000
FXUS61 KILN 222021
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
421 PM EDT WED MAY 22 2013

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO LIFT NORTHEAST ALONG A FRONTAL
BOUNDARY THIS EVENING...BEFORE A WEAK COLD FRONT SWINGS INTO
THE REGION OVERNIGHT. A SECONDARY FRONT WILL BRING A CHANCE OF
RAIN AGAIN ON THURSDAY. MUCH COOLER AIR WILL MOVE INTO THE REGION
ON FRIDAY... AS HIGH PRESSURE BUILDS INTO THE OHIO VALLEY THROUGH
SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
RADAR CONTINUES TO SHOW SCT CONVECTIVE ACTIVITY OVER THE FA. WHILE
THE BEST INSTABILITY IS IN THE SE...THE BETTER FORCING IS ACROSS
THE W...DUE TO LIFT FROM AN UPPER LEVEL S/W AND SFC FRONT. THIS
DISJOINTEDNESS SHOULD ACT TO LIMIT THE OVERALL COVERAGE OF THE
CONVECTION THIS EVENING AND INTO TONIGHT. SO HAVE GONE WITH 40-50
POPS FOR THE NEXT FEW HOURS AND WENT WITH SCATTERED WORDING. WITH
THE LOSS OF DAYTIME...WE SHOULD SEE A DECREASE IN ACTIVITY...BUT
WITH THE FRONT ENTERING THE REGION CANT TOTALLY RULE SOMETHING
OUT LATER IN THE NIGHT.

LOWS SHOULD FALL BACK INTO THE UPPER 50S IN THE WEST...WITH EASTERN
LOCATIONS STAYING IN THE LOWER 60S.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
INITIAL FRONT KIND OF WASHES OUT EARLY THURSDAY...BUT A SECONDARY
FRONT DROPS IN BEHIND IT. IN ADDITION...A PRETTY SHARP H5 TROF
SWINGS UP THE OHIO VALLEY. THIS SHOULD PROVIDE THE BEST LIFT OF
THIS SYSTEM. INSTABILITY WILL BE VERY WEAK...BUT JUST
ENOUGH FOR SOME RISK OF THUNDER. THE AIR MASS ALOFT WILL BE
INCREASINGLY COLD...HELPING TO LEAD TO THE POSSIBILITY OF
CONVECTIVE SHOWERS. SO UPPED POPS ON THU. WENT CATEGORICAL IN THE
NW...LIKELY POPS FOR A MUCH OF THE REST OF THE FA.

CONVECTION WILL LINGER INTO THU EVENING AS THE S/W CONTINUES TO
SWING THROUGH. HIGH PRESSURE WILL BUILD IN FOR FRIDAY. COULD SEE
SOME FAIR WX CU AS COLD AIR ALOFT KICKS THE LAPSE RATES OVER.
SKIES SHOULD THEN CLEAR FOR FRIDAY NIGHT.

HIGHS ON THURSDAY WILL HAVE A WIDE RANGE. THIS IS DUE TO THE COLD
FRONT PUSHING THRU THE REGION. HIGHS IN THE NW WILL BE LIMITED TO
THE UPPER 60S...WHILE IN THE SE THEY WILL PUSH INTO THE MID 70S.
LOWS WILL FALL PACK INTO THE 40S THURSDAY NIGHT AND ONLY WILL
REBOUND INTO THE LOWER TO MID 60S.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LARGE AREA OF HIGH PRESSURE WILL HOLD SWAY OVER THE OHIO VALLEY AND
GREAT LAKES REGION FOR THE WEEKEND. PREVIOUS MODELS WERE SHOWING A
NARROW TONGUE OF QPF/POPS PUSHING SOUTHEAST FROM THE IA/IL AREA BUT
WERE KEYING ON A H5 S/W CUTTING THROUGH THE ESTABLISHED RIDGE AND
DISSIPATING AS IT WENT DOWNSTREAM INTO THE OHIO VALLEY. THIS
SCENARIO IS STILL A POSSIBILITY BUT SEEN AS A DISTANT OUTLIER AT
THIS TIME.

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 /20Z WEDNESDAY THROUGH MONDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING
THE EARLY PART OF THE TAF PERIOD. THERE IS LOW CONFIDENCE WHEN/IF
STORMS MAY AFFECT THE TERMINALS. SO FOR THE INITIAL ISSUANCE HAVE
KEPT A VCTS IN FOR THE PERIOD OF HIGHER PROBABILITY. OUTSIDE OF
ANY STORMS CONDITIONS WILL REMAIN VFR THIS AFTERNOON AND WELL INTO
THE NIGHT. GUSTY SOUTH WINDS WILL DIMINISH AROUND 00Z AND SLOWLY
VEER. APPEARS THAT MVFR CEILINGS MAY DEVELOP REGION WIDE LATE
TONIGHT ALTHOUGH CONFIDENCE IS ONLY MODERATE IN THIS OCCURRING.
CLOUDS SHOULD LIFT TO VFR AT MOST PLACES LATE IN THE TAF PERIOD.
WINDS WILL CONTINUE TO VEER ON THURSDAY.

OUTLOOK...MVFR CEILINGS LIKELY LATE THURSDAY INTO THURSDAY NIGHT.

&&

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

&&

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