Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 311558
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1158 AM EDT MON AUG 31 2015

.SYNOPSIS...
ISSUED AT 1152 AM EDT MON AUG 31 2015

HIGH PRESSURE WILL BE OVER THE REGION THROUGH TONIGHT. MUGGY
AND WARM CONDITIONS TODAY AS SKIES WILL BE PARTLY CLOUDY AND HIGH
TEMPERATURES REACH INTO THE MIDDLE 80S. TONIGHT TEMPERATURES WILL
DROP ONLY TO THE MIDDLE TO UPPER 60S AS A CHANCE FOR SOME FOG
RETURNS TO THE NORTHERN PART OF THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EDT MON AUG 31 2015

MAINLY CLEAR SKIES, CALM WINDS, AND ELEVATED SFC DEWPOINTS HAS
ALLOWED WIDESPREAD FOG TO DEVELOP NORTHWEST OF A DIFFUSE SFC
TROUGH EARLY THIS MORNING...MAINLY ALONG/NORTHWEST OF THE HWY 24
CORRIDOR. GIVEN CURRENT OBS, HIGH SFC-900 MB RH FIELDS, AND WHAT
OCCURRED UPSTREAM YESTERDAY HAVE OPTED FOR A DENSE FOG ADVISORY
THROUGH 13Z IN THESE AREAS. DIURNAL MIX OUT/UP TO A SCT-BKN CU
FIELD IS THEN EXPECTED MID MORNING INTO EARLY AFTERNOON.

BUILDING HEAT/INSTABILITY FOR THE AFTERNOON MAY ALLOW A FEW POP UP
STORMS TO FIRE AMID THE AFOREMENTIONED WEAK SFC TROUGH...LOCATED ON
THE NORTHERN FRINGE OF LEFTOVER WEAKNESS IN THE MID/UPPER LEVEL
HEIGHT FIELD. THIS FAVORS AREAS MAINLY SE OF THE HWY 24 CORRIDOR IN
INDIANA AND OHIO FOR A MENTIONABLE LOW POP. DRY/WARM OTHERWISE WITH
FOG POSSIBLY A CONCERN ONCE AGAIN LATER TONIGHT IN THE SAME AREAS.


&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM EDT MON AUG 31 2015

PREVIOUS FORECAST APPEARS TO BE IN GOOD SHAPE FOR THE LONG TERM
PERIOD WITH MAIN FORECAST THEMES CENTERING ON INCREASED HEAT...AND
DIURNALLY ENHANCED POTENTIAL OF ISOLATED SHOWERS/STORMS.

FOR TUESDAY/TUESDAY NIGHT MAIN FEATURE OF INTEREST WILL BE RESIDUAL
VORT MAX FROM SYSTEM WHICH SHEARED OUT OVER THE LOCAL AREA
YESTERDAY. WATER VAPOR IMAGERY MORNING DEPICTING SOME DISCERNIBLE
UPPER LEVEL CIRCULATION WITH THIS FEATURE...AND COULD BE ENOUGH
FORCING FOR ISOLATED SHOWERS/STORMS MAINLY DURING PEAK HEATING ON
TUESDAY. DESPITE LOW LEVEL WAA BEGINNING TO RAMP UP IN THE
AFTERNOON...EFFECTS FROM WAA INDUCED CLOUDS/DPVA ASSOCIATED WITH
VORT MAX SHOULD LIMIT HIGHS TO THE LOWER TO MID 80S FOR MOST
LOCATIONS. HAVE KEPT TUESDAY NIGHT DRY AT THIS TIME BUT SOME
POSSIBILITY MAY EXIST FOR ISOLATED SHOWER DEVELOPMENT DUE TO
COMBINATION OF MEANDERING VORT MAX AND SOME ISENTROPIC ASCENT
ASSOCIATED WITH DEPARTING COOL POCKET. WEDNESDAY POPS MAY BE A BIT
MORE QUESTIONABLE WITH CONSENSUS OF LATEST DETERMINISTIC GUIDANCE
TENDING TO DRIFT THIS VORT MAX SOUTHEAST OF THE AREA. HESITANT TO
PULL ISO POPS FOR WEDNESDAY HOWEVER GIVEN BROAD ISENTROPIC ASCENT
COUPLED WITH DIURNAL INSTABILITY...SO NO MAJOR CHANGES MADE TO
PREVIOUS FORECAST. BIGGER STORY FOR THE MID WEEK PERIOD WILL BE
THE TRANSITION TO ABOVE NORMAL TEMPS...WITH EXPECTED BETTER
INSOLATION ON WEDNESDAY AND WAA ALLOWING HIGHS TO REACH INTO THE
UPPER 80S MOST LOCATIONS.

FOR THURSDAY AND FRIDAY IT STILL APPEARS AS THOUGH VERY WEAK PACIFIC
ORIGIN WAVES MAY TRY TO PROGRESS THROUGH BUILDING UPPER LEVEL
RIDGING ACROSS THE REGION. HOWEVER...WILL KEEP FORECAST DRY AT THIS
TIME GIVEN WEAK NATURE OF FORCING AND THE LIKELY MORE QUESTIONABLE
SFC BASED INSTABILITY BY THIS TIMEFRAME. WARM CONDITIONS TO CONTINUE
THROUGH THE WEEKEND...ALTHOUGH BUILDING ANTICYCLONE ACROSS SOUTHEAST
CANADA/NORTHEAST CONUS SHOULD TEND TO ALLOW NORTHEAST LOW LEVEL FLOW
TO EVOLVE ACROSS THE REGION KEEPING TEMPS IN CHECK INTO MID 80S. THE
NEXT CHANCE OF MENTIONABLE PRECIP SHOULD HOLD OFF UNTIL AFTER THIS
FORECAST PERIOD WITH THE POTENTIAL OF A MORE SIGNIFICANT UPPER
TROUGH MOVING ACROSS NORTH CENTRAL CONUS.

 &&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 109 AM EDT MON AUG 31 2015

LIGHT WINDS, RESIDUAL NEAR SURFACE MOISTURE, AND MAINLY CLEAR
SKIES ALREADY ALLOWING LIFR FOG TO FILL IN JUST NNW OF KFWA AND
ALL AROUND KSBN. SEE NO REASON WHY FOG DOESN`T FILL IN AT EACH
TERMINAL EARLY THIS MORNING...ALTHOUGH SOME QUESTION REMAINS ON
WHETHER 15 KT FLOW AT 925 MB PROVIDES ENOUGH MIXING TO KEEP THIS A
STRATUS/FOG MIX INSTEAD OF WIDESPREAD QUARTER MILE OR LESS
VISIBILITIES. CONDITIONS SHOULD RAPIDLY IMPROVE AFTER 14Z WITH VFR
CONDITIONS AND LIGHT SW WINDS ANTICIPATED BY EARLY-MID AFTERNOON.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 109 AM EDT MON AUG 31 2015

LIGHT WINDS, RESIDUAL NEAR SURFACE MOISTURE, AND MAINLY CLEAR
SKIES ALREADY ALLOWING LIFR FOG TO FILL IN JUST NNW OF KFWA AND
ALL AROUND KSBN. SEE NO REASON WHY FOG DOESN`T FILL IN AT EACH
TERMINAL EARLY THIS MORNING...ALTHOUGH SOME QUESTION REMAINS ON
WHETHER 15 KT FLOW AT 925 MB PROVIDES ENOUGH MIXING TO KEEP THIS A
STRATUS/FOG MIX INSTEAD OF WIDESPREAD QUARTER MILE OR LESS
VISIBILITIES. CONDITIONS SHOULD RAPIDLY IMPROVE AFTER 14Z WITH VFR
CONDITIONS AND LIGHT SW WINDS ANTICIPATED BY EARLY-MID AFTERNOON.


&&

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

$$

SYNOPSIS...LOTHAMER
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...STEINWEDEL/MARSILI


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