Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 282318

Area Forecast Discussion
National Weather Service Des Moines IA
618 PM CDT Wed Oct 28 2020

.DISCUSSION.../Tonight through Wednesday/
Issued at 234 PM CDT Wed Oct 28 2020

Summary...Temperatures will see-saw back and forth almost daily
through the next several days between cool 30s-40s and warmer 50s
as a series of fronts move through. These frontal passages will
all be dry, though the weekend will be breezy. By next week warmer
temperatures are likely.

Details...Weather across the CONUS is currently dominated by two
large low pressure centers - one bringing heavy ice accumulations
and heavy rain to the southern plains and the second, Hurricane
Zeta approaching the Gulf Coast. The placement of these systems
has allowed for southwest flow into the area today with
temperatures warming into the 50s. Snowpack across northwest has
diminished throughout the day, as evidenced on GOES-East imagery.

Overnight a shortwave trough will move across the area and pull a
cold front across the state. Winds will transition to northerly this
evening and Thursday`s temperatures will be 10 or more degrees
cooler than what was seen today. We`ll see a bit of recovery on
Friday as return flow increases warm air advection into the area.
WAA continues into Saturday with highs in the 50s making a return.
This will be short-lived as yet another shortwave pushes through,
knocking highs on Sunday back into the 30s and 40s. The back-and-
forth over the weekend between shortwaves will result in fairly
breezy conditions. With a  tight pressure gradient across the area
expect to see gusts of 20-30+ mph this Halloween weekend so anyone
outdoors this weekend will want to be mindful of capes and wings.

The western thermal ridge builds into the area next week with
temperatures responding accordingly. By Tuesday and Wednesday
highs will crack 60 degrees again for most of the area. Models
have indicated 850mb temperatures of 14-17C, so it is possible
that temperatures will be even warmer that what is currently
forecast. At this time frame nudged temperatures a bit, but did
not make a huge jump in temperatures as model confidence is not
high at this time range.


.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 618 PM CDT Wed Oct 28 2020

Main concern will be increasing wind aft 06z and lowering cigs to
MVFR, briefly IFR as cold front heads south across the area. North
winds and shield of stratus will arrive KMCW aft 06z with area
spreading south to KDSM through 10z. Brief push of wind with gusts
to 20kt expected as well. VFR conditions will return aft 16-18z as
high pressure builds into the region and winds lessen in strength
remainder of forecast period. /rev




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