Forecast Discussion
NWS Omaha/Valley, NE

652
FXUS63 KOAX 181747
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1247 PM CDT Mon May 18 2026

.KEY MESSAGES...

- Potential for more severe weather today, mainly across
  southeast Nebraska and southwest Iowa. Large hail, damaging
  winds, strong tornadoes, and flash flooding will all be
  possible.

- Cooler weather moves in on Tuesday with potential for morning
  frost for northeast Nebraska on Wednesday.

- Another active pattern may set up going into next weekend with
  chances for more storms, and possibly severe weather.

&&

.DISCUSSION...
Issued at 1155 PM CDT Sun May 17 2026

Today and Tonight...

We had a deceivingly cool, cloudy start to the day.  Temperatures
this morning started off in the 50s at 9 AM, and dipped into the
upper 40s over northeast Nebraska. Farther south, however, Falls
City had already warmed to 70 degrees, on the warm side of a cold
front draped from Beatrice, to Offutt AFB, towards Shelby, IA.
Spotty showers and a few rumbles of thunder developed behind the
boundary this morning. A strong shortwave trough will continue to
eject eastward this afternoon, bringing forcing for large-scale
ascent. Despite the lingering cloud cover, very steep lapse rates
aloft and daytime heating of a moist low-level airmass will likely
support strong instability south of the cold front. Mesoanalysis
depicting strong thetaE advection from central Kansas through
southeast Nebraska and southwest Iowa depicted the abrupt resurgence
of a volatile airmass. Storms have already begun to fire on the warm
side of the boundary over northwest Kansas, and are expected to
develop over far southeast Nebraska by 2 PM this afternoon. Initial
isolated supercells will have the greatest potential for producing
strong, potentially violent tornadoes, very large hail, and damaging
winds, with the greatest risk in far southeast Nebraska. By 4 or 5
PM, CAMS depict more widespread clusters of storms developing, with
the potential for supercell structures. While not as extreme as the
possible intensity over far southeast Nebraska, these storms,
primarily along and southeast of a line from Lincoln to Omaha will
still be capable of producing large hail, damaging winds, and
perhaps a tornado or two.

In addition to hail, winds, and a chance for tornadoes, heavy rain
will also become an issue overnight. Last night`s round of
convection brought around 0.5" to 1" of rain across the forecast
area. The potential for a few training storms with 3"+ per hour
rates on top of the already saturated soils will create the
potential for flash flooding across parts of far southeast Nebraska
and southwest Iowa tonight. Therefore, a Flood Watch remains in
effect until 7 AM Tuesday for southeast Nebraska and parts of
southwest Iowa.

Tuesday and Beyond...

We`ll see the cold front clear well to the south and east of our
area by Tuesday, putting a cooler Canadian air mass in place
across the region. Tuesday will start out cloudy once again, but
really clear by the afternoon as high pressure builds over our
area. High temperatures on Tuesday will only reach into the
upper 50s to mid 60s. With clear skies and nearly calm winds,
this lends to potential for frost early Wednesday. Overnight
lows will drop into the mid 30s for northeast Nebraska to low
40s across southeast Nebraska and southwest Iowa. Cooler weather
holds into Wednesday though we do see a reversal to southerly
winds and start to advect moisture back into the region. An
upper-level shortwave could potentially bring a few showers to
the area Wednesday afternoon and evening, but the ensembles
haven`t picked up on this latest change in the deterministic
guidance. In any case, this wouldn`t be anything impactful.

A better chance for showers and storms moves in Thursday as the
longwave trough that`s been nearly stationary over the western
US shifts eastward toward our area. With temperatures still in
the sixties for highs, I wouldn`t anticipate much of a severe
weather threat with this system for our area.

Temperatures start to rebound on Friday though as we see
enhanced warm air advection ahead of a deepening surface low
which develops on the lee side of the Rockies over eastern
Colorado and western Nebraska. Depending on the track of this
system, we could potentially see more active weather next
weekend with several chances for storms.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1244 PM CDT Mon May 18 2026

Widespread IFR/MVFR ceilings are observed across terminals this
afternoon. Will see an area of scattered showers and storms
overspread KLNK and KOMA after 21z. Have refined timing a bit with
this issuance, but expect further refinements and adjustments.
Storms that affect terminals will likely become severe with strong
winds, very large hail, and the potential for a tornado. Have added
a transition to -SHRA at KOMA and KLNK after 01/02z. Ceilings will
bounce between MVFR/IFR overnight, before largely becoming MVFR late
in the TAF period. Winds from the north northeast will turn to the
north northwest this evening, with gusts gradually increasing to 25
to 30 kts, persisting for the rest of the TAF cycle.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch through Tuesday morning for NEZ065-066-068-078-
     088>093.
IA...Flood Watch through Tuesday morning for IAZ090-091.

&&

$$

DISCUSSION...KG/McCoy
AVIATION...Castillo

NWS OAX Office Area Forecast Discussion

Forecast Discussion
NWS Hastings, NE

590
FXUS63 KGID 181944
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
244 PM CDT Mon May 18 2026

.KEY MESSAGES...

- A handful of severe storms capable of producing large hail,
  damaging wind gusts or an isolated tornado will be possible
  between 3-8PM today. The severe threat will mainly be for
  places near and east of HWY-81.

- A few showers, areas of drizzle and non-severe thunderstorms
  will be possible this afternoon across areas outside of the
  severe threat.

- Highs, following the passage of a cold front today, will peak
  in the 50s and 60s for much of the area. A few north central
  Kansas locations as well as far southeast Nebraska areas
  could see highs in the 70s.

- The next chance of precipitation will come Wednesday night
  (40-50% chance).

- Highs the rest of the week will stay in the 60s for
  Tuesday/Wednesday/Thursday, the low to mid 70s for Friday and
  the upper 70s to low 80s for Saturday.

&&

.DISCUSSION...
Issued at 244 PM CDT Mon May 18 2026

A broad upper level trough over the Rockies has been the driving
force for severe weather yesterday and today. Water vapor
imagery shows an upper level wave crossing much of the Central
Plains this afternoon. Severe thunderstorms are currently going
up along a boundary stretching from Hebron, NE to Lincoln, KS,
as of 2:30 PM CDT. The main threat are a few tornadoes, golf
ball size hail, and wind gusts up to 60 mph. Severe weather is
forecast for Mitchell and Jewell continues in KS and Thayer
county in NE. Storms will move out the region by the late
afternoon with a majority of the severe weather threat off to
the east. Areas behind the cold front, which is much of the
county warning area, will see low stratus lingering into tonight
causing light rain and drizzle.

Tonight, temperatures are forecast to drop down into the mid to
upper 30s across the county warning area. However, cloud cover
and elevated winds, around 15 mph, will likely keep frost from
forming. Low stratus should start to clear out by the early
morning hours west to east. Tomorrow, temperatures are forecast
to climb up into the 60s. Low temperatures tomorrow night are
forecast to drop down into the lower to mid 30s across the
northern half of the warning area. Unlike tonight, winds are
forecast to be on the lighter side allowing frost to potentially
form.

Southwesterly flow aloft will continue across the Central
Plains. A shortwave trough is forecast to move through the
region Wednesday bringing forth chances for more precipitation.
Temperatures will remain on the cooler side through the middle
of the week as the cooler airmass lingers across the Plains.
Thus, temperatures are forecast to range from the 60s to low
70s through Friday. Daily chances for thunderstorms returns from
Wednesday night into the weekend. NSSL machine learning program
and the CSU machine learning program are pegging Friday with a
low chance of Severe weather mainly across the southern half of
the county warning area. It is possible this low chance of
severe weather shifts further south. Temperatures will warm
this weekend as an upper level ridge begins to build across the
Central US. This warm pattern will continue into early next with
conditions drying out. The NBM 25th to 75th percentiles have
high temperatures ranging from the lower 80s to the mid 90s.
Thus, fairly high confidence on above normal temperatures to
start out next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 101 PM CDT Mon May 18 2026

For KGRI/KEAR Airports:

MVFR conditions will continue to across the much of the area
this afternoon through tonight. Low stratus could could cause
to SHRA and DZ for the next few hours. The low stratus will
clear west to east late tonight/early tomorrow morning bringing
back VFR conditions by tomorrow afternoon. There is a chance
for so TSRA near KGRI this afternoon, but convection will likely
stay off to the east. Winds are forecast to remain out of the
north through the period. Wind gusts are forecast to diminish
tonight, but winds will remain elevated around 14 kts during the
overnight hours.

&&

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

&&

$$

DISCUSSION...Johnson
AVIATION...Johnson

NWS GID Office Area Forecast Discussion