Chalco, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

980
FXUS63 KOAX 260517
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1217 AM CDT Sun Jul 26 2026

.KEY MESSAGES...

- Dangerous heat continues Sunday, with peak heat index values
  of 110 to 118 degrees expected.

- Extreme heat remains possible Monday, especially across
  southeast Nebraska and southwest Iowa, where heat index values
  couch reach 110 to 115 degrees.

- A few strong storms may develop Sunday evening, mainly across
  northeast Nebraska, with damaging winds the primary threat.
  Additional storms are possible Monday evening.

&&

.DISCUSSION...
Issued at 1036 PM CDT Sat Jul 25 2026

Tonight and Sunday...

Earlier this evening, an MCS tracked across southeast South Dakota,
grazing extreme northeast Nebraska before gradually weakening and
moving east-southeast into western Iowa. The decaying complex will
leave a shield of mid- to upper-level cloud cover across much of the
area overnight. We could also see some patchy fog overnight in
southwest Iowa where RH values will be the highest. Temperatures and
humidity exceeded most guidance today. Widespread highs reached the
upper 90s to lower 100s, while dewpoints remained in the upper 70s
to low 80s, higher than forecast by most guidance. This resulted in
widespread heat index values of 115 to 120 degrees. Given this
overperformance, the entire forecast area was upgraded to an Extreme
Heat Warning this afternoon, which will remain in effect into Sunday
evening.

Sunday is shaping up to be another dangerously hot day as the region
remains beneath a mid- to upper-level ridge covering much of the
central Plains. Lingering cloud cover is expected to diminish during
the morning, allowing strong mixing into the warm air aloft.
Temperatures may once again over perform guidance, with highs
forecast in the upper 90s to low 100s and dewpoints remaining in the
upper 70s to low 80s. Peak heat index values of 110 to 118
degrees are expected. Southerly winds will also increase during
the afternoon, with gusts of 25 to 30 mph, though this will
provide little relief from the extreme heat.

Another chance for storms will arrive Sunday evening near a surface
trough. Strong instability will develop during the day, with MLCAPE
values exceeding 2500 J/kg. However, deep-layer shear and large-
scale forcing for ascent will remain modest, and CAM guidance
continues to offer varying solutions regarding storm coverage and
whether initiation will occur at all in the area. Should storms
develop, the greatest chance will be across northeast Nebraska
into western Iowa during the evening, where PoPs of 15-30% are
in place. Activity would then gradually move southeastward and
weaken. Damaging wind gusts will be the primary hazard, with
DCAPE values of 1500-1800 J/kg supporting the potential for
gusts up to 75 mph. Hail up to around 1 inch in diameter cannot
be ruled out initially, though the very warm near surface air
should limit hail from reaching the ground. Any lingering
showers and cloud cover will shift southward into early Monday.

Monday...

Dangerous heat will continue into Monday, though confidence is lower
regarding its overall extent. In addition to any lingering
convective debris or cloud cover, a shortwave disturbance rounding
the ridge across the northern Plains will push a cold front
southward through the area. This will shift low-level winds from
southerly to northeasterly and cut off moisture transport. The front
will have only a limited effect on temperatures, with highs still
expected in the mid 90s to low 100s, assuming residual cloud cover
clears. However, it should lower dewpoints, particularly across
northeast Nebraska where the frontal passage is expected before peak
heating. This will produce a considerable dewpoint gradient, ranging
from the upper 70s across southwest Iowa to the lower 60s across
northeast Nebraska.

Peak heat index values may reach around 115 degrees across southeast
Nebraska and southwest Iowa, decreasing to near 100 degrees across
northeast Nebraska. Given the lower confidence in cloud cover and
frontal timing, areas generally along and south of Interstate-80
remain split between a Heat Advisory and an Extreme Heat Watch with
no headlines currently in place northward. A few evening storms
could also develop along the front across the southern portion of
the area, with a 15-30% chance currently in place. Model
soundings indicate plenty of instability, yet again, with a
profile supportive of strong wind gusts.

Tuesday and Beyond...

The aforementioned shortwave disturbance will weaken the ridge into
the work week, with a somewhat more comfortable post-frontal air
mass settling into the region. High temperatures should fall into
the low to mid 90s for much of the work week, remaining slightly
above seasonal norms.

Additional shortwave disturbances rounding the ridge will bring
periodic precipitation chances through the period, with the greatest
potential currently forecast Thursday into Friday, with PoPs of 40-
60% in place.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1217 AM CDT Sun Jul 26 2026

Cloud remnants from a decaying storm complex have approached
terminals early this morning. However, expecting this to remain
in VFR and should see VFR conditions prevail for the rest of
the cycle. A few stray showers could impact KOFK after 06z today,
but chances remain less than 15% at this time. Outflow from the
storms will switch winds within the next hour to the north
northeast and north northwest at KOFK and KOMA, respectively but
remain less than 12 kts. By the noon hour, should see winds
ramp up from the south with gusts of 20 to 25 kts at terminals
before subsiding after 01z at most locations. More storms may
develop after 00z Monday and impact KOFK/KOMA, but chances
remain less than 20% at this time.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Extreme Heat Warning until 7 AM CDT Monday for NEZ011-012-
     015>018-030>034-042>045.
     Extreme Heat Warning until 9 PM CDT this evening for
     NEZ050>053-065>068-078-088>093.
     Extreme Heat Watch from this evening through Monday evening
     for NEZ052-053.
     Heat Advisory from 9 PM this evening to 10 PM CDT Monday for
     NEZ050-051-065>068-078-088>093.
IA...Extreme Heat Warning until 7 AM CDT Monday for IAZ043.
     Extreme Heat Warning until 9 PM CDT this evening for IAZ055-
     056-069-079-080-090-091.
     Extreme Heat Watch from this evening through Monday evening
     for IAZ055-056-069-079-080-090-091.

&&

$$

DISCUSSION...Wood
AVIATION...Castillo