330
FXUS63 KOAX 091915
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
215 PM CDT Tue Jun 9 2026

.KEY MESSAGES...

- Hot and humid conditions continue today with a Heat Advisory
  in effect for most of the area.

- A non-zero chance for a severe storm exists this afternoon
  over the area. Better chances (50-70%) for storms are expected
  for primarily areas northwest of a line from Columbus to
  Decatur, Nebraska after 7 pm. These will likely become severe
  with damaging winds the main threat.

- More showers and storms develop late Wednesday night into
  Thursday morning, and may be strong to severe with large hail,
  strong winds, and heavy rain.

&&

.DISCUSSION...
Issued at 215 PM CDT Tue Jun 9 2026

.SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...

19z RAP objective analysis depicts a longwave H5 trof over the
western CONUS, while ridging dominates much of the southeast CONUS.
Southwesterly flow remains in place for much of the Central and
Northern Plains. The southwesterly H8 flow has led to continued WAA
and increased moisture transport over the forecast area. Tds remain
muggy at this hour, ranging from the mid 60s to low 70s resulting in
a rather uncomfortable air mass. As highs reach the mid to upper 90s
today, expect heat index values to reach the 100F range. While some
low stratus is seen moving east northeast near Lincoln, some
thinning in cloud cover is observed. After collaboration with
neighboring offices and with this being one of the first heat waves
of the year, have maintained the Heat Advisory for the area through
02z.

In addition to the heat, the increasingly warm and unstable airmass
will provide fuel for our severe weather threat this afternoon and
into the evening/overnight hours. Model guidance suggests a sfc low
currently over eastern WY deepening and tracking east, while a
dryline/sfc front extends southward toward western Nebraska. The
environment near and ahead of this feature appears very favorable
for severe storms capable of all hazards. Abundant sfc based
instability of 3,000 to 4,000 j/kg of CAPE with little to no CIN
is seen from BUFKIT soundings, and 0-8 km bulk shear spanning
the depth of the CAPE profile ranges around 40 to 50 kts. This
environment is suggestive of supercell formation, but a few
questions remain regarding how convection will evolve/develop.

Latest CAM guidance still shows a few discrepancies on how this
afternoon/evening could play out. CAMs like the NAM 4km Nest
suggest some potential for storms firing as early as 20z well
ahead of the dryline/front along the fringes of our CWA, while
other CAMs suggest some general light showers in the vicinity.
Should an updraft develop and be able to sustain itself, it will
likely become severe with all hazards on the table. The very
steep lapse rates of 8 deg C/km will result in very large hail
in addition to a damaging wind threat. Low level curvature
observed in hodographs along with 0-3 km and 0-1 km SRH well
above 200 m2/s2 suggests favorable conditions for tornadoes.
Confidence in this scenario occurring remains rather low given
current CAM solutions not really latching on to this scenario.

Higher chances for severe convection are expected after 00z as
initial, discrete convection merges into an MCS across central
Nebraska. The MCS will bring more of a damaging wind threat (75+ mph
gusts) over western into northwestern portions of the county warning
area. If storms can develop ahead of the main linear feature and
remain discrete, these will likely become supercells with the
potential for some very large hail and tornadoes given the already
mentioned favorable low level curvature/SRH as the H8 LLJ
strengthens.

For this forecast update, PoPs remain at 15 to 30% by around 00z
over our far northern border area with FSD, while chances ramp up to
50 to 70% for areas along and northwest of a line from Columbus to
Decatur, Nebraska. An enhanced risk (level 3 of 5) of severe weather
remains in effect for much of northeast Nebraska, while a slight
risk (level 2 of 5) is forecast for the remainder of the area. A few
showers and storms linger into the early morning hours over
northeast Nebraska at about a 20 to 40% chance.

As we head into Wednesday, the bulk of the forecast area should see
dry conditions aside from our far southeastern areas where some more
showers and storms may develop in the afternoon (15-30%). These
should quickly push east. Highs will remain warm in the low to mid
90s with heat indices in the mid to upper 90s mainly over far
southeast Nebraska into western Iowa. CAM guidance signals more
showers and storms developing into a line just to the east of the
forecast area, after 00z. More showers and storms are forecast to
develop over the area late Wednesday into Thursday morning and are
discussed below.

.LONG TERM /THURSDAY THROUGH MONDAY/...

Early Thursday morning, there will likely be more redevelopment of
showers and storms along the nose of an H8 LLJ. In addition to some
large hail and strong wind gusts, likely will see some heavy
rain/flash flooding concerns play out. Warm cloud depths approaching
4000m with PWAT values of 2 inches (well above the 90th percentile)
should lead to efficient rainfall producers. Some uncertainty exists
on where exactly the best forcing/location for storm development
will occur so expect further adjustments made to the forecast. PoPs
gradually increase in coverage in the morning, peaking at 60 to 80%
by 09z and tapering off by the noon hour. Temperatures cool to the
upper 70s to mid 80s for highs.

Sfc high pressure moves into the area for Friday with largely dry
conditions and highs in the mid 80s to low 90s. Storm chances (50-
70%) return to the forecast for Saturday, and a few of these could
become strong to severe with the Day 5 SPC outlook showing a 15%
chance for severe weather. The active pattern continues for Sunday
and Monday as another H5 trof ejects from MT/WY southeast. PoPs
remain at 15 to 30% these days. Expect cooler highs in the mid to
upper 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1236 PM CDT Tue Jun 9 2026

VFR conditions are observed at terminals early this afternoon. A
band of low level stratus clouds ranging from 3,000 to 4,000 ft
will slowly track toward the east northeast and may clip KLNK.
Current thinking is that this stratus band will break up/thin
out by the time it reaches the terminal. A stray shower or storm
may clip terminals this afternoon, but confidence remains low
for occurrence. If a storm manages to form, it will likely
become severe. However, higher chances are expected after 03z,
particularly at KOFK when a line of severe thunderstorms tracks
east northeast. Have included -TSRA with TAF at this terminal
given highest confidence for occurrence is there. For KOMA and
KLNK, chances for -TSRA remain at around 20%. Expect any storms
to have damaging wind gusts and large hail, in addition to any
locally reduced visibilities and ceiling restrictions to
MVFR/IFR. Showers and a few storms linger after 06z but chances
remain at 15-30%.

Winds will become gusty this afternoon from the south with gusts
of 25 to 30 kts. Winds turn clockwise late in the TAF period and
remain gusty. Some LLWS overspreads terminals after 03z at KOMA
and KLNK.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Heat Advisory until 9 PM CDT this evening for NEZ011-012-015-
     017-018-031>034-042>045-050>053-065>068-078-088>093.
IA...Heat Advisory until 9 PM CDT this evening for IAZ043-055-056-
     069-079-080-090-091.

&&

$$

DISCUSSION...Castillo
AVIATION...Castillo

NWS OAX Office Area Forecast Discussion