000
FXUS63 KIWX 150534
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
134 AM EDT SAT JUN 15 2013

.SYNOPSIS...
ISSUED AT 435 PM EDT FRI JUN 14 2013

HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT PROVIDING
NEAR NORMAL TEMPERATURES. A LOW PRESSURE FRONTAL SYSTEM CURRENTLY
OVER THE PLAINS WILL TRACK EASTWARD AND BRING RAIN CHANCES BACK TO
THE INDIANA SOUTHERN MICHIGAN AND NORTHWESTERN OHIO AREA BEGINNING
SATURDAY AND PERSISTING THROUGH SUNDAY. HIGH TEMPERATURES
SATURDAY AND SUNDAY WILL BE NEAR NORMAL AND THE LOWS WILL BE ABOVE
NORMAL.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 357 PM EDT FRI JUN 14 2013

AT MID AFTERNOON...A LAKE BREEZE WAS MOVING FARTHER INLAND...WITH
CLEARING OF THE CLOUD FIELD BEHIND THIS BOUNDARY. THE REST OF THE
DIURNAL CUMULUS SHOULD DISSIPATE THIS EVENING...WITH SKIES BECOMING
CLEAR AS THE SFC RIDGE AXIS MOVES OVERHEAD. CONCERN FOR SOME PATCHY
GROUND FOG BY DAYBREAK AS LOW TEMPERATURES NEAR THE CROSS OVER
TEMPERATURE. FOR NOW...KEPT FOG OUT OF GRIDS/FCST GIVEN THE LOCAL
AND EPHEMERAL NATURE OF THE FOG. OTHERWISE...MOISTURE RETURN
INCREASES SATURDAY AHEAD OF THE APPROACHING SHORTWAVE. BETTER THETA
E ADVECTION SATURDAY NIGHT. HAVE RETAINED A CHANCE FOR THUNDERSTORMS
SATURDAY...ALTHOUGH BULK SHEAR AND AFTERNOON CAPE VALUES DO NOT
SUPPORT SEVERE STORMS. OTHERWISE PREFERRED THE COOLER MAV LOWS
TONIGHT WITH A FAIRLY SHARP RADIATIONAL INVERSION FORMING. HIGHS
SATURDAY SHOULD BE ABLE TO TOP 80 DEGREES OVER THE SOUTHEAST HALF OF
THE AREA...SO CONTINUE TO PREFER THE WARMER MAV MOS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 357 PM EDT FRI JUN 14 2013

MAIN FOCUS IN LONG TERM ON ACTIVE WEATHER SATURDAY NIGHT INTO MONDAY
BEFORE QUIET WEATHER RETURNS FOR TUES-END OF WEEK.

EXPECT SHOWERS AND THUNDERSTORMS TO BE ONGOING BY BEGINNING OF
PERIOD IN THE WEST AND INCREASE IN COVERAGE AS SHORTWAVE MOVES
ACROSS AREA. LOW LEVEL MOISTURE TRANSPORT WILL RAMP UP FROM THE WSW
ON NOSE OF LLJ WITH FAIRLY HIGH PWAT VALUES THAT COULD BRING ANOTHER
SHOT OF DECENT RAINFALL TO THE AREA. THIS MAY EXACERBATE ONGOING
HYRDO ISSUES AS MANY AREAS STILL HAVE STANDING WATER/ELEVATED STREAM
FLOWS FROM WEDS RAINFALL. AS HAS BEEN MENTIONED BY PREVIOUS
SHIFTS...SEVERE THREAT REMAINS LOW. INSTABILITY WILL BE WEAK AND
MAINLY ELEVATED WITH BEST PARAMETERS TO THE WEST OF CWA. LL SHEAR
WILL ALSO BE MARGINAL. PRECIP WILL BEGIN TO TAPER OFF SUNDAY AS
SHORTWAVE AND BEST MOISTURE EXITS. SUSPECT SUNDAY AFTN INTO
OVERNIGHT HOURS MAY BE DRY WITH NO REAL FORCING AND LACK OF MOISTURE
FOR ADDNL CONVECTION. THEREFORE HAVE KNOCKED POPS DOWN IN THAT
TIMEFRAME AND FURTHER ADJUSTMENTS MAY BE NEEDED IN THE FUTURE AS
CONVECTIVE DETAILS BECOME MORE CLEAR.

MODEL SPREAD BEGINS TO GROW A BIT BY THE END OF THE WEEKEND. GFS
CONTINUES TO BE RATHER INCONSISTENT FROM RUN TO RUN AND IS A LITTLE
ROBUST IN HANDLING SHORTWAVE DROPPING SE INTO AREA ON MONDAY. HAVE
TRENDED TOWARD MORE CONSISTENT ECMWF/GEM BLEND WHICH RESULTS IN NO
MAJOR CHANGES TO POPS PAST SUNDAY NIGHT. COLD FRONT AND NORTHERN
STREAM SHORTWAVE PROGGED TO MOVE THRU ON MONDAY. THIS WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS DURING THE DAY ON MONDAY AND
CONTINUING INTO THE EVENING HOURS WHEN PRECIP TAPERS OFF FROM WEST
TO EAST AS COLD FRONT DEPARTS. HIGH PRESSURE THEN BUILDS IN BEHIND
FRONT ON TUESDAY AND ONLY SLOWLY MOVES OFF TO THE EAST BY THE END OF
THE PERIOD. THIS WILL BRING DRY WEATHER WITH NEAR NORMAL
TEMPERATURES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 134 AM EDT SAT JUN 15 2013

SURFACE HIGH PRESSURE WILL SHIFT EAST TODAY...ALLOWING LOW LEVEL
WARM/MOIST AIR ADVECTION TO INCREASE OVER THE REGION. THE CHANCE
FOR SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THE END OF THE
TAF PERIOD AS THIS THETA-E ADVECTION COMBINES WITH WEAK ASCENT
FROM PASSING MIDLEVEL WAVE. MCS CURRENTLY OVER IOWA IS EXPECTED TO
WEAKEN AS IT MOVES INTO INCREASINGLY DRY/STABLE AIRMASS OVER THE
GREAT LAKES BUT A FEW REMNANT SHOWERS ARE POSSIBLE AT KSBN LATER
THIS AFTERNOON BEFORE MORE SUBSTANTIAL FORCED ASCENT SPREADS OVER
THE AREA LATE TONIGHT. CONDITIONS WILL REMAIN LARGELY VFR THOUGH
WITH ONLY BRIEF REDUCTIONS POSSIBLE IN PASSING CONVECTION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...SKIPPER
LONG TERM...CEO
AVIATION...AGD


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA