Damaging Winds in Iowa, June 30, 2026

Area Forecast Discussion
National Weather Service Omaha/Valley NE
611 PM CDT Tue Jun 30 2026

.KEY MESSAGES...

- Heat Advisories and Extreme Heat Warnings remain in effect for
  much of eastern Nebraska/western Iowa through this evening.
  Expect temperatures in the 90s with heat index values
  approaching 106.

- Strong to severe thunderstorms are expected tonight,
  particularly for northeastern Nebraska. Gusty winds, hail and
  locally heavy rainfall are the main concerns with any storms
  that develop.

- Expect temperatures to reach the 90s each day through the end
  of the week. Daily chances for showers and storms will be
  possible.

&&

.DISCUSSION...
Issued at 148 PM CDT Tue Jun 30 2026

The forecast period starts out with high pressure over the eastern
CONUS, an upper low over Saskatchewan and Manitoba, and southwest
flow over the Central High Plains and Great Plains. Warm gulf air is
streaming into the region today, leaving us with noticeably muggy
and uncomfortable conditions. The main change in the heat related
part of the forecast for today was bringing dewpoints up a bit
across the region as many models have not been high enough over the
past couple of days. We are still on track to reach the low to mid-
90s across the region this afternoon with heat index values ranging
from 99-106 degrees. The Heat Advisory and Extreme Heat Warning
products will continue through this afternoon and into the start of
this evening. A few showers with maybe an isolated rumble of thunder
remain possible along the KS/NE border.

Heading into tonight, temperatures are expected to cool into the low
to mid-70s for locations that have been under the heat related
products. Factoring this in as well as local criteria for heat and
expected temperatures and heat indices, at this point, the warning
and advisory will not be extended.

A stationary boundary remains draped across central Nebraska this
afternoon into this evening. There is still disagreement in where
storms will develop and set up this evening/tonight across the
region. The NAMNest for example, has thunderstorms developing from
Ft. Morgan, Colorado to Kimball, Nebraska, lifting to the northeast
and bowing out as it moves into the Omaha CWA. The HRRR shows
thunderstorms are expected to develop across western Kansas, lifting
to the northeast through the evening and overnight hours along the
boundary. There is consensus that northeastern Nebraska stands the
best chance of storms tonight for our area, based on current models;
however, areas further south toward Lincoln, Omaha, and Red Oak, are
not entirely in the clear. As far as severe weather potential is
concerned, similar to last night, a wind and hail threat appears the
most likely hazards with any storms that develop and make it into
our area. Storms that are able to cross the boundary will make it
into a favorable environment for storms, with DCAPE values of 1200-
1600 J/kg, MLCAPE values of 2500+ J/kg, and steep lapse rates.
Additionally, precipitable water values ranging from 1.0" to
1.8" will also be in place, so any thunderstorms that develop
drop some localized heavy rainfall.

The upper ridge remains in place through the rest of the week and
into the weekend for the region, with southwest flow over the Great
Plains. This will allow high temperatures to remain in the 90s each
day while lows are in the 60s and 70s. Given the position of the
ridge and the CWA location, we will continue to have a series of
disturbances moving through the region over the coming days. These
will bring chances for showers and thunderstorms, a few of which may
become strong to severe.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 608 PM CDT Tue Jun 30 2026

A front is draped across the area with southerly flow south of
it and light and variable flow along it at KOFK. Expect to see
southerly winds continue overnight and picking up speed after
sunrise. Overnight, some low-level wind shear is anticipated
with winds at FL019 at 45 knots from 210 degrees.

Thunderstorm development late this evening and overnight are
most likely to affect KOFK. Have added two hours of VCTS to
account for this for now from 05Z to 07Z. Expect this timing to
be tweaked as the system shows itself later this eve.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Heat Advisory until 9 PM CDT this evening for NEZ015-034-044-
     045-050-051-065>068-078-088>093.
     Extreme Heat Warning until 9 PM CDT this evening for NEZ052-
     053.
IA...Heat Advisory until 9 PM CDT this evening for IAZ043-055.
     Extreme Heat Warning until 9 PM CDT this evening for IAZ056-
     069-079-080-090-091.

&&

DISCUSSION...ANW
AVIATION...Nicolaisen