Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 081802
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
102 PM EST MON FEB 8 2016

.SYNOPSIS...
ISSUED AT 1143 AM EST MON FEB 8 2016

ACCUMULATING SNOWFALL IS EXPECTED ACROSS MUCH OF THE GREAT LAKES
THROUGH AT LEAST THURSDAY. AMOUNTS DURING ANY ONE PERIOD WILL BE
GENERALLY LIGHT BUT THE LONG DURATION OF THE EVENT MAY ALLOW AREAS
NEAR LAKE MICHIGAN TO SEE BETWEEN 6 AND 12 INCHES OF SNOW BY THE
TIME THURSDAY MORNING ROLLS AROUND. ARTIC AIR WILL IMPACT THE
REGION LATER THIS WEEK DROPPING HIGHS INTO THE TEENS TO LOW 20S
AND LOWS IN THE SINGLE DIGITS ABOVE ZERO. TODAYS HIGH TEMPERATURES
WILL RANGE FROM THE LOWER 30S IN THE WESTERN INDIANA TO THE LOWER
40S IN WESTERN OHIO. LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS
IN SOUTHWESTERN INDIANA TO THE MIDDLE 20S IN NORTHWESTERN OHIO.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 424 AM EST MON FEB 8 2016

PRIMARY FOCUS FROM NEAR TERM THROUGH WED NIGHT IS TO DELAY ONSET OF
PRIMARY LES EVENT OWING TO SLOW SWRN GRTLKS FUJIWHARA WITH CONSERTED
COLD POOL PLUNGE DLAD. INITIAL SHEARED ENVIRONMENT AND MODEST
DIFFERENTIALS TO PROVIDE SOME LAKE ENHANCEMENT OF SYNOPTIC
MOISTURE/ARCTIC FRONTAL SHSN WITH EPISODIC WAVES OF ENHANCED
DEFORMATION/DCVA EMANATING FROM THE UPPER MS VLY REGION. UNTIL
180 KT ULVL JET PRESENTLY TOPPING RIDGE/FAR NRN BC DRIVES SWD
TOWARDS LWR MO VALLEY ON TUE WILL LES INGREDIENTS TO CONGEAL. LAKE
EFFECT CAPE AND LAKE INDUCED EQL APPEAR BROADLY RAMPED WITH
RESPECT TO TIME AND PEAK ON ORDER OF 400 J/KG AND 13 KFT WED AFT
RESPECTIVELY. ANTICIPATE A FEW LES BANDS TO BECOME WELL
ESTABLISHED AND PERSIST TUE NIGHT INTO WED...IF NOT INTO FIRST
HALF WED NIGHT BEFORE DOWNTURN STARTS. TOTAL ACCUMS ESTABLISH WELL
WITHIN RANGE OF MULTIMODEL COBB AVERAGES WITH/WITHOUT COMPACTION
AND CLOSE TO OR SLIGHTEST UPWARD NUDGE OVER PRIOR FORECASTS AND
CONSISTENT WITH TRENDS.

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 424 AM EST MON FEB 8 2016

DEEP UPPER LEVEL TROUGH WILL BEGIN TO FINALLY PULL AWAY FROM THE
AREA. NW FLOW WILL PERSIST THROUGH AT LEAST THE FIRST HALF OF
THURSDAY WITH HIGH CHC TO LIKELY POPS WARRANTED FOR LIGHT QPF/ACCUMS
AS DELTA T`S IN THE MID 20S. ALIGNMENT OF DGZ AND BEST LIFT WILL NOT
BE FULLY MESHED BUT STILL ENOUGH TO HOLD ONTO HIGHER POPS THAN
DEPICTED BY SUPERBLEND OF MODELS.

LOW LEVEL FLOW AND THERMAL CONTRIBUTIONS WILL BECOME MORE
CHALLENGING AFTER THURSDAY WITH REGARDS TO SFC TEMPERATURES AS WELL
AS LAKE EFFECT POTENTIAL. MED RANGE MODELS CONSISTENT WITH REGARDS
TO -28 TO -34 C CORE OF 850 TEMPS ACCOMPANYING DEEP UPPER LOW.
HOWEVER...WHERE THIS WILL END UP IS LESS CERTAIN. 12Z RUNS OF GFS
AND ECMWF WERE MORE TOWARDS THE NE STATES. 00Z GFS HOLD WITH THIS
IDEA, BUT 00Z ECMWF BRINGS CORE OF COLD AIR INTO THE EASTERN GREAT
LAKES. AT THIS POINT...WILL MAINTAIN PREVIOUS IDEA OF SLGT CHC TO
CHC POPS CLOSER TO THE LAKE. ENOUGH CONFIDENCE IN COLDER TREND TO
LOWER TEMPS A FEW DEGREES FRI INTO SAT. IF CORE OF COLDER AIR DOES
COME FURTHER WEST...THEN A SIGNIFICANT DROP IN TEMPS WILL BE
WARRANTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 101 PM EST MON FEB 8 2016

MVFR CONDS XPCD THIS PD AS UPR LOW SETTLES IN ACRS THE WRN LAKES.
HWVR FAR BTR MID LVL MSTR AND INHERENT DYNAMICS WILL REMAIN WEST
OF THE TERMINALS THROUGH THIS AFTN BFR SHIFTING EWD OVERNIGHT
TIMED W/LT PD INFLUX OF LL CAA. THIS WILL SPURN MORE
SIG/WIDESPREAD SHSN DVLPMNT LT TONIGHT PRIMARILY INVOF OF KSBN
GIVEN PROXIMITY OF INFLUXING LK BASED MSTR FLUX W/A PD OF IFR VSBY
RESTRICTION PSBL YET WILL HOLD A BIT MORE OPTIMISTIC PER
CONFLICTING NR TERM MODEL SIGNALS AND GREATER LIKELYHOOD OF MORE
SIG LK EFFECT SNOW BANDS FORMING/HOLDING WEST OF THE TERMINAL.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 AM TUESDAY TO 10 AM EST THURSDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...T


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