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000
FXUS63 KOAX 122030
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
330 PM CDT Fri Apr 12 2024

.KEY MESSAGES...

- Fire danger will be in the very high category on Saturday
  afternoon.

- Much warmer temperatures are expected Saturday through Monday,
  with highs in the middle to upper 80s.

- There is a very high (90%) chance of thunderstorms Monday
  evening through Tuesday afternoon. Thunderstorms may become
  severe during this time frame, with the greatest potential
  focused over southeast Nebraska and southwest Iowa.

&&

.DISCUSSION...
Issued at 330 PM CDT Fri Apr 12 2024

Very quiet across the area early this afternoon as a surface ridge
was sliding through with an upper level ridge axis approaching from
the west, leading to light winds and plenty of sunshine.
Temperatures as of 3 PM were in the mid to upper 60s.

As the surface ridge pushes off to the east this evening, we`ll
have a tightening pressure gradient ahead of surface low
pressure off to our northwest, which will bring strengthening
southerly flow and warm air advection to the area for Saturday.
As a result, expect widespread highs in the 80s with south winds
gusting 20 to near 30 mph in some spots, along with RH values
in the lower to mid 20s. This will lead to very high fire danger
for much of the area, with a few pockets of extreme fire danger
at times, pending how much mixing we can do. Guidance is in
decent agreement that we`ll have a batch of mid to high clouds
move in by early afternoon which may limit things a bit, but
model soundings still show plenty mixing, generally to at least
800 mb or so. The good news is that winds aren`t CRAZY strong in
that layer, with most guidance topping out at around 30 kts.
That said, some shortwave energy sliding through Saturday
afternoon along with moisture transport increasing and pointing
toward southeast NE could lead to some "shower" development
(little, if anything will reach the ground with how dry it will
be) that could bring down some stronger wind gusts from aloft.
As it stands, we`re not reaching Red Flag Warning criteria
anywhere, but we could be close, especially with any enhanced
mixing.

The warm weather will stay in place Sunday and Monday with upper
level ridging remaining in place. NAEFS guidance has trended
slightly cooler at 850 mb, so it may be tougher to mix down into the
90s and hit record highs, but still could be close in a few spots.

Attention then turns to shower and storm chances Monday through
Tuesday and possibly Wednesday. A potent shortwave trough and
associated surface low will begin to push into western NE by Monday
afternoon. Strong southeasterly flow ahead of the system will be
ushering in plenty of moisture as guidance suggests about a 50/50
shot of 60+ dewpoints reaching Omaha Monday afternoon (would be the
first time since last October) with GEFS/EPS/GEPS mean SBCAPE values
right around 1000 J/kg and 90th percentile values near 2000 J/kg.
Guidance is also in good agreement that we`ll see fairly strong
moisture transport pointing into our area by Monday afternoon as a
surface warm front advances northward. Thinking this should be
enough for shower and storm development in the afternoon, but
questions remain on just how organized they`d be with quite a bit of
spread remaining on how quickly the cutoff low ejects eastward and
thus how far east the strongest flow aloft/deep layer shear will be
at that time. If we do have the stronger shear in place, there would
be a severe weather threat with any afternoon/early evening storms,
with all hazards possible. If the shear isn`t here yet, the threat
would be quite a bit less, but certainly not 0. Additional storm
development will then take place Monday evening/early Tuesday
morning as the stronger forcing and cutoff low push in. The severe
weather threat with these later storms will likely depend on what
happens earlier (i.e. afternoon storms could eat away at the
instability and lead to little threat, or lack of afternoon storms
would mean a higher threat). We`ll see a continued storm threat into
Tuesday as the surface low is progged to move directly through the
forecast area. Assuming we see the previous round(s) of storms,
would think instability will be lacking for much of a severe weather
threat, but it may not take much being that close to the surface
low. Overall, we`re highly confident we`ll have thunderstorms move
through the area, but confidence is lower on some of the details,
including the overall severe weather threat, especially with
potential multiple rounds of storms impacting later storm
development.

Precip looks to continue on the back side of the low into Wednesday
morning with northwest flow cooling us back into the 60s and 70s.
Another shortwave trough and surface cold front look to slide
through sometime Wednesday night through Thursday, bringing our next
chance of precip and even cooler air, with highs in the 40s and 50s
by Thursday/Friday. Still quite a bit of model spread in timing and
strength of said shortwave, but if it`s timed just right, can`t
completely rule out some snow mixing in at times, especially in
portions of northeast NE.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1226 PM CDT Fri Apr 12 2024

VFR conditions expected through the period with clear skies into
Saturday morning. Northwest winds will become south-
southeasterly this afternoon/evening and generally remain under
10 kts into mid-morning Saturday. Speeds will then increase,
with some gusts nearing 20 kts while some mid to high level
clouds move in late in the period.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...CA