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 240623
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
223 AM EDT THU JUL 24 2014

.SYNOPSIS...
A COLD FRONT SHIFTING SOUTHEAST THROUGH THE OHIO VALLEY THIS
AFTERNOON WILL CONTINUE TO BRING A THREAT FOR SHOWERS AND A FEW
THUNDERSTORMS ALONG AND AHEAD OF IT...MAINLY NEAR AND SOUTH OF THE
OHIO RIVER TONIGHT...BEFORE COOL AND DRY HIGH PRESSURE BUILDS IN
FOR THURSDAY. THIS FEATURE WILL PROMISE SEVERAL DAYS OF
COMFORTABLE HUMIDITY AND BELOW NORMAL TEMPERATURES BEFORE LOW
PRESSURE AND A DEVELOPING WARM FRONT APPROACH AND PASS THROUGH THE
AREA SATURDAY AND SUNDAY...WITH A RETURN OF A WARM AND HUMID
AIRMASS...AND THE THREAT FOR SHOWERS AND THUNDERSTORMS. ONCE THIS
SYSTEM PASSES...YET ANOTHER PLUNGE OF COOLER AIR WILL RETURN TO
THE OHIO VALLEY FOR THE FIRST PART NEXT WEEK...WITH BELOW NORMAL
TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OBJECTIVE MESOANALYSIS AT 23.19Z INDICATES THAT OUTFLOW FROM
DECAYING MCS FROM THIS MORNING HAD PUSHED THROUGH MOST IF NOT ALL
OF THE WFO ILN FORECAST AREA...WITH WNWLY FLOW AT MOST SITES. THIS
HAS SCOURED DEEPER INSTABILITY OUT OF THE AREA...THOUGH THE COLD
FRONT AT 18Z WAS STILL ANALYZED FROM NEAR CINCINNATI TO JUST SOUTH
OF COLUMBUS. BOUNDARY LAYER MOISTURE LAGGED A BIT BEHIND THE
FRONT...BUT DEW POINTS IN NORTHERN INDIANA/OHIO WERE FALLING INTO
THE LOWER 60S ON SLIGHTLY STRONGER NORTHERLY FLOW. THE BEST
SURFACE-BASED INSTBY AT 19Z RESIDED SOUTH OF THE OHIO RIVER WHERE
MLCAPE FROM 1000 TO 1500 J/KG REMAINED. HOWEVER...OBSERVATION-
DERIVED SHEAR VALUES IN THIS MODEST INSTBY REGION WERE WEAK...WITH
0-6KM BULK SHEAR < 20 KTS...AND VERY WEAK LOW LEVEL FLOW.
THUS...THINK THE SEVERE THREAT IS PRETTY NEGLIGIBLE GIVEN THE
PRESENCE OF MID/UPPER LEVEL CIRRUS THAT CONTINUES TO TEMPER THE
HEATING POTENTIAL...AND INABILITY FOR ANY RENEWED CONVECTIVE
DEVELOPMENT /CNTL INDIANA/ TO MAINTAIN ITSELF. WITH A COUPLE OF
VERY WEAK RIPPLES OF LOW PRESSURE POTENTIALLY DEVELOPING ALONG
FRONT /ONE ALREADY ANALYZED NEAR CVG AND ANOTHER IN SERN
MO/...WILL HANG ONTO RAIN CHANCES IN THE EVENING MAINLY
ALONG/SOUTH OF THE OHIO RIVER WHERE THE ADVANCING COLD FRONT AND
ANY OF THESE WEAK RIPPLES MAY INDUCE A FEW UPDRAFTS OR SHOWER
AREAS THROUGH THE NIGHT. THIS IS SUPPORTED BY DECENT HEIGHT FALLS
THROUGH THE NIGHT AND A MORE FAVORABLE MID/UPPER LEVEL JET
DEVELOPMENT OVER THE UPPER GREAT LAKES AS THE NIGHT WEARS
ON...SUGGESTING AT LEAST A LITTLE REDEVELOPMENT IS POSSIBLE THIS
EVENING OR OVERNIGHT IN NRN KY/SCNTL OH NEAR OR BEHIND THE FRONT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A COOL/DRY THURSDAY IS EXPECTED AS HIGH PRESSURE BUILDS IN FROM
THE NORTH. 925MB TEMPS DURING PEAK HEATING AROUND 16C WILL SUPPORT
MAINLY TEMPS IN THE 70S DURING THE DAY WITH LIGHT NELY FLOW AS
HIGH PRESSURE WILL BE SITUATED OVER WESTERN ILLINOIS. PWAT WILL
DROP SIGNIFICANTLY THROUGH THE DAY TO 0.60" OR SO...AND SHOULD SEE
A MIX OF CLOUDS AND SUN WITH AFTERNOON CUMULUS. SURFACE DEWPOINTS
SHOULD MIX OUT/FALL INTO THE LOWER-MID 50S DURING THE AFTERNOON.

THIS SETS UP ANOTHER COOL NIGHT /FOR LATE JULY STANDARDS/ ACROSS
THE AREA WITH WIDESPREAD LOWER/MID 50S ON THURSDAY NIGHT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AT 12Z FRIDAY...SURFACE HIGH PRESSURE WILL BE CENTERED DIRECTLY OVER 
THE OHIO VALLEY...FULLY ENCOMPASSING THE ILN CWA WITH A FAIRLY DRY 
AIR MASS. VERY TRANQUIL CONDITIONS ARE EXPECTED FOR FRIDAY...WITH 
MAX TEMPS FORECAST WITHIN A FEW DEGREES OF 80.

ONE LARGE MID-LEVEL TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL 
BEGIN TO MOVE AWAY BY FRIDAY NIGHT...AS THE PATTERN BEGINS TO 
FLATTEN ACROSS THE OHIO VALLEY FOR MOST OF THE WEEKEND. THIS WILL 
ACTUALLY PUT THE REGION MORE INTO THE STRONGER FLOW ALOFT...BRINGING 
THE POSSIBILITY FOR CONVECTIVE SYSTEMS TO MOVE EAST OR SOUTHEAST 
THROUGH THE AREA. THERE REMAINS SOME UNCERTAINTY IN TIMING OF THESE 
SMALLER FEATURES THROUGH THE WEEKEND...PRECLUDING USING HIGHER POPS 
IN THE FORECAST QUITE YET. SEVERAL MODELS ALLOW FOR SOME LIGHT QPF 
TO MOVE INTO THE REGION FRIDAY NIGHT...THOUGH RH VALUES IN THE LOW 
LEVELS ARE NOT VERY HIGH. THIS SUGGESTS PERHAPS SOME SPRINKLES OR 
DISSIPATING SHOWERS AS WARM ADVECTION BEGINS OVER THE REGION...WITH 
A SHARP INCREASE IN THETA-E NOTED ALOFT...AND GENERALLY MOVING 
WNW-TO-ESE. FORCING ON SATURDAY APPEARS NEBULOUS...SO POPS HAVE BEEN 
KEPT IN THE LOW CHANCE CATEGORY...THOUGH THE AIR MASS WILL BECOME 
HOT AND HUMID.

ON SUNDAY...A MORE PRONOUNCED FRONT WILL BE MOVING EASTWARD THROUGH 
THE REGION. BOTH THE GFS AND ECMWF HAVE CONSISTENTLY DEVELOPED ONE 
OR SEVERAL CONVECTIVE COMPLEXES TO THE WEST OF THE ILN CWA ON 
SATURDAY NIGHT...DRIVING THEM THROUGH THE REGION IN THE WESTERLY 
FLOW...WITH FAIRLY WET CONDITIONS EXPECTED THROUGH THE DAY. POPS FOR 
SUNDAY HAVE BEEN INCREASED SLIGHTLY AS A RESULT OF THIS 
CONFIDENCE...AND IT IS LIKELY THAT CHANCES WILL HAVE TO BE INCREASED 
FURTHER AS SOON AS THE EXACT TIMING OF THE CONVECTION BECOMES MORE 
CERTAIN.

A RATHER SHARP UPPER TROUGH WILL BE MOVING SOUTH THROUGH THE GREAT 
LAKES ON SUNDAY AND INTO MONDAY...DRIVING THE AFOREMENTIONED COLD 
FRONT...AND A SURFACE LOW THROUGH SOUTHERN MICHIGAN. THIS TROUGH 
WILL ESTABLISH ITSELF RATHER ROBUSTLY ACROSS THE EASTERN HALF OF THE 
COUNTRY...IN A WELL-ADVERTISED PATTERN SHIFT TOWARD ANOTHER ROUND OF 
BELOW-NORMAL TEMPERATURES. 12Z GFS/ECMWF PROJECTIONS SHOW THE 
COOLEST AIR OVER THE OHIO VALLEY AT 12Z TUESDAY MORNING. 

PRECIPITATION CHANCES SEEM MORE LIKELY ON MONDAY RATHER THAN LATER 
IN THE WEEK...THOUGH STILL ON THE LOWER END OF THE SCALE (AND LIKELY 
DIURNALLY DRIVEN).

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
COLD FRONT HAS PUSHED SOUTH OF THE OHIO RIVER. WAVE OF LOW PRESSURE
TRAVELING ALONG THIS FRONT IN NRN KY HAS SLOWED ITS PROGRESSION
BUT ALL LINGERING PRECIPITATION SHUD REMAIN SHOULD OF THE TAF SITES.
THIS FRONT WILL PUSH SOUTH TODAY WITH HIGH PRESSURE BUILDING INTO
THE REGION. LINGERING MVFR CIGS AT THE SRN TAF SITES WILL GIVE WAY
TO A PERIOD OF VFR CIGS BETWEEN 3500 AND 5000 FEET. THESE CIGS
WILL PARTIALLY CLEAR THE TAF SITES EARLY THIS MORNING. IN LOW
LEVEL CAA PATTERN EXPECT A GOOD DEAL OF CUMULUS DEVELOPMENT TODAY.
FCST SOUNDINGS BACK THIS UP WITH MOISTURE INDICATED BETWEEN 4000
AND 5000 FEET. WILL ALLOW FOR VFR THESE CIGS INTO THE LATE AFTN
WITH CLEARING THIS EVENING AS THE SFC HIGH BUILD IN.

NORTHEAST WINDS AROUND 10 KTS WILL PREVAIL THRU THE DAY BEFORE
BECOMING LIGHT THIS EVENING.

OUTLOOK...THUNDERSTORMS POSSIBLE SATURDAY AND SUNDAY.

&&

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

&&

$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...HATZOS
AVIATION...AR






National Weather Service
Disclaimer Privacy Policy