-- Discussion containing changed information from previous version are highlighted. --
141
FXUS63 KOAX 281127
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
627 AM CDT Fri Jun 28 2024

.KEY MESSAGES...

- Moderate flooding is ongoing or expected to begin along the
  Missouri River the next day or two. It`s forecast to last into
  next week for Omaha and points south.

- A few severe storms are possible this afternoon and evening
  with the potential for large hail, damaging winds, localized
  flash flooding, and perhaps a tornado or two.

- Quiet and cooler for the weekend, with highs in the mid 70s to
  lower 80s. Then warming back up and becoming more active for
  the holiday week.

&&

.DISCUSSION...
Issued at 419 AM CDT Fri Jun 28 2024

.Today and tonight:

A mid/upper-level low and associated trough from southern parts
of Alberta and Saskatchewan into the northern Rockies and
adjacent High Plains will track southeast into the northern
Plains and upper MS Valley by tonight. In the low levels, a
surface low situated over central SD early this morning will
develop east into MN by afternoon while a trailing cold front
advances southeast through our area this afternoon and evening.

Ahead of the front, warm advection along a 40-50 kt low-level
jet has fostered widely scattered thunderstorms along and south
of I-80 as of 3 AM. And, latest CAM output suggests that
activity will gradually shift east out of the area by 6 or 7
AM. While some small hail is possible with the strongest
updrafts, warm midlevel temperatures and resultant melting
effects are likely to limit hail sizes.

By this afternoon, the models suggest that moderate to strong
instability will develop ahead of the front moving into the
area. However, considerable variability exists in the number of
thunderstorms that actually develop along/ahead of the boundary
this afternoon into evening. Should storms develop and become
sustained, the combination of the moderate to strong instability
and strengthening deep-layer shear will support organized storm
modes, including supercells capable of large hail and damaging
winds. The tornado threat remains uncertain due to relatively
weak low-level shear. However, given the presence of the
boundary in the area, a tornado or two certainly cannot be ruled
out. Locally heavy rainfall also is a concern, especially
across southeast NE and southwest IA.

Additional thunderstorms developing over western NE and vicinity
this afternoon and evening will move toward the area tonight
with most models suggesting that the strongest activity will
remain to our west and south.

Highs today will be in the mid 80s to lower 90s.


.This weekend:

Cooler and drier conditions are expected as surface high
pressure builds through the region. Highs will be in the mid 70s
to lower 80s on Saturday, and in the mid to upper 70s on
Sunday.


.Monday into Thursday:

The 00z global models are in good agreement in suggesting that
another mid-level trough will slowly advance from northern
Intermountain Region through the north-central U.S. during this
time frame. In the low levels, an associated surface front is
forecast to settle south through the area Tuesday before
stalling across KS and MO by the middle of next week. That
pattern evolution appears favorable for additional severe
weather and flash flooding chances, especially on Monday and
Tuesday with the ongoing river flooding potentially being
exacerbated/prolonged.

Near-seasonal daytime temperatures are forecast with highs in
the 80s to low 90s.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
-- Changed Discussion --
Issued at 617 AM CDT Fri Jun 28 2024

By 17Z today, isolated showers and thunderstorms are expected to
develop across eastern Nebraska and western Iowa. Certainty in
timing and coverage of storms is still low at this time, so
have kept specific timing of convection potential out of KLNK
and KOFK TAFs for now, and put a TEMPO group in the KOMA TAFs.
Storms along and south of the I-80 corridor (KLNK and KOMA) have
the potential to be severe with damaging winds up to 60 knots
and hail up to 2 inches in diameter. Timing of greatest threat
for this will be between 22Z and 05Z. A front will also push
through the region today, moving through KOFK as early as 15Z
and pushing south and east of the region by 06Z. Winds ahead of
the front will be out of the south, and will veer to become
northwesterly behind the front.
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&&

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

&&

$$

DISCUSSION...Mead
AVIATION...Darrah