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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 122346
AFDILN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
746 PM EDT WED JUN 12 2013

.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM AND ASSOCIATED STRONG COLD FRONT WILL MOVE
THROUGH THE REGION LATE TONIGHT AND THURSDAY MORNING. STRONG TO
SEVERE STORMS WILL BE POSSIBLE AHEAD OF THIS COLD FRONT THIS
EVENING AND OVERNIGHT. HIGH PRESSURE WILL WORK INTO THE REGION
THURSDAY NIGHT...OFFERING COOLER TEMPERATURES AND DRY WEATHER.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
UPDATED FORECAST FOR LATEST TORNADO WATCH ISSUANCE FOR PARTS OF
CENTRAL OH. THIS WATCH WAS ISSUED EAST OF THE SEVERE THUNDERSTORM
WATCH FOR DISCRETE CELLS THAT ARE DEVELOPING AND MOVING SE. THIS
CONVECTION SEEMS TO BE DEVELOPING ALONG AND NEAR THE WARM FRONT.

UPDATED FORECAST FOR LATEST SEVERE THUNDERSTORM WATCH ISSUANCE.
MADE MINOR ADJUSTMENTS TO POPS AND TEMPERATURES UP TO 00Z.
CONVECTIVE SYSTEM WAS FORMING IN NORTHERN IL...WI...AND IA LATE
THIS AFTERNOON. EXPECT CONVECTIVE SYSTEM TO APPROACH WESTERN PARTS
OF FA IN THE 8 PM TO 9 PM TIME FRAME. THIS IS BASED ON A FORWARD
SPEED OF 45 KTS BASED ON 21Z ILN SOUNDING.


LATEST FORECAST BASED ON MORE PROGRESSIVE MODELS/UKMET
     GFS...NAM. A SIGNIFICANT SHORTWAVE IN NW FLOW ALOFT WILL DROP
SE FROM THE UPPER MS VLY INTO THE OH VALLEY BY THU MORNING. THE
ASSOCIATED SFC LOW PRESSURE TO DEEPEN AND TRACK ACROSS NRN INDIANA
AND OHIO TONIGHT. CAPE VALUES ON AVERAGE 4000 J/KG APPROACHING
AROUND 5000 J/KG IN THE SOUTH THIS AFTERNOON. SO FAR THIS
AFTERNOON THE CAP HAS INHIBITED DEEP CONVECTION ACROSS THE
SOUTHERN PART OF THE REGION. EXPECT CONVECTION TO DROP SE INTO
ILN`S COUNTIES. CONTINUED HIGH CHANCE POPS IN THE NORTH AND
BROUGHT CHANCE IN SOUTH FOR EARLY EVENING HOURS. THE PRIMARY
THREATS FROM THESE STORMS WILL BE DAMAGING WINDS AND LARGE HAIL
ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. IN ADDITION
SOME OF THE THUNDERSTORMS MAY PRODUCE SOME HEAVY RAINFALL.

EXPECT CAP TO WEAKEN IN RESPONSE TO MID-LEVEL COOLING AND
LIFT...AS UPSTREAM MID LEVEL S/W DIGS SOUTHEAST. EXPECT THUNDERSTORM
COMPLEX TO DROP SE ACRS IL AND INDIANA INTO ILNS FA OVERNIGHT.
INCREASED POPS TO CATEGORICAL OVERNIGHT. MIXED LAYER CAPES STILL
LOOK TO BE AROUND 2000 J/KG THIS EVENING WITH STRENGTHENING LOW
LEVEL JET INCREASING TO ABOUT 50 KTS. GIVEN STRONG DYNAMICS AND
INSTABILITY...SIGNIFICANT SEVERE WEATHER EVENT POSSIBLE WITH THE
BEST TIME BETWEEN 03Z AND 06Z. AN ORGANIZED CONVECTIVE SYSTEM
SHOULD DROP SE ACRS ILNS FA.

MODELS HAVE BEEN CONSISTENT IN SHOWING THE POTENTIAL FOR
WIDESPREAD DAMAGING WIND EVENT TONIGHT. EXPECT THE MAIN THREAT TO
BE DAMAGING WIND GUSTS. LARGE HAIL AND HEAVY RAIN WILL ALSO BE
POSSIBLE. GIVEN LOW LEVEL SHEAR...ISOLD TORNADOES WILL ALSO BE
POSSIBLE.

LOWS IN UPPER 60S TO LOWER 70S.

LOOKED AT POTENTIAL FOR FLOOD OR FLASH FLOOD WATCH BUT LOOKS TO BE
MARGINAL SITUATION AT THIS TIME. WITH PROGRESSIVE NATURE OF SYSTEM
DO NOT EXPECT TO SEE WIDESPREAD FLOODING OR FLASH FLOODING ISSUES. DECIDED
TO CONTINUE TO MONITOR TO SEE HOW SITUATION SETS UP.

WILL CONTINUE TO HIGHLIGHT SEVERE WEATHER THREATS AND HEAT IN
HWO. ILN IS PLANNING ON A 21Z SOUNDING TO ASSESS THE INSTABILITY
AND THE STRENGTH OF THE CAP.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE SEVERE WEATHER THREAT SHOULD END BY DAYTIME MORNING HOURS ON
THURSDAY. THUNDERSTORMS WILL END FROM WEST TO EAST THROUGH MIDDAY
THURSDAY. DRY CONDITIONS WILL RETURN TO THE FA AS HIGH PRESSURE
MOVES INTO THE REGION THURSDAY NIGHT. COOLER AIR WILL WORK INTO
THE FA ON THURSDAY AS A COLD FRONT MOVES THROUGH THE AREA. THE
HIGHS THURSDAY WILL BE IN THE 70S AND THE LOWS THURSDAY NIGHT WILL
BE IN THE 50S.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRING FAIR WEATHER WITH LIGHT WINDS AND
SEASONABLY COOL TEMPERATURES ACROSS THE AREA FRIDAY THROUGH
SATURDAY MORNING. WENT WITH A BIAS CORRECTED BLEND FOR
TEMPERATURES DURING THE FRIDAY AND FRIDAY NIGHT PERIODS.

THE LOW LEVEL RIDGE SHIFTS EAST OF THE REGION ON SATURDAY RESULTING
IN RETURN FLOW WITH INCREASING MOISTURE AND MEAN TEMPERATURES. MID
AND UPPER LEVEL FLOW WILL FLATTEN TO A ZONAL PATTERN SATURDAY NIGHT
THROUGH SUNDAY NIGHT AS AN UPPER TROUGH AND WEAK SURFACE LOW OVER
SOUTH CENTRAL CANADA DIGS SOUTHEAST TOWARD THE GREAT LAKES.
DISTURBANCES EMBEDDED IN THIS ZONAL FLOW WILL BRING PERIODIC CHANCES
FOR SHOWERS AND THUNDERSTORMS TO OUR REGION SATURDAY NIGHT THROUGH
SUNDAY NIGHT. NIGHTTIME TEMPERATURES DURING THIS TIME PERIOD WILL BE
MILD...WITH CLOUD COVER AND DEWPOINTS IN THE 60S EXPECTED TO BE
PRESENT.

BY MONDAY MODELS ARE INDICATING THE TROUGH AND SURFACE LOW OVER THE
GREAT LAKES WILL LIFT NORTHEASTWARD...WHICH WILL HELP TO DRAG A COLD
FRONT ACROSS OUR AREA. THIS WOULD RESULT IN UNSETTLED WEATHER ON
MONDAY INTO MONDAY EVENING...FOLLOWED BY A DRYING TREND MONDAY NIGHT
AND TUESDAY.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
TAF SITES WILL BE IMPACTED BY SEVERE THUNDERSTORMS TONIGHT AS
VIGOROUS LOW PRESSURE MOVES TO NORTHERN OHIO. A VERY HUMID AIRMASS
AND INCREASING WIND FIELDS WILL CONTRIBUTE TO THUNDERSTORM
FORMATION. THUNDERSTORMS CELLS MERGING INTO A LINE SHOULD REACH
TAF SITES FROM AROUND 04Z TO 07Z. WILL MONITOR RADAR AND UPSTREAM
OBS AND WILL INCREASE WIND GUSTS TO ABOVE THE 45 KNOTS CURRENTLY
IN THE FORECAST IF NECESSARY.

IFR VISIBILITIES AND MVFR CEILINGS ARE EXPECTED WITH THE
THUNDERSTORMS. ONCE THE THUNDERSTORMS MOVE EAST EARLY
THURSDAY...MVFR CEILINGS WILL PERSIST FOR A FEW HOURS NEAR A
TRAILING COLD FRONT BEFORE CEILINGS RISE AHEAD OF HIGH PRESSURE
AND DRIER AIR ARRIVING FROM THE NORTH.

OUTLOOK...ADDITIONAL THUNDERSTORMS POSSIBLE SUNDAY.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...PARKER
NEAR TERM...PARKER
SHORT TERM...PARKER
LONG TERM...LATTO
AVIATION...CONIGLIO