Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 110739

Area Forecast Discussion
National Weather Service Des Moines IA
239 AM CDT Tue May 11 2021

.DISCUSSION.../Today through Monday/
Issued at 230 AM CDT Tue May 11 2021

Some areas of frost remain possible over northern Iowa through the
early morning hours as temperatures have fallen into the 30s. Drier
air pushing in from the north may hinder frost development in some
areas as T-Td spreads increase. A quiet series of days lie ahead as
surface high pressure lingers nearby and the upper jet is shunted
south of the region. A shortwave skirts through the central Plains
today, but will only result in mid/high cloud cover over the
southern half of the state. Temperatures through the Thursday
steadily warm through the 60s. Ripe conditions for strong raditional
cooling may lead to additional frost development north and east
tonight, however dry air may once again be a limiting factor.

Southerly surface flow returns as the high pressure shifts east
later Thursday into Friday. Multiple windows for much needed
rainfall exist Friday and into the weekend as models bring a series
of shortwave troughs through the Upper Midwest. The first instance
occurs Friday as a plume of mid-level theta-e advection phases with
appreciable kinematic support aloft. The shower activity may be
enhanced during the morning hours on the nose of a waning low level
jet, but enough forcing and moisture hangs around to keep precip
chances in the forecast through the day. Both GFS/EC and their
respective ensemble means bring additional waves of scattered to
widespread precip across the area over the weekend, but confidence
in precip timing and possible amounts is low at this time. Any
notable threat of strong to severe storms may struggle to
materialize as the instability axis holds south across KS/MO. As
mentioned by the previous shift, NBM temps may be too warm Friday
and beyond and may need to be adjusted downward as precip timing and
coverage becomes more certain.


.AVIATION.../For the 06Z TAFS through 06Z Tuesday night/
Issued at 1155 PM CDT Mon May 10 2021

High clouds will be moving in from Nebraska overnight through the
afternoons. This will mainly be over DSM and OTM. The other
terminals should be mostly clear. Wind gusts up to 15 kts
possible, but not expected to be an issue.


Frost Advisory until 8 AM CDT this morning for IAZ004>007-



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