111
FXUS63 KDMX 211957
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
257 PM CDT Wed May 21 2025

.KEY MESSAGES...

- Cool and mostly cloudy Thursday. Drizzle could occur.

- Precipitation chances return late Friday and into the weekend.
  The chance for severe weather is very low.

.DISCUSSION...
Issued at 256 PM CDT Wed May 21 2025

Low pressure has moved east and is over far northern Ohio with an
inverted trough extending west into far northeast Iowa and southern
Minnesota. That inverted trough has moved slowly north today with
some partial clearing getting into parts of central and southwest
Iowa. Hudson Bay upper low pressure is settling south and will
settle into the western Great Lakes region late tonight into
Thursday. This will switch the upper flow to nearly straight
northerly  and this will lead to the boundary to the north and the
cloud cover to move back south during this time period. This will
lead to another cool day across Iowa. There is some potential for
drizzle to occur as low level saturation occurs and some weak
vertical ascent with in this saturated layer. Have lowered
temperatures into the upper 50s to low 60s at most location and may
need to lower severe degrees more pending how quickly the backside
of the cloud cover scatters from north to south.

Surface high pressure will be over Iowa Thursday night and Friday
morning which may lead to an opportunity for radiational cooling and
some areas, particularly into west central Iowa to have overnight
lows fall into the upper 30s. That high pressure will be come more
oriented from southeast to northwest as low pressure moves into the
Texas/Oklahoma panhandle regions and with a transition to upper
level modified zonal flow, moisture will stream north and overrun
the surface boundary into parts of Iowa. Still uncertainty on how
far north this overrunning will occur this weekend but the highest
chances for precipitation will be over the southwest and less to the
northeast from late Friday and into the weekend. Again, no severe
weather is anticipated and temperatures will remain cool in the 60s
for highs. The cool May weather may persist into early next week
with the upper ridge being a bit delayed by a slower moving upper
low. This may also delay the return of highs in the 70s until mid
next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1236 PM CDT Wed May 21 2025

MVFR cigs are in place across parts of central and northern Iowa
with conditions improving over southern Iowa. This trend will
continue with slowly improving conditions moving from south to
north. A few showers may occur in vicinity of KMCW/KALO yet this
afternoon. Another area of stratus will arrive from north to
south late tonight into Thursday morning. That area of cloud
cover may reach IFR or lower and may contain some drizzle. The
wind will be primarily from the west/northwest and may be over
12kts at times.

&&

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

&&

$$

DISCUSSION...Donavon
AVIATION...Donavon