843
FXUS63 KOAX 150526
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1226 AM CDT Sat Aug 15 2026

.KEY MESSAGES...

- Periodic chances for showers and storms continue into the
  weekend, briefly clearing Sunday evening through Monday.

- Temperatures remain near or just below normal on Saturday with
  highs dropping below normal across our area Sunday-Monday.

- Periodic chances of showers and storms return Monday night
  through Thursday with late week looking mild and dry.

&&

.UPDATE...
Issued at 1106 PM CDT Fri Aug 14 2026

A band of storms have developed along a boundary to our south
and appear likely to lift north into southeast Nebraska over the
next few hours. While model soundings show they will have to
overcome a fairly stout dry layer below 700-mb, a few 00Z CAMs
show they could persist across southeast Nebraska into southwest
Iowa overnight. Have added PoPs overnight for these areas to
account for this. Shear will remain weak, so not expecting any
of these storms to organize into anything severe though locally
heavy rainfall will be possible.

&&

.DISCUSSION...
Issued at 855 PM CDT Fri Aug 14 2026

We had a limited area for potential storms this evening over
southwest Iowa, but cloud cover kept temperatures slightly too
cool for air parcels to be able to lift above the inversion in
place around 750-800 mb. We saw agitated cu try to develop, but
nothing was able to take off. Now the shortwave has passed,
precip chances have dwindled, with clouds forecast to continue
to break up across our area. More significant clearing expected
over northeast Nebraska setting up an excellent scenario for
fog development. This will expand south and east, more as low
stratus overnight with reduced visibility still likely for areas
along and north of a line from Seward to Plattsmouth, east to
Red Oak, IA. A Dense Fog Advisory may be necessary for a portion
of northeast Nebraska, but it`s uncertain at this time the
extent of potential dense fog.

Meanwhile, recent heavy rain has led to rises on local rivers.
Maple Creek near Nickerson is cresting just around Minor Flood
Stage here at 8-9pm, so a Flood Warning was issued along this
creek through 10pm.

Zooming back out to the big picture, a broad upper-level ridge
remains in place over the Central Plains and Mid-Mo River
Valley. Shortwaves inducing mesoscale vorticity maxima have
been triggering our showers and storms the last couple of
nights. The good news is tonight is looking pretty quiet, but
the next shortwave arrives Saturday morning bringing more
showers and weak storms to the region. Morning cloud cover
should limit the amount of surface-based instability, but steep
lapse rates around 750-600 mb will create enough elevated
instability for a few storms to develop through the morning.
Strongest activity with this MCV should stay down in northeast
KS into northern Missouri through Saturday afternoon. More
likely we see scattered showers with a few embedded weak
thunderstorms through the day, starting with the arrival of the
MCV around 6am, diminishing mid-morning, and reigniting during
the afternoon around 3pm-ish clearing east by 7pm.

Another shortwave will trigger showers and storms along the
elevated thermal front over southeast Nebraska and southwest
Iowa Saturday night into early Sunday. Not expecting anything
organized as though we have plenty of elevated instability,
shear through the storm layer is relatively weak.

The upper-level ridge shifts eastward on Sunday putting us in
more zonal southwesterly flow aloft. As this occurs, we see a
push of northerly low-level winds finally clear the stationary
boundary to our south during the afternoon. This will clear any
lingering shower/storm chances and limit our daytime highs on
Sunday, only reaching the mid 70s north to low 80s south.

We stay mostly dry on Monday as the upper-level regime continues
to shift to a more zonal flow pattern between the flattening
ridge to our east and building ridge over Baja California. The
milder Canadian air mass remains in place, keeping highs in the
low-to-mid 80s. We to see a slight chance of showers and storms
in far northeast Nebraska Monday from potential nocturnal storms
moving in from Central Nebraska, but precip chances are only
around 20 percent.

Tuesday into Wednesday will bring back a more active
northwesterly flow pattern as ridging continues to build out
west. Better precip chances return to northeast Nebraska Monday
night into early Tuesday. A trough dips out of
Saskatchewan/Manitoba bringing another cold front south through
the Dakotas into northern Nebraska Tuesday night/early
Wednesday. Models slightly differ on the behavior of this front,
with some stalling it across our area bringing a more extended
period of showers and storms. Others clear it out to our south
leading to a drier Wednesday afternoon into Thursday. In either
case, milder temperatures look to persist through the end of the
week with cooler canadian High staying in place across the
region going into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1226 AM CDT Sat Aug 15 2026

Low clouds and fog will lead to MVFR to IFR ceilings and
visibility across much of the area into Saturday morning, with
fog expected to dissipate by 14-15Z. A few storms will also push
across southeast NE and southwest IA overnight, though current
track would keep them southeast of TAF sites. Additional shower
and storm development is expected by late morning/afternoon,
with OFK with the highest chances of seeing TS. Ceilings should
improve through the day with VFR conditions expected outside of
storms by mid to late afternoon. Winds will remain light and
mostly easterly to southeasterly overnight, before they become
northerly by late morning/early afternoon.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.

&&

$$

UPDATE...McCoy
DISCUSSION...McCoy
AVIATION...CA