Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 042334
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
734 PM EDT WED MAY 4 2016

.SYNOPSIS...
ISSUED AT 335 PM EDT WED MAY 4 2016

SHOWERS WILL SPREAD ACROSS THE AREA OVERNIGHT AS A LOW PRESSURE
SYSTEM MOVES THROUGH THE REGION. TEMPERATURES WILL REMAIN IN THE LOW
40S TONIGHT. DRY CONDITIONS EXPECTED BY TOMORROW AND WILL PERSIST
THROUGH FRIDAY. HIGHS TOMORROW WILL GENERALLY BE IN THE LOW TO MID
60S BUT WILL BE COLDER NEAR LAKE MICHIGAN. WARMER CONDITIONS ON
FRIDAY BUT ANOTHER COLD FRONT WILL ARRIVE ON SATURDAY WITH ANOTHER
CHANCE FOR RAIN.

&&

.UPDATE...
ISSUED AT 723 PM EDT WED MAY 4 2016

BAND OF RAIN IN DEFORMATION ZONE CONTS TO MOVE SLOWLY SOUTH ACROSS
THE WRN PORTION OF THE CWA EARLY THIS EVE. MODELS SUGGEST THIS
BAND WILL GRDLY WEAKEN OVERNIGHT AS DRIER ADVECTS IN FROM THE NNE.
IN THE MEANTIME CATEGORICAL POPS IN ORDER FOR THIS AREA AT LEAST
THROUGH THE EVE. TEMPS HAVE FALLEN INTO THE UPR 30S/L40S ACROSS
WRN PORTIONS OF THE CWA... BUT SHOULDN`T FALL MUCH MORE OVERNIGHT
AS COLD POOL ALOFT SHIFTS SE OF THE AREA AND FAIRLY STRONG LOW
LEVEL MIXING CONTS.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 335 PM EDT WED MAY 4 2016

COMPACT AND ROBUST MIDLEVEL VORT MAX ON CYCLONICALLY SHEARED SIDE
OF 100+ KT UPPER JET IS CURRENTLY MOVING OVERHEAD. MOST OF THE
AREA CURRENTLY RESIDING IN DRY SLOT BUT MIDLEVEL DEFORMATION BAND
ON NORTHERN FLANK OF WAVE...ALREADY INTO OUR MICHIGAN
COUNTIES...WILL SWING THROUGH OUR CWA LATER THIS EVENING AND
OVERNIGHT. FORCING NOT AS STRONG AS THIS MORNING AND BETTER
MOISTURE/INSTABILITY HAS SHIFTED OUT OF THE AREA BUT STILL EXPECT
SCT/NUM SHOWERS WITH AROUND A TENTH OR SO OF ADDITIONAL QPF. BEST
CHANCES WILL BE IN OUR NORTH. PRECIP SHOULD EXIT BY TOMORROW
MORNING AS MIDLEVEL LOW CONTINUES TO PULL RAPIDLY SOUTHEAST. COLD
TEMPS ALOFT AND DECENT SURFACE HEATING COULD GENERATE A STRAY
CONVECTIVE SHOWER IN OUR EASTERN COUNTIES BUT STEADILY INCREASING
HEIGHTS/AVA AND DRY AIR ADVECTION WARRANT JUST A SILENT 10 POP AT
THIS TIME. DO EXPECT A HEALTHY CU FIELD TOMORROW THOUGH AND THAT
SHOULD LIMIT THERMAL RECOVERY SOMEWHAT. TOUGH HIGH TEMP FORECAST
IN OUR NORTHWEST GIVEN LINGERING MARINE INFLUENCE IN N/NW FLOW.
AREAS NEAR THE LAKE WILL LIKELY REMAIN UNDER INVERSION AND
STRUGGLE TO REACH THE LOW 50S WHILE MOST OF OUR AREA MIXES INTO
THE LOW/MID 60S. SOUTH BEND AREA RIGHT ON THE LINE ARE COULD BUST
IN EITHER DIRECTION.

TEMPS TONIGHT EXPECTED TO REMAIN IN THE LOW 40S GIVEN ABUNDANT
CLOUDS/PRECIP AND STRONG WINDS. MUCH BETTER RADIATIONAL COOLING
SETUP THURSDAY NIGHT AS SKIES CLEAR AND N/NW GRADIENT RELAXES.
CURRENT GUIDANCE SUGGESTS ENOUGH THERMAL MODIFICATION TO KEEP LOWS
AT OR ABOVE 40 SO FROST THREAT APPEARS LOW AT THIS POINT BUT WILL
KEEP AN EYE ON THIS PERIOD...ESPECIALLY FOR OUR FAR NORTHERN
ZONES.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 PM EDT WED MAY 4 2016

FRIDAY STILL SHAPING UP TO A BE NICE DAY. AVA FROM APPROACHING
RIDGE AXIS SHOULD MAINTAIN A DRY/SUBSIDENT ENVIRONMENT. LATE DAY
WAA AND NEARLY FULL SUN SHOULD PUSH HIGHS TO AROUND 70F FOR MOST
LOCATIONS WITH A LATE-DAY PUSH TO MID 70S IN OUR WESTERN COUNTIES.
GFS AND ECMWF STILL KICKING OUT SOME SPURIOUS CONVECTIVE QPF ON
LEADING EDGE OF THETA-E SURGE BUT CONDITIONS APPEAR UNFAVORABLE
FOR ANY PRECIP AND MAINTAINED DRY FORECAST. BETTER CHANCE FOR RAIN
WILL ARRIVE ON SATURDAY AS NEXT SHORTWAVE DIVES ACROSS THE GREAT
LAKES AND SENDS A COLD FRONT THROUGH OUR AREA. MODELS HAVE TRENDED
FASTER WITH THIS FRONTAL PASSAGE...SUGGESTING IT MAY BE KNOCKING
ON OUR DOORSTEP AT 12Z. THIS LIMITS PRECIP POTENTIAL SOMEWHAT.
BEST PV ADVECTION WILL BYPASS US TO THE NORTH AND PRECIP CHANCES
FOR THE OHIO VALLEY WILL DEPEND ON DIURNAL DESTABILIZATION TO
COMPENSATE. AN EARLY FRONTAL PASSAGE WILL LIMIT OUR PRECIP CHANCES
SOMEWHAT...THOUGH STILL WORTHY OF MID/HIGH RANGE CHANCE POPS...AND
WILL ALSO LIMIT POTENTIAL FOR ANY STRONG/SEVERE STORMS.

INCREASING CONFIDENCE FOR COOL AND DRY CONDITIONS ON SUNDAY AS
MODELS CONTINUE TO SUGGEST FRONT WILL CLEAR OUR AREA AND ALLOW WEAK
HIGH PRESSURE TO SETTLE SOUTH. EXPECT MOSTLY SUNNY SKIES WITH TEMPS
SLIGHTLY BELOW NORMAL...HIGHS GENERALLY MID TO UPPER 60S. CHANCE OF
RAIN RETURNS EARLY NEXT WEEK AS LARGE SOUTHWEST CONUS CUTOFF LOW
LIFTS NORTHEAST. FRONT WILL RETURN NORTHWARD THOUGH CONFIDENCE ON
TIMING REMAINS LOW AND STAYED CLOSE TO CONSENSUS POPS FOR NOW.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 723 PM EDT WED MAY 4 2016

BAND OF RAIN IN DEFORMATION ZONE TO NW OF MID LEVEL LOW MOVG SE
ACROSS THE AREA SHOULD CONT TO IMPACT SBN AT LEAST THROUGH THE EVE
WITH MVFR/IFR CONDITIONS. BULK OF THIS RAIN BAND SHOULD REMAIN
WEST OF FWA BUT LOW MVFR CIGS FAIRLY WIDESPREAD ACROSS THE AREA
AND EXPECTED TO CONT THROUGH EARLY THU. DRIER AIR SHOULD MOVE IN
FROM THE N-NE THU AS UPR LOW MOVES CONTS TO MOVE SE AWAY FROM THE
AREA ALLOWING CONDITIONS TO BECOME VFR THU MORNING AND CONT
THROUGH THE DAY... THOUGH SOME LOW VFR CIGS LIKELY, ESPECIALLY AT
FWA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT THURSDAY FOR LMZ043-
     046.

     GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LMZ043-046.

&&

$$

UPDATE...JT
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...AGD
AVIATION...JT


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