IWX issues Area Forecast Discussion (AFD) at Aug 21, 2:24 PM EDT080
FXUS63 KIWX 211824
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
224 PM EDT Thu Aug 21 2025
.KEY MESSAGES...
- Fog possible late tonight.
- There is a low chance (10-30%) for showers Saturday afternoon.
- Significant cooldown Sunday through the middle of next week.
- Dangerous swimming conditions for southeast Lake Michigan beaches
possible Sunday into Monday.
&&
.DISCUSSION...
Issued at 224 PM EDT Thu Aug 21 2025
Quiet, seasonable weather will persist through at least Friday night
as the center of high pressure drifts southward into the region.
Northeast winds will diminish as a result with a period of optimal
radiation cooling tonight potentially allowing low stratus and/or
fog to develop, best chances for fog along/north of US 24 toward
daybreak. Any fog or stratus likely lifts by mid-late morning,
leaving a mainly sunny and pleasant Friday afternoon with highs near
80F.
A low pressure system tracking east through the Canadian Prairies and
toward James Bay will drive a cold front through the local area
Saturday afternoon into Saturday evening, with available guidance
still differing in exact timing of the fropa. There is agreement
however on lacking convergence and moisture on the front, with the
pre-frontal environment likely capped as well. Point chances for a
shower or storm along the front str on the low side (10-30%) as a
result.
A touch of some fall-like weather remains a consistent theme in
ensemble and deterministic model solutions Sunday through the middle
of next week as single digit 850 mb air advects in. This will occur
as several shortwaves track through in northwest flow providing non-
zero chances for a few showers, mainly diurnally driven, and
additional surges of cooler air. The lake will also activate in this
regime hinting at better rain chances closer to Lake MI at
times.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 733 AM EDT Thu Aug 21 2025
Predominantly MVFR/VFR conditions at the taf sites, with the
exception of KSBN who is hovering at the edge of VLIFR/LIFR
with a 200-400 ft cloud deck (KEKM just to the east is at
OVC002ft). The 11:31z observation at KSBN just came in with
400ft ceilings and 4SM BR reported. Clouds are quickly scouring
out to the south-southeast and I suspect that this will be
short lived, so only have a tempo until 13z. Outside of that
we'll improve to MVFR through the morning and then VFR shortly
after that. KFWA is currently VFR but upstream we still see some
1500-2500 ft ceilings that are moving southwest--arriving (if
they stay MVFR) around the 13-16z period. Some of the guidance
builds them back to around 3500 ft before arriving, and it
seems quite variable so just have a tempo for 2kft to cover at
this point. With light/variable winds and mostly clear skies
tonight expect we'll see some ground fog/BR towards the 9-12z
time frame at both sites, so have 4SM BR in that period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Steinwedel
AVIATION...Andersen
Source:
IWX issues Area Forecast Discussion (AFD) at Aug 21, 2:24 PM 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!
