140
FXUS63 KOAX 280442
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1142 PM CDT Thu Mar 27 2025

.KEY MESSAGES...

- There`s a 20-40% chance of storms in southeast NE and
  southwest IA this evening, with a 5-15% chance of severe
  storms. The main threats will be hail and possibly damaging
  winds, mainly between 7 PM and midnight.

- Very high to potentially extreme fire danger Friday with near
  record high warm temperatures. A Fire Weather Watch is in
  effect for much of the area.

- Additional severe storm chances (5-10% chance) Friday night,
  mainly in northeast NE into west-central IA. The main threat
  will once again be hail.

- Widespread rain chances Saturday (60-90%) with snow mixing in
  Saturday night into Sunday in portions of northeast NE. Snow
  accumulations less than 1/2". There is also a small chance
  (5-10%) for severe storms in southeast NE and southwest IA
  Saturday afternoon.

&&

.DISCUSSION...
Issued at 332 PM CDT Thu Mar 27 2025

Fairly quiet early this afternoon with temperatures in the mid
60s to mid 70s and light southerly to easterly breeze. Early
afternoon analysis showed a surface warm front stretching from
south-central NE to east-central NE then back southeast into
south-central IA and MO. Will need to keep a close eye on the
frontal position heading into this evening as low level moisture
transport ramps up and starts pointing into the area, as it
should provide a focus area for thunderstorm development. Latest
guidance continues to suggest plenty of instability to work
with, with HREF mean SBCAPE values of 1500-2000 J/kg in vicinity
of the front. While deep layer vertical shear is on the weaker
side, there should be just enough for some degree of storm
organization and low level shear profiles are actually fairly
impressive, especially in the NE/KS/IA/MO border area. However,
CAMs continue to suggest very little if any thunderstorm
development in this area, likely owing to fairly weak forcing
(moisture transport isn`t THAT strong) and overall the air is
relatively dry looking at model soundings. That said, CAMs tend
to struggle in some of these weakly-forced scenarios and just
given the physical setup---moisture transport pointing into a
boundary with decent instability and an eroding cap---tend to
think we`ll at least SOME thunderstorm development in far
southeast NE into far southwest IA this evening. Right now,
giving it a 20-40% chance for a given location down there,
generally between 7 PM and midnight. If storms develop, the
environment would be sufficient for a severe storm threat, with
hail being the biggest threat followed by damaging wind. Can`t
completely rule out a tornado with the low level hodograph
curvature, but relatively high cloud bases should limit that
threat.

For Friday, the front will be off to our north while a surface
low pushes through SD and starts dragging a cold front toward
the area. Ahead of the low and front, a tightening pressure
gradient will yield strong southwesterly winds. EPS mean gust
values show 40+ mph for most of the area, so would certainly
expect that during the afternoon. As you go into northeast NE
and closer to the approaching cold front, winds will be a little
weaker and more in the 20-30 mph range along the pre-frontal
trough, though a ribbon of very dry air will be present in this
area leading to RH values in the teens to lower 20s. So to
summarize, northeast NE will see drier air, but weaker winds,
while areas southeast will see higher RH, but stronger winds.
Either way, in both areas expect very high to potentially
extreme fire danger, along with temperatures getting up into the
mid to upper 80s for many, and possibly 90 in a few spots.
Therefore, issued a Fire Weather Watch for much of the area,
with the counties not included expected to be on the lower end
of that 20-30 mph gust range (still could be close though).

By Friday evening, the cold front will stall somewhere across
the area (consensus says roughly along a Columbus to Onawa
line). As moisture transport strengthens and points into front,
expect thunderstorm development once again. The strongest deep
layer shear looks like it`ll remain behind the front and
moisture availability will be pretty marginal, but still could
be just enough ingredients for some stronger to isolated severe
storms during the evening hours.

As we go into Saturday morning, another surface low over
eastern CO will start to push east through KS with an associated
persistent deformation band of precipitation across a good
chunk of the area during the day Saturday. Still some
differences in timing and track between various pieces of
guidance which will impact spatial coverage of the precip and
how long it lasts into Sunday. For example, the 27.12Z ECMWF is
farther north and faster and keeps the precip rather light in
southern portions of the area, ending most things Sunday
morning. In contrast, the 27.12Z GFS is farther south and gives
nearly the entire area at least a half inch of moisture and is
also slower, lingering precip through much of Sunday. In
addition, there is some weak shortwave energy moving in on the
back side of the system which could linger precip even longer,
but overall these details are a little messy. Finally, cold air
will be wrapping in on the back side of the system as it pushes
out, which could allow some snow to mix in at times into Sunday,
mainly in northeast NE. However, amounts look they`ll be less
than 1/2 inch.

We`ll dry out Monday as surface high pressure passes by just to
our north. However, guidance is now in better agreement that
we`ll see another stronger low pressure system slide through the
area and bring us additional precipitation chances sometime
Tuesday into Wednesday. That said, still quite a few differences
on exact timing and track which will also impact precipitation
type, but current consensus gives us 30-60% chances through the
day Tuesday and peaks our chances in the 60-75% range Tuesday
evening into early Wednesday. Beyond that guidance really
diverges with a wide variety of solutions, so overall forecast
confidence from Wednesday on is quite low.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1135 PM CDT Thu Mar 27 2025

VFR conditions will prevail at the TAF sites tonight. Winds will
increase out of the south/southwest early in the period, with
LLWS developing across the region. LLWS dissipates as surface
winds continue to gust to 30+kts at all three sites by 14Z.
A line of showers and storms is forecast to develop between
00-06Z Saturday. Chose to leave thunder mention out for the time
being, given the uncertainty as to exactly where storms will
develop.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Fire Weather Watch from Friday afternoon through Friday
     evening for NEZ012-015-017-018-031>034-042>045-050>053-
     065>068-078-088>093.
IA...Fire Weather Watch from Friday afternoon through Friday
     evening for IAZ043-055-056-069-079-080-090-091.

&&

$$

DISCUSSION...CA
AVIATION...KG