Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 242045
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
345 PM CDT Sun Jul 24 2016

.SHORT TERM.../Tonight/
Issued at 210 PM CDT Sun Jul 24 2016

Cold front has passed southeast of the forecast area however the
high dewpoints are lagging post front a bit from Ottumwa to Lamoni
with dewpoints still in the upper 70s. Greatest instabilities are
tied to the sfc boundary wind shift line with drier air moving in
and increasing CIN. Initial storms over Northern Missouri may move
along the mean flow and clip into far Southern Iowa though any
organized storms should remain to the south. High pressure has been
moving into Northwest Iowa from the Dakotas and Nebraska this
afternoon and is helping bring dew points in the low to mid 60s to
the state. An area of theta-e advection focused near 600 mb is
moving over Northern Iowa and Southern Minnesota and is generating
very high based showers and isolated thunderstorms. Will keep low
pops going through the remainder of the afternoon before
diminishing. Very pleasant overnight with the lows in the 60s.
Isolated pockets of fog could occur with winds light and the ground
remaining wet in may areas.

.LONG TERM.../Monday through Sunday/
Issued at 210 PM CDT Sun Jul 24 2016

Overview...Not much of concern through the long term. Quiet, cooler,
less humid period through Tuesday as high pressure slides through
and the upper level zonal flow transitions to northwest flow.
Wednesday into the weekend much more unsettled with northwest flow
settling in and multiple short waves, with Wednesday to Thursday
wave most rigorous at the moment.

Monday and Tuesday...High pressure will slide in from the west
providing clear, pleasant conditions, especially compared to the
heat and humidity of the last few days. Early week temperatures will
return towards normal with highs in the mid to upper 80s.
Additionally, dew points will reside in the 60s compared to the 70s
to near 80 of late.

Wednesday through Sunday...As upper level flow begins to take on a
more meridional component, a number of shortwaves appear set to move
through. Models continue to depict a main wave, Wednesday into
Thursday, followed by an end of week wave Friday into Saturday.
Unfortunately though, models are not in the strongest agreement with
timing and extent, resulting in never ending at least low end pops
between waves. The main wave Wednesday into Thursday continues to be
signaled as the strongest and is reflected as such in POP trends.
The Euro is the most aggressive with the wave, eventually digging a
low into the Great Lakes, while the GFS quickly ushers the wave to
the east. Supporting factors for severe weather during the time
frame are lackluster, with borderline to unsupportive shear and weak
lapse rates through the profile. Bigger concern will be potential
for efficient/heavy rainfall, though remains a small concern overall
outside of urban areas with healthy crops and a period of dry
weather ahead of time. The end of week wave continues within the GFS
solutions, while the Euro has backed off, tending to keep the region
drier.

Temperatures through this Wendesday to Sunday period will back down
into the lower 80s, with a few upper 70s for highs, as the northwest
flow steepens and the region battles the aforementioned periods of
showers and storms and possibly persistent cloud cover.

&&

.AVIATION.../For the 18Z TAFS through 18Z Monday afternoon/
Issued at 1245 PM CDT Sun Jul 24 2016

Band of MVFR clouds remains over South Central Iowa and will
impact the KOTM vicinity this afternoon. Otherwise VFR conditions
are expected through the forecast period. Breezy northwest winds
this afternoon diminishing overnight.


&&

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

$$

SHORT TERM...Donavon
LONG TERM...Curtis
AVIATION...Donavon



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