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FXUS63 KIWX 071947

Area Forecast Discussion
National Weather Service Northern Indiana
247 PM EST Sat Dec 7 2019

Issued at 247 PM EST Sat Dec 7 2019

Quiet weather conditions are expected to continue into tonight 
and Sunday. Lows tonight will drop to near 30 degrees, with highs 
on Sunday in the mid 40s to low 50s. A low pressure system will 
then lift into the region with periods of rain and drizzle Sunday
night through Monday night. Drier and much colder weather will 
follow into the middle of the week behind this system, with lake 
effect snow showers possible across southwest Lower Michigan on 
Tuesday and Wednesday.


.SHORT TERM...(This Evening through Sunday)
Issued at 247 PM EST Sat Dec 7 2019

Low to mid level southerly flow will ramp up tonight into Sunday as 
the center of sfc high pressure shifts east toward the Mid Atlantic 
and height falls overspread the Central US. This will yield milder
temps with lows near 30 tonight and highs in the mid 40s to low
50s tomorrow. The associated broad and weak isentropic upglide in
this regime will eventually allow low clouds to fill in later
tonight into Sunday. Some light drizzle also cannot be ruled out
by Sunday afternoon, though point chances remain too low for
anything higher than a "silent" 10 PoP at this time. Becoming
somewhat breezy otherwise tomorrow with gusts up to 20-25 mph.


.LONG TERM...(Sunday Night through Saturday)
Issued at 247 PM EST Sat Dec 7 2019

Plume of deeper moisture within a strengthening 40-50 kt low level 
jet is still on track to bring periods of rain/drizzle and mild 
temps later Sunday night into Monday. The higher rainfall amounts 
(>0.50") are expected across southern and eastern portions of the 
forecast area where greater moisture transport is anticipated. Fog 
may settle across northern zones during this time given moisture 
pooling and lighter winds near a sfc boundary sagging toward the 
region. This front will get a kick southeast through the local 
area Monday night as a sfc wave develops in response to good left 
exit upper jet support and ongoing mid level cyclonic pva. More 
organized precipitation will taper off in its wake with temps 
dropping a good 15-20 degrees. 

Drier and much colder air will follow post-frontal into the middle 
of the work week. 850 mb delta T's into the low-mid 20s will favor a 
solid Lake MI response on Tuesday and Wednesday. However, a more 
westerly component to the low level wind field, inversion heights 
near 5 kft, and limited synoptic moisture will likely limit snow 
amounts and higher PoPs to Berrien/Cass/St Joe counties in southwest 
Lower MI. With that said, cold temps/limited vis/light accums could 
still create icy roads in these locations, especially later Tuesday 
night into Wednesday when a secondary vort swings through the Great 
Lakes. Temps will then quickly recover back to near seasonal norms 
by Friday and Saturday. 


.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1220 PM EST Sat Dec 7 2019

VFR will persist through tonight given abundant dry air in the
lower levels. Midlevel clouds will also scatter through the
evening. Strong LLJ will bring increasing moisture and low clouds
Sunday. MVFR likely though exact timing remains uncertain at this


LM...Small Craft Advisory from 10 PM this evening to 4 PM EST Sunday 
     for LMZ043-046.



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

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