Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 182350

Area Forecast Discussion
National Weather Service Northern Indiana
650 PM EST Mon Feb 18 2019

Issued at 218 PM EST Mon Feb 18 2019

High pressure will briefly build in tonight into Tuesday with
skies trending mostly clear to partly cloudy. Lows tonight will
generally drop into the teens, with highs on Tuesday near 30
degrees. A storm system will bring a wintry mix of snow and
freezing rain later Tuesday night into Wednesday morning. Light
snow and ice accumulations may make for difficult travel during
this time. Precipitation then changes over to spotty drizzle and
light rain Wednesday afternoon and evening before ending. Drier
conditions will then follow Thursday into Friday with
temperatures near normal for late February.


.SHORT TERM...(This Evening through Tuesday)
Issued at 218 PM EST Mon Feb 18 2019

Broken, diurnally enhanced, MVFR stratocu field and isolated
flurries will diminish in coverage into this evening given loss of
daytime heating and continued deep layer subsidence/drying under
building heights aloft. This process will also allow low level
ridging to build in tonight-Tuesday with light winds and skies
trending mostly clear to partly cloudy.


.LONG TERM...(Tuesday Night through Monday)
Issued at 218 PM EST Mon Feb 18 2019

The large scale pattern will remain unchanged through this period
as southeast US ridging persists downstream of a Western CONUS
longwave trough. This will keep the local area in a somewhat
active west- southeast flow regime as several pieces of
jet/shortwave energy eject northeast out of the Four Corners.

The first shortwave of interest will lift into the Midwest and
Great Lakes bringing a wintry mix to rain/drizzle scenario later
Tuesday night into Wednesday. The Lower Great Lakes currently look
to avoid the heavier precipitation with this event as better deep
layer QG support bypasses west and influx of deeper GOM moisture
within LLJ core remains locked up closer to the Ohio River.
Thermal profiles favor snow to start later Tuesday night before
loss of ice nuclei (mid level dry slot) and eventual top down
warming supports a change to freezing rain/drizzle Wednesday
morning...and likely all spotty drizzle/light rain near the sfc
occlusion by Wednesday afternoon and evening as sfc temps warm
above freezing. Light snow/ice amounts may make for a slick
Wednesday AM commute and this will be something to monitor going
forward. Quiet/seasonable conditions are then expected behind this
system for Thursday and Friday as high pressure once again
briefly builds in.

12z model guidance has continued to be in overall good agreement
in a more phased, deeper, low level reflection taking a more
northerly track through the Upper Midwest and Western Lakes by
later Saturday and Sunday. Heavy rainfall (thunderstorms?) within
the leading warm/moist conveyor belt and strong gradient winds
appear to be the potential hazards at this time, though confidence
in details at this range is obviously very low.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 648 PM EST Mon Feb 18 2019

Anticipate gradual decrease in lake effect clouds throughout
northern Indiana into early tonight as Northern Plains ridge
spreads eastward into the western Great Lakes. Some detail
provided for backed/east to southeast flow on Tuesday as ridge
settles into the Lower Great Lakes.




SHORT TERM...Steinwedel
LONG TERM...Steinwedel

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