FXUS63 KIWX 302313
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
613 PM EST Mon Jan 30 2023

.SYNOPSIS...
Issued at 311 PM EST Mon Jan 30 2023

Scattered lake effect snow persists tonight and lingers into
Tuesday accumulating up to around an inch mainly in Lake MI 
adjacent counties. A few slick spots may be possible where
accumulations occur. Otherwise, cold temperatures take over
between tonight and Wednesday with single digits and teens
for lows and teens and twenties for highs.

&&

.SHORT TERM...(This Evening through Tuesday)
Issued at 311 PM EST Mon Jan 30 2023

The slow moving baroclinic zone continues to slide southeast away 
from the area and this will take the synoptic precipitation away as 
we move more into the work week, especially as surface high pressure 
moves in. On the northern side of the high pressure system, a shear 
out area of vorticity located within a broad trough moves across the 
southern portion of Lake Mi between tonight and much of Tuesday. 
Columnar moisture is trending drier through the aforementioned 
period, but wouldn't be surprised to continue to see some sputters 
and starts from it as low level wind convergence lingers into at 
least Tuesday morning and favorable theta-e lapse rates exist. Lake 
induced inversions rise up to around 850 mb or just above 4 kft with 
some dry air above it. As a result, will continue to carry PoPs in 
the lake adjacent counties. Could see a few tenths of accumulation, 
but this should just trend towards nuisance/festive snow flurries by 
Tuesday midday. The last shortwave moves through Tuesday 
evening/night and trajectories turn more southerly by that point so 
should be able to see some of the lake effect cloud cover shift 
northward as well.

The main story, though, will be the cold single digit and teens 
temperatures nudging in by Tuesday morning, especially west of US-31 
and into our northeast. While wind gusts are expected to stay in the 
tens of knots Tuesday, wind chills will be cold with single digits 
and teens, but with a few negative readings also west of US-31. 
Highs struggle to reach very far into the 20s Tuesday. At least we 
have a chance to see the sun by day's end Tuesday.

&&

.LONG TERM...(Tuesday Night through Monday)
Issued at 311 PM EST Mon Jan 30 2023

With the high pressure center overhead Wednesday, skies are expected 
to have limited cloud cover allowing for a mostly sunny day. 
Temperatures are also expected to be a little higher as low level 
temperatures return to a similar value as they have today with 
slight warm advection noted achieving 20s for highs. 

Then, a cold front pushes through later Thursday in conjunction with 
a developing low pressure system moving eastward from the Northern 
Great Lakes towards northern parts of the Northeast. Expect this to 
be a dry FROPA, though clouds will likely increase with its passage. 
Highs Thursday reach back to seasonable at either side of 30 
degrees, but temperatures will fall back to the teens and single 
digits for lows Thursday night and Friday night.

Will allow for a resurgence of lake effect snow Thursday night 
through Friday, however, the quick moving trough should limit 
its overall extent. 

Pacific air floods the United States again as the western CONUS 
ridge gives way to a diving trough and this allows for a return of 
warmer temperatures this weekend. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 610 PM EST Mon Jan 30 2023

Higher end MVFR ceilings to persist with moisture trapped beneath
large scale subsidence inversion. Minor lake effect lingers into 
midday Tuesday at KSBN as weakly cyclonic flow and strong 
inversion limits lake induced mixed layer depth, despite moderate 
thermal instability/near 20C delta t. Some breaks possible Tuesday
afternoon as low level ridging continues to build into southern 
portion of Upper Great Lakes.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Small Craft Advisory until 4 AM EST Tuesday for LMZ043-046.

&&

$$

SYNOPSIS...Roller
SHORT TERM...Roller 
LONG TERM...Roller 
AVIATION...Murphy


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