118
FXUS63 KDMX 232337
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
537 PM CST Sat Nov 23 2024

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

.KEY MESSAGES...

- One more day of above normal highs in the 40s to 50s Sunday
  before much colder temperatures make a return Monday, with
  even colder temperatures incoming to end the week/next
  weekend (highs in the 20s!).

- Low chances, (<15%) for drizzle or light rain Sunday night,
  especially northeast. Fog is also possible across northern
  Iowa.

- Low confidence (~20%) in precipitation potential (timing,
  location, impacts) for the midweek. Continue to monitor the
  forecast.

&&

.DISCUSSION...
Issued at 300 PM CST Sat Nov 23 2024

Overall pleasant November day ongoing today as temperatures have
warmed nicely, well into the 40s to even mid 50s in a few locations
as of early afternoon. Surface to mid-level flow out of the south to
southwest respectively will continue tonight into Sunday ahead of an
approaching shortwave and associated cold front which will keep
temperatures a bit warmer tonight, generally in the 30s. Cloud cover
will also continue to increase into Sunday morning and beyond. This
cloud cover may end up being a bit of a spoiler on the extent of our
high temperatures Sunday, but still overall pleasant and above
normal for this time of year in the 40s to mid 50s. It will be the
last warmer day for awhile as the cold front moving through the area
later Sunday into Monday will cool high temperatures a good 10-15+
degrees into Monday with highs in the 30s to low 40s. These cooler
temperatures are then expected to persist through the upcoming week
with the highs in the 30s/low 40s and low temperatures in the teens
to 20s before temperatures fall even further late week behind a
stronger push of cold air bringing highs tumbling to only the 20s by
next weekend with lows in the single digits to teens. Enjoy your
last few days of warmer temperatures and try to complete any fall
projects this weekend before temperatures get much cooler through
the week! It`s also time to find those winter coats if you haven`t
already!

Confidence in the temperature forecast through the week remains
high, with even a 75-100% probability of temperatures remaining less
than 30 degrees by next Saturday/November 30. These confidence
levels are not matched in the precipitation forecast through the
upcoming week. First up is the low, generally less than 15%, chance
for precipitation tomorrow night with the aforementioned shortwave.
Although the bulk of the precipitation chances remain to the east of
the area, varying levels of moisture remain in soundings which could
lead to some different scenarios if the moisture lines up with the
forcing. The most likely solution in soundings (though still low,
the less than 15%), would be drizzle generally in the northeast. The
most robust model remains the NAM with only pixels of any QPF
throughout portions of the area in the HREF probability matched mean
24 hour QPF product. In saying this, overall probabilities of
measurable precipitation in northern to northeastern Iowa are
actually 10-20% for QPF >0.1" Further northwest, some soundings
do indicate ice introduction which could mean some flurries late
Sunday night, though other soundings keep drier conditions
through the mid- levels. With the overall trends of saturation
and lowering cloud bases, the more widespread impact may
actually just be fog. Given the varying trends in model guidance
and degrees of saturation, confidence in any one precipitation
scenario remains lower and will have to continue to monitor the
situation through the next 24 hours. Outside of the fog, the
good news in all of this is impacts should be fairly minimal
with the low amounts of QPF.

As we look ahead to the upcoming week, multiple waves drift through
the overarching zonal upper flow through mid week, the most notable
on Wednesday into Thursday. Although the GFS continues to sink the
greater precipitation chances to the south of the area, the Euro has
actually started coming back northward in the latest runs, similar
to what it was doing several days ago. Timing and location
differences continue to make it difficult to settle on any one
scenario and its associated impacts, but we will continue to monitor
trends and provide additional updates in the coming days. &&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1140 AM CST Sat Nov 23 2024

Lingering stratus this morning has largely dissipated across
eastern areas with early morning fog having also cleared as well
leaving VFR conditions across the area. Additional clouds have
already started moving into the area, but in the shorter term
will be largely high to mid-level clouds and thus remaining as
VFR. Some lower clouds begin to filter into the area early
Sunday bringing the eventual return of some MVFR ceilings to
the area, but probabilities increase to above 50% chances after
the end of this TAF period so will address further in future
issuances. Winds will largely be out of the southeast to south
through the period and near to less than 10 knots.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 537 PM CST Sat Nov 23 2024

VFR conditions will persist overnight and much of Sunday with
continued high cloud cover at most sites. KMCW will see
restrictions first with decreasing ceilings across northern
Iowa by mid to late morning on Sunday. MVFR ceilings will slowly
extend south, reaching KFOD/KALO by the end of the period
tomorrow evening and beyond the current period at KDSM/KOTM.
Winds remain out of the southeast through the period with a
shift to northerly winds Sunday evening. The wind shift and
further ceiling reductions will be addressed in future updates.


&&

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

&&

$$

DISCUSSION...KCM
AVIATION...Hagenhoff