FXUS63 KIWX 111806

Area Forecast Discussion
National Weather Service Northern Indiana
106 PM EST Mon Dec 11 2023

Issued at 105 PM EST Mon Dec 11 2023

Lake effect low clouds will dissipate from west to east into early
this evening. Otherwise, seasonable temperatures for the first
half of the week will slowly climb to above normal by the weekend.


.SHORT TERM...(Today and Tonight)
Issued at 220 AM EST Mon Dec 11 2023

Lake effect precip will continue to wind down this morning as
midlevel trough axis exits and subsidence inversion heights steadily
lower. Low level winds also back quickly 12-18Z becoming
southwesterly by this afternoon. Latest hi-res guidance does suggest
some isolated showers may persist a few hours after 12Z and have
extended slight chance PoP's accordingly but this activity will be
very light and very isolated if it does occur. We will also continue
to see increasing lack of ice nucleation as inversion heights lower
supporting more light drizzle/mist than snow. However, extremely
light QPF and still relatively warm ground/road temps will likely
prevent any impacts to the morning commute. Dry conditions assured
by midday though there is enough residual boundary layer moisture to
support lingering stratocu until late afternoon. This will keep a
lid on high temps with latest guidance suggesting highs may struggle
to get much above the mid 30s. WAA and a steady SW gradient will
offset clearing skies tonight and expect lows to hold in the
mid/upper 20s.


.LONG TERM...(Monday through Saturday)
Issued at 220 AM EST Mon Dec 11 2023

WAA continues into Tue ahead of a cold front being driven by
northern Lakes midlevel trough. Moisture return and forcing for
ascent are virtually nil for our area and no precip is expected
(just a few midlevel clouds early in the day). Late day arrival may
allow our SE zones to climb into the mid 40s while NW zones
struggle to reach 40F. Strong subsidence/high pressure then
settles into the Ohio Valley for Wed setting us up for some chilly
nights with ideal radiational cooling. Lows near 20F are expected
with highs on Wed again only around 40F.

Slow but steady moderation in temps expected through the weekend as
low level ridge slowly moves east. Highs near 50F possible by the
weekend. Continued split flow will keep our area mostly dry. Low
chance of precip Fri night/Sat as next northern stream shortwave
moves through the area. Still a ton of spread with this small-scale
feature though and latest NBM came in almost entirely dry through
the whole period. Still some low chances for rain but definitely not
much as typical El Nino pattern maintains an active southern jet
stream locking up better moisture well to our south.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 105 PM EST Mon Dec 11 2023

Resolving the ending time of 2500-3500 foot cigs remains the
primary aviation forecast challenge. Backed southwesterly flow
will continue to advect much drier low level air eastward from
Illinois through this afternoon. Timing of improvement to VFR has
been kept largely intact from previous forecast, with perhaps
slightly later scattering at KFWA to the 23Z-00Z timeframe.

A strong upper level vort tracking across south central Canada
will reach the northern Great Lakes Tuesday morning. A fairly
strong southwest gradient and weak pocket of sfc pressure falls
drifting across Michigan will allow for southerly flow to ramp up
overnight. Confidence in sfc wind gusts is low as strengthening
low level inversion could temper gusts tonight. Did include a 3 to
5 hour window of marginal LLWS conditions from west to east at
terminals tonight. Associated cold front will pass across northern
Indiana on Tuesday allowing for steeper low level lapse rates and
westerly gusts into the 20-25 knot range.


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




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