Saint Marys Cemetery Iowa Weather Forecast Discussion

554
FXUS63 KDMX 131932
AFDDMX
Area Forecast Discussion
National Weather Service Des Moines IA
232 PM CDT Mon Oct 13 2025
.KEY MESSAGES...
- Shower chances increase from south to north tonight into
  Tuesday. Shower chances will persist north Tuesday night into
  early Wednesday.
- Mild to warm conditions return Wednesday through Friday.
- A few storms possible Friday and Saturday.
&&
.DISCUSSION...
Issued at 229 PM CDT Mon Oct 13 2025
Very slow moving surface boundary is just to the south and east of
the area this afternoon. Dew points in the upper 50s and 60s are
pooled along the boundary. Ridge of high pressure is moving in
behind this boundary and it has brought much drier air into central
and northwest Iowa with dew point values dropping into the 30s this
afternoon. A portion of the dew point drop this afternoon can be
attributed to diurnal mixing so there should be a modest bounce back
up towards sunset. Theta-e advection will commence overnight into
Tuesday and will begin to overrun the surface ridge as winds aloft
above 4 kft turn southerly. This will lead to descending cloud bases
overnight and Tuesday with increasing chances for showers from south
to north during this period. Continued the trend of delaying the
onset of precipitation due to the saturation process and the dry
layer beneath cloud bases. The precipitation chances will become
more focused over the northern third of Iowa Tuesday night and in
vicinity of the theta-e advection focus. Light rain may linger into
Tuesday evening in central and southern Iowa as some saturation
remains before some dry air entrainment arrives. Thunderstorm
chances through this period remain quite low. Mid-level lapse rates
remain below 6 C/km much of the period and while very low MUCAPEs
may develop with ideal particle lift points, the vertical extent of
lift is quite shallow and likely will not result in lightning. This
process is already occurring over eastern Kansas and Oklahoma where
the latest lightning data is not returning anything.
Clouds will keep conditions cool over northern Iowa while highs over
the south will be dependent if some sunshine can occur which despite
the arrival of the drier air, is not a certainty.
Upper level ridging will become reestablished on Wednesday then a
transition to steeper southwest flow to end the work week as the
ridge moves east. This will result in seasonably warm conditions
return on Wednesday with highs back into the mid to upper 70s for
the southwest half of Iowa. High may reach the 80s in some areas on
Thursday then slightly cooler on Friday. The moisture return
profiles for both low level Gulf moisture advection and the combined
Gulf and Pacific mid-level moisture contribution is more favorable
with the enhances southwest flow. This environment will be more
favorable for a few thunderstorms as the main boundary and short
wave pass through the area. At this point though, any activity will
likely be sub-severe. A long wave trough and upper northwest flow
follows for the weekend. At this point, the NBM forecast for Sunday
looks a bit on the warm side unless extreme mixing can occur, which I
should note is possible. Gusty winds in this type of setup would
seem likely as well.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1220 PM CDT Mon Oct 13 2025
Breezy north wind at times early this afternoons with wind
speeds gradually decreasing after 20z. Local MVFR cigs will
impact KOTM to start the period. These cigs will rise slowly and
scatter this afternoon leaving to a return to VFR. Mainly VFR
through this evening then cigs will be lowering overnight.
Likely MVFR cigs and perhaps a few showers at times late tonight
into Tuesday morning at KDSM/KFOD. Other sites will not have as
much impact from cigs and showers until after this forecast
period.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Donavon
AVIATION...Donavon

NWS DMX Office Area Forecast Discussion