French, Indiana Weather Forecast Discussion

035
FXUS63 KIWX 081028
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
628 AM EDT Mon Sep 8 2025
.KEY MESSAGES...
- Temperatures in the 70s and low to mid 80s through Wednesday
  will rise into the mid to upper 80s for Friday and Saturday.
- Dry with mostly clear to partly cloudy skies through Friday.
- Low precipitation chances return Saturday and Saturday night with
  increasing cloud cover.
&&
.DISCUSSION...
Issued at 304 AM EDT Mon Sep 8 2025
Surface high pressure centered over the Great Lakes today will
gradually drift eastward through Wednesday. At 500mb, the slight
trough/relatively zonal flow today will be replaced by an amplifying
ridge through Wednesday (especially east of IN-15). Expect dry
conditions with mostly clear to partly cloudy skies, light winds,
and highs in the 70s, low-mid 80s through Wednesday. Lows will be in
the 40s and 50s. Otherwise, could be some ground fog early this
morning with optimal radiational cooling. As of this writing, only a
few obs have dropped to 1-3SM or less, and most are just north of
our southern MI counties.
On Wednesday, the ridge east of IN-15 becomes more amplified as a
broad trough stemming from an upper level low over Hudson Bay moves
eastward. The surface cold front associated with this feature seems
lag westward before washing out as the trough drops over the Great
Lakes, so many of the models have dry conditions persisting through
the day. There are some that have speckles of potential showers late
Wednesday afternoon-evening with daytime heating, however moisture
is severely lacking. I kept any pops out of the forecast for this
period given very low confidence.
The upper level trough continues eastward through Friday, allowing
for the broad ridge centered over TX/Desert SW to build into our CWA
through Saturday morning. This will keep us dry and bring temps
solidly into the 80s, with several locations reaching the mid-upper
80s. Lows will be in the 50s, maybe even low 60s.
Friday night (00z) into Saturday several models have a closed low
move over James Bay drop S-SE towards the Ontario/Quebec border and
perhaps into northern Lake Huron/Lake Superior (For example, the
ECMWF has the 561 dam low over Northern Lower MI/Eastern Upper MI by
12z Sun; GFS is further east north of Lake Ontario). The trough
extends southwest of the low into our area/the Upper Great Lakes,
though there is disagreement as to whether or not the ridge holds or
breaks down--so that will obviously dictate whether or not we have
precipitation chances Saturday into Saturday night, possibly Sunday
if the ECMWF-like solutions are correct. Depending on how the larger
scale flow sets up, we could be at the nose of a LLJ streaming
moisture north from the gulf. 850mb temps could be as high as 15-19C
Saturday, so highs will be creeping into the mid-upper 80s for many
locations. Sunday may be quite warm as well, but confidence is lower
given the major pattern discrepancies that develop for that time
period. Have low chance (20 percent) pops Saturday through 8 am ET
Sunday to cover this potential now-especially given lower
confidence.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 628 AM EDT Mon Sep 8 2025
Surface high pressure is overhead today limiting cloud cover and
keeping dry air around. Will continue to keep fog out of the TAFs
although shallow ground fog is possible into this morning. High
pressure also helps to keep the gradient down and limit wind speed
and gusts. Winds will be out of the south and southeast through the
period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...MCD
AVIATION...Roller

NWS IWX Office Area Forecast Discussion