Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 310023
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
823 PM EDT THU OCT 30 2014

.SYNOPSIS...
ISSUED AT 822 PM EDT THU OCT 30 2014

A STRONG STORM SYSTEM ACROSS THE NORTHERN GREAT LAKES WILL DROP
INTO THE REGION ON FRIDAY BRINGING RAIN SHOWERS ALONG WITH WINDY
AND COLDER CONDITIONS. AS COLDER AIR FILTERS INTO THE AREA FOR
FRIDAY...SOME SNOW IS ALSO POSSIBLE...BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. SNOW SHOWERS ARE EXPECTED TO DIMINISH
FRIDAY NIGHT AS THE STORM SYSTEM PULLS OFF TO THE EAST...BUT
UNSEASONABLY COOL CONDITIONS WILL PERSIST INTO THE WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 408 PM EDT THU OCT 30 2014

UPPER LEVEL SYSTEM DIGGING INTO THE GREAT LAKES TONIGHT WILL
BRING STRONG NORTHWEST WINDS TO THE AREA...ALONG WITH A
LIKELIHOOD OF RAIN AND SNOW SHOWERS LATE TONIGHT THROUGH FRIDAY.

WATER VAPOR IMAGERY THIS AFTERNOON DEPICTS A SHORT WAVE ACROSS
THE MID MS RIVER VALLEY THAT SHOULD TAKE A TRACK PRIMARILY JUST
SOUTH OF THE LOCAL AREA THIS EVENING. A NARROW ZONE ZONE OF WEAK
WARM ADVECTION/FRONTOGENESIS MAY ALLOW A FEW SPRINKLES TO
OVERSPREAD MAINLY FAR SOUTHERN PORTIONS OF THE AREA LATE
AFTERNOON/EARLY EVENING. ATTENTION FOR THE REMAINDER OF THE NIGHT
WILL FOCUS ON MORE POTENT UPPER PV ANOMALY CURRENTLY DROPPING
ACROSS THE NORTHERN GREAT LAKES. AN INITIAL WEAK SFC TROUGH IS
EXPECTED TO TRACK ACROSS THE LOCAL AREA DURING THE OVERNIGHT
HOURS IN ASSOCIATION WITH EASTWARD PROGRESSION OF AFOREMENTIONED
MID MS VALLEY SHORT WAVE...WHICH WILL BE FOLLOWED BY THE MUCH
STRONGER COLD FRONTAL PUSH AFTER DAYBREAK FRIDAY. ISALLOBARIC
COUPLET IS NOT EXPECTED TO BE OVERLY STRONG WITH THIS
SYSTEM...BUT STRONG COLD ADVECTION AND DEEPENING MIXED LAYER WILL
SUPPORT POST FRONTAL WIND GUSTS OF AROUND 40 TO 45 MPH ACROSS
ESPECIALLY NORTHWEST THIRD OF THE AREA FRIDAY MORNING...WITH A
FEW GUSTS TO 50 TO 55 MPH NOT OUT OF THE QUESTION CLOSER TO THE
LAKE MICHIGAN SHORELINE. GUSTS MAY BE SOMEWHAT MORE TEMPERED
ACROSS SOUTHEAST HALF OF THE FORECAST AREA WHERE LOW LEVEL
GRADIENT WILL BE A BIT WEAKER AND CHARACTERIZED BY MORE
PRONOUNCED LOW LEVEL CYCLONIC FLOW. WILL ISSUE A WIND ADVISORY
FOR FAR WEST/NORTHWEST LOCATIONS FOR FRIDAY MORNING THROUGH
FRIDAY EVENING. CRITERIA LEVEL GUSTS ARE EXPECTED TO BE
MAINTAINED THE LONGEST INTO FRIDAY EVENING CLOSER TO THE LAKE
MICHIGAN SHORELINE. A LAKE SHORE FLOOD ADVISORY WILL REMAIN IN
EFFECT FOR FRIDAY/FRIDAY NIGHT WITH SOME BEACH EROSION AND MINOR
SHORELINE FLOODING POSSIBLE GIVEN STRONG WINDS/WAVES AND SLIGHTLY
ABOVE AVERAGE LAKE MICHIGAN WATER LEVELS.

IN TERMS OF PRECIPITATION...A BAND OF FAIRLY STRONG LOW LEVEL
FRONTOGENESIS PRECEDING MAIN UPPER TROUGH SHOULD SPREAD RAIN
SHOWERS ACROSS NORTHWEST PORTIONS OF THE AREA IN THE 09Z-12Z
TIMEFRAME...OVERSPREADING THE REMAINDER OF THE AREA THROUGH
FRIDAY MORNING. A BRIEF LULL IN PRECIP COVERAGE MAY OCCUR BETWEEN
MORE FRONTALLY FORCED PRECIP AND STRONGER UPPER LEVEL DPVA
ACCOMPANYING THE STRONGER UPPER VORT MAX. LOW LEVEL WET BULBS
SHOULD SUPPORT PRIMARILY RAIN SHOWERS THROUGH EARLY AFTERNOON
ACROSS MOST LOCATIONS...WITH SOME SNOW SHOWERS POSSIBLY MIXING IN
FROM NORTHWEST TO SOUTHEAST FRIDAY AFTERNOON INTO EARLY EVENING.
ALL INDICATIONS STILL POINT TOWARD LAKE EFFECT RAIN SHOWERS
BECOMING MORE PROMINENT BY LATE MORNING...LIKELY EVOLVING INTO A
DOMINANT SINGLE BAND...ALTHOUGH FORECAST SOUNDINGS DO SUGGEST
ABOUT 30 DEGREES OF SHEAR IN CLOUD BEARING LAYER. LAKE INDUCED
INSTABILITY PROFILES STILL LOOK QUITE IMPRESSIVE PER NAM BUFFER
SOUNDINGS...WITH LAKE INDUCED EQUILIBRIUM LEVELS TO AROUND 20K FT
BY MIDDAY. THUS...HAVE MAINTAINED CHANCE THUNDER MENTION THROUGH
THE DAY ACROSS THE EXTREME NORTHWEST. WITH A LONG RESIDENCE TIME
OF LOW LEVEL PARCELS GIVEN NORTHERLY FETCH...CONFIDENCE REMAINS
LOW IN EXTENT OF SNOW SHOWERS LATER IN THE AFTERNOON WITH CONCERN
THAT BOUNDARY LAYER MODIFICATION MAY BE A BIT TOO MUCH TO
OVERCOME. HAVE LARGELY REMAINED WITH PREVIOUS FORECAST IDEA OF
INCH OR LESS ACCUMULATIONS DOWNWIND OF THE LAKE...AND MAINLY A
BIT INLAND WHERE INFLUX OF SLIGHTLY DRIER LOW LEVEL AIR MAY AID
IN FROZEN PTYPE FOR A TIME. EXACTLY WHERE MORE DOMINANT BANDING
SETS UP IS ALSO OF LOW CONFIDENCE DEPENDING ON EXACT
TRACK/STRENGTH OF MID LEVEL SYSTEM AS IT DROPS INTO THE SOUTHERN
GREAT LAKES...AND A CLUSTER OF HIGHER RES SOLUTIONS DEPICT MORE
DOMINANT BANDING SHIFT WEST OF THE AREA.

FOR TEMPS...HAVE UTILIZED NON-DIURNAL CURVE FOR FRIDAY WITH
STEADY OR SLOWLY FALLING TEMPS THROUGH THE DAY UNDER STRONG COLD
ADVECTION.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 408 PM EDT THU OCT 30 2014

INITIAL FOCUS WILL BE ON EXPECTED LAKE EFFECT BAND WHICH MAY BE
RESIDING NEAR OR JUST OVER FAR WESTERN PARTS OF THE FORECAST
AREA. BEST WINDOW FOR ANY PRECIP (LIKELY IN THE FORM OF SOME WET
SNOW) WILL BE IN THE 00Z TO 03Z WINDOW BEFORE THE FLOW BECOMES
MORE NNE AND MOVES INTO FAR NW INDIANA. MORE INTENSE SNOW SHOWERS
COULD PRODUCE SOME LIGHT ACCUMULATIONS IN GRASSY AREAS BUT ROADS
SHOULD HOPEFULLY REMAIN ONLY WET EXCEPT FOR ELEVATED SURFACES. IN
THE EAST...SFC LOW WILL BE RAPIDLY REFORMING OVER THE CAROLINAS
FRIDAY EVENING AND MOVE OFF THE EAST COAST ON SATURDAY. INVERTED
TROUGH FROM THE LOW INTO THE OHIO VALLEY...WILL PERSIST THROUGH
SATURDAY MORNING BEFORE SHIFTING EAST. HIGHEST POPS WILL PERSIST
IN THE EVENING WITH TAPERING OVERNIGHT. PRECIP BY THIS POINT
SHOULD ALSO BE IN THE FORM OF WET SNOW WITH A DUSTING OF SNOW
POSSIBLE ON GRASSY AREAS. WINDY CONDITIONS WILL SLOWLY SUBSIDE
THROUGH THE NIGHT WITH GREATEST HEADLINE WORTHY AREA BEING ALONG
THE LAKE SHORE WITH TIGHTEST GRADIENT EARLY EVENING.

COLD HIGH PRESSURE MOVES ACROSS THE AREA OVER THE WEEKEND WITH
HIGHS IN THE 40S (THINK MANY AREAS MAY STRUGGLE TO REACH 40 EVEN
WITH SUNSHINE ON SATURDAY). TEMPERATURES WILL MODERATE BACK
CLOSER TO NORMAL FOR THE START OF THE WEEK AS LOW PRESSURE
DEVELOPS ACROSS THE PLAINS AND TRACKS INTO CANADA FOR THE MIDDLE
OF THE WEEK. A COLD FRONT WILL EXTEND FROM THE FRONT WITH AT
LEAST SOME MOISTURE RETURN BY THE MONDAY NIGHT TO TUESDAY NIGHT
PERIOD. LIKELY POPS WERE INTRODUCED IN LAST FORECAST AND WHILE
NOT OVERLY WILD THIS FAR OUT WITH POPS THIS HIGH WILL STICK WITH
SIGNALS AND KEEP GENERAL IDEA IN PLACE. YET ANOTHER WAVE WILL
QUICKLY APPROACH WEDS NGT WARRANTING SLGT CHC POPS MAINLY NE
WHERE BETTER MSTR AND LIFT WILL EXIST AS MAIN TROUGH IMPACT
CENTRAL/NORTH GREAT LAKES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 815 PM EDT THU OCT 30 2014

DETERIORATING CONDITIONS AS NORTHERN GREAT LAKES CYCLONE
INTENSIFIES AS 120-150M/12HR FALLS CONGEAL ACROSS NORTHERN
INDIANA. FRONTAL WIND SHIFT DETAIL PUSHED AN HOUR BACK FOLLOWED
BY SHRA POTENTIAL EARLY FRI AM AS CIGS LOWER TO HIGH END MVFR
FOLLOWED BY POTNL LAKE ENHANCED PERIOD OF HEAVIER SHRA INVOF KSBN
LATE AM INTO MIDDAY...WITH EPISODIC IFR CONDITIONS POSSIBLE. SIG
BUMP IN WIND SPEED/GUSTS AS DEEPER CAA INVADES FRI AFTN...HIEST
NEAR LAKE MICHIGAN/KSBN. CONTINUE GREATER OPTIMISM AT
KFWA...REMOVED FROM LAKE MICHIGAN ADDITIVE MOISTURE...WITH
CONDITIONS ABOVE FUELING/ALTERNATE REQUIREMENTS. COOLING OF SFC-
2KFT LAYER WETBULB TEMPS COULD SUPPORT MIX TO RASN...THOUGH MORE
LIKELY JUST BEYOND CURRENT FCST PD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY FROM 7 AM TO 10 PM CDT FRIDAY FOR INZ003.

     LAKESHORE FLOOD ADVISORY FROM 7 AM FRIDAY TO 4 AM CDT SATURDAY
     FOR INZ003.

     WIND ADVISORY FROM 10 AM EDT /9 AM CDT/ TO 8 PM EDT /7 PM CDT/
     FRIDAY FOR INZ004-005-012>015-020-022.

MI...WIND ADVISORY FROM 8 AM TO 11 PM EDT FRIDAY FOR MIZ077.

     LAKESHORE FLOOD ADVISORY FROM 8 AM FRIDAY TO 5 AM EDT SATURDAY
     FOR MIZ077.

     WIND ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR MIZ078-079.

OH...NONE.
LM...STORM WARNING FROM 8 AM TO 8 PM EDT FRIDAY FOR LMZ046.

     GALE WARNING FROM 8 PM FRIDAY TO 5 AM EDT SATURDAY FOR LMZ046.

     GALE WARNING FROM 8 AM FRIDAY TO 5 AM EDT SATURDAY FOR LMZ043.

&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...FISHER
AVIATION...MURPHY


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