Area Forecast Discussion
Issued by NWS Northern Indiana

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903
FXUS63 KIWX 201927
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
227 PM EST Mon Nov 20 2017

.SYNOPSIS...
Issued at 215 PM EST Mon Nov 20 2017

Mostly clear but breezy conditions are expected tonight into
Tuesday morning. Low temperatures will remain above freezing
in the middle 30s. Clouds will increase on Tuesday as a cold
front moves through the region. There will be a chance for light
rain showers near this front followed by a low chance for light
lake effect showers Tuesday night near Lake Michigan. Wednesday
through Friday should remain dry with seasonably cool
temperatures. Thanksgiving day will have high temperatures in the
upper 30s to lower 40s.

&&

.SHORT TERM...(This Evening through Tuesday)
Issued at 214 PM EST Mon Nov 20 2017

Fast moving short wave will race across the northern CONUS and
southern Canada tonight and Tuesday. An associated cold front will
swing through the local area Tuesday afternoon and evening with
colder air to follow. Moisture and frontal scale lift remain limited
with this system as elongated high pressure from the Atlantic to the
deep south keeps return flow at bay. Models still hinting at
possibility of some very light pcpn though soundings show pronounced
mid level dry slot with little saturation. Will stay with some low
chance pops but only a few hundredths pcpn expected. Highs in the
mid 40s expected ahead of front but afternoon temps should drop
with fropa.


&&

.LONG TERM...(Tuesday Night through Monday)
Issued at 214 PM EST Mon Nov 20 2017

The general benign weather pattern for late November expected to
continue into early next week. Series of weak and moisture starved
systems will pass by mainly to our north with weak cold fronts
pushing through our area every few days. No significant moisture
sources or pcpn events anticipated.

Weak signal for light lake effect showers still in place Tuesday
night but as previously discussed a similar setup to this past Sat
night with inversion heights only around 5kft and very dry air
above this level. Models have even trended a little weaker with
upward vertical velocities within shallow saturated layer below
inversion. Still likely enough to develop some narrow and weak
multi-band clouds and light showers or flurries but at this time
still not expecting any accums.

Overall seasonably cool and mainly dry is the primary message rest
of this week with brief warm up into 40s on Friday after a cold
start early Friday morning. Colder air this weekend still on track
with low chances for light pcpn again with another front and
northwest flow in its wake over Lake Michigan. Medium range models
not a good indicator for lake effect but GFS shows possibility of a
brief window with deeper moisture and longer fetch Sat night into
early Sunday. Will have to see how this plays out for possible
accums but for now will stay with low chance pops in typical NW
areas.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1231 PM EST Mon Nov 20 2017

Wind gusts have already reached around 25 kts this aftn and
expect this through the aftn period. Sfc high pressure over ern TN
this aftn will shift ewd overnight with a frontal boundary approaching
from the wrn Gtlks. Expect passage at KSBN to be around the end
of the fcst period so opted to keep winds from the sw until 18Z.
Otherwise VFR conds through Monday with only mid level clouds
moving into the region tmrw morning.

VFR this period as sfc ridging drifts ewd through the TN valley.
Fairly vigorous return flow though by aftn with swrly gusts aoa
25kts.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Gale Warning through Tuesday morning for LMZ043-046.


&&

$$

SYNOPSIS...Lashley
SHORT TERM...Lashley
LONG TERM...Lashley
AVIATION...Frazier


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