IWX issues Area Forecast Discussion (AFD) at Oct 23, 2:05 AM EDT811
FXUS63 KIWX 230605
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
205 AM EDT Thu Oct 23 2025
.KEY MESSAGES...
- Lake effect rain showers persist (especially north of US 30)
through Thursday.
- Widespread frost/freeze is possible along and south of US 30 Friday
morning with low temperatures in the low to mid 30s. Some
locations south of US 24 may see temperatures at or below 32F.
- Below normal temperatures continue through the weekend and
into early next week.
&&
.DISCUSSION...
Issued at 230 PM EDT Wed Oct 22 2025
A strong low pressure system centered over southwestern Ontario
continues to bring active weather to much of the Great Lakes region.
As the attendant trough of the system pivots through the CWA today,
ample cloud cover and scattered lake effect rain showers have been
ongoing mainly north of US 30. Gusty west/northwest winds will
continue to push cold air over the warmer waters of Lake Michigan,
thus, allowing for lake effect rain showers to continue overnight
and into the day on Thursday. I'd expect showers to be mainly
confined along and north of US 30, with the highest chances for rain
(80%+) to be across southern Lower Michigan. Rainfall amounts over
the next 24 hours could be as high as 0.50" to 1". Due to a tight
pressure gradient across the Great Lakes, gusts to 30 mph are
possible this afternoon and evening. Winds will start to
diminish but still could gust as high as 20 to 25 mph on
Thursday.
A drier, cooler airmass will get pulled south across the Midwest and
upper Great Lakes on Thursday night as the low pressure system
departs off to the east. This presents a tricky setup because
lingering lake effect clouds will likely keep locations downwind of
Lake Michigan in the low 40s for lows. However, dependent on how
much cloud cover there is and how quickly winds diminish, areas
along and south of the US 24 corridor could drop into the low 30s
for lows Thursday night. I did consider issuing a Freeze Watch for
my Indiana counties south of US 24, but ultimately decided to hold
off due to how much uncertainty there is. Current thinking is that
while NBM probabilities favor a widespread freeze (60-70% probs of
temperatures at or below 32F south of US 24), the blend may be too
quick to decrease cloud cover Thursday night into Friday morning.
Overall, my confidence in which locations could see a freeze is
highest (>50%) in White, Cass, Miami, Grant, Blackford, and Jay
counties, although areas of frost are definitely on the table as far
north as US 30 in both Indiana and northwest Ohio. Will let
subsequent shifts decide how to handle this setup and if any
headlines will be warranted.
Dry conditions return just in time for the weekend. Highs will be in
the low 60s both days with intermittent sun and clouds. A low
pressure system will slide through the mid Mississippi valley, with
very low chances (15% or less) for a stray sprinkles or shower south
of US 24. An active fall weather pattern resumes early next week.
Chances for rain return Monday and Tuesday as yet another low
pressure system traverses the central Plains and into the Upper
Midwest. Temperatures will continue to be below normal into early
next week.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 200 AM EDT Thu Oct 23 2025
Higher end MVFR or VFR conditions should persist through much of
this forecast valid period. Lake induced instability still
maintaining some respectability early this morning with
scattered to numerous lake effect rain showers persisting across
far northern Indiana into southern Lower Michigan. The nature of
the fetch still supports areas north and northeast of KSBN for
best chances of these rain showers, but expecting intermittent
periods of light rain/sprinkles at KSBN through the overnight
hours. Drier low level air will gradually advect across the
western/southern Great Lakes today with lower confidence in
measurable precip at KSBN after 12Z. It is possible additional
periods of light rain may need to be included however. Periodic
cigs in the 2-3k ft range are possible at KSBN overnight, but
overall the trend should be more favored for VFR cigs as the
drier low level air advects into the region. Low levels remain
well mixed, and gusts to 20 knots will likely continue through
much of the daytime period. Gust magnitude should diminish more
sharply into this evening as a ridge of high pressure begins to
build in from the west.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Frost Advisory from midnight EDT /11 PM CDT/ tonight to 11 AM
EDT /10 AM CDT/ Friday for INZ008-009-012-014-017-018-116-
203-216.
Freeze Warning from midnight tonight to 11 AM EDT Friday for
INZ013-015-020-022>027-032>034.
OH...Frost Advisory from midnight tonight to 11 AM EDT Friday for
OHZ004-005-015-016-024-025.
MI...None.
MARINE...Small Craft Advisory until 5 AM EDT Friday for LMZ043-046.
&&
$$
DISCUSSION...Johnson
AVIATION...Marsili
Source:
IWX issues Area Forecast Discussion (AFD) at Oct 23, 2:05 AM EDT---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
