Forecast Discussion
NWS Omaha/Valley, NE

624
FXUS63 KOAX 161055
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
555 AM CDT Sat May 16 2026

.KEY MESSAGES...

- Showers and storms gradually taper off early this morning.

- Warm Saturday with highs in the upper 80s to low 90s. Strong
  to severe storm chances expected for the afternoon (30%) and
  evening hours, with more storms possible in the late evening
  and overnight (60-80%).

- Continued threat for severe storms Sunday and Monday with all
  hazards possible.

- Temperatures cool down for Tuesday through Thursday in the 60s
  and 70s.

&&

.DISCUSSION...
Issued at 1206 AM CDT Sat May 16 2026

.SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

0448z KOAX radar imagery nicely depicts a frontal boundary extending
from near Cortland northeast toward Nebraska City and Red Oak, IA.
Convection has largely weakened along this front at this hour,
and should continue to push east southeast into western IA.

As we head into early Saturday morning, should see an H5 longwave
trof over the western US undergo considerable deepening. As the
longwave deepens, should see a few shortwaves eject ahead of the
main longwave base, while at the sfc, lee cyclogenesis ensues over
Colorado into the Nebraska Panhandle area. Closer to home, the sfc
boundary will linger over the forecast area with most locations
reaching highs in the upper 80s to low 90s. Expect to see a
reservoir of 2,000 to 3,000 j/kg of MLCAPE pooling near and just
ahead of the sfc boundary by the afternoon. Along with the steep
lapse rates and strong 0-6 km bulk shear of 40 to 50 kts, should see
supercells develop with the potential for large hail, damaging
winds, and the potential for a tornado. The latest SPC outlooks show
a Slight risk (level 2 of 5) for much of eastern Nebraska into
western Iowa.

Latest CAM guidance still shows some discrepancies regarding
afternoon convection, however. Models such as the NAMNest, HiRes
FV3, NSSL WRF, and HiRes ARW keep the baroclinic zone farther south
over southeast Nebraska and ignite convection there. Notably, the
HRRR ignites convection farther north over northeast Nebraska given
the more northward placement of the baroclinic zone. Will also need
to pay attention to the late evening into the overnight hours.
Severe convection associated with the primary sfc low over northeast
Colorado should blossom by 00z, congealing into an MCS and pushing
east over much of central into eastern Nebraska and western Iowa.
While damaging winds will be the main threat with the feature
overnight, flash flooding is certainly plausible, particularly over
urban areas where they see repeated passage/training of storms. PoPs
for Saturday remain at around 30% in the afternoon but really ramp
up to 60 to 80% areawide after 00z. Regarding rainfall amounts,
should see anywhere from a quarter to half inch of rain, with a
few locations in western Iowa seeing closer to an inch.

For Sunday, will see the longwave trof continue to deepen, with
another shortwave ejecting from the Rockies area northeast toward
the Panhandle. The H8 low should intensify with a strong low level
jet developing on the eastern periphery. This should help bring in
increased moisture transport along with strong warm advection,
helping push highs into the low to mid 90s. Winds will also be
fairly strong out of the south at 30 to 35 mph with gusts up to 40
mph. While these strong winds may lead to some spots across eastern
Nebraska reaching Red Flag criteria, these appear to be
collocated in areas where previous rainfall and ongoing green-
up has reduced risk of rapid fire spread.

Instability will pool in the warm sector of the approaching sfc low
ranging from 3,000 to 4,000 j/kg and combined with the strong shear
of 45 to 50 kts, will again see a threat for severe convection. The
potent 40-55 kt LLJ should help increase low level curvature in
hodographs as seen per BUFKIT soundings. Combined with 25 to 30 kts
of 0-1 km bulk shear and ~200 m2/s2 of 0-1 km SRH, should see the
potential for tornadoes in addition to large hail and damaging
winds. The convective environment will likely be influenced by how
Saturday plays out and any remaining morning convection, so please
make sure to stay tuned to the latest forecast for updates. At this
time, SPC has an Enhanced (level 3 of 5) risk of severe storms
particularly over northeast Nebraska, with a Slight (level 2 of 5)
encompassing the rest of the area. PoPs gradually increase Sunday
afternoon to 50%, with 60 to 80% PoPs areawide by the evening hours.

.LONG TERM /MONDAY THROUGH FRIDAY/...

For Monday, severe potential will continue over a large portion of
the forecast area. Similar to previous days, another shortwave
ejects towards the Central Plains, inducing lee sfc cyclogenesis
with a boundary extending through the forecast area. Strong bulk
shear of 50 to 60 kts combined with an abundant amount of sfc based
CAPE will lead to this continued threat. Similar to Sunday, all
hazards will be on the table in addition to a continued flash flood
threat.

Quiet conditions are forecast for the rest of the long term forecast
period with temperatures generally in the 60s and 70s. Thursday may
see our far northwest counties being clipped by some 20% PoPs but
most remain dry. Expect a warming trend to take place by Friday and
thereafter as indicated by the latest CPC outlooks.

Generally quiet conditions are expected for the remainder of the
extended with cooler temperatures.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 552 AM CDT Sat May 16 2026

VFR conditions are forecast through much of the period, with
northerly to east-northeasterly winds in place as of 11z. Expect
winds to gradually increase in speed over the course of the
morning/early afternoon hours, with winds starting to gust to
20-25 kts. Late in the afternoon and into the early evening,
thunderstorm chances return to the area, with more isolated
activity starting initially near KOMA at times, before
additional activity arrives from the west. The most likely times
are highlighted in the TAFs for a 2-3 hour period, with the
second round listed as rain showers primarily, which may
transition to prolonged thunderstorm chances in future updates.

&&

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

&&

$$

DISCUSSION...Castillo
AVIATION...Petersen

NWS OAX Office Area Forecast Discussion

Forecast Discussion
NWS Hastings, NE

970
FXUS63 KGID 160813
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
313 AM CDT Sat May 16 2026

.KEY MESSAGES...

- Widespread coverage of strong to severe storms is likely this evening
  to tonight (mainly between 6PM-1AM). All severe hazards will
  be possible (large hail up to the size of golf balls, damaging
  wind gusts up to near 70 MPH and an isolated tornado may be
  possible)

- A few more severe storms (threat concentrated mainly north of
  I-80) will again be possible Sunday afternoon to evening.
  Baseball size hail and damaging thunderstorm wind gusts up to
  70 MPH may be possible within the strongest storms. A few
  tornadoes will also be possible.

- A 3rd consecutive day of severe activity will roll into Monday evening,
  though the threat will mainly be concentrated south and east
  of the Tri-Cities.

- Near-critical to critical fire weather concerns look return
  for likely to return to a southwest portion of the area
  Sunday given strong southerly winds blowing near 20-30 MPH and
  gusting as high as 30-40 MPH.

- Highs in the mid 80s and 90s today and Sunday will drop to the upper
  50s to low 70 Tuesday following the passage of a cold front
  Monday. A steady increase in highs will likely trail through
  the end of next week.


&&

.UPDATE...
Issued at 312 AM CDT Sat May 16 2026


Today...Widespread afternoon to evening severe weather potential.

The chance for severe weather will return each night through Monday
with the best potential for more widespread activity occurring this
afternoon and tonight. These active next few day comes as an upper-
level trough amplifies across the western CONUS. A stationary front
that glided south and into Kansas overnight, will be expected to
switch directions and shift back north later this afternoon and
evening. This feature will likely help trigger off some afternoon and
evening severe convection across much of Kansas and Nebraska.

The airmass surging in behind the northward lifting boundary will
serve as a source of fuel for these storms as a moist (mid 50s to
low 60s dewpoints) and unstable airmass (2,000-3,5000J/kg of CAPE)
marches in from behind. In addition, a moodiest amount of shear (40-
50kts of bulk shear) from veering winds and steep low-to-mid level
lapse rates (7-9 C/km) point towards an all severe hazard scenario at
first (large hail, damaging winds and an isolated tornado possible).

Storms that erupt earlier in the afternoon (6-8PM window) may start
out more discrete and supercellular in nature before congealing into
an expansive storm cluster later this evening. The best potential
for a brief tornado spin up would occur along this earlier window
while LCLs are at their lowest points and storm inflow is less
likely to be altered from neighboring storms. Storms later on,
especially as the nocturnal 50-60kt low-level jet winds up, could
quickly morph into a expansive MCS that races east/northeast across
much of the area through the rest of the evening and night. Damaging
wind will quickly become the primary hazard with the 6z HRRR even
suggesting a bowing/QLCS structure forming later on in these storms
life cycle. The severe threat should wane after 1AM as the last
lingering storms generally drop below severe criteria. A few
localized areas of flooding may have to be monitored for locations
that receive an extended period of the heavier downpours.

As result of today`s conditions, an enhanced risk of severe weather
will be in place across our far western portions of the area (areas
mainly west of a line from Buffalo to Franklin counties in Nebraska
and Phillip county in Kansas) with a slight risk across the rest of
the area. Storms will generally have the best potential to materialize
across the enhanced risk area. Before any convective activity takes
place this afternoon, highs should be on track to reach the mid 80s
to low 90s with steady 10-15MPH easterly winds, turning more
southeasterly through the day.


Sunday...Potentially heightened severe threat, mainly concentrated
north of I-80.

The final shower/storms lingering behind Saturday nights activity
should be well clear of the area come Sunday morning. Yet another
potentially severe event may also be possible Sunday afternoon to
evening. The feature of note that will drive the storm chances
Sunday will the the presence of a strengthening surface low across
western Kansas/Nebraska. The track of this surface cyclone will be
crucial for identifying where the warm sector will lie and where the
peak daytime destabilization will take place (broad area of 2,000-
3,000J/kg CAPE with 7-9 C/km low-to-mid level lapse rates).

The latest CAM guidance continues to show that a triple point
(where the cold front, warm front and dryline meet) tracking right
through the heart of south central Nebraska during the afternoon.
All of the essential ingredients needed for a higher end type of
severe event currently look to be present (instability, shear and
moisture). The biggest question yet to be fully understood is where
storms will initialize and how expansive storm coverage may become.

The latest 6z HRRR guidance continues to keep a majority of the
activity further northward and closer to the triple point rather
than along the dryline stretched out to the south (where the NAMNEST
has been suggesting). If this scenario is actualized, the better
storm potential would be mainly concentrated north of I-80 with very
few storms elsewhere. The Day-2 SPC convective outlook keeps a
majority of central Nebraska included in an enhanced risk.

Temperatures for Sunday could warm up to the 90s to maybe even the
low triple digit across a few north central Kansas locations. Given
the condensed pressure gradient from the deepening surface low,
gusty southerly winds up to 30-40 MPH look to file in across much of
north central Kansas and east central Nebraska. The gusty winds in
combination with a fairly prevalent dry slot protruding along the
southwest trail of the surface low looks likely to bring near
critical to critical fire weather concerns back to our far southern
Nebraska and north central Kansas areas for Sunday afternoon.


&&

.DISCUSSION...
Issued at 427 PM CDT Fri May 15 2026

This evening-overnight: No major changes in the latest thinking
regarding severe weather potential. Still appears the main
threat area will focus in the far E/SE portions of the forecast
area...along and ahead of a weak boundary. There`s not a lot of
temperature differences on either side, and winds are weak such
that convergence isn`t very strong either. Main differentiators
is moisture, with dew points in the mid 50s in places like
Hebron vs. lower 30s in the Tri-Cities. It got quite warm/hot
out there today, so areas that do have decent low level moisture
have moderate instability in the 1000-2000 J/kg range amidst
steep mid level lapse rates over 8 C/km. Wind shear is modest,
but sufficient, for organized deep convection with latest SPC
mesoA page indicating 30-40kt of effective deep layer shear,
decreasing with SW extent. Forecast soundings and sfc T/Td
spreads >30 degrees suggest inverted-V profiles/elevated bases
and wind gusts as the primary severe threat. The steep mid level
lapse rates and modest shear also support a severe hail threat,
particularly in the initial cores. Expect fairly quiet
conditions between midnight through early afternoon Saturday.

Saturday PM: The next round of potential severe weather will
come as early as late Saturday afternoon, but more likely during
the evening into early overnight hours. A deepening upper trough
over the W CONUS will begin to exert it`s influence by later in
the day in the form of modest height falls and difluent and
divergent upper level flow. Latest CAMs appear to be converging
on a general solution where today`s weak boundary stalls out,
then lifts northward as a warm front during the afternoon,
reaching central Nebraska by 00Z Sunday. Most likely area for
convective initiation will favor areas to our west along the
High Plains within a broad swath of Erly upslope flow and closer
to the arriving height falls. This activity will likely congeal
into one or two MCSs that roll E/NE during the late evening and
overnight, sustained by a strong LLJ increasing to 50-60kt by
03Z. Moderate to strong instability (MLCAPE as high as 2000-3000
J/kg), strong effective deep layer shear (40-50kt) - including
strong upper level storm-relative flow/venting - and very steep
low to mid level lapse rates all suggest potential for upper-
end type hail and damaging wind. In fact, wind-driven large hail
could be a concern. Will also need to watch the southern end of
an expected MCS or any embedded supercells, esp ones that
interact with the warm front, for a few tornadoes. This would be
most concerning in the 00-03Z time frame as LCLs lower and low
level SRH ramps up with the aforementioned LLJ.

The above scenario is the one that appears to be most probable
at this time (MCS rolling off the High Plains later in the day
with primarily a hail/wind threat), but isolated late afternoon
CI eastward into our area along the warm front is also
plausible...a la the 18Z HRRR. This scenario is highly
conditional due to some capping and weaker forcing, but
potentially high- impact, if it were to pan out. This scenario
would increase the high- end hail threat (up to around baseball
size) and also probably the tornado threat. Want to see more CAM
consistency before ramping up this messaging.

Sunday: appears any convection from Saturday night will have
shifted N/NE of the area by sunrise Sunday AM...setting the
stage for strong destabilization of a broadening warm sector. In
general, appears there will be most of the ingredients necessary
for a higher-end severe weather threat, including strong
tornadoes...but as always, the details matter and are still
murky this far out. With the lack of AM convection, don`t think
instability will be an issue, and the arrival time of stronger
upper level forcing appears to be well-timed towards the peak
heating hours. So even through mid level temps will be quite
warm (14C+) early in the day...some cooling/height falls
towards 00Z Mon along with strong destabilization should be
enough to support robust CI. Once storms form, should have
most/all of the ingredients in place for significant severe
weather...with the main uncertainty lying in the location of a
likely triple point (closer to Lexington or closer to Tri-
Cities) and QUALITY of boundary layer moisture. Some models
(e.g. 12Z EC) really mix the BL and lowers Tds into the
50s...whereas the NAM shields the BL a bit more and maintains
mid to upper 60s Tds through the late afternoon. RRFS is
somewhat in between. Thus...this casts some uncertainty on
mainly the tornado threat...at least early on in the convective
cycle. Threat could increase in time - even per the 12Z EC -
with gradual lowering of LCLs and increasing low level shear.
Not sure what convective mode would be by then, though. Still
plenty of time to hash out those details.

System as a whole has trended slower...which brings more of our
area into play for another round of significant severe weather
potential on Monday. This looks to be our last day (for at least
a few days) of severe weather threat as the upper trough finally
moves through Monday night. Haven`t looked into details of
Monday and beyond very much today since there`s plenty of
impactful weather in the short term.

One last thing...still monitoring the potential for a wedge of
critical fire weather conditions to punch into far W/SW zones
behind the dry line Sunday afternoon. Phillips down into Rooks
County would be most at risk, even if they see rain Saturday
night, as much of the fine (1hr) fuels are still susceptible to
large fire growth.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1128 PM CDT Fri May 15 2026

For KGRI/KEAR Airports:

VFR conditions for the first 12 to 15 hours will give way to
a developing showers and thunderstorm risk in the last part
of the forecast. Initially, winds have turned northeast behind
a cold front and maintained around 12 kts. This should continue
overnight and Saturday morning though windspeeds should taper
off a bit as pressure rises fade. We expect a mostly clear sky
overnight but increasing mid/high clouds thorugh the midday
hours at both airports on Saturday. The main story later
Saturday will be developing showers and thunderstorms in the
late afternoon & evening. Increasing low level moisture and
advancing will spell fairly widespread coverage of showers and
storms after 3-4 pm and continue through the evenings. Look for
occasionally MVFR ceilings as more steady preciptiation sets up.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.

&&

$$

UPDATE...Stump
DISCUSSION...Thies
AVIATION...Moritz

NWS GID Office Area Forecast Discussion