Funnel Clouds in Iowa, July 17, 2021

Area Forecast Discussion
National Weather Service Des Moines IA
628 PM CDT Sat Jul 17 2021

...Updated 00z Aviation...

.DISCUSSION.../Tonight through Saturday/
Issued at 236 PM CDT Sat Jul 17 2021

High pressure situated over the western Great Lakes will continue to
settle slowly southwest over the next few days. This high is not the
most clean system with a ribbon of moisture trapped beneath it with
a fair amount of cumulus around most of the edges. A few showers
have developed over far southwest Iowa today and into southeast
Nebraska. A ribbon of slightly agitated cumulus showing up on
satellite over northeast Iowa that are also faintly showing up as
radar returns. A few high res solutions trying to develop shows over
parts of northern Iowa yet this afternoon. It is possible an
isolated small shower does develop but at this point probably not
worth painting a broad 20 pop across the area. The diurnal cumulus
will diminish this evening then looking at the potential for more
areas/patches of fog overnight, mainly favored in the river valley
areas but not too dissimilar than this morning.

Sunday will be similar to today with highs in the low 80s and with
some cumulus development. Again, low chances for a few showers to
develop by the afternoon as a weak system moves in from the east and
into southeast Iowa. Still with such a weakly forced system, tough
to add widespread low pops for this. The fog potential will likely
last into Sunday night into Monday morning and again Monday night as
the high moves overhead. Possible at some point that widespread fog
to even dense fog will eventually become possible and may become the
main impactful weather early in the forecast.

The western upper high will gradually nudge further east Tuesday and
through the rest of the week and the surface high will begin to
depart to the east. As this occurs, the return of southern flow and
gradually increasing temperatures aloft arrive with the thermal
ridge inching closer. This will lead to temperatures increasing
through the week with highs reaching the 90s by Thursday. The one
caveat during this time is a couple backdoor boundaries that may
clip into northeast Iowa on Wednesday and again late in the week
that could lead to some convection and also cooler weather on the
northeast side of the boundary. A more realistic chance for storms
may arrive next weekend as the upper flow becomes more
progressive.

&&

.AVIATION.../For the 00Z TAFS through 00Z Sunday evening/
Issued at 626 PM CDT Sat Jul 17 2021

A few cumulus clouds are currently present, but these will
dissipate shortly after sunset. Patchy fog is possible early in
the morning on Sunday. At this time, hard to pinpoint if this
would impact any terminals directly, thus will leave mostly out
of the 00z TAFs. Quiet weather conditions.

&&

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

DISCUSSION...Donavon
AVIATION...Krull

Hazardous Weather Outlook
National Weather Service Des Moines IA
313 PM CDT Sat Jul 17 2021

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-181100-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
313 PM CDT Sat Jul 17 2021

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.