208
FXUS63 KOAX 041931
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
231 PM CDT Sat May 4 2024

.KEY MESSAGES...

- Cooler through tomorrow, with highs in the 60s and dry
  weather expected.

- There chance of severe thunderstorms (15 to 30 percent
  chance) Monday afternoon and evening.

- Additional chances for showers and storms possible through the
  end of the week, but no organized threat for severe storms.

&&

.DISCUSSION...
Issued at 201 PM CDT Sat May 4 2024

This afternoon - Sunday:
Low clouds from this morning are continuing to break up and
should continue to clear out through this afternoon.
Temperatures are currently in the upper 50s to low 60s and
should get up into the low-to-mid 60s this afternoon. High
pressure currently sits across the state of Nebraska leading to
these clearing skies and the northerly winds across the eastern
part of the state. This surface high will make its way east
through the afternoon and evening, causing winds to become
lighter and nearly calm and variable overnight tonight. As it
shifts east of our area early Sunday morning, we`ll see winds
turn southeasterly and start to increase ahead of our next
system which will be developing back across the lee side of the
Rockies on Sunday.

A large upper-level trough makes its way into Nevada and the
Desert Southwest on Sunday, with a leading shortwave generating
a couple different surface lows along the lee side of the
Rockies by Sunday evening. Ahead of these developing systems,
we`ll see increasing southerly flow with a strong Low-Level Jet
setting up Sunday evening which will bring a significant surge
of moisture to central then eastern Nebraska Sunday evening
through the overnight hours.

Monday:

Expect shower chances to increase overnight starting in central
Nebraska spreading into eastern Nebraska by Monday morning. By
Monday afternoon we should see significant environmental
destabilization and environmental shear develop out ahead of a
dry line which will move through during the late afternoon and
evening hours. This will be our window for severe weather,
mainly between 4 PM and midnight, when we could see large hail,
damaging winds, and tornadoes. The Weather Prediction Center has
also highlighted our area with a Slight Risk (15% chance) for
flash flooding as well. Rainfall amounts in excess of an inch
are in the forecast, and these amounts are likely too
conservative. We may need to increase them as we get closer to
the event.

Tuesday - Friday:

After the system on Monday moves out, we see an interesting
development in the upper-level pattern with a Rex Block setting
up along the West Coast toward the end of the week. This will
put us in a persistent northwesterly flow pattern with a
stubborn trough over the eastern CONUS which will lead to a
cooler, showery pattern which the Climate Prediction Center is
picking up on. While highs on Tuesday and Wednesday are in the
70s, they fall back down in the 60s for Thursday and Friday with
low chances for showers and thunderstorms on and off through the
end of the forecast period.


&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1211 PM CDT Sat May 4 2024

Low clouds are scattering out this afternoon with skies expected
to become mostly clear. Winds out of the north-northwest gusting
to 25 kt should weaken over the next few hours and continue that
trend through the evening. With light winds overnight and clear
skies, we`re a little concerned for fog development overnight
tonight, though none of the forecast guidance is suggesting it
at this time. Will do some more in-depth analysis before the
next TAF package to see if the potential needs to be included.
We`ll see winds shift to southeasterly overnight, starting to
increase around 15-16Z which would clear out any fog that might
develop.

&&

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

&&

$$

DISCUSSION...McCoy
AVIATION...McCoy