Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Graphics & Text | 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 011802
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
202 PM EDT WED OCT 1 2014

.SYNOPSIS...
ISSUED AT 1038 AM EDT WED OCT 1 2014

DRY CONDITIONS AND MORE SEASONABLE TEMPERATURES ARE EXPECTED
THROUGH TONIGHT AS HIGH PRESSURE MOVES THROUGH THE REGION. ABOVE
NORMAL TEMPERATURES ARE EXPECTED ON THURSDAY...BEFORE RAIN CHANCES
RETURN TO THE AREA THURSDAY AFTERNOON INTO FRIDAY MORNING. COLDER
AIR WILL OVERSPREAD THE REGION FRIDAY INTO THE WEEKEND BEHIND A
STRONG COLD FRONT.

&&

.UPDATE...
ISSUED AT 1032 AM EDT WED OCT 1 2014

CHANGES MADE TO INCREASE CLOUD COVER SW AS STRATUS WAS ADVECTING
NW BACK INTO SOUTHWESTERN PARTS OF THE FORECAST AREA. MODELS STILL
MIX OUT MUCH OF THIS AS PEAK HEATING OCCURS SO FORECAST TREND
REMAINS MORE AND MORE SUNSHINE INTO THIS AFTERNOON AS THE UPPER
SYSTEM PULLS AWAY. TEMPS MAY NEED SOME ADJUSTING DEPENDING ON HOW
LONG THE CLOUD COVER HANGS ON.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT WED OCT 1 2014

DRY WX WILL PERSIST TODAY INTO THIS EVENING AS HIGHLY AMPLIFIED MID
LEVEL RIDGE AXIS TRANSLATES EAST THROUGH THE GREAT LAKES
REGION...LEAVING SKY COVER AND TEMPS AS PRIMARY FOCUS THIS PERIOD.
TRAPPED/RESIDUAL BOUNDARY LAYER MOISTURE UNDER WEAKENING SUBSIDENCE
INVERSION SHOULD ALLOW LOW CLOUDS TO HANG IN THROUGH MUCH OF THE
MORNING ACROSS NORTHERN/EASTERN ZONES BEFORE DIURNAL
MIXING/ANTICYCLONIC FLOW SCATTERS/LIFTS CLOUD BASES. THIS CLEARING
AND RISING HEIGHTS ALOFT WILL SUPPORT WARMER HIGHS...LIMITED
SOMEWHAT BY REDUCED MIXING DEPTHS (NEAR 900 MB) GIVEN STRONG
SUBSIDENCE AND ESE TRAJECTORIES IN THE LOW LEVELS. COULD SEE SOME
PATCHY FOG EARLY THIS MORNING ALONG SOUTHERN EDGE OF CLOUDS...WITH
RECENT DRY SPELL PRECLUDING A MORE WIDESPREAD DENSE FOG/IMPACTS.

SHORTWAVE EJECTING NORTHEAST TOWARD THE UPPER MIDWEST/NRN LAKES UNDER
PARENT CYCLONE LIFTING INTO MANITOBA WILL FOLD EASTERN FRINGE OF
MOISTURE CHANNEL INTO FAR WESTERN PORTIONS OF THE FA BY LATE
TONIGHT. INCREASING CLOUDS AND SLIGHTLY WARMER MINS IN STRENGTHENING
SW FLOW WILL RESULT...WITH PCPN EXPECTED TO REMAIN WEST OF THE FA
THROUGH 12Z THU.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 438 AM EDT WED OCT 1 2014

PRIMARY CHANGES RELEGATED TO INCREASE POPS THU AFTERNOON INTO FRIDAY
MORNING. COMPLEX/DEEP UPSTREAM BROAD TROF TO RECARVE WESTWARD AS ND
VORTEX LIFTS DUE NORTH AND FOSTERS SHARPENING OF LONGWAVE TROF AXIS
WITH FOCUS OF INTENSE SHORTWAVE ENERGY/PVU ANOMALY FROM CNTL MT INTO
INTERMOUNTAIN REGION. THIS FEATURE DRIVES EASTWARD INTO PLAINS ON
DY2...WITH STRONG OK FRONTAL WAVE BY 12 UTC THU. MEANWHILE STRONG
NORTHERN BC WAVE BEGINS SEWD DIG INTO PLAINS TROF. LEADING DEEP
CROSS- LATITUDINAL FLOW TO AFFORD STRONG 0-1KM MOISTURE FLUX
CONVERGENCE THROUGH THE OZARKS/MID MS VALLEY INTO FAR WRN INDIANA.
CONTD LOW CHC POPS ON EASTERN MOISTURE TRANSPORT/PSEUDO WARM FRONTAL
LEAF...THOUGH BACKED TIMING WITH OVERALL SLOWING CONSENSUS. INITIAL
LACK OF MUCAPE SHOULD PRECLUDE TSRA UNTIL AFTERNOON.
THEREAFTER...INTO EARLY THU NIGHT...STRENGTHENING HODOGRAPHS YIELD
40-50 KTS DEEP LAYER SHEAR ACROSS WESTERN HALF CWA. COINCIDENT
MUCAPE GENERALLY AOB 500 J/KG SHOULD BE SUFFICIENT FOR ISOLD
CONVECTION ALONG WITH STRONGLY FORCED LOW LEVEL PARCEL ASCENT. LATE
FRONTAL TIMING ALONG WITH ANTICIPATED PREFRONTAL/RAIN COOLED AIR AND
LAGGED MID TROPOSPHERIC TROF/HEIGHT FALL CENTROID MAY KEEP BEST
FOCUS FOR SEVERE SOUTHWEST THROUGH WEST...PRIMARILY OZARKS INTO
CENTL IL. SLOWER FRONTAL TIME MAY NECESSITATE NEED FOR FRIDAY
MORNING CONVECTION MENTION IN FAR EASTERN CWA...HELD OFF MENTION
ATTM...GIVEN LOW LEVEL JET FOCUS APPEARS TO SHIFT EWD NEAR DAYBREAK
INTO MID/UPPER OHIO VALLEY...IN ADDITION FAVOR TARGETED TSRA MENTION
VS MULTIPERIOD/ENTIRE CWA BROADBRUSH GIVEN DUBIOUS THERMODYNAMICS.

NON DIURNAL CURVE FRIDAY WITH STRONG CAA/CLOUD COVER. AFOREMENTIONED
CANADIAN VORTEX DIGGING INTO PRIMARY TROF TO DUMBBELL SECOND
STRONGER HEIGHT FALL CENTROID SOUTHEASTWARD THROUGH NORTHERN PLAINS
AND CONGEAL ACROSS CWA WITH NEAR 200M/12 HR FALLS THROUGH SOUTHWEST
GREAT LAKES FRIDAY EVENING. CONSENSUS LIES ON SECONDARY FRONTAL
DEVELOPMENT ACROSS UPPER GREAT LAKES F72-84 AS SHORTWAVE APPROACHES.
WITH A LAGGARD LOW LEVEL/WESTERN LAKES MOISTURE POOL HAVE RAISED
POPS ESPECIALLY FRIDAY NIGHT INTO EARLY SAT AMID CYCLONIC 925-8H
FLOW WITHIN BACKGROUND OF GENERAL ASCENT THAT SHOULD EASILY GENERATE
SCT SHRA ACRS CWA. GENERAL MODEL CONSENSUS WITH GOOD ECMWF
SUPPORT STILL AFFORDS CLIPPER SUN NIGHT INTO MONDAY FOR ANOTHER
SHRA CHC...STILL BLO WET BLENDED GIVEN MOISTURE CONCERNS. THEREAFTER
INCREASE CHAOS ALONG WITH NO STRONG SIGNAL AS NEITHER GFS ENSEMBLE
AVERAGE NOR ECMWF EXHIBITING SIG STRONGER THAN CLIMO
POPS...SUPPORTIVE OF NIL WX MONDAY NIGHT INTO MIDDLE NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 159 PM EDT WED OCT 1 2014

VFR CONDITIONS EXPECTED TO PREVAIL AS LOW CLOUDS CONTINUE TO MIX
OUT. HIGH CLOUDS FROM UPSTREAM CONVECTION WILL SLOWLY EDGE EAST
AND THICKEN WITH TIME LATER TONIGHT INTO THURSDAY. ANY
PRECIPITATION WILL HOLD OFF TILL AFTER 18Z THURS.

&&

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

$$

UPDATE...FISHER
SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...MURPHY
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.