Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 161132
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
632 AM CDT Sat Mar 16 2024

 ...Updated for the 12z Aviation Discussion...

.KEY MESSAGES...

- High fire weather danger this afternoon with strong northwest
  winds developing. Burning is discouraged.

- Notably cooler weather by tonight and into Monday, then
  moderating temperatures Tuesday and Wednesday.

- Precipitation chances return in the latter half of the coming
  week, but with low confidence in details.

&&

.DISCUSSION...
Issued at 247 AM CDT Sat Mar 16 2024

Skies are currently mostly clear across Iowa with moderate
southwest breezes and temperatures easing into the upper 30s
and lower 40s. Change is on the way however, as a sharp trough
is dropping into southern Minnesota and will surge across our
forecast area later this morning. Behind the front winds will
turn to northwest and increase significantly, with speeds of 20
to 25 mph and gusts over 30 mph at times by this afternoon
making for a blustery day. Cooler temperatures will also flow
in, but we should still see highs in the upper 40s north to near
60 far south, where the front will move through several hours
later after some daytime warming has been achieved.

Fire weather danger remains concerning today, due to the
strength of the winds and relatively low humidity. However,
with minimum RH around 30-35 percent predicted, and fuels
remaining damp in many areas due to recent rainfall, a Red Flag
Warning has not been issued at this time. Additionally, upstream
satellite imagery and high-res model guidance indicates
potential for areas of low clouds moving over about the
northeast half of the area this afternoon, which would somewhat
mitigate mixing/gustiness/RH concerns. Still, will be messaging
a high fire danger and plan to issue a Special Weather Statement
to that effect later this morning.

A secondary boundary, bringing even cooler temperatures will
cross our area late tonight or Sunday morning and reinforce
strong and gusty northwest winds once again during the day on
Sunday. With lower temperatures and more cloud potential,
elevated fire weather conditions should again remain below RFW
levels. It will be a cold and blustery day however, with
afternoon highs only in the mid 30s north to lower 40s south.
This should make Sunday the first day this month with a below
normal average temperature.

Monday morning will be cold, with lows in the mid teens to lower
20s, however temperatures will then moderate by Tuesday and
Wednesday with highs climbing back into the 50s on both days in
most areas. In the latter half of the coming week the forecast
becomes more uncertain in a split flow regime, with several
subtle impulses moving through strong 500 mb flow to our north,
concurrent with a broad 500 mb trough creeping eastward over the
Southern Plains and Ozarks around Thursday and Friday. Long-
range models have been having difficulty resolving the details
of the interaction between the northern stream and southern
trough, and as a result precipitation placement is highly
variable between various solutions. This results in several
consecutive days of 20-40 POPs from Wednesday night or Thursday
through the end of the forecast period, however, we may see a
proverbial gap scenario develop where the precipitation mostly
remains to our north and south and much of the period remains
dry in Iowa with just periods of light precipitation. Will await
a clearer trend in solutions for this period before deviating
from the current POP strategy.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 632 AM CDT Sat Mar 16 2024

Winds will turn from WSW to NW this morning as a front surges
through the area. Ahead of the boundary LLWS will continue at
DSM/OTM for another couple hours. Behind the front NW winds will
strengthen substantially, with gusts to 25-30 KT for much of the
afternoon. Low clouds around FL025-040 will also spread from MN
down into NE IA and may briefly product MVFR ceilings, mainly at
MCW, however most upstream observations are VFR at just above
FL030, so have mentioned only VFR in the TAFs for now, with
amendments possible later this morning.

&&

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

&&

$$

DISCUSSION...Lee
AVIATION...Lee


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