Chalco, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

388
FXUS63 KOAX 250444
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1144 PM CDT Thu Jul 24 2025

.KEY MESSAGES...

- Heavy rainfall is possible along a slow-moving boundary today
  into Friday, which may lead to localized flooding across
  southeast Nebraska and southwest Iowa.

- A renewed stretch of dangerous heat is possible late this
  weekend into early next week.

&&

.DISCUSSION...
Issued at 228 PM CDT Thu Jul 24 2025

Today and Tonight...

The synoptic pattern this afternoon features a mid- to upper-level
ridge over the eastern CONUS and a closed low moving onto the
California coast. Between these two systems, zonal to southwesterly
flow aloft continues across the region, allowing shortwave
disturbances to round the ridge and move into the area. At the
surface, a stationary front remains draped across southeast NE into
central IA. As of 2 PM, objective analysis depicts a vorticity
maxima pushing into southeast NE and northeast KS. The amount of
convective development we see with the approaching disturbance still
remains somewhat uncertain. The overhead cloud shield and lingering
showers remaining from morning convection has limited
destabilization, with MLCAPE values generally under 750 J/kg
near the boundary. Bulk shear values also remain weak, limiting
storm organization and reducing the potential for strong to
severe storms. CAM guidance has continued to push the axis of
heavier rainfall a bit further south, with convection primarily
developing on the southern fringe of the cloud shield over
northeast KS into northwest MO. However, with several boundaries
in place and a vorticity maxima incoming, I would not rule out
precipitation over-perfoming the slim coverage in CAM guidance
this evening.

Depending on how much convective development we end up receiving,
locally heavy rainfall remains a primary concern, especially in
southeast NE and southwest IA. Any storms that do move into the area
will be efficient rainfall producers, with PWAT values above 2" and
warm cloud depths approaching 4 km. Multiple round of these
efficient rain-producing storms over an already saturated area will
be something to keep a close eye on. Localized rainfall totals of 2
to 4 inches will be in play. A Flood Watch remains in effect for
portions of southeast NE through Friday evening.

Despite the cloud cover that has been slow to clear out this
morning, afternoon highs are still expected in the low to mid 80s
across the area. However, dewpoints in the low 70s will maintain a
moist and uncomfortable airmass.

Friday...

On Friday, two additional vorticity maxima are forecast to move into
the region from the southwest, helping to lift the stalled front a
bit further north. The first disturbance is expected to arrive
during the overnight period, potentially initiating storms across
southeast NE and southwest IA, primarily along and south of I-80
(PoPs 50-70%). A brief lull in activity may occur in the early
afternoon before the second disturbance arrives, prompting
redevelopment along the front through the afternoon (Pops 30-60%). A
35-40 kt LLJ is expected to nose into the area during the evening,
increasing the coverage of showers and storms.

Once again, weak shear will limit any severe weather potential, with
localized heavy rainfall and flooding the primary concern. Strong
moisture transport will continue, supporting PWAT values near 2" and
warm cloud depth of 4-4.5 km, contributing to efficient rainfall
rates. WPC places the southern portion of the CWA in a Slight Risk
(level 2 of 4) for excessive rainfall both today and tomorrow.
Lingering cloud cover will keep highs in the low 80s, with the humid
conditions continuing.

Saturday...

Precipitation may linger into Saturday morning before gradually
tapering off, allowing skies to clear through the day. With
increasing sunshine, afternoon highs are expected to rise into the
upper 80s to low 90s. However, lingering low-level moisture will
help push Heat Index values near 100, making for a hot and humid
afternoon.

Sunday and Beyond...

Through the remainder of the weekend, the upper-level ridge over the
southeastern CONUS will begin to expand into the region, bringing a
warming trend. Sunday and Monday are expected to be the hottest days
of the forecast period, with highs climbing into the mid to upper
90s and Heat Index values reaching between 105 and 110. These
conditions may warrant heat headlines in the coming days, though
confidence will depend on the potential for weak disturbances to
introduce cloud cover and mitigate temperatures.

A shift in the pattern is anticipated on Tuesday, as an incoming
shortwave helps amplify a trough over Ontario and Quebec while
flattening the ridge locally. This may allow a cold front to sweep
through the area. Ahead of the front, temperatures could still reach
the upper 80s to mid 90s Tuesday afternoon. Rain and storm chances
increase Tuesday evening into the overnight period (PoPs 30-50%)
with the passage of the disturbance. Various machine learning-based
guidance highlights a 5-14% probability of severe weather, though
confidence in any timing or details remains low in this extended
time frame.

Behind the system, a cooler post frontal airmass with lingering
precipitation will keep highs Wednesday and Thursday in the
upper 70s to low 80s.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1144 PM CDT Thu Jul 24 2025

VFR conditions observed at the start of the TAF period.
Satellite imagery is already showing some high based clouds
filtering in from the south in response to an approaching
system.

Will eventually see ceilings and visibilities deteriorate to
MVFR from south to north after 08z. Some potential exists for
ceilings drop to IFR a little more northward than seen in the
00z issuance, so have added a TEMPO group at KOFK for IFR
reductions from 12 to 14z and also at KOMA from 11 to 13z. Have
also adjusted timing for arrival of IFR ceilings at KLNK. Some
brief drops to LIFR may occur at KLNK from 11 to 14z.

Ceilings will rise gradually in the late morning into the
afternoon hours. May see some showers and storms affect KLNK
after 19z, but given model guidance has trended precipitation
farther south, have decided to remove mentions from this
issuance and will refine in subsequent issuances.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch through late Friday night for NEZ090>093.
IA...None.

&&

$$

DISCUSSION...Wood
AVIATION...Castillo