Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 310022
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
822 PM EDT MON MAR 30 2015

.SYNOPSIS...
ISSUED AT 340 PM EDT MON MAR 30 2015

LOW PRESSURE MOVING THROUGH THE GREAT LAKES WILL SPREAD LIGHT RAIN
TO AREAS NORTH OF HIGHWAY 30 OVERNIGHT WITH LOWS IN THE UPPER 30S
TO LOWER 40S. DRY CONDITIONS WILL RETURN TOMORROW WITH HIGHS
GENERALLY IN THE 50S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM EDT MON MAR 30 2015

UPPER LEVEL JET STREAK WILL TRANSITION INTO THE GREAT LAKES
TONIGHT AND SEND A STRENGTHENING MIDLEVEL VORT MAX THROUGH THE
REGION. TIGHT BAROCLINIC ZONE IS ALREADY IN PLACE OVER THE GREAT
LAKES AND THIS WAVE WILL INCITE A GOOD 850MB FRONTOGENETIC
RESPONSE...ESPECIALLY GIVEN REDUCED STABILITY ABOVE THIS LAYER.
TRACK IS NOT FAVORABLE FOR MOST OF OUR CWA THOUGH. ACTIVE FRONTAL
ZONE WILL BE DRAPED ACROSS CENTRAL MICHIGAN AND ONLY CLIPS OUR FAR
NORTHEAST COUNTIES. STILL SOME DISAGREEMENT AMONG LATEST NWP WITH
RESPECT TO EXACT TRACK AND THIS WILL HAVE A LARGE EFFECT ON HOW
MUCH OF OUR CWA SEES PRECIP GIVEN VERY SHARP CUTOFF TO FORCED
ASCENT. KEPT OVERALL SPIRIT OF PREVIOUS FORECAST BUT DID INCREASE
POPS OVER OUR NORTHEAST HALF BASED ON LATEST HI-RES GUIDANCE.
AREAS SOUTH OF US-30 MAY REMAIN COMPLETELY DRY. FORECAST SOUNDINGS
SHOW LOWEST 2 KFT IS WARM ENOUGH TO SUPPORT AN ENTIRELY RAIN
EVENT IN AREAS THAT DO SEE PRECIP. NOT IMPOSSIBLE THAT OUR FAR
NORTHEAST COULD SEE A BRIEF MIX DUE TO WET BULB EFFECTS BUT
CHANCES AND IMPACTS ARE TOO LOW FOR INCLUSION IN THE FORECAST.
RAIN SHOULD EXIT BY TOMORROW MORNING WITH DRIER AIR RETURNING TO
THE REGION.

LOWS TONIGHT WILL PROBABLY STAY ON THE WARM SIDE GIVEN INCREASING
SOUTHWEST GRADIENT WITH PASSING SURFACE LOW. NUDGED INHERITED
FORECAST UP JUST A BIT. HIGHS TOMORROW WILL BE SLIGHTLY COOLER THAN
TODAY GIVEN BRIEF RETURN TO NNW FLOW/CAA. DECENT MIXING DEPTHS UNDER
INCREASING SUN WILL AT LEAST PARTIALLY OFFSET CAA THOUGH AND HIGHS
IN OUR SOUTHWEST COULD STILL REACH THE UPPER 50S.


&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM EDT MON MAR 30 2015

TRANSITION TO A MORE BONA-FIDE SPRING PATTN XPCD THIS PD W/LONGER
TERM SUGGESTIONS OF GENERAL WKNG OF NEG HGT ANOMALIES UP ACRS ERN
CANADA AND MORE TROUGHING ACRS THE WRN US BOTH OF WHICH HAVE BEEN
LAGGING FOR SVRL MONTHS.

BEGINNING OF PD LOOKS STELLAR W/SIG LL THERMAL MODERATION AHD OF
POTENT NRN STREAM SW SWEEPING THROUGH SRN CANADA. SWWD TRAILING FNTL
BNDRY ASSOCD/W THIS SYS LOOKS ACTIVE THU AFTN TIMED W/NWD REACH OF
LL GOMEX MSTR RTN AND PERHAPS SOME RISK FOR THUNDER. HWVR WILL AWAIT
LTR GUIDANCE AS FNTL TIMING MAY BE POOR W/LIMITED SFC BASED
DESTABILIZATION AND EXTENT OF NWD MOISTENING.

TAIL END OF UPR LVL DISTURBANCE EJECTS EWD FRI W/SFC WAVE XPCD TO
DVLP INVOF THE OH RVR VALLEY. NWD REACH OF POTENTIAL OVERRUNNING
PCPN SHIELD ASSOCD/W THIS SYS STILL QUITE UNCERTAIN AND KEPT
W/SUBDUED N-S POP GRADIENT.

UNSETTLED PATTN LOOKS TO INCREASE THROUGH NXT WEEK W/TEMPS
MODERATING TO AOA NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 805 PM EDT MON MAR 30 2015

WESTERLY LOW LEVEL FLOW WILL INCREASE THIS EVENING IN ADVANCE OF
A CLIPPER SYSTEM THAT WILL DROP INTO THE GREAT LAKES REGION. LOW
LEVEL WARM FRONT PUSHING ACROSS SOUTHERN LOWER MICHIGAN/FAR
NORTHERN INDIANA WILL CONTINUE TO LEAD TO SOME LIGHT RAIN AT KSBN
OVER THE NEXT FEW HOURS. THE CHANCE OF RAIN WILL DECREASE AFTER
03Z AS LOW LEVEL FRONT SURGES EASTWARD. WILL MAINTAIN DRY
CONDITIONS AT KFWA WHERE LOW LEVEL DEW POINT DEPRESSIONS ARE
EXPECTED TO REMAIN MORE SUBSTANTIAL. HAVE ALSO MADE NO CHANGE TO
PREVIOUS LLWS MENTION DUE TO AFOREMENTIONED 50 KNOT WESTERLY FLOW
AT 2K FT PRECEDING THE CLIPPER. A BRIEF WINDOW MAY
EXIST...ESPECIALLY AT KSBN...FOR HIGHER END MVFR CIGS WITH PASSAGE
OF SFC WAVE TUESDAY MORNING. WINDS SHOULD BACK SOUTHWEST IN
ADVANCE OF APPROACHING SFC WAVE THIS EVENING...AND THEN VEER
NORTHWEST FOR TUESDAY BEHIND THIS WAVE WITH SPEEDS OF 10 TO 15 KNOTS.

&&

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

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...MARSILI


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