San Pierre, Indiana Weather Forecast Discussion

968
FXUS63 KIWX 182325
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
725 PM EDT Thu Sep 18 2025
.KEY MESSAGES...
- Remaining warm through the weekend with above normal high
  temperatures in the 80s.
- Chances of rain return for the weekend, especially later Sunday
  into Sunday night (50-60%).
&&
.DISCUSSION...
Issued at 207 PM EDT Thu Sep 18 2025
More of the same into tonight and Friday as upper level ridging
lingers between a low pressure center over the North-central US and
an upper trough over southeast Canada. A backdoor cool front
associated with the southeast Canada trough drops into northern
zones tonight into Friday morning with the only potential impact
being patchy fog early Friday in its wake thanks to some marine
influence from Lake Huron/Erie.
Weak height falls overspread the region Friday night into this
weekend as the Plains low/upper trough evolves east toward the MS
River Valley and western Great Lakes. This will bring initial low
(20-30%) chances for a few showers into mainly western IN and
southwest MI Friday night into Saturday as a weak shortwave and
elevated warm front lift through. Most of the area will remain dry
however with more clouds around and temps still above normal for
late Sept.
Late Sunday into Sunday night still appears to be the best
opportunity (50-60%) for greater rain shower coverage and perhaps a
few embedded storms as a more pronounced shortwave and surge of
deeper moisture track east-northeast through the western/lower Great
Lakes. Predictability then falls off into next week as the broad
upstream trough eventually cuts off under building south-central
Canada heights. Opted to hold with NBM daily broadbrush PoPs as a
result (mainly 20-50%) through at least the mid-week periods given
expectations for moist low levels with a front and this meandering
upper low nearby. High temperatures will be a bit cooler in this
regime (near normal), though humidity levels will be more
elevated.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 725 PM EDT Thu Sep 18 2025
Height falls ensue over the next 24 hours as the ridging overhead
breaks down and the trough to our west slowly approaches. Even
still, antecedant dry air allows for prevailing VFR conditions
across the bulk of the TAF period. Bufkit soundings indicate more of
a shallow ground fog if it forms at all and aviation guidance keeps
us devoid of fog. Given the arrival of the trough winds veer around
from northerly to southerly and southwesterly by TAF period`s end.
Wind do continue to stay light though.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Steinwedel
AVIATION...Roller

NWS IWX Office Area Forecast Discussion