514
FXUS63 KDMX 162346
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
646 PM CDT Thu Apr 16 2026

 ...Updated for the 00z Aviation Discussion...

.KEY MESSAGES...

- Enhanced (Level 3 of 5) Risk for severe storms in central to
  eastern Iowa on Friday. Large hail, damaging wind gusts, and
  tornadoes are possible.

- Much cooler this weekend with overnight lows in the 20s and 30s.

- Mild and dry to start the week with thunderstorms returning
  to the forecast by late week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 243 PM CDT Thu Apr 16 2026

Tranquil conditions across Iowa this afternoon offer a welcome
respite from what has been an active weather week. Skies across the
area are clear with southerly flow pushing temperatures through the
70s to near 80 this afternoon. In western Iowa drier conditions are
in place, allowing for deeper mixing. That has resulted in wind
gusts of 20-25 mph this afternoon and relative humidity falling
under 30%. This has made for elevated fire weather concerns
there, though rapid green up is quickly shutting the door on the
fire weather season.

All eyes are on Friday as an amplified upper level trough shifts
east with strong associated surface low and cold front. The front is
expected to pass across Iowa through the day, pushing into eastern
Iowa by around 00z. Breezy conditions ahead of the front with strong
southerly flow into the area ahead of the surface low with
substantial moisture transport into the area. Soundings indicate 20-
25 mph sustained winds ahead of the front with gusts of 30-35+
mph. The atmosphere will quickly destabilize with 3000+ J/kg of
MLCAPE (4000+ MUCAPE) and 7-8+ C/km mid level lapse rates in
the warm sector. 35-45 kts of 0-6 km shear will help to organize
storms, initially discrete, growing upscale as the line pushes
east.

Convective initiation is expected along and head of the cold front
in the warm sector on Friday afternoon between 2-4pm. The
initial discrete mode will support tornado and hail growth. As
storms grow upscale expect the primary hazards to transition
over to damaging winds with embedded tornadoes along the line.
0-1 km SRH is around 100-200 m2/s2 in central Iowa, increasing
over 300 m2/s2 in eastern Iowa where the tornado threat is
highest.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 243 PM CDT Thu Apr 16 2026

Post frontal winds remain strong as the switch around to the
northwest with strong cold air advection into the area (plus
subsidence and a tight pressure gradient - all the ingredients for
breezy winds). Expect post-frontal wind gusts of 20-30+ mph to last
through Friday evening and the day on Saturday. The cold front will
make for a cool weekend with highs on Saturday in the low 50s.
Combined with those breezy conditions, it will not be the most
comfortable day for outdoor activities. Saturday night through
Sunday morning temperatures bottom out in the upper 20s to low
30s across Iowa and will pose a problem to any sensitive
vegetation. Sunday will see light winds and modest temperature
recovery into the low 60s. Thermal ridging increases into next
week with 70s returning to the area. The week starts of mild and
dry, then thunderstorm chances return by late week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 642 PM CDT Thu Apr 16 2026

Clear skies and light to breezy southerly winds continue early
this evening and will persist into the night. A brief period of
low level wind shear may develop overnight, especially at times
when wind gusts are weaker, which is expected intermittently
tonight. A front passing through the area tomorrow will then
bring gusty winds and a wind shift from southerly to
northwesterly. A few thunderstorms are possible along this
front, although this most likely farther south and east. Have
included this potential at KALO and KOTM where confidence is
highest. It`s possible KDSM also experiences a very brief period
of thunder, but the highest chances are to the east, and
therefore have left out of this TAF issuance.

&&

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

&&

$$

SHORT TERM...Hagenhoff
LONG TERM...Hagenhoff
AVIATION...Dodson