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000
FXUS63 KOAX 260822
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
322 AM CDT Fri Apr 26 2024

.KEY MESSAGES...

- Several rounds of showers and thunderstorms are expected
  through the weekend.

- Severe weather appears likely (>80% chance) during the
  afternoon and evening hours on both Friday, Saturday, and
  perhaps Sunday.

- Flash flooding is also a concern due to the potential for
  repeated thunderstorm activity over the same areas.

&&

.DISCUSSION...
Issued at 319 AM CDT Fri Apr 26 2024

Today...

Multiple rounds of showers and thunderstorms traversed
eastern Nebraska and southwest Iowa overnight, fueled by a
robust southerly low-level jet. Heavy rain with these storms
required the issuance of a handful of flood advisories over
parts of northeast Nebraska.

Despite the dreary start to the day, expect clouds to begin to thin
across parts of southeast Nebraska by early Friday afternoon.
Moderate instability will blossom in this region, ahead of an
approaching dry line. Strong bulk shear vectors of 40-55kts are
possible across much of the forecast area late Friday morning
and into the early afternoon, as a low pressure system begins to
move through northeast Nebraska. Supercells will become the
most likely storm mode Friday afternoon. Given the steep lapse
rates, and robust low level jet. Very large hail will be the
primary threat, along with a few tornadoes (some of which may be
strong). Heavy rain and strong winds would also be possible
with any supercell that forms. The current CAM solutions have
storms developing around 2 PM and moving out of southwest Iowa
around 8 PM. One potentially limiting factor to the Friday
afternoon/evening event would be how far north the narrow
channel of sufficient instability reaches. Even the latest model
solutions vary on how much clearing and atmospheric recovery we
will see after noon today. However, it is clear that any
supercells that do become established will be capable of
producing damage.

Friday Night through Saturday...

Once the rain shuts down Friday evening, the remainder of the night
Friday night into Saturday morning looks quiet, especially for those
participating in outdoor activities Saturday morning.
However, that break will be short-lived as another round of severe
weather potential develops Saturday afternoon by 4 PM and beyond, as
a frontal boundary from the first system is reinvigorated by the
next closed low moving out of the Rockies. This allows widespread
showers/storms to redevelop across the region Saturday night, with
the next round of severe storms possible along/south of Interstate
80. Once again, all modes of severe storms would be possible,
including another round of supercells with potential tornadoes and
very large hail. Given the multiple rounds of storms Saturday night,
compounded with the rainfall we received overnight tonight and will
receive this evening, we will have to keep a close watch on flooding
potential with an increasing risk for flash flooding.

Sunday and Beyond...

Another round of storms will close out our weekend on Sunday, as the
second low pressure system passes through the forecast area. While
the best chance for more well-developed/stronger storms will likely
remain off to our east, the passage of the surface low through the
heart of our CWA brings concerns for a few low-topped supercells
with tornadic potential.

We finally receive a break from the active weather pattern on
Monday and into early next week, with just a few minor showers
and storms possible Tuesday and Wednesday. Temperatures will
generally top out in the 70s next week, with a few locations
reaching the low 80s on Tuesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1231 AM CDT Fri Apr 26 2024

Our first round of thunderstorms continues to move through
eastern Nebraska and western Iowa tonight. Expect periods of
reduced visibilities, down to 1 mile in the strongest storms.
Ceilings will dip to IFR at all three sites tonight and into
early Friday morning before lifting to MVFR around 18Z. Our next
round of storms will arrive between 20-23Z Friday afternoon.
While a few of these storms are expected to be severe, the exact
timing and location remains questionable at this time.

&&

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

&&

$$

DISCUSSION...KG
AVIATION...KG