Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 270447
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1147 PM CDT Tue Jul 26 2016

.SHORT TERM.../Tonight/
Issued at 2 PM CDT Tue Jul 26 2016

Surface ridge across eastern Iowa will continue to slowly drift
eastward overnight. The dry airmass associated with the ridge will
remain across Iowa for much of the night providing tranquil
weather. However, southerly flow will increase on backside of the
high toward the end of the period and the weak low level jet
over the plains will veer toward northwest Iowa toward the end of
the period. Showers and a few storms will approach northwest Iowa
during this time and Will see mid and high clouds increase in the
northwest portions of the forecast area toward daybreak although
any precipitation is expected to remain to the west. Temperatures
will cool nicely this evening with relatively clear skies and
light winds although readings will level off in the northwest
during the early morning hours as winds become southerly and
clouds gradually increase.

.LONG TERM.../Wednesday through Tuesday/
Issued at 223 PM CDT Tue Jul 26 2016

Forcing and lift associated with upper system in northwest flow will
spread into the north on Wednesday and across the remainder of the
state on Wednesday night. Showers and storms will increase across
the north during the day and with precipitation expanding south
and east Wednesday night. Instability will remain weak to moderate
along with weak low level shear. Therefore, the severe threat
appears to be rather minimal at this point with any severe storms
remaining isolated with hail/wind being the main concern.
Localized heavy rainfall may also occur given Pwats increasing to
above 1.5" as well. The threat of precipitation will shift
gradually eastward on Thursday with limited coverage of showers
during the day into Thursday night. Another shortwave dropping
through the state on Friday will present another threat for
showers and a few storms, mainly across the southwest half of the
forecast area where moisture will remain.

There will be a continuing threat of isolated precipitation into
the weekend, but at this point nothing large or overly organized
appears in store for the forecast area. In fact, temperatures will
be at or below normal. However, upper ridging is expected to begin
building into the central United States by early next week with
temperatures climbing above normal for Iowa.

&&

.AVIATION.../For the 06Z TAFS through 06Z Wednesday night/
Issued at 1144 PM CDT Tue Jul 26 2016

Aviation concern overnight involves potential for radiational fog.
Left 5SM vsby at KALO and KMCW though confidence not terribly high
in fog potential at those locations. Left 4sm at KOTM, where there
is a possibility for a brief period of lower vsbys. TSRA likely
coming in towards the end of this TAF period into the Thursday
morning. Will let subsequent TAF updates address this precip in
more detail.

&&

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

$$

SHORT TERM...Cogil
LONG TERM...Cogil
AVIATION...Kotenberg



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