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000
FXUS63 KIWX 300548
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
148 AM EDT WED JUL 30 2014

.SYNOPSIS...
ISSUED AT 143 AM EDT WED JUL 30 2014

A STRONG LOW PRESSURE SYSTEM OVER SOUTHEASTERN CANADA WILL RESULT IN
CONTINUED COOL WEATHER IN OUR AREA WITH SCATTERED...PRIMARILY AFTERNOON
SHOWERS AND THUNDERSTORMS THROUGH THE NEXT FEW DAYS. LOWS TONIGHT
WILL BE IN THE LOWER AND MIDDLE 50S WITH HIGHS ON WEDNESDAY IN THE
MID 70S.

&&

.UPDATE...
ISSUED AT 815 PM EDT TUE JUL 29 2014

WEAK MID/UPPER LEVEL TROUGH WILL CONTINUE TO TRACK ACROSS
SOUTHEAST HALF OF THE AREA EARLY THIS EVENING. BULK OF SHOWERS AND
ISOLATED THUNDERSTORMS HAVE EXITED THE AREA IN ASSOCIATION WITH
THIS SHORT WAVE. ANOTHER PROGRESSIVE...LOW AMPLITUDE MID LEVEL TROUGH
CURRENTLY WORKING ACROSS CENTRAL WISCONSIN WILL TRACK INTO THE
SOUTHERN GREAT LAKES LATE THIS EVENING. WHILE INSTABILITY WILL BE
WANING...WEAK FORCING FROM THIS WAVE AND ADDITIONAL UPDRAFT
GENERATION ALONG COMPOSITE OUTFLOW FROM ONGOING CONVECTION...SHOULD BE
ENOUGH TO SUSTAIN SOME SHOWERS INTO AT LEAST NORTHWEST THIRD OF
THE AREA LATE EVENING INTO THE OVERNIGHT. HAVE ADDED SOME POPS
ACROSS THE NORTH LATER THIS EVENING INTO THE OVERNIGHT...AND MAY
NEED TO EXTEND POPS FURTHER SOUTHEAST IF UPSTREAM TRENDS PERSIST.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM EDT TUE JUL 29 2014

FIRST DISTURBANCE MOVED THROUGH THIS MORNING WITH JUST SOME MID
CLOUDS. IN ITS WAKE...SUNSHINE HAS ALLOWED TEMPS TO QUICKLY JUMP
INTO THE LOWER 70S WITH THE EXCEPTION OF ALONG THE LAKE WHERE LAKE
SHADOW WAS ALREADY INLAND. BAND OF WIDELY SCT SHOWERS AND STORMS
RAPIDLY DEVELOPED AND WILL DRIFT SE OVER THE NEXT COUPLE OF HOURS
BEFORE DISSIPATING EARLY EVENING. MAIN THREAT WILL BE BRIEF HEAVY
RAIN...WIND GUSTS TO 40 MPH AND SMALL HAIL ALTHOUGH THE STRONGER
CELLS COULD SEE BORDERLINE ISOLATED NEAR SEVERE HAIL. SKIES WILL
BECOME MOSTLY CLEAR BY MID EVENING. COOLER NIGHT STILL ON TAP BUT
NOT AS BAD AS LAST WITH TEMPS IN THE LOW 50S EAST AND NORTH TO MID
50S WEST/SOUTH.

ANOTHER DISTURBANCE/WEAK SFC FRONT WILL MOVE INTO THE AREA WEDNESDAY
AFTERNOON. PRIOR TO ITS ARRIVAL TEMPS SHOULD BE ABLE TO CLIMB INTO
THE LOW TO MID 70S EXCEPT AGAIN ALONG THE LAKE SHORE AREAS WHICH
WILL MAKE A RUN AT 70 AND THEN HOLD STEADY OR FALL A BIT WITH LAKE
BREEZE. HAVE HELD WITH GENERAL IDEA OF POPS WITH SOMEWHAT BETTER
CONDITIONS IN PLACE FOR SHOWER DEVELOPMENT. GIVEN HOW THINGS HAVE
WORKED OUT TODAY AND BETTER SETUP TOMORROW HAVE INCREASED POPS
SOMEWHAT...BUT STILL IN CHC CATEGORY WITH HIGHEST EAST GIVEN BEST
TIMING IN THE EAST IN AFTERNOON.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 PM EDT TUE JUL 29 2014

HIGH PRESSURE OVER THE NRN PLAINS WILL BUILD EAST INTO THE UPR
GRTLKS BY THU AS DEEP OCCLUDING LOW OVER SERN CANADA GRDLY WEAKENS.
ASSOCIATED UPR LOW OVER JAMES BAY WILL ALSO FILL IN THIS TIME FRAME
BUT A LINGERING TROF/COOL POOL ALOFT IS EXPECTED TO PERSIST
SOUTHWARD ACROSS THE GRTLKS/OH VALLEY INTO THE WEEKEND. THIS MAY
PROVIDE SUFFICIENT DIURNAL INSTABILITY FOR ISOLD/SCT AFTN
SHOWERS/TSTMS IN OUR AREA LATE THIS WEEK. UPR TROF EXPECTED TO MOVE
EAST OF THE AREA ON SUNDAY WITH RIDGING ALOFT BUILDING IN ON
MONDAY RESULTING IN DRY CONDITIONS WITH TEMPS WARMING BACK UP TO
NEAR NORMAL FOR EARLY AUG. ANOTHER SHRTWV EXPECTED TO TOP STRONG
WRN NORTH AMERICA RIDGE OVER THE WEEKEND AND MOVE TO SE CANADA ON
TUE. LATEST MEDIUM RANGE MODELS DISAGREE ON AMOUNT AMPLIFICATION
ASSOCIATED WITH THIS SYSTEM AND SUBSEQUENT SOUTHWARD PUSH OF SFC
CDFNT. LEANED TOWARD WEAKER GFS WHICH SUGGESTS MAINLY DRY
CONDITIONS IN OUR AREA AS WK CDFNT STAYS TO THE NORTH DURING THE
DAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 146 AM EDT WED JUL 30 2014

PRIMARILY VFR MET CONDITIONS THROUGH THE FORECAST PERIOD. LIGHT
PRIOR RAINFALL INVOF KFWA ALONG WITH BASIN DRAINAGE WITH ADDITIVE
MOISTURE VIA EVAPOTRANSPIRATIVE CROPS HAS ALLOWED SURFACE
DEWPOINT OR UPPER 50S/NEAR 60 TO POOL INTO UPPER WABASH/MAUMEE
BASINS...AND COULD YIELD MVFR VSBSY NEAR DAYBREAK.
OTHERWISE...SIMILAR SCENARIO AS SEEN YDAY WITH MID TROPOSPHERIC
COLD POOL REMAINING FROM NORTH OF LAKE SUPERIOR INTO NWRN OH WITH
SOLD/SCT CONVECTION POTENTIAL INCREASING BY MIDDAY...AND HAVE
ADDED VCSH TO KFWA 16-23 UTC. SUFFICIENT INLAND SCOUR DOWNWIND OF
LAKE MICHIGAN SHOULD PRECLUDE OCCURRENCE AT KSBN.

&&

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

$$

UPDATE...MARSILI
SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...MURPHY


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