Area Forecast Discussion
Issued by NWS Des Moines, IA

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602
FXUS63 KDMX 212039
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
339 PM CDT Tue Mar 21 2017

.SHORT TERM.../Tonight through Wednesday/
Issued at 340 PM CDT Tue Mar 21 2017

Band of precip that pushed through central IA today has diminished
some and pushed into far eastern IL. CAA expected across the state
tonight with an area of high pressure moving eastward across the
northern plains and nosing into Iowa tonight. Return flow will begin
early Wednesday into the western/northern CWA with a push of
waa/theta-e advection. Could see some light precip with this push of
moisture/weak lift, but overall better lift further north/west.
Therefore dropped pops some and cut back on coverage. Low level
winds also coming off the large area of high pressure/dry air and
could prevent some of the precip from even reaching the ground.

.LONG TERM.../Wednesday night through Tuesday/
Issued at 340 PM CDT Tue Mar 21 2017

Area of high pressure quickly moves east into Thursday with upper
level ridging setting up across the central US and a deep upper
trough moving through the southern Rockies. Return flow sets up in
earnest into Thursday, with strong waa/moisture advection off the
Gulf and into Iowa. Warm front to lift northward through the CWA and
could see some precipitation and storms spread across the state
through the day/evening as energy ejects out of the southwest US
trough and moves through the central US ridge. Could initially see
some light fzra across northern IA Thursday morning before low level
moisture increases and precip turns over to all rain. Warm front to
stall across northern IA into Thursday night/Friday as southerly
flow ramps up with H85 winds at 50-60kts and strong push of moisture
into the central US. Upper low/sfc low to become stacked across the
western high plains by early friday, and slowly lift ENE through the
day Friday into Saturday. This will allow for a long duration
precipitation event as warm, moist air continues to stream into IA
with several rounds of showers/storms expected. Upper low to
continue to linger across MO into Saturday with wrap-around moisture
and precipitation still anticipated, and pushes toward the Great
Lakes into Sunday.

Expect to see a break in precip chances sometime Sunday, before a
second system ejects out of the southwest US and through the region
bringing additional chances for rain into Monday of next week. With
the extended chances of rainfall, could see quite a bit of QPF
through early next week with around an inch or more of widespread
rain amounts through the weekend. This could lead to some rises on
local streams/rivers especially across northeastern portions of the
area where streamflows are already higher. As for temperatures, a
cooler day is expected for Wednesday with much warmer temps to end
the week into next week.

&&

.AVIATION.../For the 18Z TAFS through 18Z Wednesday afternoon/
Issued at 1227 PM CDT Tue Mar 21 2017

Band of RA/SN has pushed southward of KDSM as of 17z, but will
continue to impact south central Iowa including KOTM through 19z
with visibility restrictions down to 2SM or less possible at
times before improving. Otherwise, VFR conditions will prevail
over central Iowa through today and tonight. Northerly winds will
gradually become easterly later today and through the night.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...Beerends
LONG TERM...Beerends
AVIATION...Martin



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