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 280834
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
434 AM EDT MON JUL 28 2014

.SYNOPSIS...
ISSUED AT 143 AM EDT MON JUL 28 2014

MUCH COOLER AND DRIER AIR WILL FILTER INTO THE REGION BEHIND THE
FRONTAL SYSTEM THAT BROUGHT SCATTERED STORMS ON SUNDAY. DRY
CONDITIONS AND COOLER THAN NORMAL TEMPERATURES ARE EXPECTED FOR
MUCH OF NEXT WEEK. AFTERNOON HIGHS TODAY WILL BE IN THE LOWER
70S...EXCEPT UPPER 60S CLOSER TO LAKE MICHIGAN. LOWS TONIGHT WILL
BE WELL BELOW NORMAL...DROPPING INTO THE LOWER 50S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM EDT MON JUL 28 2014

BENIGN NEAR TERM WITH EXPUNGEMENT OF WARM/MOIST AIRMASS. VIGOROUS
SHORTWAVE VORTEX PRESENTLY OVER CENTRAL LAKE ERIE TO CONTINUE
EASTWARD TRACK INTO UPSTATE NEW YORK TODAY. WHEREUPON VORTEX IS
SHUNTED NORTHWARD BY STALWART BLOCKING REGIME OVER NORTHERN/WESTERN
ATLANTIC AND RIDGING FROM TEXAS PLATEAU NORTHWARD INTO FAR NORTH
CENTRAL CANADA. PRIMARY NORTHERN QUEBEC LONGWAVE TO GRADUALLY
RETROGRADE TO JAMES BAY BY 12 UTC TUE. SURFACE DEWPOINTS TYPICALLY
10-15F COOLER OVER 24 HOURS PRIOR...PRIMARILY IN MID/UPPER 50S.
NAM12 AND TO LESSER EXTENT HRRR3KM ATTEMPT TO GENERATE LIGHT SHRA BY
MIDDAY EARLY AFTERNOON MAINLY ACROSS SERN CWA. MODIFIED POINT
SOUNDINGS OF 79/56 YIELD ONLY LTE 200 J/KG AND SUSPECT DEGREE OF DRY
AIR AOA 750 MB TO PROVIDE AMPLE DRY ENVIRONMENTAL AIR ENTRAINMENT TO
HINDER CU FIELDS VERTICAL DEVELOPMENT AND LEAN TOWARD CONTINUED DRY
FORECAST. 925MB THERMAL TROF UPSTREAM THIS AM FROM LAKE HURON SWD
THROUGH NORTHERN LOWER MI TO SOUTHERN WI...AND PROGGED OVERHEAD BY
00 UTC TUE. THIS ALONG WITH EASTWARD EXTENSION OF NORTHERN PLAINS
RIDGE INTO NORTHERN IL/NWRN IN SHOULD ALLOW FOR RAPID
DECOUPLE/STRONG LONGWAVE LOSSES FOR LOWS GENERALLY ABOUT 10F BELOW
CLIMO TONIGHT. SOME CONCERN THAT HIGH BASED STRATOCU DECK MAY IN
ADVANCE OF SHORTWAVE DROPPING THROUGH WESTERN GREAT LAKES...HOWEVER
PRESENCE UNCERTAIN AND TIMING SHOULD BE LATE ENOUGH TO HAVE ALREADY
ALLOWED TEMPS TO DROP INTO LWR 50S BY THE EARLY AM HOURS.

&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 432 AM EDT MON JUL 28 2014

AN UPPER LEVEL TROF WILL REMAIN OVER THE WESTERN GREAT LAKES REGION
FOR AN EXTENDED PERIOD AS AN UPSTREAM UPPER RIDGE REMAINS PARKED
OVER WESTERN NORTH AMERICA. AT THE BEGINNING OF THE PERIOD...HAVE
ADDED A CHANCE FOR SHOWERS AND A SLIGHT CHANCE FOR THUNDER TUESDAY
AFTERNOON...OTHERWISE HAVE KEPT THE FORECAST DRY. ON TUESDAY...COOL
MID LEVEL TEMPERATURES WILL ALLOW AFTERNOON CAPE VALUES TO RISE TO
BETWEEN 500 AND 1000 J/KG PER MODIFIED NAM/WRF SOUNDING. THE
AFTERNOON INSTABILITY COMBINED WITH WEAK UPSTREAM ENERGY SHOULD BE
ENOUGH TO ALLOW SHOWERS AND ISOLATED STORMS TO DEVELOP BY EARLY
AFTERNOON. THE ACTIVITY SHOULD DISSIPATE BY EARLY EVENING AS THE
ATMOSPHERE STABILIZES. FOR THE REST OF THE PERIOD...GFS AND ECMWF
850 MB FORECAST TEMPS WERE VERY UNIFORM FROM WEDNESDAY THROUGH
SUNDAY...GENERALLY BETWEEN 11C AND 13C. FAVOR THE GFS MEAN ENSEMBLE
TEMPS WITH HIGHS IN THE 70S AND LOWS IN THE 50S FOR THE REST OF THE
PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 150 AM EDT MON JUL 28 2014

STRONG 20-25KT NWRLY FLOW THROUGH RESIDUAL MOISTURE ALLOWING FOR
STRATUS DECK TO COVER NORTHERN IN/LOWER MI PENINSULA. ADDITIVE
LAKE MI MOISTURE ALLOWING FOR SOME LOWER CIGS ACROSS SW LWR MI
THAT COULD EFFECT KSBN AND COVER WITH TEMPO IFR CIGS THROUGH EARLY
AM HOURS. MORE OPTIMISTIC AT KFWA FARTHER REMOVED FROM LAKE
ENVIRONMENT AND LET PREDOMINANT FUELING/ALTERNATE REQUIREMENTS
SUFFICE UNTIL 14 UTC. THEREAFTER...GREATER MIXING AND EXTREMELY
DRY AIR ALOFT WILL AID IN RISING CU BASES WITH RELATIVELY RAPID
CLOUD COVERAGE DECAY.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR INZ003.

MI...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ077.

OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...SKIPPER
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.