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 160923
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
423 AM EST TUE DEC 16 2014

.SYNOPSIS...
ISSUED AT 125 AM EST TUE DEC 15 2014

AN UPPER LEVEL DISTURBANCE AND LOW PRESSURE AREA WILL MOVE ACROSS
THE REGION ACCOMPANIED BY PERIODS OF RAIN THROUGH THIS MORNING.
LINGERING RAIN SHOWERS WILL PERSIST INTO THIS AFTERNOON. THE
PRECIPITATION WILL MIX WITH SNOW AND THEN CHANGE TO ALL SNOW
TONIGHT. SOME LIGHT SNOW ACCUMULATIONS ARE POSSIBLE TONIGHT...
ESPECIALLY OVER NORTHWEST INDIANA AND FAR SOUTHWEST LOWER
MICHIGAN. COLDER WEATHER WILL BE IN STORE FOR MID WEEK BEHIND
THIS SYSTEM. HIGHS TODAY SHOULD REACH THE MID AND UPPER 40S. LOWS
TONIGHT WILL BE MAINLY IN THE 20S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EST TUE DEC 16 2014

AN UPPER LOW WAS OVER NORTHERN IL AND WILL TRACK EAST ACROSS FAR
NORTHERN INDIANA AND SOUTHERN LOWER MICHIGAN LATER TODAY. AN AREA
OF RAIN ASSOCIATED WITH A SHORT WAVE WILL MOVE ACROSS THE FORECAST
AREA EARLY TODAY. RADAR AND SURFACE REPORTS INDICATED ISOLATED
SLEET WAS MIXED IN WITH THE RAIN. ANY SLEET WILL BE BRIEF AND SHOULD
BE LOCAL AND SHOULD HAVE MINIMAL IMPACTS WITH SURFACE TEMPERATURES
AROUND 45 DEGREES. THE MAIN AREA OF LIFT WITH THE UPPER LOW IN
THE TROWAL WILL TRANSLATE NORTHEAST OUT OF THE AREA...ALLOWING
PRECIPITATION AMOUNTS TO BECOME LIGHT THIS AFTERNOON. THE REMAINING
PRECIPITATION WILL MIX WITH AND CHANGE TO SNOW TONIGHT AS COLDER
AIR SPREADS BACK OVER THE AREA...ALTHOUGH ONLY LIGHT AMOUNTS OF
SNOW ARE EXPECTED.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EST TUE DEC 16 2014

ONLY MINOR VARIANCES WARRANTED FROM PRIOR FORECAST AND CORROBORATING
LATEST MODEL BLEND. CONTINUE UNIMPRESSED WRT LES RESPONSE MIDWEEK
GIVEN NOMINAL SATURATION DEPTH. 295 DEGREE CBL FLOW VEERS TO ABOUT
310 THROUGH WED/WED NIGHT...THOUGH LWR TEENS DIFFERENTIALS
GENERATING LTE 200 J/KG LAKE INDUCED CAPE WITH LK INDUCED EQL ONLY
TOPPING 4KFT WED AFTN/EVE. THEREAFTER...925-8H COLD POOL SHIFTS WELL
EWD THROUGH LWR GRTLKS/WRN PA BY DAYBREAK...PUTTING FINAL KIBOSH ON
ALREADY LACKLUSTER CONDITIONING. ADVANCE OF UPSTREAM NRN PLAINS/SRN
CANADA RIDGING POSES DIFFICULTY WRT CLOUD COVER AS DIRTY
RIDGE/TRAPPING SUBSIDENCE INVERSION AGAIN APPEARS PSBL THU/FRI.
MODELS TRENDS WRT EVOLUTION OF COMPLEX MULTI-EMBEDDED SHORTWAVE WEST
COAST TROF HAS BEEN DECIDEDLY SOUTHWARD SHUNT WRT SFC CYCLOGENESIS
FRI/SAT. COLLABORATIVELY REMOVED HIGH BIAS BLENDED POPS FRI
NIGHT...AND ONLY TOKEN LIGHT SNOW CHCS SAT...PERHAPS WITHIN LAGGED
INVERTED TROF WITHIN NRN DUMBBELL OF HEIGHT FALL CENTROID TRACKING
THROUGH SRN GRTLKS. NEXT SYSTEM TO WATCH APPEARS TO BE NRN STREAM
CLIPPER FOR POTNL LIGHT ACCUM ABOUT DY8.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 121 AM EST TUE DEC 16 2014

THE CORE OF THE UPPER LOW WAS OVER NW IL AND WILL TRACK EAST
ACROSS SOUTHERN LOWER MICHIGAN LATER TODAY. ANOTHER AREA OF RAIN
ASSOCIATED WITH AN UPPER LEVEL SHORT WAVE AND ACCOMPANIED BY LOW
CIGS AND VSBYS WILL SPREAD OVER THE TERMINALS EARLY IN THE TAF
PERIOD. EXPECT LOW TO VERY LOW IFR CONDITIONS EARLY THIS MORNING
AS THE UPPER LEVEL SYSTEM MOVES OVER THE AREA. SOME IMPROVEMENT IS
LIKELY AS THE LOW MOVES EAST FOLLOWED BY DRIER AIR SPREADING
ACROSS THE AREA NEAR THE END OF THE TAF PERIOD. HOWEVER...CIGS
MAY STILL BE IFR AT THE END OF THE TAF PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 5 AM EST
     THURSDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MARSILI/SKIPPER
SHORT TERM...SKIPPER
LONG TERM...MURPHY
AVIATION...SKIPPER


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.