Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 161745

Area Forecast Discussion
National Weather Service Northern Indiana
145 PM EDT Mon Apr 16 2018

Issued at 350 AM EDT Mon Apr 16 2018

Scattered snow showers, possibly mixed with rain, are expected to
continue into tonight as a cold upper level system moves through
the region. Cool temperatures will continue tonight dropping back
into the 20s, but will be able to warm upper 30s to mid 40s
Tuesday. A warming trend takes hold into midweek when we have
another chance for rain.


.SHORT TERM...(Today and Tonight)
Issued at 344 AM EDT Mon Apr 16 2018

Deep mid level circulation to track through the southern Great
Lakes today. Cold air advection deepens with lake enhancement and
minor perturbations to bring mix ra/sn showers with marginal
surface temperatures lending partial melt. Inland lake region
expected to remain frozen precipitation type proximal to low level
cold core. Gradual decrease in precipitation response overnight
as system energy transfers to mid Atlantic region. Of note are
apparent temperatures into the middle/upper teens late tonight
into early Tuesday, owing to magnitude of low level cold pool and
lack of decoupling.


.LONG TERM...(Tuesday through Sunday)
Issued at 344 AM EDT Mon Apr 16 2018

Intervening surface ridge between downstream and upstream vortex
presently moving into northern CA. Plains cyclogenetic response
midweek with similar track through southern portion of Great Lakes.
Sufficient warm sector establishment to largely maintain
precipitation as liquid, save for northeast CWA late Wednesday
night. Thereafter an extended dry period for Thursday into at least
early next week as another system cuts off over four corners region
Friday and tracks eastward through Gulf states. Rexing ridge to
dominate north of this vortex, through the plains and into the
western Great Lakes. Gradual thermal moderation through the period,
though only to near/slightly below normal by early next week, with
surface ridge of dry/CP Canadian Rockies origin.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 136 PM EDT Mon Apr 16 2018

An upper level low pressure system overhead slowly pushes off to
the east during the day today, but not before allowing for low
clouds, scattered drizzle and light snow showers. Within the
stronger snow showers, as low as IFR visibility is possible
especially closer to SBN as lake enhancement and diurnally forced
instability augment their intensity. With an enhanced pressure
gradient and diurnal forcing, gusty winds will continue into the
evening tonight, relaxing some overnight, but then picking up
tomorrow within the temperature gradient and diurnal forcing.
Overnight, expect low MVFR CIGs to moderate towards higher MVFR


LM...Small Craft Advisory until 5 PM EDT Tuesday for LMZ043-046.



LONG TERM...Murphy

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