS FIELD NEAR THE BOUNDARY. EXPECT THIS TO PUSH TOWARDS THE SOUTHWEST PART OF THE FORECAST AREA LATE IN THE DAY AND WILL HAVE TO CONTINUE TO MONITOR WHETHER CONVECTION CAN DEVELOP THERE. AT THIS POINT THINK SUBSIDENCE IN WAKE OF CURRENT ACTIVITY WILL BE ENOUGH OF A DETRIMENT THROUGH THE REMAINDER OF THE DAYLIGHT HOURS. HIGH RESOLUTION GUIDANCE IS KEEPING THE AREA DRY AFTER CURRENT COMPLEX MOVES OUT AS WELL. HAVE SUBSTANTIALLY LOWERED TEMPERATURES PARTICULARLY IN THE NORTHERN COUNTIES. STILL COULD SEE A LATE RALLY INTO THE MID 80S ACROSS THE TRI-STATE AND FURTHER EAST ALONG THE OHIO RIVER.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... NEXT DISTURBANCE IN THE NORTHWEST FLOW ALOFT WILL AFFECT THE AREA TONIGHT. THERE ARE INDICATIONS A LARGE COMPLEX OF STORMS/MCS WILL FORM OVER MINNESOTA AND WISCONSIN AND DIVE SOUTHEASTWARD. SOME TIMING AND PLACEMENT DISCREPANCIES EXIST...BUT THE MOST LIKELY TRAJECTORY APPEARS TO BE TOWARD THE NORTHERN HALF OF THE CWA...SO HAVE ALIGNED POPS ACCORDINGLY. IF AN ORGANIZED MCS DEVELOPS...THERE MAY BE AN ATTENDANT RISK FOR STRONG TO DAMAGING WINDS. HOWEVER THE DIURNALLY UNFAVORABLE TIMING MAY LEAD TO A WEAKENING TREND. SPC HAS PLACED THE WESTERN HALF OF THE CWA IN A SLIGHT RISK. ALSO...WPC HAS PLACED THE AREA IN A SLIGHT RISK OF EXCESSIVE RAINFALL DUE TO THE MULTIPLE CLUSTERS OF THUNDERSTORMS WITH HEAVY RAIN. WITH A MOIST AIRMASS AND CLOUD COVER...LOWS WILL ONLY DROP INTO THE LOWER 70S IN MANY SPOTS. MORE STORMS WILL BE POSSIBLE ON FRIDAY...BUT COVERAGE IS IN QUESTION AS CONFIDENCE DECREASES ON INDIVIDUAL FEATURES IN THE NORTHWEST FLOW. HOWEVER...HIGH PRECIPITABLE WATER VALUES AND THE LINGERING BOUNDARY ACROSS THE REGION WILL ACT IN FAVOR OF THUNDERSTORM DEVELOPMENT DURING PEAK HEATING. A SIMILAR SCENARIO APPLIES TO SATURDAY. COMPLICATING MATTERS IS A SLIGHT CHANGE IN THE PATTERN ORIENTATION FROM SATURDAY INTO SUNDAY. THE CENTRAL CONUS RIDGE IS EXPECTED TO CONTINUE TO BUILD...AS A TROUGH DIGS OVER THE WESTERN ATLANTIC. THERE ARE NOW INDICATIONS THAT HIGH PRESSURE OVER THE ST. LAWRENCE VALLEY WILL NOSE SOUTHWESTWARD...SERVING TO BACK DOOR FRONT THE LOW LEVEL BOUNDARY. THIS MAY SHIFT THE FOCUS OF ANY STORMS THAT DEVELOP. BY SUNDAY THE LOW LEVEL BAROCLINIC ZONE BECOMES MORE DIFFUSE...LOW LEVEL FLOW WEAKENS...AND ATMOSPHERIC MOISTURE LESSENS...SO STORM CHANCES MAY BE PRETTY LOW. FRIDAY AND SATURDAY WILL LIKELY BE THE WARMEST DAYS OF THE SHORT TERM PERIOD WITH HIGHS IN THE UPPER 80S TO LOWER 90S. HEAT INDICES IN THE SOUTHWEST WILL BE NEAR 100. BY SUNDAY...THE NORTHEAST SURFACE FLOW MAY HELP LIMIT TEMPERATURES A BIT. WITH HIGH DEW POINTS...OVERNIGHT LOWS WILL CONTINUE TO RESIDE ON EITHER SIDE OF 70. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... GETTING INTO MONDAY-TUESDAY...THE RIDGE CONTINUES TO BUILD WITH HEAT/HUMIDITY. FLOW BECOMES VERY LIGHT THROUGH THE BULK OF THE TROPOSPHERE AND IT BECOMES QUESTIONABLE IF COVERAGE OF DAYTIME/EVE STORMS WARRANTS MENTION. RIGHT NOW HAVE RUN 15-25% RAIN CHANCES BOTH OF THESE DAYS...AND THAT MAY BE TOO HIGH. INTO WEDNESDAY...SOME HINTS OF HEIGHT FALLS WHICH MAY ALLOW A LITTLE STRONGER FLOW OR A WEAK SHORTWAVE TROUGH TO CROSS THE GREAT LAKES. SO A BETTER STORM THREAT THEN...HOWEVER AT THIS TIME RANGE THIS IS A VERY LOW CONFIDENCE FORECAST GIVEN CONDITIONAL NATURE OF THE RIDGE BUCKLING. SO ALL IN ALL...HAVE TENDED TO FOCUS RAIN CHANCES NEAR PEAK HEATING INTO THE EVENING AND ALLOW FOR SOME DRY NIGHTS/EARLY MORNINGS. FLY IN OINTMENT WILL BE ANY FORWARD PROPAGATING MCS THAT SURVIVES THROUGH THE NIGHT...ORIGINATING TO OUR NORTHWEST AND FALLING DOWN NNWLY FLOW EITHER SATURDAY MORNING OR SUNDAY MORNING. LOW CONFIDENCE STORM CHANCE...BUT HIGH CONFIDENCE WARM/HUMID PATTERN IS THE STORY FOR THE SAT-WED TIMEFRAME. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
SHOWERS AND THUNDERSTORMS WILL MOVE EAST OF ALL TAF SITES EARLY IN THE PERIOD. HOWEVER THERE ARE SOME LOWER CLOUDS BEHIND THE SHIELD OF PRECIPITATION. SO HAVE ALLOWED FOR A FEW HOURS OF POSSIBLE MVFR CEILINGS. BEYOND THAT THERE SHOULD BE A QUIESCENT PERIOD WITH VFR LATE IN THE DAY. APPEARS THAT ADDITIONAL CONVECTION WILL DEVELOP NORTHWEST OF THE REGION AND MOVE SOUTHEAST TONIGHT. AT THIS POINT THE COLUMBUS TERMINALS HAVE THE HIGHEST PROBABILITY OF BEING IMPACTED AND THE CINCINNATI TERMINALS THE LOWEST. PLENTY OF UNCERTAINTY WITH CONVECTIVE EVOLUTION SO HAVE KEPT TAFS GENERIC USING VCTS TO INDICATE PERIOD OF BEST CHANCE OF STORMS. IT IS POSSIBLE THAT SHOWERS AND STORMS COULD PERSIST INTO FRIDAY. BUT CONFIDENCE IS TOO LOW TO INCLUDE MENTION OF PRECIPITATION THAT FAR OUT IN TIME. OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY EVENING THROUGH SATURDAY.
-- End Changed Discussion --
&& .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM... SHORT TERM...SNYDER LONG TERM...BINAU AVIATION...

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