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000
FXUS63 KIWX 151732
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
132 PM EDT WED MAY 15 2013

.SYNOPSIS...
ISSUED AT 1118 AM EDT WED MAY 15 2013

A FRONTAL BOUNDARY WILL MOVE SLOWLY SOUTH THROUGH THE REGION INTO
TONIGHT...STALLING OUT OVER CENTRAL INDIANA AND OHIO. SHOWERS AND
A FEW THUNDERSTORMS WILL BE POSSIBLE SOUTH OF ROUTE 24 IN INDIANA
AND OHIO INTO THIS EVENING. DRIER AND SLIGHTLY COOLER AIR WILL
ARRIVE NORTH OF THE FRONT AND LINGER INTO FRIDAY. THE FRONT IS
EXPECTED TO BUCKLE BACK NORTHWARD THIS WEEKEND WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING.

&&

.UPDATE...
ISSUED AT 1118 AM EDT WED MAY 15 2013

UPDATED GRIDS/ZONES TO REFLECT RADAR/CLOUD TRENDS AND WELL AS
TEMPS.

BAND OF LIGHT SHOWERS/VIRGA WAS SLOWLY DRIFTING SOUTH ROUGHLY FROM
MONTICELLO TO FT WAYNE TO OTTAWA OHIO. OVERALL COVERAGE HAS BEEN
SLOWLY DECREASING ALONG THE EASTERN FLANK OF THE FRONT WITH SOME
INCREASE IN COVERAGE NOTED TO THE WEST AS A SMALL CLUSTER OF
SHOWERS/ISOL THUNDER WAS MOVING TOWARDS THE SW CORNER OF THE AREA.
AHEAD OF THE FRONT TEMPS HAVE MANAGED TO CLIMB INTO THE MID TO
UPPER 70S WITH LOCALLY STRONGER WINDS MIXING DOWN IN THE 25 TO 30
MPH RANGE. CLOUD COVER IMMEDIATELY ALONG THE FRONT HAS ALLOWED FOR
SLIGHTLY COOLER TEMPS BUT MOST LOCATIONS HAVE BEEN RECOVERING NORTH
OF THE CLOUD COVER WITH HILLSDALE ALREADY INTO THE UPR 70S. LOWER
DEWPTS WERE WORKING IN ACROSS THE NE WITH A SLOW SOUTHWARD TREND
EXPECTED INTO TONIGHT. OVERALL HIGHS TODAY STILL APPEAR
ACHIEVABLE...ALTHOUGH MID 80S COULD BE A STRETCH IN FAR SE AREAS
IF CLOUD COVER LINGERS MORE THAN A FEW HOURS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EDT WED MAY 15 2013

VIGOROUS RISE FALL COUPLET ASSOCD/W UPSTREAM CDFNT TRAILING SWWD FM
PARENT UPR TROUGH ACRS CNTRL ONTARIO WILL MAKE FOR A BREEZY PD THIS
MORNING BFR DIMINISHING THIS AFTN AS SHALLOW POST FNTL CAA WING TUCKS
SWD. HWVR WARM START WITHIN RESIDUAL LL THERMAL RIDGE AND STG MIXING
WILL ALLOW FOR ANOTHER WELL ABV NORMAL DAY WRT TEMPS SANS BERRIEN
COUNTY/NRN LAPORTE WHERE LANDBREEZE WILL BE ACCENTUATED EARLY IN
POST FNTL REGIME.

OTRWS GENERAL LL MSTR RTN AHD OF THIS SYS HAS BEEN POOR AS SEEN IN
00Z RAOBS AND SEE LTL REASON TO HOLD W/PRIOR FAR SRN CWA BOUND POPS
THIS AFTN/OVERNIGHT. THUS IN LIGHT OF BULK OF 00Z MODEL GUIDANCE
DVLPG SHRA/TSRA WELL SWD THROUGH DOWNSTATE IN/IL WILL ADJUST PRIOR
POPS SHARPLY DOWNWARD. SCT HIGH BASE SHRA W/CLD BASES AOA 150 KFT
OVR NE IL MAY YET YIELD A SPRINKLE ACRS N HALF PRIOR TO 14Z BUT
ISOLD AT BEST AND NOT WORRY OF INCLUSION TO START.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 408 AM EDT WED MAY 15 2013

WEAK ANTICYCLONIC FLOW ACROSS THE GREAT LAKES WITH FRONTAL BOUNDARY
FORCED SOUTH OF THE AREA SHOULD RESULT IN MAINLY DRY WX AND SLIGHTLY
COOLER TEMPS (YET STILL ABOVE NORMAL) BY THURSDAY AND FRIDAY. DID
OPT TO HANG ONTO LOW CHC POPS FOR CONVECTION IN OUR FAR SOUTHWEST
DURING THESE PERIODS WITH THETA-E/INSTABILITY GRADIENT NEAR.

AMPLIFICATION IN THE LONGWAVE PATTERN IS EXPECTED THIS WEEKEND AS A
WESTERN CONUS UPPER TROUGH EJECTS INTO THE PLAINS. THIS WILL ALLOW
AN UPPER LEVEL RIDGE TO AMPLIFY INTO THE GREAT LAKES REGION.
EXPECTING MAINLY DRY WX AND WARMING TEMPS UNDER THIS FEATURE BUT
CANNOT COMPLETELY RULE OUT A PERIOD OF RAIN/THUNDER IN ANY ONE
PERIOD GIVEN BROAD/WEAK ISENTROPIC ASCENT OVER THE NORTHEASTWARD
MIXING DIFFUSE SFC BOUNDARY...AND LOW PROBABILITY OF A CONVECTIVELY
ENHANCED SHORTWAVE BREAKING THROUGH THE RIDGE INTO THE LOCAL AREA.
BEST CHANCES FOR THIS APPEARS TO BE SATURDAY WITH CAPPED WARM SECTOR
POTENTIALLY BUILDING IN BY SUNDAY.

DEEPER GULF MOISTURE LOOKS TO GET ADVECTED NORTH EARLY NEXT WEEK
AS A NEGATIVE HEIGHT ANOMALY/DEEP LOW EMERGES OVER THE
CORNBELT/UPPER MIDWEST. INCREASING CHANCES FOR CONVECTION WILL
RESULT AS SHORTWAVES ROTATE THROUGH THE SOUTHERN/EASTERN FRINGE OF
THIS CIRCULATION AMID INCREASING INSTABILITY/FLOW.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 131 PM EDT WED MAY 15 2013

FRONTAL BOUNDARY WAS LOCATED VCNTY OF KFWA AS OF 17Z. EXPECTING A
SLOW SOUTHWARD TREND OVER THE NEXT COUPLE OF HOURS WITH WINDS
EVENTUALLY BECOMING NW. NW FLOW AND LOWER DEWPTS HAS ARRIVED AT KSBN
WITH LITTLE OVERALL WX EXPECTED AS MAIN FOCUS REMAINS SOUTH OF THE
AIRPORT. AT KFWA...CAN RULE OUT A STRAY HIGH BASED SHOWERS THROUGH
THE REMAINDER OF THE AFTERNOON...BUT NO SIG IMPACT ON OPERATIONS.
WINDS WILL DECOUPLE TONIGHT AND BECOME VARIABLE AS FRONT STALLS TO
THE SOUTH OF THE AREA. ANY PRECIP TONIGHT INTO THURS SHOULD REMAIN
ACROSS CNTRL INDIANA.

&&

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

$$

UPDATE...FISHER
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...FISHER


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