402
FXUS63 KDMX 242330
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
630 PM CDT Tue Sep 24 2024

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

.KEY MESSAGES...

- Shower activity dissipates this evening with cool temperatures
  overnight.
- Milder temperatures return Wednesday through Monday.
- Impacts from Helene appear to remain mostly south and east of
  forecast area.

&&

.DISCUSSION...
Issued at 337 PM CDT Tue Sep 24 2024

Have had a few isolated strong storms develop in instability axis in
the far southwest forecast area this afternoon.  There have been a
couple of reports of quarter to half dollar sized hail with the
strongest storm but the activity seems to be slowly waning.
Anticipate this convection to persist over the next few hours but
any of the activity in the forecast area is likely to diminish as
sunset approaches and daytime instability subsides.  The widespread
cumulus is also expected to dissipate into the evening with
generally clear skies overnight across the forecast area.  Have
undercut guidance in favored cool spots including the Nishna valleys
in the west given a very good raditional cooling setup.  Some patchy
sunrise fog may also develop in places as well.

Much of the upcoming forecast is dominated by the upper low
currently crossing the state and its eventual interaction with
Helene.  This low drops southeast of the state into Wednesday and
eventually absorbs the remnants of Helene into this weekend.  The
bulk of the moisture, forcing and activity is not expected to remain
mostly south and east of the forecast area through the weekend and
PoPs have been lowered over much of the area except in the southeast
forecast area.  Otherwise, the polar jet remains well north of the
state into Canada, therefore above normal temperatures are expected
to prevail for the next several days with any cooler air remaining
well to the north.  The jet begins to buckle into early next week
with a decent shortwave dropping into the Midwest by Monday.  This
sweeps a cold front across the state but with very limited moisture,
little chance for precipitation is expected.  However, cooler
temperatures are likely to arrive by the end of the forecast
period.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 628 PM CDT Tue Sep 24 2024

A few showers are lingering in vicinity of KDSM/KOTM early in
the period though should not reach either site. Note though an
outflow boundary may go through KDSM in the next hour or so and
bring a brief increase in wind. Otherwise VFR with light winds
into Wednesday. There is the potential for fog late tonight. At
this time confidence at any location remains low so it is not
mentioned in the forecast.

&&

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

&&

$$

DISCUSSION...Cogil
AVIATION...Donavon