IWX issues Area Forecast Discussion (AFD) at May 21, 1:39 PM EDT422
FXUS63 KIWX 211739
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
139 PM EDT Wed May 21 2025
.KEY MESSAGES...
- Rain showers through at least Thursday morning.
- Remaining cool through the weekend.
&&
.DISCUSSION...
Issued at 329 AM EDT Wed May 21 2025
Nearly stacked surface low and upper-level low continue to plague
the area today. Primarily dry across the forecast area this morning
but additional bands of showers are noted upstream in proximity to
upper-level vorticity maxima. Not much instability to work with
today but I do expected numerous showers around today as the
southern edge of the 700mb low tracks moves overhead. Remaining cool
as well; highs in the low-60s are some ten degrees below normal.
Showers linger overnight and Thursday but decrease in coverage by
Friday as this low is finally kicked east by an incoming central US
ridge.
Primarily dry this weekend with weak high pressure over the Great
Lakes, bookended by a New England low and Colorado low. The modest
nature of this high allows model guidance to attempt some slight
chance of showers but the best forcing is elsewhere. I've maintained
the existing dry forecast Saturday but cave to slight chance POPs
Sunday with the Colorado low tracking east, grazing a portion of the
forecast area or waiting until early Monday morning. Uncertainty is
high headed into next week with the ECMWF favoring a colder, faster
arrival of high pressure overhead while the Canadian and GFS favor
the Colorado low overhead.
The current high temperature forecast for Memorial Day, 66 degrees
at both climate sites (currently a 25th percentile forecast), would
be colder than the 69 degrees observed at both sites last year. If
the forecast verifies, it would be the coolest Memorial Day since
2013's 62 and 63 degrees (South Bend and Fort Wayne,
respectively.)
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 135 PM EDT Wed May 21 2025
Variable flight conditions expected at both sites through at
least the first half of the period as low pressure drifts across
the area today and wrap-around showers and low clouds linger
until it finally pulls away Thursday. Cigs have improved
somewhat compared to earlier today, hovering around 1000 ft with
drop changes in both cig and vsby as showers rotate through the
area. Vsby jumps above 4 miles at times are possible this
afternoon, but overall cigs are not expected change. After 00Z
coverage of showers may wane and/or refocus moreso near/north of
KSBN resulting in the need for a longer duration of showers/low
clouds. Further refinement may be needed for potentially lower
cigs/vsby from log redevelopment and lowering of the stratus.
Eventually the rain will move out of the area very late tonight
or early Thursday with cigs slowly improving.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement from late tonight through late
Thursday night for INZ103.
OH...None.
MI...Beach Hazards Statement from late tonight through late
Thursday night for MIZ177-277.
MARINE...Small Craft Advisory from 2 AM Thursday to 2 AM EDT Friday for
LMZ043-046.
&&
$$
DISCUSSION...Brown
AVIATION...Fisher
Source:
IWX issues Area Forecast Discussion (AFD) at May 21, 1:39 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!
