258
FXUS63 KOAX 031043
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
543 AM CDT Wed Jun 3 2026

.KEY MESSAGES...

- Highs reach the 80s today with a small chance (15-20%) for
  some showers and storms this afternoon.

- 50-70% chance for some showers and storms overnight, with the
  highest chances across northeast Nebraska. Storms may be
  strong to severe with gusty winds and small hail.

- Active pattern continues Thursday and Friday with chances for
  showers and storms. A few storms may be strong to severe both
  days.

- Brief lull in storm chances Saturday before resuming Sunday
  (30-60%) and Monday (40-60%). Temperatures remain warm in the
  upper 80s with a few low 90s by Tuesday.

&&

.DISCUSSION...
Issued at 1150 PM CDT Tue Jun 2 2026

.SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...

04z RAP objective analysis shows the 565dam closed low spinning over
southern Saskatchewan, while ridging is observed ahead of the
feature from the Southern Plains toward Michigan. Looking at the
sfc, southeasterly flow dominates much of the area given the
anticyclonic flow from the sfc high east of the area. Temperatures
remain in the mid 60s to low 70s.

As we head into the early morning hours today, the remnants of an
MCS will enter portions of northeast Nebraska after 10z per latest
CAMs. MUCAPE will be dwindling by that time, ranging anywhere from
100 to 500 J/kg, and with little shear of 10 to 20 kts, the feature
will likely fall apart by the time it enters the area. PoPs of 15 to
25% were included with this forecast update primarily over far
northeast Nebraska to account for the feature.

For the rest of the daytime hours, weak low level warm advection
should help push highs to the mid 80s. Similar to previous days,
could see a few widely scattered showers or storms develop across
the forecast area by midday into the afternoon hours (15 to 20%
chance). While instability will be abundant, weak bulk shear of 20
to 25 kts will lead to poor storm organization and an overall
limited severe threat. Farther to our northwest over central South
Dakota, better shear and instability are observed along an
approaching sfc front. CAM guidance fires off an MCS in that area
this evening, eventually taking it to the southeast and entering
northeast Nebraska where some 1500-2000 J/kg of MUCAPE lingers. Some
strong wind gusts and small hail certainly appear plausible with the
MCS initially, but some questions remain as to how long the feature
will maintain itself. The best 0-6 km bulk shear appears to be
concentrated in a corridor north of our forecast area up in FSD by I-
90, which is where solutions like the HRRR tend to keep the feature
strongest while it decays as it enters northeast Nebraska. At this
time, a marginal risk of severe weather (level 1 of 5) remains in
effect for northeast Nebraska Wednesday evening. PoPs of 50 to 70%
are currently in the forecast for northeast Nebraska, but again,
some potential exists for these chances to decrease depending on the
evolution of the environment. Convection will likely fester into the
morning hours of Thursday given a lingering H8 LLJ helping provide
some speed convergence/forcing.

Thursday will see the H5 flow become more zonal to slightly
southwesterly. A shortwave is progged to track through that flow
across the Central Plains. With temperatures warming to the mid 80s
for most locations, should see another warm day with convective
temps being reached. Skinny CAPE profiles of 500 to 1,000 J/kg
should lead to a few scattered showers and storms in the afternoon.
Despite rather poor H7-H5 lapse rates of 5 to 6 deg C/km, borderline
shear of 25 to 30 kts could yield an isolated strong to severe storm
producing strong winds or hail. Storms may also be efficient
rainfall producers with PWATs of 1.75 to around 2 inches, which is
well above the 90th percentile (around 1.34 inches per SPC sounding
climo for OAX).

Similar to today, Thursday evening will see another MCS feature
develop over the Dakotas and race southeastward. There is some
chance that the feature could again enter northeast Nebraska where
better shear and instability are forecast. At this time, a slight
risk (level 2 of 5) for severe weather is forecast for far northwest
Knox County, while a broad marginal risk (level 1 of 5) for severe
storms is forecast for much of the forecast area. PoPs of 30 to 50%
are forecast for much of eastern Nebraska and western Iowa late
Thursday morning into the afternoon, while chances really ramp up to
60 to 80% areawide by Thursday night.

.LONG TERM /FRIDAY THROUGH TUESDAY/...

Early Friday morning, some long range CAMs like the NAMNest suggest
the MCS feature lingering across the area til around 11z. Repeated
passage of storms over areas that received a lot of rainfall
Thursday afternoon could see localized instances of flash flooding.
Later in the day, should see another H5 shortwave trof track through
the area while a sfc cold front approaches from the west.
Instability will pool in the warm sector ahead of the main front,
ranging from 2,000 to 3,000 J/kg of CAPE, and combined with steep H7-
H5 lapse rates and 0-6km bulk shear around 30 kts, some threat for
severe storms will exist. Various machine learning algorithms
suggest some threat for strong to severe storms for the area, so if
you have any plans for Friday, make sure to stay up to date with the
forecast. PoPs remain at 30 to 50% for Friday afternoon, increasing
to 60 to 80% Friday evening.

For Saturday, the H5 ridge builds into the Northern Plains.
Expanding 1000-500 mb thicknesses should yield warmer temperatures,
with most areas reaching the upper 80s to low 90s. Large scale
subsidence should help limit Saturday`s storm chances, with any
chances largely confined over our far southeast areas. More chances
for showers and storms return Sunday (30 to 60%) and Monday (40 to
60%) as a wave lifts northeast from the Southern Plains toward the
Central Plains. With this forecast update, the various machine
learning algorithms indicate severe potential remaining to our south
and west. Temps remain in the mid to upper 80s both days. Primarily
dry conditions are favored for Tuesday as another H5 ridge builds
into the Northern Plains.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 538 AM CDT Wed Jun 3 2026

VFR conditions are expected to prevail throughout the forecast
period. Winds will remain calm and out of the southeast early
this morning before becoming more southerly and increasing to
12-15 kts with gusts up to 22 kts by this afternoon. Mid- and
high-level clouds will increase in coverage through the day,
with a few clouds around FL050 passing by through the late
morning and afternoon.

A cluster of thunderstorms is expected to push in from the west
after 04/04Z, with the highest confidence in impacts at KOFK.
Confidence is lower (30% chance) in thunderstorms making it to
KLNK and KOMA.

&&

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

&&

$$

DISCUSSION...Castillo
AVIATION...Wood