Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 250940

Area Forecast Discussion
National Weather Service Northern Indiana
440 AM EST Sat Feb 25 2017

Issued at 438 AM EST Sat Feb 25 2017

Colder air will continue to filter in today with some snow
showers, especially near Lake Michigan. Light snow accumulations
are likely over northwest Indiana into southwest Lower Michigan
with up to an inch expected before ending by this evening.
Temperatures will remain steady today or even continue to fall a
few degrees through the day. Lows by Sunday morning will be in the
lower to middle 20s. The colder air will be short-lived however,
as temperatures warm back into the lower to middle 40s Sunday
afternoon. Rain likely returns by midweek with temperatures into
the 50s on Wednesday.


.SHORT TERM...(Today and Tonight)
Issued at 432 AM EST Sat Feb 25 2017

Snow within upstream deformation axis/wrapped moisture to provide
brief bout of accumulating snowfall for nwrn cwa. Best and not
stellar supersaturation within thin dgz layer/uvm/dcva appears in 15-
18 UTC timeframe today for nwrn cwa. Nominal snowfall rates/partial
melt with initial warm ground/roads to likely afford accums of
generally an inch or less total. Deeper moisture/lake enhancement
and better dynamics relegated north of cwa. As upper level system
now over northern Lake Mi quickly rotates/weakens into far sern
Ont/Lwr Great Lakes by this evening snow to rapidly taper/end amid
building heights/thinning moisture profiles. As strong post frontal
cold air advection continues/deepens will provide nearly steady
temps west to slowly fall continuing west and held the line on max
temps. Degree of partial clearing late tonight along with potential
late night decouple critical with respect to lows and have favored a
bit colder than model blend with downside potential/low level
thermal troffing into nern cwa.


.LONG TERM...(Sunday through Friday)
Issued at 432 AM EST Sat Feb 25 2017

Heights rebuild rapidly in wake of latest strong cyclone moving into
northeast Canada/off New England coast affording a rapid
recovery/warming of temps through midweek. Thereafter focus
primarily on approach of deepening progressive trof. Initially
positive tilted Tue over western states to more neutral over Upper
Great Lakes by Thursday. Open gomex feed along with warm frontal
zone retreating northward with several progressive frontal waves
should provide a rather wet period Tue-Wed. As system passes to
northeast additional upper air energy digs in providing period of
strong downstream cyclogenesis with potential lake effect snow Thu
night into Fri as trailing lake aggregate trof and significantly
colder air presents with major axis Lake Mi fetch.


.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1253 AM EST Sat Feb 25 2017

Much colder air was spreading into the forecast area accompanied
by a large area of MVFR clouds upstream. As the colder air spreads
over the relatively warm waters of Lake Michigan, snow showers
are expected to develop and move inland. Most of the snow showers
should stay north of SBN, but have included some lower clouds
there along with snow showers in the vicinity. Otherwise, winds
should diminish some by this evening with conditions becoming


LM...Small Craft Advisory until 4 PM EST Sunday for LMZ043-046.



LONG TERM...Murphy

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