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 041057
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
657 AM EDT FRI SEP 4 2015

.SYNOPSIS...
ISSUED AT 400 AM EDT FRI SEP 4 2015

HOT AND HUMID WEATHER WILL CONTINUE INTO THE WEEKEND. ISOLATED TO
SCATTERED THUNDERSTORMS WILL FORM...MAINLY DURING THE AFTERNOON
AND EVENING. HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S WITH LOWS
IN THE MID TO UPPER 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM EDT FRI SEP 4 2015

CONTINUED TRENDS OF PREVIOUS FORECAST WITH MINOR BLENDING OF NEW
MODELS. RESULTED IN SLIGHT BUMP UP FOR TEMPERATURES TODAY AND
TONIGHT AS WE CONTINUE TO BE UNDER THE INFLUENCE OF STRONG RIDGE.
MODEL SOUNDINGS ALL SHOW STRONG SUBSIDENCE CAP...ESPECIALLY ACROSS
THE WESTERN THIRD OF THE CWA FOR THE NEXT 24 HOURS. THIS WILL KEEP
WIDESPREAD CONVECTION FROM DEVELOPING...HOWEVER WITH THE CURRENT
STAGNANT FLOW PATTERN AND NO APPARENT KICKER TO MOVE THE WEAK
CIRCULATION CENTER OUT OF THE GREAT LAKES FEEL THAT IT WOULD BE BEST
TO KEEP ISOLATED THUNDER. SIMILAR TO THE CONVECTION FROM YESTERDAY
INTO THE EARLY MORNING HOURS TODAY.

ADDITIONALLY...ABUNDANT SUNSHINE ACROSS THE WEST AND SOUTH WILL HELP
TO DRIVE TEMPERATURES UP ONCE AGAIN. SEVERAL OF THE SREF MEMBERS
HAVE SHOWN TEMPERATURES IN MIDDLE AND UPPER 90S ACROSS THE SOUTHERN
PORTION OF THE CWA...HAVE NOT GONE THAT HOG WILD...BUT DID BUMP
TEMPS UP A COUPLE DEGREES FOR MOST AREAS TODAY.

WHILE HUMIDITY/DEWPOINTS ARE HIGH...IT IS NOT HIGH ENOUGH TO PUSH
HEAT INDICES TO ADVISORY LEVELS. FEEL THAT WITH THE HOLIDAY WEEKEND
THIS WILL BEST BE ADDRESSED USING OUR SOCIAL MEDIA AND WEATHER STORY
GRAPHICS.

 &&

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 342 AM EDT FRI SEP 4 2015

HOT AND HUMID CONDITIONS TO REMAIN IN PLACE THROUGH THE HOLIDAY
WEEKEND GIVEN PERSISTENT LONGWAVE RIDGING OVER THE SOUTHEAST CONUS.
HIGHS DURING THIS PERIOD WILL REMAIN IN THE UPPER 80S TO AROUND 90F
GIVEN 850MB TEMPS HOVERING NEAR 18C. SATURDAY MAY BE A FEW DEGREES
COOLER THAN SUN/MON GIVEN LINGERING EFFECTS OF WEAK UPPER LOW BUT
DIFFERENCES LIKELY NEGLIGIBLE. SUNDAY CURRENTLY APPEARS TO HAVE THE
BEST CHANCE FOR LOWER 90S GIVEN NEARLY FULL SUN/DEEP PBL MIXING AND
INCREASING SW FLOW AHEAD OF APPROACHING FRONT. THAT BEING SAID...
MONDAY COULD BE EQUALLY AS WARM (ESPECIALLY FOR SOUTHEAST HALF) IF
DECAYING FRONT IS AS SLOW AND WEAK AS CURRENTLY EXPECTED. SURFACE
DEWPOINTS STILL EXPECTED TO HOVER AROUND 70F DURING THIS TIME...
YIELDING HEAT INDICES IN THE MID 90S.

WEAK PV ANOMALY WILL CONTINUE TO MEANDER AROUND THE CENTRAL GREAT
LAKES ON SATURDAY BUT WILL BE MUCH MORE DIFFUSE WITH A MORE
QUESTIONABLE IMPACT ON PRECIP CHANCES AND COVERAGE. SUSPECT THERE
WILL BE SOME ISOLATED CONVECTION GIVEN RELATIVELY MOIST SURFACE
PARCELS AND LINGERING WEAK FORCING BUT MODEL SOUNDINGS INDICATE A
MODEST CAP AND OVERALL POOR INSTABILITY GIVEN WARM TEMPS ALOFT. WILL
MAINTAIN JUST A SLIGHT CHANCE MENTION. DRY CONDITIONS EXPECTED
SUNDAY WITH STRONGER CAP/EVEN LESS INSTABILITY AND NO FORCING FOR
ASCENT AS UPPER LEVEL CIRCULATION FINALLY WINDS DOWN/EXITS.

WESTERN CONUS TROUGH EJECTS NORTHEAST BY MONDAY BUT REMAINS WELL TO
OUR NORTHWEST. MODELS SUGGEST WEAK SHORTWAVE WILL TRY TO PUSH
THROUGH OUR REGION LATE MONDAY BUT PRECIP CHANCES APPEAR TENUOUS AT
BEST GIVEN LONGWAVE PATTERN. ISOLATED AFTERNOON CONVECTION POSSIBLE
IN THE NORTHWEST BUT MAINTAINED JUST A SLIGHT CHANCE POP. SLIGHTLY
BETTER CHANCES OVERNIGHT AND INTO TUESDAY BUT BEST CHANCES FOR RAIN
CURRENTLY APPEAR TO BE WEDNESDAY AS SECONDARY TROUGH PUSHES THROUGH
OUR AREA AND FINALLY FORCES A MEANINGFUL COLD FRONTAL PASSAGE.
SLIGHTLY COOLER TUES/WED BUT REAL AIRMASS CHANGE COMES AT THE END OF
THE WEEK WHEN HIGHS DROP TO AROUND 70F WITH DEWPOINTS IN THE 50S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 649 AM EDT FRI SEP 4 2015

CLEARING SKIES IN THE WAKE OF EARLIER CONVECTION ACROSS
MICHIGAN...NORTHWEST OHIO AND FAR NORTHEAST INDIANA HAS ALLOWED
FOG TO FORM WITH THE DENSEST COVERAGE NORTH OF A KOXI-KDUH LINE.
PATCHY FOG ALONG AND SOUTH OF THIS LINE. EXPECT IFR CIGS AT KSBN
FOR THE NEXT FEW HOURS...BUT THIS WILL MIX OUT AFTER SUNRISE. WITH
THE PROXIMITY OF THE REMNANT SHORTWAVE/CONVECTION OVER LAKE
ERIE...ISOLD -TSRA ARE EXPECTED TO TRIGGER AS THE AFTERNOON
PROGRESSES. WIDESPREAD AND ORGANIZED CONVECTION IS NOT EXPECTED.
GUSTY WINDS ARE THE GREATEST RISK/THREAT. OTHERWISE - WINDS
CONTINUE LIGHT AND AND VARY ONLY SLIGHTLY THROUGH THE PERIOD.

&&

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

$$

SYNOPSIS...MURPHY
SHORT TERM...LEWIS
LONG TERM...AGD
AVIATION...LEWIS


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.