000
FXUS63 KIWX 251038
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
638 AM EDT SAT MAY 25 2013

.SYNOPSIS...
ISSUED AT 401 AM EDT SAT MAY 25 2013

HIGH PRESSURE OVER THE GREAT LAKES AND OHIO VALLEY WILL REMAIN
NEARLY STATIONARY OVER THE NEXT 24 HOURS PROVIDING GENERALLY DRY
CONDITIONS ACROSS THE AREA. HOWEVER... A FEW SHOWERS FORMING NEAR A
WARM FRONT MOVING SLOWLY NORTH THROUGH THE PLAINS MAY MAKE IT AS FAR
EAST AS INDIANA BEFORE DISSIPATING TODAY AND TONIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 452 AM EDT SAT MAY 25 2013

RIDGING ALOFT OVER THE PLAINS AND AT THE SFC ACROSS THE GRTLKS/OH
VALLEY SHOULD MOVE LITTLE OVER THE NEXT 24HRS AS DEEPENING LOW
OVER THE NERN U.S. OCCLUDES AND BECOMES VERTICALLY STACKED.
CONVECTION WHICH DEVELOPED IN LOW LEVEL THETA-E ADVECTION ZONE
WEST OF THE SFC/H85 RIDGE OVER THE DAKS YDAY WAS MOVG E-SE TOWARD
OUR AREA THIS MORNING BUT AS IT ENCOUNTERS DRY LOW LEVELS AND
OUTRUNS ITS FORCING SHOULD CONT TO WEAKEN. STILL... CANT RULE OUT
A FEW LIGHT SHOWERS MAKING IT INTO SWRN PORTION OF THE CWA TODAY
AS SUGGESTED BY MANY OF THE LATEST MODEL SOLUTIONS. SIMILAR
SCENARIO EXPECTED TONIGHT AS CONVECTION AGAIN LIKELY WILL DVLP IN
THE LOW LEVEL THETA-E ADVECTION ZONE AND MOVE E-SE IN W-NW FLOW
ALOFT UPSTREAM TOWARD OUR CWA... THUS CONTD THE LOW POPS ACROSS
THE SWRN PORTION OF THE CWA THROUGH THE 2ND PERIOD. OTRWS A
GRADUAL TRANSITION FROM MOSTLY CLOUDY TO MOSTLY CLEAR SKIES FROM
SW-NE ACROSS THE CWA EXPECTED OVER THE NEXT 24HRS.

TEMPS ALOFT HOLDING STEADY AS RIDGE REMAINS OVER THE AREA. CLOUD
COVER MAY LIMIT RISES TODAY... MAINLY SW. EXPECT HIGHS IN THE
L-M60S... COOLER NEAR THE LAKE... THOUGH WEAKER NW FLOW ALOFT SHOULD
ALLOW FOR A WARMUP INTO THE M50S THERE BEFORE LAKE BREEZE KICKS IN
TODAY. MORE CLOUDS TONIGHT SHOULD LIMIT RADIATIONAL COOLING...
EXPECT LOWS TO RANGE FROM AROUND 40 NE TO AROUND 50 SW.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 452 AM EDT SAT MAY 25 2013

AN UPPER LEVEL RIDGE WILL GRADUALLY AMPLIFY OVER THE OHIO VALLEY AND
WESTERN GREAT LAKES REGIONS EARLY NEXT WEEK. NCEP...ECMWF AND
CANADIAN GEM SHOWING A WIDE VARIETY OF SOLUTIONS HANDLING THE SHORT
WAVE ENERGY TOPPING THE RIDGE AND THE SUBSEQUENT TIMING AND
DEVELOPMENT AND COVERAGE OF SHOWERS/THUNDERSTORMS. THE GFS 00Z RUN
APPEARS TO BE AN OUTLIER AMONG SEVERAL EARLIER RUNS...WITH THE
LATEST RUN SURPRISING CUTTING SHOWER/STORM CHANCES SIGNIFICANTLY
THROUGH TUESDAY. HOWEVER...THE ECMWF HAS TRENDED GRADUALLY NORTH AND
MORE ACTIVE WITH THE SHOWER DEVELOPMENT ALONG THE LOW LEVEL THETA E
CONVERGENCE AREA. THEREFORE...FAVOR THE ECMWF. HAVE MADE SOME
SIGNIFICANT FORECAST CHANGES REGARDING THE ARRIVAL OF THE SHOWERS
INCLUDING RAISING RAIN CHANCES OVER SW AREAS SUNDAY AFTERNOON AND
ALSO RAISING RAIN CHANCES LATE SUNDAY NIGHT AND EARLY MONDAY. VERY
LIMITED CAPE SHOULD PRECLUDE STORMS FROM BECOMING SEVERE.
OTHERWISE...ANY SHOWERS OR STORMS SHOULD END BY LATE TUESDAY NIGHT
AS THE BEST FORCING SHIFTS FARTHER NORTH. KEPT HIGHS WARM/IN THE 80S
WEDNESDAY THROUGH SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM EDT SAT MAY 25 2013

VFR CONDITIONS WILL CONTINUE ACROSS THE AREA THROUGH THE
TAF PERIOD. LOW LEVEL THETA-E ADVECTION WEST OF RIDGE WAS
SUSTAINING SHRA MOVG ACROSS NRN IL...HWVR DRY LOW LEVELS AND SLOW
MOVG RIDGE OVER NRN INDIANA SHOULD RESULT IN JUST AN INCREASE AND
LOWERING OF HIGH/MID CLOUDS TODAY/TNGT. LIGHT NW WINDS WILL BECOME
E-NE TONIGHT AS RIDGE MOVES INTO OH AND A WARM FRONT MOVES INTO
THE MID MS/LWR OH VALLEYS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FROST ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR
     INZ003>009-012-014-016.

MI...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ077>081.

OH...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR OHZ001-002-004-
     005.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT


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