Logan, Iowa Weather Forecast Discussion

109
FXUS63 KOAX 102309
AFDOAX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
609 PM CDT Wed Sep 10 2025
.KEY MESSAGES...
- Highs will mostly be in the 80s into next week, though a few
  spots are expected to see lower to possibly mid 90s Friday
  and Saturday.
- Mostly dry conditions expected through Saturday. Shower and
  storm chances return Saturday night into next week, with the
  highest chances Saturday night and Sunday evening (30-50%).
&&
.DISCUSSION...
Issued at 349 PM CDT Wed Sep 10 2025
Water vapor imagery this afternoon features a deep cut off mid-
upper system slowly swirling eastward across the western third
of the CONUS, while ridging builds further into the High and
Great Plains regions. A messy surface pattern has meant little
to the sensible weather today, aside from a ribbon of moisture
that has resulted in fog formation over the last two days across
the forecast area -- especially over northeastern Nebraska.
Highs have reached into the lower-to-mid 80s area-wide with
pleasant southeasterly winds underneath fair weather cumulus
aside from some clouds with slightly deeper extent that could
result in a sprinkle (~10% chance) south of Interstate 80 into
the early evening. With the growing influence of the incoming
mid/upper ridge, lows overnight are expected to be warmer and in
the lower 60s/upper 50s, very close to where our current
dewpoints lie. This should result in a limited to completely
reduced area of fog overnight, due to the limited cooling and
slightly stronger winds overnight as we start to see stronger
winds spread from the west tomorrow.
Beginning tomorrow, we`ll start a warming trend that carries us
knee-deep into temperatures that reach over 10 degrees warmer
than our normal values both Friday and Saturday. Ensemble
guidance suggests that we continue to sit on the lower end of
guidance, but have crept up in the right direction over recent
forecasts as the signal continues to hold and strengthen, with
the biased corrected solutions pumping the breaks on the heat
(which is likely due to our recent cooler patter that we are
breaking out of). Highs Friday and Saturday will push into the
upper 80s to low 90s area-wide, with summer-like temperatures
striking back as folks head outside to enjoy a non school/work-
filled couple of days. Fortunately dewpoints aren`t expected to
be oppressive with crops continuing to cure, with heat indices
not straying more than a few degrees above the surface
temperatures (meaning no locations hit 100 degrees). We see our
max temperatures from the early half of the weekend turn cooler
and level out in the low-to-mid 80s going into next week as the
mid/upper pattern turns from ridging to westerly/northwesterly
flow.
Looking at precipitation chances for the period, we`ll see a
shortwave or two lobbed eastward from the main low to the west,
trying to ride the ridge in the general vicinity of the
forecast area. The main chances for rain and storms to watch for
will be associated with the ejecting low to the west, that
should push through the area late Saturday through Sunday,
bringing widespread chances for rain and storms -- including a
low-end threat for severe weather. As of now, things should be
driven by modestly supportive lapse rates/instability and some
better shear compared to what we`ve seen most of the summer. By
the time that the Saturday/Sunday chances move through, timing
and location of additional precipitation becomes more murky as
models diverge in their handling of the ejecting and
deamplifying low. All three global deterministic solutions do
depict another potent mid/upper shortwave quickly falling in
behind the departing one for the early-to-mid work week, but
we`ll see as to when models line up precipitation better over
the area.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 609 PM CDT Wed Sep 10 2025
VFR likely to remain through the TAF period, though patchy fog
may develop in areas where wind becomes nearly calm overnight.
Only around a 10% chance fog impacts any of the terminals.
Mostly clear skies again on Thursday with southeasterly winds
gusting to 20-25 kt during the afternoon hours.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Petersen
AVIATION...McCoy

NWS OAX Office Area Forecast Discussion