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 290822
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
422 AM EDT MON SEP 29 2014

.SYNOPSIS...
ISSUED AT 415 AM EDT MON SEP 29 2014

A WEAK HIGH PRESSURE SYSTEM ACROSS OUR AREA THIS MORNING WILL
MOVE SOUTH ACROSS THE OHIO VALLEY TODAY AND TONIGHT... WHILE A
COLD FRONT OVER THE UPPER GREAT LAKES MOVES SOUTH TO OHIO AND
INDIANA BY TUESDAY MORNING. FAIR WEATHER WITH UNSEASONABLY WARM
TEMPERATURES WILL CONTINUE OVER THE AREA TODAY. SCATTERED SHOWERS
ARE EXPECTED TONIGHT... ESPECIALLY NORTHEAST OF ROUTE 33... AS THE
FRONT MOVES THROUGH THE AREA. HIGHS TODAY WILL BE IN THE UPPER 70S
AND LOWER 80S... WITH LOWS TONIGHT IN THE UPPER 40S OVER SOUTHERN
MICHIGAN AND IN THE LOWER TO MIDDLE 50S OVER NORTHERN INDIANA AND
NORTHWEST OHIO.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM EDT MON SEP 29 2014

SFC RIDGE REMAINS OVER THE SRN GRTLKS/OH VALLEY THIS MORNING BUT
WAS GRDLY WKNG IN RESPONSE TO SHRTWV REMNANTS OF IA CUT-OFF UPR LOW
MOVG SLOWLY EAST ACROSS IN/MI. SOME CIRRUS REMAINS OUT AHEAD OF THIS
SYSTEM OVER OH WHILE REMAINDER OF THE AREA WAS CLEAR. SOME OF THE
RURAL METARS SUGGESTING PATCHY RADIATIONAL COOLING FOG WITH VSBYS
OCNLY DOWN TO 1/4MI. WHILE EXPECT THE FOG WILL BECOME A LITTLE MORE
WIDESPREAD... GIVEN LACK OF PERSISTENCE IN SGFNT VSBY RESTRICTIONS
THUS FAR... DOUBT A DENSE FOG ADVISORY WILL BE NEEDED.

MODELS FAIRLY CONSISTENT THIS MORNING SUGGESTING VORT MAX AT TAIL
END OF POSITIVE TILT SHRTWV MOVG ACROSS SE CANADA WILL DIG SEWD
ACROSS THE UPR GRTLKS TODAY/TNGT WITH A CLOSED H5 FORMING OVER LAKE
HURON BY TUE MORNING. STRONG FORCING ASSOCIATED WITH THIS SYSTEM
SHOULD COMPENSATE FOR LACK OF MOISTURE RESULTING IN AT LEAST SCT
SHOWERS OVERNIGHT. BUMPED UP POPS IN THIS PERIOD... ESPECIALLY
ACROSS THE NE PORTION OF CWA WHERE STRONGEST LIFT/DEEPEST MOISTURE
EXPECTED. WK ELEVATED INSTABILITY FCST BY MODELS SUGGESTS A FEW
LIGHTNING STRIKES ALSO PSBL IN THAT AREA BUT GIVEN THIS SHOULD BE
ISOLATED AT BEST... HELD OFF ADDING TSTMS TO FCST ATTM.

IN ADVANCE OF THE FRONT TODAY... WK WAA AND CONTD DRY AIRMASS SHOULD
RESULT IN TEMPS SIMILAR IF NOT A BIT HIGHER THAN YDAY. BUMPED FCST
HIGHS UP WITH U70S/L80S EXPECTED THIS AFTN. LOW LEVEL EVAPORATIONAL
COOLING ASSOCIATED WITH THE SHOWERS AND RATHER STRONG CAA BEHIND
CDFNT SHOULD ALLOW TEMPS TO FALL INTO THE U40S IN OUR MICHIGAN
COUNTIES AND L-M50S OVER THE INDIANA/NW OH ZONES TONIGHT... DESPITE
INCREASING CLOUDINESS LIMITING RADIATIONAL COOLING.

&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 415 AM EDT MON SEP 29 2014

AN UPPER TROF WILL MOVE SOUTHEAST ACROSS THE GREAT LAKES REGION
EARLY TUESDAY. OVERALL...THE ECMWF HAS BEEN HANDLING THIS SYSTEM
WELL THE PAST FEW RUNS...WITH AN ACCOMPANYING SURGE OF COOL AIR
BEHIND THE FRONT. THE GFS CONTINUES TO TREND COOLER WITH THE MEX
HIGHS TUESDAY...16 DEGREES COOLER AT SBN SINCE THE FRIDAY EVENING
RUN. THESE COOL TEMPERATURES APPEAR ON TRACK GIVEN VERY CHILLY AIR
ALREADY IN PLACE JUST NORTH OF LAKE SUPERIOR WITH SLEET AND SNOW
OBSERVED THIS PAST EVENING. THEREFORE...HAVE CUT HIGHS TUESDAY AND
LOWS TUESDAY NIGHT SUBSTANTIALLY TO COME MORE IN LINE WITH THESE
EXPECTATIONS THAT ARE SUPPORTED BY THE TRENDS OF THE GFS AND THE
VERY CHILLY NAM/MET FORECAST TEMPERATURES. HAVE EXPANDED THE AREAS
OF SHOWERS TUESDAY MORNING. SUFFICIENT SATURATION OF THE 850/500 MB
LAYER WITH ENOUGH LIFT SHOULD ALLOW SHOWERS TO SPREAD ACROSS THE
EASTERN PORTION OF THE AREA. OTHERWISE...A STRONGER SYSTEM IS
EXPECTED LATE THIS WEEK. KEPT THE MENTION OF A CHANCE FOR THUNDER
BASICALLY THURSDAY AFTERNOON INTO EARLY FRIDAY MORNING. CONVECTIVE
AVAILABLE POTENTIAL ENERGY IS LIMITED...BUT MOISTURE AND LIFT
SHOULD BE SUFFICIENT FOR STORMS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED
AT 128 AM EDT MON SEP 29 2014

WK HIGH PRESSURE RIDGE OVER THE AREA EARLY THIS MORNING RESULTING
IN NEARLY CALM WINDS. A WK SHRTWV WAS MOVG THROUGH NE INDIANA
CAUSING SOME CIRRUS. THIS SHOULD PUSH EAST OF THE AREA OVERNIGHT.
STRONG RADIATIONAL COOLING EXPECTED TO CAUSE BR TO FORM AT THE
TERMINALS WITH MVFR CONDITIONS BY DAYBREAK. VFR CONDITIONS SHOULD
RETURN BY LATE MORNING. A STRONGER SHRTWV AND BACKDOOR CDFNT WILL
MOVE SOUTH ACROSS THE GRTLKS TONIGHT CAUSING WINDS TO SHIFT FROM
W-NW TO NORTH. AREA OF LOW CIGS FOLLOWING THIS FRONT SHOULD
OVERSPREAD NRN INDIANA TONIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 8 PM EDT TUESDAY
     FOR LMZ043-046.

&&

$$

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


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.