Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KIWX 311737
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
137 PM 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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 125 PM EDT MON AUG 31 2015

VFR CONDITIONS FOR MUCH OF FORECAST PD. HOWEVER...POTENTIAL
EXISTS YET AGAIN FOR PERIOD OF IFR VSBYS IN BR/FG ACROSS NRN IN.
RELATIVELY LACKLUSTER MIXOUT TODAY/HIGH AFTERNOON DEWPOINTS BODE
WELL FOR BR FORMATION TOWARD DAYBREAK AS SHARP SFC BASED INVERSION
PEAKS 10-12 UTC.

&&

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

$$

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


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.