Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Wilmington, OH banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4][-5][-6][-7][-8][-9]



000
FXUS61 KILN 210237
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
937 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK SURFACE HIGH PRESSURE WILL GRADUALLY MOVE EAST OF THE OHIO
VALLEY BY SUNDAY. AS SOUTHERLY WIND FLOW INCREASES...TEMPERATURES
WILL BEGIN TO WARM EARLY IN THE WEEK. CHANCES FOR RAIN WILL
INCREASE BY TUESDAY...AS A STRONG LOW PRESSURE SYSTEM MOVES INTO
THE GREAT LAKES. WINDY AND COOL CONDITIONS ARE EXPECTED AFTER THE
LOW MOVES AWAY IN THE MIDDLE OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
FAST MOVG H5 S/W HAS KICKED OFF SOME FLURRIES IN CENTRAL OHIO LATE
THIS AFTERNOON INTO THIS EVENING. LATEST RADAR LOOP IS SHOWING
THAT THESE ARE SLOWLY EXITING THE REGION AND SHOULD BE GONE IN THE
NEXT HOUR OR SO.

THE PERSISTENT LOW LEVEL CLOUDS ARE FINALLY SHOWING SIGNS OF
BREAKING UP...WITH CLEAR SKIES VISIBLE IN MUCH OF KENTUCKY. AS THE
CENTER OF THE SFC HIGH DRIFTS EAST TONIGHT...EXPECT SOME OF THE
CLEARING TO WORK INTO THE TRI-STATE.

UPPED THE LOW TEMPS FRO TONIGHT A DEGREE OR TWO BASED ON THE
AMOUNT OF CLOUD COVER EXPECTED TONIGHT.


&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
A PATTERN CHANGE WILL BEGIN ON SUNDAY ACROSS THE OHIO VALLEY.
SURFACE HIGH PRESSURE WILL BE CENTERED WELL EAST OF THE
REGION...AND THE AXIS OF A LOW-AMPLITUDE MID-LEVEL RIDGE WILL BE
SHIFTING GRADUALLY TO THE EAST AS WELL. THIS WILL SET UP A REGIME
OF DEEP SOUTHERLY FLOW BY SUNDAY NIGHT...ESPECIALLY ONCE THE
GRADIENTS BEGIN TO TIGHTEN IN ADVANCE OF THE TROUGHING MOVING
THROUGH THE PLAINS STATES. DURING THE DAY ON SUNDAY...THE IMPACTS
FROM THIS WILL BE RELATIVELY MINOR...WITH LITTLE TO NO CHANGE IN
SURFACE FLOW. HOWEVER...WITH TEMPERATURES BEGINNING TO WARM
ALOFT...SIGNIFICANT BREAKS IN THE CLOUDS ARE FINALLY EXPECTED TO
DEVELOP. WITH SUN...TEMPERATURES WILL BE ABLE TO RISE 5-8 DEGREES
FROM SATURDAY TO SUNDAY...ESPECIALLY IN THE SOUTHERN CWA (WHERE
CLOUDS SHOULD ERODE MORE QUICKLY).

AS MONDAY BEGINS...STRENGTHENING SSW 850MB WINDS WILL BEGIN TO
FEED MOISTURE INTO THE MIDDLE OHIO VALLEY. ON THE NOSE OF THE
MOISTURE PUSH...WEAK ISENTROPIC ASCENT WILL ALLOW FOR THE
POSSIBILITY OF SOME LIGHT SHOWERS. FOLLOWING PROBABILITY PLOTS
FROM THE 15Z SREF...IT APPEARS THAT ANYTHING THAT DEVELOPS WILL
MOVE NORTHEAST THROUGH THE CWA BETWEEN 12Z AND 21Z...AND WILL NOT
BE DIRECTLY ASSOCIATED WITH THE IMPENDING LARGE-SCALE ACTIVITY
STILL FAR OFF TO THE WEST. COMING OUT OF ANOTHER COOL OVERNIGHT
PERIOD...PRECIPITATION TYPE AT ONSET WOULD BE SOMEWHAT IN
QUESTION...BUT ANY AMOUNTS ARE EXPECTED TO BE VERY LIGHT.
ONLY A 20-PERCENT CHANCE WAS ADDED TO THE FORECAST.

A SUBSTANTIAL WARMING IS EXPECTED ON MONDAY...AS LOW-LEVEL FLOW
MAKES THE SWITCH TO THE SOUTH (SSW AT 850MB AND SSE AT THE
SURFACE). A SLIGHT UPWARD ADJUSTMENT WAS MADE FROM THE PREVIOUS
FORECAST...WITH LOWER 50S NOW EXPECTED IN THE FAR SOUTHERN CWA.

STRENGTHENING FLOW WILL KEEP TEMPERATURES FROM FALLING MUCH ON
MONDAY NIGHT...AND NON-DIURNAL TEMPERATURES WERE REQUIRED FOR THE
FORECAST GRIDS. WITH A SLOWING IN THE MODEL TRENDS FOR THE
PROGRESSION FOR THE NEXT SYSTEM...POPS WERE REDUCED FOR THE MONDAY
NIGHT PERIOD...WITH THE ONSET OF WIDESPREAD PRECIPITATION
APPEARING LIKELY TO HOLD OFF UNTIL TUESDAY.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
HAVE USED A BLEND OF THE 12Z ECMWF AND WPC GUIDANCE FOR THE LONG 
TERM FORECAST.  THE ECMWF IS FASTER...DEEPER...BUT MORE QUICK TO 
TAKE STRONG LOW PRESSURE FROM THE OHIO VALLEY REGION TUESDAY NIGHT 
TO SOUTHERN ONTARIO BY THURSDAY MORNING. THE GFS IS SLOWER...NOT AS 
DEEP...AND ROTATES MORE OF A SFC TROUGH THROUGH THE REGION ON 
THURSDAY/CHRISTMAS. THE ECMWF/WPC BLEND IS PREFERRED AT THIS TIME.

AN UPPER TROUGH IS FORECAST TO PIVOT AND BECOMES NEGATIVELY TILTED 
AS IT LIFTS THROUGH THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. 
THIS SCENARIO WILL EVENTUALLY PUSH SURFACE LOW PRESSURE AND COLD 
FRONT ACROSS THE FORECAST AREA. ABOVE NORMAL TEMPERATURES ARE 
EXPECTED AHEAD OF THE SYSTEM WITH TEMPERATURES COOLING OFF TOWARD 
MORE SEASONAL NORMALS IN CAA BEHIND THE COLD FRONT. 

IN TERMS OF PCPN CHANCES...THEY ARE EXPECTED TO STEADILY INCREASE AS 
FORCING GETS CLOSER/STRONGER BY TUESDAY NIGHT INTO WEDNESDAY 
MORNING. AM EXPECTING RAIN SHOWERS ACROSS THE ENTIRE AREA TUESDAY 
INTO TUESDAY NIGHT. COVERAGE WILL DECREASE SOME ON WEDNESDAY AS THE 
STRONGEST LIFT MOVES NORTHEAST. THERE IS SOME EVIDENCE THAT SOME 
EMBEDDED THUNDER MAY OCCUR WITH THIS SYSTEM...BUT HAVE DECIDED TO 
HOLD OFF THE MENTION ATTM. COLDER AIR COMING IN ON THE BACK SIDE OF 
THE SYSTEM WILL CAUSE A CHANGE OVER TO SOME SNOW SHOWERS LATER 
WEDNESDAY INTO WEDNESDAY NIGHT. SNOW SHOWERS WILL TAPER OFF BY 
THURSDAY MORNING/CHRISTMAS.  CONSIDERING THE WARMER AIR AHEAD OF THE 
SYSTEM AND TEMPERATURES BOTTOMING OUT MAINLY IN THE 30S BY THURSDAY 
MORNING...AM ONLY EXPECTING MINOR SNOW ACCUMULATIONS WITH THE SNOW 
SHOWER ACTIVITY. IT APPEARS THE BIGGEST IMPACT WITH THIS WEATHER 
SYSTEM WILL BE THE WIND. HOWEVER...WITH THE ECMWF SOLUTION...THE 
STRONGEST WINDS MAY REMAIN NORTH OF OUR AREA WEDNESDAY NIGHT.

RIDGING DEVELOPS RATHER QUICKLY LATE THURSDAY AND MOVES EAST
THURSDAY NIGHT. THIS WILL ALLOW FOR MODEST WARM AIR ADVECTION AHEAD 
OF THE NEXT LOW PRESSURE SYSTEM AND COLD FRONT THAT WILL APPROACH 
THE REGION ON FRIDAY. THE COLD FRONT WILL SLOWLY MOVE THROUGH THE 
AREA FRIDAY NIGHT AND SATURDAY. WILL CONTINUE WITH A CHANCE OF RAIN 
SHOWER AHEAD OF THE COLD FRONT WITH PERHAPS A BRIEF MIX WITH OR 
CHANGE OVER TO SOME SNOW SHOWERS BEFORE TAPERING OFF ON SATURDAY. 
TEMPERATURES WILL REBOUND AGAIN ON FRIDAY AND THEN COOL OFF TOWARD 
SEASONAL NORMALS BY SATURDAY.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
MVFR CLOUD DECK CONTINUES TO BLANKET THE REGION. A FEW HOLES HAVE
DEVELOPED IN IT FROM TIME TO TIME...BUT THEY HAVE FILLED BACK IN.

AS THE CENTER OF HIGH PRESSURE BEGINS TO SLIP EASTWARD LATE
TONIGHT...DRIER LOW LEVEL AIR FROM CENTRAL KY WILL WORK INTO THE
TRI-STATE. EXPECT THE CVG/LUK TAFS TO BE THE FIRST TO GO VFR...IN
THE 08-09Z TIME RANGE. AS SUNDAY PROGRESSES THE DRIER AIR WILL
GRADUALLY WORK NORTHWARD...ALLOWING KDAY TO EXPERIENCE THE VFR
CONDITIONS. IT IS LOOKING LIKE THE CENTRAL OHIO TAFS WILL BE THE
LAST PLACE THE DRIER AIR WORK IN...SO EXPECT THE MVFR CONDITIONS
TO LINGER PAST 18Z.

OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY
INTO THURSDAY...ALONG WITH WINDY CONDITIONS.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...HATZOS
NEAR TERM...SITES
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES






National Weather Service
Disclaimer Privacy Policy