Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 010842
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
442 AM EDT WED OCT 1 2014

.SYNOPSIS...
ISSUED AT 1242 AM EDT WED OCT 1 2014

DRY CONDITIONS AND MORE SEASONABLE TEMPERATURES ARE EXPECTED TODAY
INTO 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.

&&

.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 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1242 AM EDT WED OCT 1 2014

BKN/OVC MVFR STRATOCU DECK WILL LIKELY LINGER ACROSS NORTHERN
INDIANA THIS MORNING AS LOW LEVEL MOISTURE REMAINS TRAPPED UNDER
STRONG INVERSION. BRIEF VIS REDUCTION AND LOWERING OF CIGS INTO
MVFR FUEL ALTERNATE RANGE REMAINS POSSIBLE IN MAINLY 07-13Z
WINDOW GIVEN EXPECTED COOLING IN BRIEF CLEAR PATCHES SHOWING UP ON
SATELLITE. OTHERWISE...IMPROVEMENTS TO VFR ANTICIPATED BY LATE
MORNING OR EARLY AFTERNOON AS SUBSIDENCE/MIXING HELPS SCATTER/LIFT
LOW CLOUDS.

&&

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

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...MURPHY
AVIATION...STEINWEDEL


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