Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 261830
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
230 PM EDT SUN APR 26 2015

.SYNOPSIS...
ISSUED AT 535 AM EDT SUN APR 26 2015

A RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD ACROSS THE REGION
EARLY THIS WEEK...WITH COOL AND DRY AIR SPREADING OVER THE AREA.
SOME CLOUDS WILL DEVELOP LATER THIS MORNING AND LINGER OVER EAST
AREAS THIS AFTERNOON. HIGHS TODAY WILL BE MAINLY IN THE 50S. LOWS
TONIGHT AND MONDAY NIGHT WILL BE MAINLY IN THE 30S WITH FROST
POSSIBLE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 419 AM EDT SUN APR 26 2015

A RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD ACROSS THE REGION WITH
COOL AND DRY AIR SPREADING OVER THE AREA. THERE SHOULD BE ENOUGH
MOISTURE TRAPPED UNDER THE BASE OF A WEAK SUBSIDENCE INVERSION TO
ALLOW CLOUDS TO DEVELOP LATER TODAY WITH DAYTIME HEATING AND
MIXING... ESPECIALLY OVER EAST AREAS. OTHERWISE...WITH DAYTIME
HEATING AND MIXING...WINDS WILL PICK UP SOME THIS MORNING WITH GUSTS
REACHING UP TO 20 MPH. WINDS SHOULD DECOUPLE TONIGHT AND BECOME
LIGHT. ADDED PATCHY FROST OVER WEST AREAS WHERE SKIES SHOULD BE
CLEAR TO MOSTLY CLEAR. TEMPERATURES SHOULD FALL TO WITHIN 1 TO 2
DEGREES OF FREEZING OVER FAR SOUTHWEST LOWER MICHIGAN INT NORTHWEST
INDIANA. OPTED TO HOLD OFF ON THE ISSUANCE OF A FROST ADVISORY FOR
NOW GIVEN MORE MARGINAL CONDITIONS AND GIVEN TEMPERATURES WERE DOWN
INTO THE 20S ON 2 OF THE PAST 3 NIGHTS.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 419 AM EDT SUN APR 26 2015

TROF ROTATING AROUND DEEP LOW OFF THE NEW ENGLAND COAST IS EXPECTED
TO MOVE ACROSS OUR AREA MONDAY. SOME LOW LEVEL INSTABILITY SHOULD
SUPPORT PARTLY-MOSTLY CLOUDY SKIES... ESPECIALLY ERN PORTIONS OF THE
CWA... BUT MOISTURE EXPECTED TO BE LACKING FOR ANY SHOWERS. TEMPS
SHOULD MIX OUT INTO THE M50S... EXCEPT ONLY IN THE M-U40S NEAR LAKE
MICHIGAN WITH ONSHORE FLOW. SOME STRATO CU MAY PERSIST MONDAY
NIGHT... ESPECIALLY OVER ERN PORTIONS OF THE AREA WHERE LOW LEVEL
FLOW WILL BE A LITTLE MORE CYCLONIC. WITH BETTER RADIATIONAL COOLING
NW AND A COOL START TO THE NIGHT... EXPECT PATCHY FROST OVERNIGHT NW
WITH MINS IN THE L30S... RANGING TO AROUND 40 SE. WK UPR RIDGE
EXPECTED TO BUILD INTO THE AREA TUE PROVIDING CONTD FAIR WX WITH
SLIGHTLY WARMER TEMPS.

MEDIUM RANGE MODELS CONT TO SUGGEST UPR LOW OVER SWRN CONUS TODAY
WILL MOVE EAST TO KY/TN BY WED AND MERGE WITH SECOND SYSTEM DROPPING
S-SE FROM CENTRAL CANADA FORMING A FAIRLY DEEP TROF OVER THE ERN
CONUS THU. STILL SGFNT DIFFERENCES IN TIMING/EVOLUTION OF THIS TROF
BUT DECENT AGREEMENT THAT BEST MOISTURE/FORCING WILL BE E-SE OF OUR
CWA SO MAINTAINED JUST SLIGHT CHC OF SHOWERS IN THIS TIMEFRAME. CAA
ASSOCIATED WITH THE LOW DROPPING S-SE FROM CANADA SHOULD RESULT IN
TEMPS REMAINING A BIT BLO NORMAL WED-THU.

UPR RIDGE EXPECTED TO BUILD INTO THE GRTLKS FRIDAY AS ERN CONUS TROF
MOVES TO THE WRN ATLANTIC. THIS SHOULD PROVIDE FAIR WX WITH HIGHS A
BIT ABOVE NORMAL IN THE U60S. WARMUP SHOULD CONT SATURDAY AS A
SHRTWV MOVES EAST FROM THE NRN PLAINS INTO THE UPR MIDWEST/GRTLKS.
SOME TIMING/STRENGTH DIFFERENCES IN THE MODELS WRT THIS SYSTEM...
BUT APPEARS WORTHY OF LEAVING LOW SUPERBLEND POPS AND ADDING SLIGHT
CHC OF -RW TO FCST FOR FRI NGT-SAT TO NRN PORTIONS OF THE CWA.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 158 PM EDT SUN APR 26 2015

A SERIES OF VORT LOBES ROTATING AROUND SOUTHEAST CANADIAN UPPER
TROUGH WILL BRING SOME STRATOCU TO PORTIONS OF NORTHEAST INDIANA
TONIGHT INTO EARLY MONDAY. AFTER DIURNAL VFR CU THIS
AFTERNOON...ATTENTION WILL SHIFT TO STRONGER VORT MAX DROPPING OUT
OF SOUTHERN ONTARIO FOR MONDAY MORNING. MVFR ARE A CIGS LATER
MONDAY MORNING TOWARD THE END OF THIS FORECAST VALID PERIOD...BUT
WILL HOLD WITH VFR CONDITIONS FOR THE 18Z TAFS. IN TERMS OF
WINDS...LAKE ENHANCEMENT HAS LED TO NORTH-NORTHWEST WINDS GUSTING
TO 15-20 KNOTS AT KSBN WITH MIXED LAYER SUPPORTING GUSTS TO AROUND
15 KNOTS ELSEWHERE. WINDS WILL DIMINISH EARLY EVENING...BUT
MODERATE GRADIENT OVERNIGHT SHOULD MAINTAIN WINDS OF 5 TO 10 KNOTS
THROUGH TONIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

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


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