000
FXUS63 KIWX 150816
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
416 AM EDT WED MAY 15 2013

.SYNOPSIS...
ISSUED AT 408 AM EDT WED MAY 15 2013

A COLD FRONT WILL DROP INTO THE REGION TODAY PROVIDING A CHANCE
OF SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT
SOUTH OF ROUTE 24 IN INDIANA AND OHIO. MAINLY DRY AND SLIGHTLY
COOLER WEATHER IS ANTICIPATED ON THURSDAY AND THURSDAY NIGHT AS
HIGH PRESSURE BUILDS INTO THE GREAT LAKES. THERE IS A LOW CHANCE
FOR PRECIPITATION FRIDAY INTO SATURDAY AS THE FRONTAL BOUNDARY
LIFTS BACK NORTH INTO THE REGION. THE THREAT FOR SHOWERS AND
THUNDERSTORMS WILL GRADUALLY INCREASE SUNDAY INTO EARLY NEXT WEEK
AS A LOW PRESSURE SYSTEM EJECTS INTO THE CENTRAL UNITED STATES.

&&

.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 06Z TAFS THROUGH 06Z WEDNESDAY MORNING)
ISSUED AT 220 AM EDT WED MAY 15 2013

VFR CONDS WILL CONT THROUGH THE VALID TAF PD. UPSTREAM CDFNT ACRS
ERN IA IN ASSOCN/W SW TROUGH PROGRESSING EWD THROUGH CNTRL ONTARIO
THIS MORNING WILL ACCELERATE EWD NR TERM.  TRAILING SRN PORTION OF
THIS BNDRY XPCD TO STALL OUT THROUGH CNTRL IL/IN THIS AFTN ALG NRN
TERMINUS OF MID LVL CONFLUENCE ZONE. HWVR THIS FTR XPCD TO SETTLE
FAR ENOUGH S TO PRECLUDE ANY ASSOCD WX AT EITHER TERMINAL THIS PD AS
POST FNTL FLW VEERS NWRLY AND STG LK SHADOWING COMMENCES THIS AFTN.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ043-046.

&&

$$

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


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