Flash Flood Warning 12, NWS Omaha, NE

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1217 PM CDT Thu Jun 4 2026

.KEY MESSAGES...

- Multiple rounds of storms are expected through Friday. Severe
  weather is possible with large hail, damaging winds, and flash
  flooding the main concerns. An isolated tornado is also
  possible.

- Daily chances for showers and storms are expected across at
  least some of the area from Saturday through Wednesday as a
  series of disturbances move through the region.

- Expect a return to the 90s Monday through Wednesday as a ridge
  sets up to our northeast. Excessive heat may be possible.

&&

.DISCUSSION...
Issued at 1217 PM CDT Thu Jun 4 2026

An active period of weather begins today. A convectively, reinforced
shortwave is lifting northeast over the central Plains this morning.
A low-level MCV is also evident south of KUEX. These features will
support the re-intensification and development of storms through
this afternoon into this evening. A few stronger storms are already
developing across northern Kansas within the broader MCV. As we move
through the remainder of this morning into the afternoon, daytime
heating into the upper 70s to lower 80s will help destabilize the
environment. While overall shear remains marginal (20-30kts), low-
level SRH will be higher (200 m^2/s^2) and more supportive of
organized storms. A very moist environment has taken shape as well.
These factors will support at least some risk of damaging winds or a
brief tornado or two. Large hail is less likely with a very moist
environment and a high freezing level. The other significant concern
is flash flooding. Precipitable water values are exceeding 1.5"
which is above the 90th percentile for today. This supports
torrential rainfall with rainfall rates easily becoming as high as
1+" per hour. With this concern, a Flash Flood Watch is in effect
for southeast Nebraska and southwest Iowa into tonight. The one
limiting factor is that once storms develop, the eventual cold pool
should keep storms moving to the east, limiting training potential.
Any showers and storms taper off after midnight as temperatures
slowly cool into the 60s.

Heading into Friday, a lull is anticipated as subsidence and mid-
level height rises behind today's system keeps a cap on storms
throughout much of the day. It will get hot as a result, with
temperatures easily pushing the upper 80s to near 90. Plentiful
moisture remains in place and this will be a loaded gun by late
afternoon. Very high levels of instability are anticipated with CAPE
values rising to between 3000-4000 j/kg. A weak disturbance moving
into the region and a broader trough over the Upper Mississippi
River Valley helps to erode the cap through evening. An isolated
storm remains possible through the late afternoon, but eventual
storm development appears most likely along a slowly southward
sagging front. Along and behind the front, storms are anticipated.
The high instability and effective shear around 30 kts support a
risk of large hail, perhaps very large, damaging winds, and perhaps
a tornado. That said, continued storm development along the front
may eventually limit the severe risk. This then leads to the other
hazard on Friday of flash flooding. Similar to today, very high
precipitable water and slow-moving storms support torrential
rainfall. If storms train along the front, especially across
southeast Nebraska and southwest Iowa, this may be especially
concerning. A Flash Flood Watch may be required with this potential.

The pattern quiets down a little this weekend as a trough passes
south of the area. This limits our thunderstorm potential on
Saturday. It will be muggy as temperatures warm into the upper 80s.
Storms return to the forecast on Sunday as a long series of
disturbances moves across the area heading into next week. These
disturbances lift out of the Rockies towards the north Plains as a
summertime pattern takes shape. A building ridge over the central
and eastern CONUS with a trough over the western CONUS supports
warming temperatures and continued storm chances each day.
Widespread 90s are likely by Tuesday before approaching the mid to
upper 90s by the end of next week. Isolated severe weather remains
possible with thunderstorm chances, but the main hazard begins to
shift towards excessive heat as it remains muggy as temperatures
climb.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1155 AM CDT Thu Jun 4 2026

Showers are overspreading the region with a few thunderstorms
beginning to develop over southeast Nebraska. VFR conditions
should largely prevail with south winds continuing. Beginning
around 20-21Z more widespread thunderstorm development is
forecast. These thunderstorms are likely to produce brief
reductions in visibility to MVFR or IFR. At this time, the bulk
of activity should remain mainly southeast of LNK and OMA, but
trends will continue to be monitored. Winds will back towards
the southeast also. Any thunderstorms should shift eastward away
from TAF sites after 23-00Z. Overnight, after 06Z, ceilings
fall to MVFR and perhaps IFR as low clouds overspread much of
the area. These conditions may last through much of the morning
on Friday.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch through late tonight for NEZ052-053-066>068-
     088>093.
IA...Flood Watch through late tonight for IAZ069-079-080-090-091.

&&

DISCUSSION...Chehak
AVIATION...Chehak