648
FXUS63 KDMX 070850
AFDDMX
Area Forecast Discussion
National Weather Service Des Moines IA
350 AM CDT Mon Oct 7 2024
.KEY MESSAGES...
- Cold and potential frost early this morning, then calm and
seasonal conditions today. Smoky skies developing south and
west this afternoon.
- Warming trend through the week, with unseasonably warm highs
in the 80s through the second half of the week.
- More seasonal conditions look to return by the end of the
weekend.
&&
.DISCUSSION...
Issued at 345 AM CDT Mon Oct 7 2024
Fairly benign pattern over the region today, as surface high
pressure sets in behind the departing upper level trough to our
east. Loosening pressure gradients have lead to calm winds over the
state, allowing temperatures to cool significantly under clear skies
early this morning. Temperatures as of this writing have already
fallen into the 30s and 40s, with a few points nearing freezing,
especially in the north and through the Nishna valleys. Moisture
content is relatively low with dew points generally in the upper 20s
to 30s, but if this cooling continues through the morning hours,
wouldnt be surprised to see some frost reports from those cooler
areas in northern and western Iowa.
Surface high pressure will pass over Iowa today, leading to light
winds, seasonal temperatures and an unenthused forecaster who is
looking for just about anything he can talk about. Luckily for the
forecaster, there will be some smoke drifting overhead today as the
high pressure continues further east. This smoke will primarily
impact the southwestern half of the state, producing a smoky tint to
the skies and sunset in the afternoon and evening. However, with
cooler air aloft and less mixing today, this smoke will remain aloft
and shouldnt cause any impacts at the surface. Further north in the
state, a small pocket of mid-level moisture will bring a brief
period of cloud cover this morning, which will steadily dissipate as
it meets the drier air to the south.
Northwest flow continues through much of the week, with shortwaves
passing near the state tonight and again on Wednesday. However, with
the upper level ridge to the west and hurricane Milton hogging the
moisture in the gulf, the chances for any precipitation as these
pass through is effectively zero. Therefore, if youre looking for
some actual weather to read about, youll have to head over to the
National Hurricane Center and Floridian NWS offices, cause you wont
find much here!
For our area, of greatest note will be the steadily increasing 850
hPa temperatures as the upper ridge creeps further east. Highs
return to unseasonably warm values by Wednesday, with temperatures
in the 80s being common through the second half of the week.
Fortunately, this warm up appears short lived as our next change in
pattern comes in the way of two upper troughs dropping out of
Canada. As of right now, the first looks to just graze us Friday
night into Saturday, then the second digs further south into the
state on Saturday night into Sunday, both bringing cooler air as
they pass. Current deterministic guidance have dry mid-level air
negating precipitation chances with these waves, but with it being 5
to 6 days out, will continue to monitor any future changes in this
trend. Ensemble guidance shows a more muted picture of these two
waves, but still reflects the general pattern of a trough digging
into the eastern CONUS this weekend. More to come on this as we get
further into the week!
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1052 PM CDT Sun Oct 6 2024
Confidence remains high in VFR conditions at the terminals
through the period. Light winds from the northwest will become
variable as high pressure passes through the state. As it
departs, winds under 10 knots will have some degree of a
westerly component at most terminals by Monday afternoon. High
level, western US originated wildfire smoke may drift over DSM
and OTM near and after 0z Tuesday.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Dodson
AVIATION...Ansorge
NWS DMX Office Area Forecast Discussion