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000
FXUS63 KIWX 160811
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
411 AM EDT THU MAY 16 2013

.SYNOPSIS...
ISSUED AT 359 AM EDT THU MAY 16 2013

DRY CONDITIONS ARE EXPECTED TODAY INTO FRIDAY MORNING AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES FORCING A FRONTAL BOUNDARY
SOUTH INTO CENTRAL INDIANA. THIS FRONT IS EXPECTED TO BUCKLE BACK
NORTH LATER FRIDAY INTO THE WEEKEND WITH A LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS MAINLY SOUTH OF ROUTE 30 IN INDIANA AND MICHIGAN
EACH DAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED LATE THIS WEEK
INTO THIS WEEKEND. CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
EARLY NEXT WEEK AS A STORM SYSTEM APPROACHES FROM THE WEST.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

STALLED SFC TROUGH JUST SOUTH OF CWA HAD CONVECTIVELY
ACTIVATED LT LAST EVE FM SE NE EWD INTO CNTRL OH AND XPC A CONTD NR
TERM SWD PUSH IN RESPONSE TO BOTH AUGMENTED CONV OUTFLW AND CANADIAN
SFC RIDGING BLDG SEWD ACRS THE LAKES.

LTL DRIVING IMPEDES GOING FWD FOR ADDNL ACTIVITY ACRS SRN PORTION OF
CWA AFT DAYBREAK AS BNDRY REMAINS HUNG UP ACRS CNTRL IL/IN. HWVR NRN
TERMINUS OF SUFFICIENT LL THETA-E GRADIENT REMAINS JUST CLOSE ENOUGH TO
HOLD W/ISOLD MENTION EXTREME SRN IN COUNTIES THIS AFTN TIMED
W/BRIEF/WK FNTL SCALE CIRC DURING PK HEATING.

OTRWS VERY DRY MONTH SO FAR YIELDING A GROWING POS FEEDBACK LOOP IN
DIURNAL TEMP TRENDS AND THUS ADJUSTED MAXES HIGHER/MINS LOWER.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU MAY 16 2013

MID LEVEL CIRCULATION DEPICTED NICELY ON MORNING WATER VAPOR IN
COLORADO WILL PROPAGATE EAST-NORTHEAST INTO THE UPPER MIDWEST AND
WESTERN GREAT LAKES FRIDAY INTO FRIDAY NIGHT. WEAK/BROAD ISENTROPIC
UPGLIDE IN ADVANCE OF THIS FEATURES WILL HELP FORCE/MIX A CENTRAL
IN/IL QUASI STATIONARY BOUNDARY BACK NORTH INTO THE SOUTHWEST
PORTION OF THE IWX CWA BY FRIDAY AFTERNOON/NIGHT. MODEST
DESTABILIZATION INVOF THE FRONTAL BOUNDARY MAY SUPPORT ISO/SCT
SURFACE BASED CONVECTION FRI AFTN/EVE HERE WHILE A FEW
SHOWERS/SPRINKLES ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE MAY
SURVIVE INTO THE REST OF THE FA OVER DRY SUB CLOUD WEDGE. ONLY LOW
CHANCE POPS WARRANTED AS DEEPER MOISTURE/FORCING WITH AN OKLAHOMA
CONVECTIVELY ENHANCED WAVE TRACKS SOUTH OF THE FA INTO THE OH/TN
VALLEYS WITH GRADUAL HEIGHT RISES LOCALLY.

BUCKLING OF THE UPPER LEVEL FLOW IS ANTICIPATED OVER THE WEEKEND AS
STRONG PACIFIC JET ENERGY CARVES OUT A FORMIDABLE UPPER TROUGH
ACROSS THE INTERMOUNTAIN WEST AND HIGH PLAINS. THIS AMPLIFICATION
WILL ALLOW AN UPPER RIDGE TO BUILD INTO THE MIDWEST/GREAT LAKES WITH
MAINLY DRY/WARMER CONDITIONS ANTICIPATED. CANNOT RULE OUT ISO/SCT
AFTERNOON CONVECTION ON SATURDAY WITH INCREASINGLY DIFFUSE SFC
BOUNDARY STILL IN THE VICINITY AND MODEST INSTABILITY. LOWERED POPS
ON SUNDAY AS CAPPING LIKELY LIMITS VERTICAL GROWTH UNDER MID LVL
RIDGE AXIS.

THE DEEP LAYERED TROUGH ENTERING THE PLAINS ON SUNDAY WILL EVOLVE
INTO A CLOSED LOW ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
MONDAY INTO TUESDAY AS HIGH LATITUDE BLOCK SETS UP OVER CENTRAL
CANADA. 00Z MODEL SUITE CONTINUED TO SLOW THIS SYSTEM WITH MONDAY
NOW LOOKING DRIER/WARMER WITH CAPPED RIDGE POSSIBLY HOLDING ON FOR
ONE MORE DAY. SYSTEM FILLS EASTWARD TUESDAY INTO WEDNESDAY WHICH
WILL BRING INCREASING CHANCES FOR SHOWERS/STORMS (POSSIBLY STRONG TO
SEVERE) TO THE AREA AS A FRONTAL BOUNDARY NEARS AND SHORTWAVES
ROTATE THROUGH AMID INCREASING INSTABILITY/FLOW.

TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
ONLY MADE MINOR TWEAK TO LOWS STAYING CLOSE TO THE 00Z MODEL
CONSENSUS INITIALIZATION. BUMPED UP HIGHS EACH DAY...GENERALLY ABOVE
CLIMO/GFS BIASED CONSENSUS BLEND...ESPECIALLY SUNDAY THROUGH TUESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 350 AM EDT THU MAY 16 2013

VFR CONDS THROUGH THE PD. SFC RIDGING BLDG SEWD OUT OF
CANADA ACRS THE GREAT LAKES THIS PD WILL KEEP STALLED SFC TROUGH AND
ASSOCD CONVN AT BAY SOUTH OF THE TERMINALS.


&&

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

$$

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


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