308 
FXUS63 KIWX 191900
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
300 PM EDT Tue Oct 19 2021

.SYNOPSIS...
Issued at 300 PM EDT Tue Oct 19 2021

Dry and mild conditions tonight into Wednesday will give way to 
chances for scattered showers and a few thunderstorms Wednesday 
night. A trend toward cooler temperatures and mainly dry conditions 
are then expected for the end of the week and weekend. 

&&

.SHORT TERM...(This Evening through Wednesday)
Issued at 300 PM EDT Tue Oct 19 2021

Dry and stable airmass under an upper level ridge axis will maintain 
quiet wx conditions into tonight and Wednesday, though there will 
likely be an increase in mid clouds and southwest winds tomorrow 
afternoon as a Rockies low pressure system to lifts east-northeast 
toward the IA/MN. Warm advection will be ongoing otherwise with 
lows in mid 40s to low 50s tonight, and highs in the low-mid 70s 
Wednesday. 

&&

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 300 PM EDT Tue Oct 19 2021

The above mentioned closed low will open and take a more easterly 
route through the southern Great Lakes by later Wednesday night and 
Thursday as it encounters the southern fringes of a negative height 
anomaly dropping into northern Ontario. The initial window of moist 
isentropic ascent in deepening southwest flow will provide a chance 
for scattered showers Wednesday evening as top-down saturation 
commences. Better chances likely arrive overnight into early 
Thursday though along a narrow pre-frontal 1"+ pwat axis, with iso 
embedded thunder possible as modest theta-e advection destabilizes 
the mid levels. Coverage and duration may be limited locally however 
given quick progression of the system, better low level convergence 
focused north into central MI, and somewhat poor near sfc moisture 
return.

A brief intrusion of the system mid level dry slot is likely for a 
time on Thursday before a weakening secondary trough and deeper 
moisture pivots back through later Thursday with additional chances 
for scattered showers. The higher probs for showers will be closer 
to Lake MI where some enhancement is likely with delta T's pushing 
well into the teens. Cooler and cloudy otherwise on Thursday with 
highs generally in the low-mid 60s.

Broad mid level troughiness will linger into Friday and Saturday on 
the southwest fringe of a deep closed low sprawling over southeast 
Canada. The result locally will be cooler temps and mainly dry 
conditions, though cannot completely rule out a few showers in any 
period as several low amplitude shortwaves progress through in 
cyclonic wnw flow aloft.

Confidence in daily specifics quickly diminish Sunday into early 
next weekend as ensemble guidance continues to differ on how quickly 
blocking breaks down and when/if eastern pacific shortwave energy 
can move through with increasing rain chances. Opted to hold with 
broadbrush NBM low-mid chance PoPs during these periods as a
result.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 100 PM EDT Tue Oct 19 2021

VFR conditions expected through the TAF period with southwest 
winds generally 10kts or less. 

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...Steinwedel
SHORT TERM...Steinwedel
LONG TERM...Steinwedel
AVIATION...JAL


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