Altoona, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

336
FXUS63 KDMX 111201
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
601 AM CST Wed Nov 11 2026

 ...Updated for the 12z Aviation Discussion...

.KEY MESSAGES...

- Few rain showers and thunderstorms in portions of northeast
  to eastern Iowa this morning.

- Blustery northwest winds are expected today with winds
  sustained around 15-20 mph and gusts to around 35 mph, the
  highest winds and gusts in the southwest half of the state
  today. Winds remain breezy through Thursday as well.

- A cooling trend begins today with a chilly end to the week
  expected. Highs fall into the 40s starting Thursday with
  overnight lows in the 20s to 30s tonight and in the 20s by
  Thursday night.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 241 AM CST Wed Nov 11 2026

The surface high pressure has moved off to the east of the state
early this morning with the upper trough quickly swinging through
the state here through the overnight and morning hours today and
arriving in the Great Lakes Region by midday. The associated surface
low is tracking further south than guidance suggested at this time
yesterday and has slightly increased the possibility for some rain
showers/sprinkles here overnight into early Wednesday morning in
northern/northeast and then eastern Iowa. Radar returns have started
to increase over northern Iowa though forecast soundings suggest
ample dry air remains in the low levels. With the more southerly
track of the low, there has been a fairly substantial increase
in mid- level moisture than seen at this time yesterday.
Initially this moisture is largely above 700mb but will lower
through the overnight and will try to erode the lower level dry
air to bring the showers to the surface. Upstream observations
have already noted a decrease in dew point depressions in
northwest Iowa closer to the low increasing confidence somewhat
that certainly some sprinkles, but even some showers with time
will occur into this morning in our area. Not expecting these
showers to amount to much though some thunder could occur with
some available instability in east central Iowa. As the low
wraps around as it moves eastward, some additional showers or
sprinkles may be possible following the initial push which ends
later this morning in the east (prior to midday). These will
again be fighting dry air which increases again in the mid-
levels by afternoon and will be very spotty in coverage anyway.
Have kept PoPs focused to this morning but will continue to
monitor should any low PoPs be needed this afternoon.

The more notable impacts today will be from the gusty winds and
falling temperatures. The pressure gradient continues to tighten
through the morning with winds turning to be out of the northwest on
the backside of the low/cold front with increasing cold air
advection today into tonight. This will result in the start of our
cooling trend which will continue through the end of the week. Highs
today fall back towards the upper 40s through the 50s but will feel
even colder with the gusty northwest winds sustained around 15-20
mph and gusts to around 35 mph, the strongest winds and gusts
in the southwest half of the state. Winds drop off some later
this afternoon but remain elevated through the night and into
Thursday with the sustained cold air advection and subsidence
keeping gusts of at least 15-30 mph around through much of the
day Thursday. Lows tonight will be chilly and in the upper 20s
to 30s but are held up by expected cloud cover. This cloud cover
could have some breaks in it though which may allow for some
locations to dip even further.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 204 PM CST Tue Nov 10 2026

The cooler airmass fully settles in by Thursday as a Canadian
surface high, centered near Winnipeg, advects a cold and dry arctic
airmass into the Upper Midwest. This continued cold air advection
will limit Thursday`s high temperatures into the mid-40s, a chilly
trend that will hold through the end of the workweek. With the
Canadian high firmly in control, skies will remain largely clear
Thursday night into Friday morning. The combination of clear skies,
light winds and a very dry boundary layer will set the stage for
optimal radiational cooling, allowing for overnight lows Thursday
and Friday nights to plummet into the lower to mid 20s. Dry and
quiet conditions persist through Saturday.

Our next potential window for precipitation arrives Sunday morning
as a mid-level low tracks across the Southern Plains. Moisture
return ahead of this system could spark a few showers across the
Plains; however, there remains considerable uncertainty regarding
the system`s northward extent. Depending on the exact track, some
light showers could skirt southwest Iowa. That being said,
persistent dry air in the low levels may prove difficult to
overcome, likely limiting measurable precipitation this far north.
Given the uncertainty, low-end 15-20% PoPs have been introduced for
southwest Iowa, and trends will be closely monitored for future
adjustments. Subsidence and dry conditions are expected to return by
the start of next week, accompanied by a slight moderation in the
airmass as highs rebound back to the 50s.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 545 AM CST Wed Nov 11 2026

Few showers and thunderstorms have manged to get going in east
central Iowa but have remained outside of the 10SM range ring
for KALO. A few more spotty showers could occur at times this
morning or afternoon but coverage will be very spotty and
confidence in impacts at any terminal is far too low to include
any precipitation mentions. The most likely locations would be
KALO or KMCW, though again confidence is less than 15%. Next
aviation concern is cloud cover with stratus expected to
increase with time this morning into afternoon and then evening.
There will likely be some breaks in the clouds at times and
cloud decks are largely expected to remain VFR through the bulk
of the TAF period. Gusty winds are also expected today with
gusts to around 25 knots.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...05
LONG TERM...TDR
AVIATION...05