000
FXUS63 KIWX 291243
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
743 AM EST TUE JAN 29 2008

.AVIATION...
WIND SHEAR REMOVED WITH 12 UTC ISSUANCE. EARLIER PIREP RELAYED
THROUGH KFWA TOWER AND LOWEST WLCI3 GATES 50-60 KTS...NOW CLOSER
UPSTREAM OBS NOW MORE GUSTY AND WILL FORGO MENTION AS BL BECOMES
MORE MIXED WITH TIME. RAIN CHANCES...ALONG WITH SRLY WINDS WILL
INCREASE AS CONVERGENCE AND LOW LEVEL MOISTURE INCREASES AHEAD OF
A STRONG FRONTAL BOUNDARY THROUGHOUT THE DAY. THE MAIN FCST
PROBLEM/CONCERN WRT TIMING AND IFR CONDITIONS WILL CONTINUE TO BE
PASSAGE OF SAID FRONT LATER THIS EVENING. ABRUPT WIND
SHIFT/INCREASE AND ASSOCIATE TEMPERATURE FALL. MARKED VSBY
REDUCTION DUE TO SNOW/BLSN AND LOW END OF IFR AT KSBN WITH TOTAL
OBSCURATION AT TIMES WHERE HEAVIEST SNOW IS EXPECTED.

&&

.SHORT TERM...
TODAY AND TONIGHT. CRUX OF FCST FALLS WITH TIMING OF COLD FRONT.
PREFERENCE OF PAST FEW DAYS HAS LIED WITH SLOWER GFS/UKMET/ECMWF
WITH SRN STREAM CYCLOGENESIS IN PART FROM F-DY3 PREFERENTIAL EPAC
CA CLOSED CIRCULATION HANDLING. NOW NAM HAS TURNED TRIED/TRUE 180
TO MODEL OF CHOICE IN SHORT TERM WITH SLOWER FROPA/HINT OF
CYCLOGENETIC WAVE...AND WITH OBSERVATIONAL ISALLOBARIC FALLS ACRS
ARK AND 1KM EVE/EARLY AM MODIS WV IMAGERY ACRS INTR MTN RGN
INDICATING 5H UPR TROF STILL UNDERGOING SHARPENING...ALL POINTING
TO SHARPENING LATITUDINAL FLOW/SLOWING FNTS EWD PROGRESSION
THROUGHOUT THE DAY...OR AT LEAST MORE IN LINE PER NAM VS. FASTER
GFS. THIS AM...A FEW AM SHRA ON NOSE OF 50-55KT 925MB JETLET.
LATER TODAY...DEEPER MOISTURE WITH TONGUE OF 50+ SFC DPS ALREADY
PUSHED TO NEAR IA/IL/MO BORDER. LATER THIS AFTERNOON BEST MOISTURE
EKES INTO FAR SRN/SERN CWA...AND WITH STRONG KINEMATIC CAN NOT
RULE OUT TSRA WITH WINDS APPROACHING SEVERE LIMITS GIVEN PARCELS
LIFTED FROM ABOUT 875 ARE WEAKLY UNSTABLE AND COMPUTED MUCAPES ARE
APPROX 20-250 J/KG...SI M1-M2 IN LONG CORKSCREWED HODO SUGGESTIVE
OF A FEW LOW TOPPED LEWP SPSBL WITH SUBSTANTIVE 0-3KM BULK SHEAR
OF 40-45KTS. ABUNDANT MOISTURE AND 7-6H DEFORMATION ZONE TO AID IN
ACCUMULATIVE SNOWFALL BEHIND ARCTIC BOUNDARY. TRACK OF 7H/12HR
HEIGHT FALLS ACRS NWRN ZNS OF NEARLY 190 METERS MAKES COBB
ALGOIRITHM NAM-WRF OUTPUT PRODUCING HOURLY SNOWFALL RATES OF 2.2
AND 1.7 INCHES AT KSBN AT 03 AND 04 UTC WED RESPECTIVELY...
PLAUSIBLE. WINTER STORM WARNINGS ISSUED LAST EVENING REMAIN
INTACT...WITH MULTI-HAZARDS SN/BLSN/WCI/NEAR WHITEOUT
CONDITIONS/ICY ROADS ACRS NWRN ZNS 2-4 INCHES GENERAL AMOUNTS WITH
LOCAL 5 PSBL FAR NWRN CWA. 1-3 WITH ADVISORY ELSEWHERE.

&&

.LONG TERM...
WEDNESDAY THROUGH MONDAY. THE PRESSURE GRADIENT WILL START OUT
RATHER TIGHT WEDNESDAY MORNING AND THEN DECREASE THROUGHOUT THE
DAY...AS HIGH PRESSURE MOVES IN. THE WESTERLY WIND WILL GIVE JUST
THE NORTHERN PART OF THE CWA SOME LAKE EFFECT SNOW CHANCES. THE
STRONG WIND IN THE MORNING CAN ALSO CAUSE AREAS OF BLOWING SNOW.
THEN DRY WITH HIGH PRESSURE IN PLACE WEDNESDAY NIGHT THROUGH
THURSDAY. AN UPPER LEVEL TROUGH IS PROGGED TO BE DIGGING THROUGH
THE SOUTH CENTRAL U.S. WEDNESDAY NIGHT...GENERATING A SURFACE LOW.
ON THURSDAY THIS SYSTEM WILL MOVE NORTHEASTWARD TOWARDS THE CWA.
THEN THURSDAY EVENING/NIGHT THE LOW IS PROGGED TO MOVE
NORTHEASTWARD THROUGH THE OHIO RIVER VALLEY. THE GFS IS THE MOST
PROGESSIVE WITH THE SYSTEM...MOVING THE LOW TO WESTERN OHIO BY 12Z
FRIDAY...WHEREAS THE ECMWF ONLY MOVES THE LOW TO WESTERN KENTUCKY
AND THE NAM MOVES IT TO CENTRAL KENTUCKY. THIS WILL BRING SNOW
CHANCES TO THE AREA. PROFILES ALSO INDICATE THAT SOME FREEZING
RAIN OR SLEET COULD BE POSSIBLE WITH THE SNOW FROM LATE THURSDAY
NIGHT INTO FRIDAY MORNING. FRIDAY THE GFS MOVES THE LOW TO NEW
ENGLAND AND THE ECMWF MOVES IT ONLY TO CENTRAL OHIO. DID NOT ALTER
THE FORECAST FOR THIS SYSTEM WITH SOME TIMING ISSUES YET. FRIDAY
NIGHT IS DRY THOUGH AS THE MODELS DO MOVE THE SYSTEM FAR ENOUGH TO
THE NORTHEAST AND MOVE HIGH PRESSURE INTO OUR AREA. DIFFERENCES ON
SATURDAY ALSO. ECMWF MOVES A SHORTWAVE INTO THE AREA WHEREAS THE
GFS MOVES A LOW TO JAMES BAY UP IN CANADA WITH A FRONT DOWN INTO
THE GREAT LAKES. SUNDAY NIGHT INTO MONDAY THERE COULD BE ANOTHER
SYSTEM TO MOVE THROUGH OUR AREA BUT MODELS ARE NOT CONSISTENT YET
WITH IT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
     WEDNESDAY FOR INZ007-009-017-018-023>027-032>034.

     WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 10
     AM EST /9 AM CST/ WEDNESDAY FOR INZ003>006-008-012>016-020-
     022.

MI...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
     WEDNESDAY FOR MIZ081.

     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     WEDNESDAY FOR MIZ077>080.

OH...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
     WEDNESDAY FOR OHZ001-002-004-005-015-016-024-025.

LM...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 1 PM EST
     WEDNESDAY FOR LMZ043-046.
     GALE WARNING UNTIL 1 PM EST WEDNESDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...LOTHAMER
AVIATION...MURPHY

----------------------------------------------------------------------

000
FXUS63 KIWX 311053
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
553 AM EST THU JAN 31 2008

.SHORT TERM...
TODAY THROUGH FRIDAY. FOCUS ON STORM AND UPGRADE OF HEADLINES TO
WINTER STORM WARNING. EVENING 1KM MODIS WV IMAGERY DEPICTS POTENT
ENERGY OVR 4 CORNERS TO DIG SRN PLAINS SYSTEM PREFERENCE LIES WITH
STRONGER NAM...WITH GFS LOSING STRENGTH/FOCUS BEYOND F24.
ANTICIPATE RATHER LARGE AREA OF SNOW GIVEN BREADTH OF 7H/12HR
HEIGHT FALLS ACRS CWA OF GT 50 TO AS MUCH AS 110M FM 03 UTC FRI TO
00 UTC SAT. BEYOND 18 UTC FRI ENERGY XFER TO COAST UNDERWAY WITH
EVENT ON DOWNTURN. 03-12UTC NAM12 FRI TREMENDOUS 40-50KT
ORTHOGONAL COMPONENT FLOW TO I285K SFC AND BY 12 UTC FRI NEARLY
4.5G/KG MOISTURE TAP REACHING INTO SERN FA AROUND 870MB...QUITE
PLAUSIBLE LOOKING AT 925-850MB PLANAR LAYER VIEW WITH COLLECTIVELY
POOLED/CONVERGENT ATLANTIC AND GULF INFLOW. CERTAINLY NOT ALL IN
WITH COBB 06UTC NAMWRF OUTPUT AT KFWA OF 19.3 INCHES...YET
CERTAINLY LOOKING AT XSECTIONAL DEEP MOISTURE SATURATION IN DGZ
COLLOCATED IN OVERTURNED THETA-E...CONDUCIVE FOR MESOBANDING
ESPCLY 06-15 UTC. HAVE GONE WIDE AREA OF 7-14 FOR NOW WITH MENTION
OF AREAS OF BLSN ESPECIALLY FOR OPEN AREAS...WINTER STORM WORDING
VS. HEAVY SNOW WITH ASSUMPTION THAT IP/ZR LINE COULD SHIFT FURTHER
NWRD...HOWEVER BASED ON CENTROID OF 7H HEIGHT FALLS WELL S OF
CWA...THIS MAY BE LOW PROBABILITY. SLIGHTLY LESSER AMOUNTS FAR
NWRN ZONES...UP TO 2/10 ICE ACCUM FAR SERN ZONES WHERE WELL
DEVELOPED ISENT TROWAL BECOMES SUFFICIENT DEEP LATE TONIGHT AND
EARLY FRIDAY.

&&

.LONG TERM...
FRIDAY NIGHT THROUGH WEDNESDAY.

LAKE EFFECT IN THE WAKE OF THE DEPARTING SNOWSTORM LOOKS RATHER
BLEAK FOR THE AREA. FETCH WILL BRIEFLY LINE UP ALONG THE LONG AXIS
OF LK MICHIGAN BUT POOR PRECONDITIONING AND RESIDENCE TIME AND A
RAPIDLY CHANGING FLOW WILL ALL LIKELY SPELL DOOM FOR MUCH IN THE WAY
OF PRECIP. WILL LEAVE THE INHERITED CHC FLURRIES IN FOR FRI NGT.

WEAK SYSTEM WILL MOVE THROUGH SATURDAY NIGHT ACROSS THE NORTHERN
GREAT LAKES. LACK OF MSTR AND OVERALL LIFT WILL PRECLUDE ANY
SIGNIFICANT PRECIP SO HAVE LEFT POPS AS IS IN THE FAR NORTHERN
AREAS. OF MORE POTENTIAL CONCERN WILL BE LOW PRESSURE SET ONCE AGAIN
TO DEVELOP OVER THE KANSAS/OKLAHOMA AREA AND TRACK NORTHEAST TOWARDS
THE REGION. MUCH OF THE FORECAST AREA WILL REMAIN ON THE WARM SIDE
OF THIS SYSTEM BASED ON 1000-850 MB THICKNESS VALUES WELL ABOVE 1300
M. POTENTIAL EXISTS FOR SOME FREEZING RAIN AT THE ONSET...BUT TEMPS
THROUGH THE COLUMN SHOULD WARM ENOUGH TO LEND TO ALL RAIN. MIXED
BAG OF PRECIP TO REMAIN IN GRIDS FOR NOW UNTIL MODELS CAN FULLY
AGREE ON THERMAL PROFILES.

&&

.AVIATION...
MAIN FOCUS ON UPCOMING WINTER STORM. WILL INCLUDE FINE DETAIL TOWARD
END OF FCST PERIOD TO SERVE AS OUTLOOK FOR RAPIDLY DETERIORATING
CONDITIONS TO LIFR BY END OF FCST PERIOD. MORE DETAILS WRT SYSTEM
INCLUDING PSBL HEAVY SNOW/BLSN...LONG DURATION LIFR CONDITIONS...
WITH 12 UTC ISSUANCE.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 7
     PM EST /6 PM CST/ FRIDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST FRIDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST FRIDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY

----------------------------------------------------------------------

000
FXUS63 KIWX 041059
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
559 AM EST TUE MAR 4 2008

.SHORT TERM...
ENERGETIC SHORTWAVE CUTOFF EMERGING SAMPLED BEAUTIFULLY BY 1KM
MODIS WV IMAGERY AT 05 UTC ACRS SERN TX...BEING KICKED NORTHEAST
AS NEXT NRN STREAM POS TILT TROF PUSHES INTO INTMTN REGN. WHILE
INITIAL CONCERN WAS BACK EDGE OF PRECIP PUSHING THROUGH INTO NWRN
OH WITH BACK EDGE/CUSP OF INTIAL WAVE. INTIAL SFC/1000MB CPD OF
50-100MB IN CLEARING SKIES TO PROVIDE AN INITIAL BLOCK FOR
PRECIP AND SFC DEWPOINTS IN SINGE DIGITS JUST NW OF LK MI POSE
CONCERN FOR BERRIEN COUNTY PRECIP TOTALS SHOULD LOW LEVEL WINDS
BACK ANY PRIOR TO ONSET OF PRECIP LATER TODAY. HOWEVER...THINK GFS 
FAILS TO HANDLE QUITE AS WELL AS NAM THE LOCAL CHANGE OF THE
ISENTROPIC SURFACE AS THE SHORTWAVE APPROACHES LATER THIS EVENING
AND WITH VERY STRONG/DEEP MOISTURE. DEEP SATURATION LAYER WITH CSI
SIGNALS INVERTED EQUIV POTENTIAL TEMPERATURE/DENDRITIC
OMEGA/SATURATED NEG EPV LAYER SUGGEST BANDED HEAVY SNOW POTENTIAL
LATE THIS EVENIGN ROUGHLY LOGANSPORT TO COLDWATER AS SYSTEM LIFTED
NE. PRIOR IN SHALLOW COLD AIR PROFILES OF ZR TO ZR/IP TO IP/S SE
TO NW WITH POTETNIAL FOR SIG ICING FAR SERN ZONES. ALL HEADLINES
REMAIN IN TACT...WITH ADJUSTMENTS ONLY FOR START TIMES.

&&

.LONG TERM...
WEDNESDAY THROUGH MONDAY...SOME LINGERING LIGHT SNOW IS POSSIBLE AS 
A WEAK UPPER LEVEL SYSTEM MOVES ACROSS THE AREA EARLY WEDNESDAY. 
MORE SNOW IS POSSIBLE FOR MUCH OF THE REST OF THE PERIOD AS THE LONG 
WAVE TROF TRANSLATES INTO THE GREAT LAKE REGION AND AS WEAKER 
SYSTEMS MOVE THROUGH THE MAIN UPPER AIR PATTERN. ALSO...LAKE 
EFFECT SNOW IS POSSIBLE SATURDAY AS ARCTIC AIR SPREADS INTO THE 
REGION. TEMPERATURES SHOULD BE BELOW NORMAL THROUGH THE 
PERIOD...ESPECIALLY SATURDAY. GFS MEX MOS HIGHS IN THE 20S SATURDAY 
SEEM REASONABLE GIVEN 850 MB TEMPS CLOSE TO -20C. 



&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR INZ018-023>027-
     032>034.

     WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST 
     WEDNESDAY FOR INZ005>009.

     SNOW ADVISORY FROM 2 PM EST /1 PM CST/ THIS AFTERNOON TO 1 AM 
     EST /MIDNIGHT CST/ WEDNESDAY FOR INZ003-004.

     WINTER STORM WARNING FROM 2 PM EST /1 PM CST/ THIS AFTERNOON TO 
     7 AM EST /6 AM CST/ WEDNESDAY FOR INZ012>017-020-022.

MI...WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST 
     WEDNESDAY FOR MIZ079>081.

     SNOW ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM EST WEDNESDAY FOR 
     MIZ077-078.

OH...WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR OHZ002-004-005-
     015-016-024-025.

     WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST 
     WEDNESDAY FOR OHZ001.

LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.

&&

$$

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