Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 210551
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
151 AM EDT TUE OCT 21 2014

.SYNOPSIS...
ISSUED AT 335 PM EDT MON OCT 20 2014

COOLER AND DRIER AIR WILL OVERSPREAD THE AREA BEHIND A COLD FRONT
TONIGHT INTO TUESDAY...WITH HIGHS ON TUESDAY ONLY FORECAST TO
RECOVER INTO THE UPPER 40S AND LOW 50S. MODERATING TEMPERATURES
AND DRY CONDITIONS CAN BE EXPECTED WEDNESDAY THROUGH SATURDAY AS
HIGH PRESSURE BUILDS INTO THE REGION.

&&

.UPDATE...
ISSUED AT 141 AM EDT TUE OCT 21 2014

WHILE EXTENSIVE LAKE EFFECT CLOUD COVER WAS STREAMING SE ACROSS
THE AREA...SHOWER ACTIVITY HAS BEEN QUITE MINIMAL. COLDEST AIR WAS
STILL ARRIVING AND ACTIVITY MAY PICK UP BUT GIVEN UPSTREAM RADAR
TRENDS CAN`T SEE ANYTHING AMOUNTING TO MUCH. AS A RESULT HAVE
LOWERED POPS TO 30 PERCENT AT MOST. OTHERWISE NO CHANGES.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON OCT 20 2014

A VIGOROUS SHORTWAVE RESPONSIBLE FOR LINE OF SHOWERS/ISO THUNDER
EXITING OUR OH COUNTIES BY 20/21Z...AND A 90KT UPPER JET DROPPING
SE THROUGH WESTERN PERIPHERY OF THE BROADER MID LEVEL
TROUGH...WILL AID IN TROUGH AMPLIFICATION WITH A CLOSED 5H LOW
EVENTUALLY EMERGING OVER WESTERN PA BY LATE TUESDAY AFTERNOON.
TRAILING MOIST CYCLONIC FLOW/SHEARED VORTICITY WITH LOW LEVEL
THERMAL TROUGH BECOMING FIRMLY ENTRENCHED TONIGHT INTO TUESDAY
WILL SUPPORT COOLER TEMPS AND LIKELY ALLOW AN EXTENSIVE STRATOCU
CLOUD DECK TO TAKE RESIDENCE OVER THE ENTIRE AREA. VEERING
NORTHERLY FLOW WITH LAKE-8H TEMP DIFFERENTIALS PUSHING THE MID
TEENS (LAKE INDUCED EQUILIBRIUM LEVELS BRIEFLY TO 6-7 KFT) WARRANT
LOW-MID CHC POPS FOR SCT LAKE EFFECT SHOWERS TONIGHT-TUESDAY
MORNING. MAINLY DRY OTHERWISE OUTSIDE OF LOW CHANCE FOR ISOLATED
SHOWERS/SPRINKLES ACROSS MAINLY OH/SC LOWER MI GIVEN SLIGHTLY
BETTER MOISTURE PROFILES AND POTENTIAL FOR ADDITIONAL WEAKER
SHORTWAVE ENERGY TO SHEAR THROUGH.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON OCT 20 2014

LONG TERM PERIOD BEGINS WITH TEMPERATURES ON THE COOL SIDE AS A CUT
OFF LOW DIGS INTO THE EASTERN SEABOARD AND KEEPS THE EASTERN CONUS
UNDER MEAN TROUGHING FOR A MAJORITY OF THE WEEK. A COLD FRONT WILL
MOVE THROUGH THE CENTRAL CONUS TOWARDS THE END OF THE WEEK BUT WILL
LIKELY BE A DRY PASSAGE BY THE TIME IT REACHES OUR CWA AS THE BETTER
ENERGY REMAINS IN CANADA AND NORTHERLY WINDS FOR SEVERAL DAYS PRIOR
KEEP A DRY CP AIRMASS ACROSS THE GREAT LAKES.

LONGWAVE RIDGING WILL MOVE OVERHEAD BY THE WEEKEND WITH TEMPERATURES
WARMING INTO THE MID TO UPPER 60S BY SUNDAY AND MONDAY. WITH
SUFFICIENT SUNSHINE...HIGH TEMPERATURES MAY EVEN REACH INTO THE 70S
EARLY NEXT WEEK AS 850 HPA TEMPS OF 14C TO 16C ARE ADVECTED INTO THE
REGION AHEAD OF THE NEXT SYSTEM. THIS SYSTEM WILL BE ONE TO WATCH IN
THE LONG TERM PERIOD AS ITS ORIGINS CAN BE TRACED BACK TO BOTH SUPER
TYPHOON VONGFONG AND TROPICAL CYCLONE HUDHUD. A HEMISPHERIC WATER
VAPOR LOOP OVER THE PAST DAY SHOWS THE REMNANTS OF HUDHUD PHASING
WITH THE NE PACIFIC LOW WHICH CONTAINS THE REMNANTS OF VONGFONG.

WHILE TYPING THIS DISCUSSION...THE 12Z ECMWF HAS DECIDED TO
COMPLICATE THINGS BY COMING IN WITH A SPLIT FLOW PROGRESSIVE
PATTERN. ATTM WILL IGNORE THIS SOLUTION DUE TO AFOREMENTIONED
WESTERN PACIFIC TROPICAL ACTIVITY AND ITS PROPENSITY TO AMPLIFY THE
PATTERN ACROSS THE CENTRAL CONUS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 141 AM EDT TUE OCT 21 2014

CIGS HAVE REMAINED GENERALLY VFR OVER THE PAST SEVERAL HOURS.
WHILE OBS OCCASIONALLY SHOWING SOME MARGINAL MVFR CIGS
UPSTREAM...OVERALL TREND DOESN`T LOOK AS GOOD AS BEFORE. HAVE
CLEARED UP TEMPO GROUPS AND STICKING WITH VFR FOR NOW.

SKIES SHOULD CLEAR OUT WITH TIME BY LATE AFTERNOON AS NW FLOW
BECOMES MORE N AND NE AND EFFECTS OF UPPER LOW DIMINISH.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT WEDNESDAY FOR LMZ043-046.

&&

$$

UPDATE...FISHER
SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...BENTLEY
AVIATION...FISHER


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.