-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 231747
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
147 PM EDT THU MAY 23 2013

.SYNOPSIS...
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A COLD FRONT WILL PUSH ACROSS THE REGION THIS AFTERNOON AND EARLY
EVENING WITH A SECONDARY FRONT MOVING THROUGH TONIGHT. HIGH
PRESSURE WILL THEN BUILD IN THROUGH SATURDAY.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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SHOWERS CONTINUE TO INCREASE IN COVERAGE AS A COLD FRONT
APPROACHES THE NORTHWEST CORNER OF THE FORECAST AREA. THE FRONT
WILL PUSH EAST SOUTHEAST ACROSS THE REGION THROUGH THE AFTERNOON
INTO THE EARLY EVENING. SHOWERS WILL CONTINUE TO OCCUR OUT AHEAD
OF THIS. COULD GET SOME THUNDERSTORMS AS WELL ESPECIALLY AS THIS
MOVES EAST WHERE THERE IS A BIT MORE INSTABILITY. TEMPERATURES ARE
ALREADY AT OR NEAR DAYTIME HIGHS. EXPECT READINGS TO START DROPPING
OFF IN THE NORTHWEST BEFORE THE AFTERNOON IS OVER.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SUBSIDENCE WILL BEGIN IN EARNEST BEHIND THE COLD FRONT ON THURSDAY
NIGHT...WITH A SWITCH TO NORTHERLY WINDS ALLOWING FOR COLD
ADVECTION TO BEGIN AT THE SURFACE. THE MIN TEMP FORECAST BRINGS
THE ENTIRE CWA INTO THE LOWER TO MID 40S...WITH TEMPERATURES NEAR
40 (OR EVEN AROUND 38-39) IN THE FAR NORTHERN COUNTIES.

SURFACE HIGH PRESSURE SHOULD BE CENTERED OVER THE REGION ON
FRIDAY...AND THIS AIR MASS APPEARS QUITE DRY. 850MB TEMPS WILL
ALSO BE AT THEIR COLDEST ON FRIDAY...LEADING TO A RATHER COOL MAX
TEMP FORECAST THAT KEEPS THE ENTIRE CWA IN THE LOWER TO MIDDLE
60S.

ALTHOUGH THE SURFACE WILL STILL BE IN AN AREA OF HIGH PRESSURE BY
FRIDAY NIGHT...THE UPPER FLOW WILL SWITCH TO THE
NORTHWEST. THE SURFACE HIGH IS FORECAST TO WEAKEN BY
SATURDAY...BUT THE IMPACT OF UPSTREAM MOISTURE ALOFT LOOKS
SOMEWHAT UNCERTAIN. SOME MODELS CONTINUE TO ALLOW FOR A NARROW
STRIP OF QPF BY SATURDAY AFTERNOON AND EVENING...MAINLY IN THE SW
CWA...BUT THIS WOULD HAVE TO FALL THROUGH A VERY DRY AIR MASS IN
THE LOWEST SEVERAL HUNDRED MB. IN FACT...AT THE TIME OF
PRECIPITATION...GFS SOUNDINGS SHOW CLOUD BASES OF AT LEAST 7000
FEET. KEEPING THE FORECAST DRY APPEARS THE BETTER OPTION FOR
NOW...WITH THE SURFACE HIGH AND DRY AIR ARGUING AGAINST MUCH OF AN
IMPACT FROM WHATEVER MAY BE COMING IN ON THE NORTHWEST FLOW.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
GFS IS STILL SHOWING THESE H5 DISTURBANCES UNDERCUTTING THE RIDGE
AND NOSING INTO THE REGION MON/TUES WHERE EUROPEAN IS SOMEWHAT
SIMILAR WITH AN ELEVATED CONVERGENT LAYER BUT MUCH FURTHER
SOUTHWEST AND OUT OF CWA.

SURFACE HIGH MOVES OFFSHORE EARLY NEXT WEEK WITH DRYING SOUTHEAST
SURFACE WINDS OVER THE OHIO VALLEY. UPPER LEVEL FLOW IS SHOWING A
BROADENING OF THE H5 RIDGE AS IT MOVES OVER THE EASTERN THIRD OF THE
COUNTRY. HAVE INCREASED THE CHANCES FOR MID LEVEL DISTURBANCES TO
UNDERCUT THE RIDGE AT THIS TIME BUT KEEP THE THREAT FOR SHOWERS LOW
AT 20% TOWARDS THE MIDDLE OF NEXT WEEK.

EXPECT A GRADUAL WARMUP EACH DAY...STARTING IN THE UPPER 60S TO
AROUND 70 SATURDAY...WARMING TO NEAR 80/LOW 80S BY WED. PM LOWS WILL
BE COMFORTABLY COOL IN THE 40S THROUGH MON MORNING UNDER A DRY
AIRMASS AND THEN WARM TO THE CLIMATOLOGICAL NORMS IN THE MID 50S BY
MID WEEK.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
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A COLD FRONT WILL MOVE ACROSS THE TERMINALS DURING THE EARLY PART
OF THE TAF PERIOD. SHOWERS WILL OCCUR OUT AHEAD OF THE FRONT. BUT
OUTSIDE OF HEAVIER DOWNPOURS EXPECT CONDITIONS TO STAY VFR. AFTER
THE FRONT PASSES THE CEILINGS WILL DROP TO MVFR AND THERE WILL BE
SOME GUSTY WEST NORTHWEST WINDS. A SECONDARY TROUGH WILL FOLLOW
SEVERAL HOURS AFTER THE INITIAL FRONT. THIS WILL CAUSE WINDS TO
VEER FURTHER AND CEILINGS WILL LIKELY DROP BELOW 2000 FT. DRIER
AIR WILL PUSH ACROSS THE REGION AFTER 06Z WHICH WILL ALLOW
CONDITIONS TO RETURN TO VFR. SKIES WILL BE CLEAR WITH NORTH WINDS
LATE IN THE TAF PERIOD.

OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...