Urbandale, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

839
FXUS63 KDMX 090803
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
303 AM CDT Fri May 9 2025

.KEY MESSAGES...

- Isolated high based showers and thunderstorms across far
  northern Iowa this evening. Gusty outflow winds possible.

- Dry with a gradual warming trend this weekend with highs in
  the 80s.

- A pattern change is likely mid/late next week, which will
  bring our next chance for showers and thunderstorms.

&&

.UPDATE...
Issued at 302 AM CDT Fri May 9 2025

Sunny/mostly sunny conditions expected through afternoon due to
influence of the sfc high centered over the Great Lakes. Highs
today will be coolest in the southeast, low 70s, with mid 80s
in northwest Iowa. This somewhat unique situation is due to the
orientation of the thermal ridge.

By late in the afternoon and into the evening, a weak upper
trough/PV anomaly will move across the northern Plains.  This will
induce a sfc trough dropping sewd across SD/MN, reaching the IA
border around 7pm this evening /00z Sat/. The latest 00Z guidance
indicates that enough sfc and 0-2km moisture convergence will
likely trigger isolated to widely scattered showers/tstms in
that vicinity. Although MLCAPE values will be weak /100-400
J/kg/ forecast soundings indicate a pronounced inverted-V
type profile. As these decaying showers/storms move into Iowa,
its possible we`ll see a few stronger wind gusts around 40 mph
as indicated by the various CAM solutions /HRRR, NAMNest, RRFS/.
Most of this activity should be along and north of US Hwy 18.
Little to no rainfall is expected, as cloud bases are likely to
be > 8000 ft, resulting in a virga-ish look. This pcpn activity
should diminish pretty quickly after sunset and loss of
insolation, with dry and quiet conditions returning overnight.

&&

.DISCUSSION...
Issued at 231 PM CDT Thu May 8 2025

Departing upper low is over MO/IL as of midday and becomes absorbed
by the upper low in the northeast U.S. into tonight leaving upper
ridging continuing to move into the area into Friday. At the
surface, a Great Lakes high pressure also continues to move into the
region into Friday keeping conditions dry and increasingly warmer.
Have continued previous trend of decreasing afternoon dew points and
warming high temperatures this afternoon and again on Friday with
warmest temperatures on Friday in the northwest closest to the
thermal ridge where highs reach into the low to mid 80s. Elsewhere,
70s still prevail to end the week.

A weak northern stream shortwave and associated boundary (previously
discussed a couple days ago) diving through MN on Friday afternoon
kicks off some precipitation chances to the north of the IA/MN state
line but the forecast remains dry in Iowa with ample dry air in
place ahead of the line/boundary and overall minimal moisture to
work with in soundings. Activity is also expected to decay with time
as it progresses through MN with little in the way of instability
remaining by the time the boundary arrives Friday night with
generally weak shear. Can`t rule out some outflow gusty winds
reaching into far northern Iowa with the decaying showers/storms but
forecast soundings and hi-res guidance are not particularly enthused
about this possibility with gusts reaching up to maybe 30 knots for
a brief time.

Little change in the dry/increasingly warmer conditions is expected
into the weekend with upper ridging remaining in place as an upper
low churns over the Gulf Coast area. This low finally dislodges
northward on Monday but looks to stay east of the area with any
precipitation chances. A deepening western trough to start the work
week moves eastward across some portion of the central U.S. into mid
week but guidance remains highly variable in the track and thus
associated precipitation chances but current longer range forecast
brings some shower and storm chances Wednesday into Thursday with
details to be further refined in the coming days. Temperatures
largely in the 80s prevail Saturday and beyond with some locations
northwest approaching upper 80s to even 90 on Sunday. Increasing
winds out of the south will join these warming temperatures with
near daily breezy southerly winds Sunday into next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1027 PM CDT Thu May 8 2025

Outside of a few high level clouds passing overhead at times,
skies are expected to be mainly clear with VFR conditions
throughout the period. Winds will remain light and variable as
well.

&&

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

&&

$$

UPDATE...Fowle
DISCUSSION...05
AVIATION...Bury