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000
FXUS63 KIWX 110026
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
826 PM EDT MON MAR 10 2014

.SYNOPSIS...
ISSUED AT 820 PM EDT MON MAR 10 2014

A RIDGE OF HIGH PRESSURE WILL TRACK ACROSS THE REGION TONIGHT
BRINGING DIMINISHING WINDS AND DRY CONDITIONS. A STORM SYSTEM WILL
BEGIN TO STRENGTHEN ACROSS THE PLAINS ON TUESDAY AND WILL MOVE
INTO THE OHIO RIVER VALLEY AND SOUTHERN GREAT LAKES REGION LATE
TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM WILL BRING A MIX OF
RAIN...SNOW...AND SLEET TO THE REGION LATE TUESDAY NIGHT...WITH
ALL SNOW BY WEDNESDAY. SIGNIFICANT SNOW ACCUMULATIONS ARE POSSIBLE
BEFORE THE SYSTEM PUSHES OFF TO THE EAST TOWARD WEDNESDAY EVENING.
MUCH COLDER AIR WILL FILTER INTO THE REGION WEDNESDAY NIGHT BEHIND
THIS SYSTEM.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 358 PM EDT MON MAR 10 2014

MILD/QUIET WX TO PERSIST TONIGHT/TUESDAY WITH MAIN FOCUS ON
HEAVY SNOW POTENTIAL TUESDAY NIGHT INTO WEDNESDAY...

A NORTHERN STREAM PV ANOMALY TRACKING EAST INTO QUEBEC WILL DROP AN
INCREASINGLY DIFFUSE/SHALLOW COLD FRONT SOUTH INTO NORTHERN ZONES
TONIGHT...WITH THIS FEATURE LIKELY LAYING OUT W-E OVER CENTRAL
PORTIONS OF THE FA TUESDAY AS IT BECOMES ORIENTED WITH THE MEAN
FLOW. NOT EXPECTING ANY PCPN WITH THIS BOUNDARY THROUGH AT LEAST
TUESDAY AFTERNOON...WITH THE MAIN IMPACT BEING TREND TOWARD SLIGHTLY
COOLER TEMPS AND POTENTIAL FOR SOME FOG/STRATUS DEVELOPMENT LATE
TONIGHT/TUESDAY MORNING GIVEN SNOW MELT AND BOUNDARY LAYER
CONVERGENCE/MOISTENING FROM SHALLOW CAA UNDERCUT. FRONTAL
BOUNDARY WILL TIGHTEN UP LATER TUESDAY AFTERNOON INTO TUESDAY
EVENING IN RESPONSE TO UPSTREAM HEIGHT FALLS. EXPECTATIONS ARE FOR
A NARROW BAND OF PCPN TO DEVELOP INVOF STRENGTHENING 800-600 MB
LAYER FGEN RESPONSE NEAR/NORTH OF THE IL/WI BORDER AND SPREAD EAST
INTO LOWER MICHIGAN DURING THIS TIME...POTENTIALLY CLIPPING OUR
MICHIGAN ZONES. PTYPE LIKELY BEGINS AS RAIN BEFORE SLOWLY
TRANSITIONING TO A RAIN/SNOW/SLEET MIX HERE IN THE EVENING.

DEEP LAYERED TROUGH ENTERING THE PACIFIC NORTHWEST AS OF THIS
WRITING WILL FRACTURE EAST ACROSS THE ROCKIES LATER TONIGHT..WITH
ONE PIECE EMERGING INTO THE CENTRAL PLAINS TOMORROW. THIS UPPER WAVE
EVENTUALLY PHASES WITH AMPLIFYING/DIGGING NORTHERN STREAM ENERGY
TUESDAY NIGHT-WEDNESDAY. MODELS IMPRESSIVE WITH ~200 METER 5H
HEIGHT FALLS INTO THE NORTHERN OHIO VALLEY...SUPPORTING A
DEEPENING SFC CYCLONE TRACK EAST THROUGH SOUTHERN INDIANA/OHIO
LATER WED AM. VERY STRONG/DEEP FGEN SIGNAL AND AGEOSTROPHIC
RESPONSE UNDER MERGING UPPER JETS EXPECTED LATER TUE NIGHT.
MOISTURE ADVECTION ALSO IMPRESSIVE PER 5 G/KG TAP WITHIN 40 KNOT
CROSS ISOBARIC FLOW ON THE 300K SFC. FORCING BY WEDNESDAY MORNING
WILL THEN SHIFT TO A MORE MATURE/CLASSIC DEFORMATION AXIS. THIS
PROGGED DEEP UVM PLUME AND EXCELLENT MOISTURE TRANSPORT HAS LED TO
INCREASED CONFIDENCE FOR A RELATIVELY QUICK HITTING HEAVY PRECIP
EVENT DURING THIS TIME (MAINLY IN THE 8-18Z WINDOW).

AS ALWAYS PTYPE/SNOW AMOUNTS/IMPACTS WILL DEPEND ON TIMING/DEGREE OF
PHASING. 12Z MODEL GUIDANCE OVERALL TRENDED STRONGER/MORE
PHASED AND NORTH WITH THE TRACK OF THIS SYSTEM BRINGING PTYPE
CONCERNS FARTHER NORTH INTO SOUTHERN TWO THIRDS OF THE FA.
CURRENT EXPECTATIONS (MEDIUM CONFIDENCE) ALONG/SOUTH OF HWY 24 IN
ARE FOR PRECIP TO START AS RAIN TUESDAY NIGHT BEFORE ENDING AS A
PERIOD OF MOD-HEAVY SNOW...FOR A BRIEF WINTRY MIX CHANGING QUICKLY
OVER TO SNOW ACROSS CENTRAL ZONES...AND FOR MAINLY SNOW ACROSS FAR
NORTHERN ZONES. OPTED FOR A WINTER STORM WATCH FOR WESTERN/NORTHERN
ZONES (4-8 INCHES AND BLOWING SNOW)...BUT HELD OFF SOUTH OF HWY 24
IN INDIANA/OHIO GIVEN LATER CHANGEOVER TO SNOW (OPTED FOR A SPS AND
3-6" OF SNOW HERE).

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON MAR 10 2014

STG LL CAA WING WRAPPING IN BEHIND DEPARTING ERN OH BOMB TO START
THE PD WED NIGHT. POSITION OF SFC RIDGE AXIS AND REFRESHED DEEP SNOW
COVER WILL ALLOW TEMPS TO PLUMMET CWA WIDE. PER TRENDS SEEN IN MOS
GUIDANCE AND RAW 2M TEMP OUTPUT...WILL UNDERCUT MINS SUBSTANTIALLY.

OTRWS SHALLOW ARCTIC WEDGE WILL ERODE OUT JUST AS QUICK GOING INTO
FRI AHD OF POTENT NRN STREAM SW DISTURBANCE EJECTING EWD ACRS THE
NRN LAKES. WHILE EXTENT OF THERMAL RIDGE AHD OF THIS SYS HAS
WANED...STG MIXING XPCD SWD THROUGH THE WARM SECTOR AND AS SUCH WILL
HOLD CLOSE W/PRIOR NUMBERS.

REMAINDER OF THE PD IN FLUX W/INCONSISTENT MODEL HANDLING OF BOTH
WRN RIDGE EXTENT AND PLETHORA OF RIDGE RIDING DISTURBANCES BREAKING
SEWD INTO THE ERN US. NEAR SEASONABLE TEMPS TO START THE WEEKEND
WILL NOT LAST W/GENERAL DEEPENING OF ERN US TROUGHING. XPC MUCH OF
NXT WEEK TO REMAIN UNSEASONABLY COLD AND UNSETTLED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 820 PM EDT MON MAR 10 2014

LOW LEVEL RIDGING TO SHIFT INTO THE AREA TONIGHT BRINGING
GENERALLY LIGHT AND VARIABLE WINDS. SCT-BKN HIGH CLOUDINESS WILL
PERSIST THROUGH MUCH OF THE NIGHT BUT COMBINATION OF LIGHT WINDS
AND STRONG LOW LEVEL INVERSION SHOULD ALLOW FOR PATCHY FOG
FORMATION OVERNIGHT. GIVEN FAIRLY HIGH CROSSOVER TEMPS...IFR
CONDITIONS AND HAVE CONTINUED TO MENTION TEMPO IFR VSBYS IN THE
09Z-012Z TIMEFRAME. STORM SYSTEM DEVELOPING WEST OF THE AREA ON
TUESDAY WILL ALLOW WEST TO EAST SFC TROUGH TO SHARPEN ACROSS THE
REGION...WHICH SHOULD SUPPORT DEVELOPMENT OF LIGHT EAST NORTHEAST
WINDS ON TUESDAY. AFTER POTENTIAL MORNING FOG...VFR CONDITIONS ARE
EXPECTED THROUGH THE REMAINDER OF THIS FORECAST VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
     AFTERNOON FOR INZ003>009-012>018-020-022>025.

MI...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
     AFTERNOON FOR MIZ077>081.

OH...WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
     AFTERNOON FOR OHZ001-002-004-005-015-016.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...CEO/STEINWEDEL
LONG TERM...T
AVIATION...MARSILI


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