Altoona, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

079
FXUS63 KDMX 230424
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1024 PM CST Sun Feb 22 2026

 ...Updated for the 06z Aviation Discussion...

.KEY MESSAGES...

- Cold conditions to start the week, but milder on Tuesday,
  especially in the snow free areas.

- A 12 to 18 hour window of wintry precipitation is forecast
  Wednesday into early Thursday. Accumulating snowfall is
  possible in northern portions of the state.

- Big temperature spread/low confidence in temperatures late
  this week into next weekend.

&&

.DISCUSSION...
Issued at 149 PM CST Sun Feb 22 2026

GOES-East upper level water vapor imagery shows a shortwave trough
scooting southeastward over Iowa early this afternoon. Much of the
expansive stratus area is to the east of this shortwave track over
eastern Minnesota, Wisconsin, and northeastern Iowa. However, there
are stratus streaks (best viewed - perhaps oddly - in the Blowing
Snow RGB) accompanying this wave over western Minnesota and a small
area of the eastern Dakotas. These streaks along with the
expectation that the stratus will sink southward this evening will
bring cloud cover back towards an Estherville to Des Moines to
Centerville line. Forecast soundings do try to briefly saturate just
above the dendritic growth zone to produce flurries this evening
over our northeastern forecast area, but the depth of saturation is
quite shallow so have opted to keep forecast dry. The saturation is
fleeting as a zone of high pressure pushes into the forecast area
drying out the column resulting in clouds dissipating. With the high
also allowing for winds to diminish toward sunrise Monday,
particularly over western Iowa, this will foster a cold morning with
temperatures falling to around zero degrees and wind chills ranging
from 5 degrees below zero to 15 degrees below zero.

While highs on Monday will still be in the upper teens and 20s, mid-
level heights will be on the rise. This combined with a southerly to
westerly warm air advection flow on Tuesday will offer milder
conditions, especially in the snow free parts of the state. In these
areas, the initial National Blend of Models (NBM) is well into the
40s and is close to the 50th percentile and only a few degrees lower
than the 75th percentile for highs Tuesday. MOS guidance is actually
similar if not cooler than NBM so will hold temperatures at the
initial guidance for now in the snow free areas. For highs within
the swath of snow cover, this area will be on the cooler side of
guidance and the NBM continues to show the snow footprint well, but
temperatures are still a bit too warm. Interestingly, the MOS
guidance in these areas is at or a few degrees higher than the NBM
with modeled snowfall matching well with satellite imagery. In
addition, a shortwave trough and surface low pressure passing north
of Iowa will send a cold front through the state later on Tuesday,
resulting in breezier winds from the west and northwest. The
precipitation with this system looks to stay mostly north and
northeast of central Iowa where the stronger QG convergence will be
placed. This system will shunt the Pacific moisture southward and
while low level theta-e advection will begin ahead of the next
shortwave trough arriving Wednesday into Thursday, the moisture
return will be limited. The precipitation axis is bouncing around in
its placement in the deterministic, ensemble, and AI models, but
most of these agree that some portion of central Iowa is still on
track for a 12 to 18 hour period of wintry weather and likely
accumulating snowfall to some portion of northern Iowa as well.
Beyond Thursday, temperatures Friday into next weekend show great
spread between the 25th and 75th percentile - some pushing near 35
degrees on Saturday. Thus, confidence in the deterministic NBM
forecast temperatures is low.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1024 PM CST Sun Feb 22 2026

Low stratus continues to dissipate as dry air moves in over
Iowa, which has led to an increasing likelihood for clouds to
decrease sooner than expected, as all terminals should return to
VFR conditions around 06z if not shortly afterward. Outside of
high clouds streaming in later in the day, mostly clear skies
are largely anticipated, as any lower clouds generally remain
east of the state. Winds will continue to decrease, turning
light and variable as high pressure settles overhead, then
turning southerly into the evening.

&&

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

&&

$$

DISCUSSION...Ansorge
AVIATION...Bury