Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 192322
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
622 PM CDT THU MAY 19 2016

.SHORT TERM.../Tonight/
Issued at 311 PM CDT Thu May 19 2016

Main forecast concern was focused on low chance pops across far
southern Iowa towards Friday morning. Models are in decent
agreement with a weak 500mb shortwave to cut across Kansas into
northern Missouri. The forcing with this system remains very weak
and the bulk of it looks to remain Missouri. Anything that does
develop will be very high based and any rain should have a
difficult time reaching the ground without evaporating first.
Kept a sliver of slight pops going past 09z Friday over the
southern two tiers of counties. Certainly confident in the
abundant cloud cover over much of the forecast area overnight. The
afternoon cumulus field will dissipate with the sunset then
increase with weak theta-E advection past 06z from the south. Went
slightly above guidance in the south to coincide with the
aforementioned cloud cover.

.LONG TERM.../Friday through Thursday/
Issued at 311 PM CDT Thu May 19 2016

System in the central plains will lift northeast into Missouri by
daybreak on Saturday.  While models continue to produce light
showers on Saturday across central and western Iowa, forcing is
weak a best a generally subsidence is increasing through the day
across the area. Have continued the threat of a few showers and
foresee not much more than a few sprinkles or very light rainfall
before the threat ends by afternoon. Otherwise, the rest of the
weekend will see quiet and pleasant weather as warm advection
continues. Temperatures on Sunday should also be warmer as thermal
ridging slowly pushes closer to the state with readings well into
the 70s.

The well advertised transition to southwesterly upper flow as
large western trof develops is still expected into next week.
First significant wave to eject from this trof will arrive in the
Plains on Sunday afternoon with widespread convection to the west
of Iowa. The surface front associated with this system will
approach Iowa overnight with some convection spreading into the
west after midnight. However, the moist low level flow will veer
into the state on Monday along with some modest forcing producing
scattered convection during the day. Shear is somewhat
unidirectional with modest instability which may lead to some
severe weather with peak heating. There appears to be a break in
the action Monday night into Tuesday with weak shortwave ridging
passing through the region. However, the next wave approaches on
Tuesday night into Wednesday with warm advection/theta-e advection
increasing. Therefore, another active period is expected during
this time with the potential for additional severe weather and
heavy rainfall. Temperatures into next week will remain near or
above normal as southerly flow continues into the Midwest although
convection and cloud debris may limit how warm it eventually gets.

&&

.AVIATION.../For the 00Z TAFS through 00Z Friday evening/
Issued at 622 PM CDT Thu May 19 2016

Clouds to spread northward through the CWA late tonight, with CIGS
becoming BKN050-070 by Saturday. Chance of a brief shower at KDSM
and KOTM, however uncertainty at how far north precip will push.
Therefore have left them dry for now. Winds to remain out of the
south to southeast through the period.

&&

.DMX Watches/Warnings/Advisories...None.

&&

$$

SHORT TERM...Podrazik
LONG TERM...Cogil
AVIATION...Beerends



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