154
FXUS63 KOAX 222309
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
609 PM CDT Wed May 22 2024

.KEY MESSAGES...

- A line of strong to severe thunderstorms is expected to
  move through Thursday evening into early Friday (80-90%
  chance). Damaging winds will be the primary threat, but
  additional localized flooding, large hail, and a tornado or 2
  cannot be ruled out. Additional rainfall amounts are expected
  to generally be below 1 inch.

- Rivers will remain elevated over the next day or 2, with
  some minor flooding continuing, especially along portions of
  the Missouri River.

- Additional storm chances through Memorial Day weekend,
  especially Saturday evening and Sunday. Severe weather could
  be possible at times, but confidence in exact timing and
  location is low.

&&

.DISCUSSION...
Issued at 400 PM CDT Wed May 22 2024

Fairly quiet across the region early this afternoon with just
some cumulus clouds as surface ridging was passing through.
Really the only thing of note was some ongoing river flooding at
some points, though most that experienced impacts were starting
to see the water recede. Otherwise, temperatures as of 3 PM
were in the upper 60s to lower 70s.

Unfortunately the quiet weather looks short-lived as a
shortwave trough currently over the Pacific Northwest will slide
east into the Dakotas Thursday with an associated surface low
dragging a cold front into our area by Thursday evening.
Strengthening southerly flow ahead of the front will usher in a
warm, moist, and fairly unstable airmass with dewpoints in the
lower to mid 60s and SBCAPE values of 1500-2500 J/kg. Could see
a few storms start to bubble in southeast NE by late Thursday
afternoon as moisture transport starts to increase and point
into our area, but the main concern will be a line of storms
expected to develop along the front to our west/northwest and
move through our area during the evening/overnight hours into
early Friday morning. Shear looks sufficient for organized
severe storms with pretty good low level curvature indicating
potential for some embedded tornadoes within the line. The big
question will be the eastward extent of the severe weather
threat, with many CAMs indicating it could become outflow
dominant and fall apart as it pushes farther into eastern NE.
Still, some guidance shows 0-3 km shear vectors will be fairly
strong and oriented at least somewhat perpendicular to the line,
suggesting it could hold together longer. Overall, confidence
in this detail is rather low. Bottom line, a line of strong to
severe storms will likely bring strong to damaging winds to
portions of the area Thursday night, along with potential for
some hail and a tornado or 2. The line does look like it`ll move
through fairly quick, so flooding isn`t a huge concern, but wet
soils combined with efficient rain producers (PWAT near 1.5"
and warm cloud depths near 3500 m) suggest some localized flash
flooding could occur.

Surface high pressure Friday should lead to another quiet, nice
(maybe a touch cool for some) day with highs in the mid 60s to
mid 70s. For the holiday weekend, we`re looking generally dry
through Saturday afternoon, but an upper level trough will begin
pushing through by Saturday evening with a surface low progged
to track through KS through Sunday, bringing additional shower
and storm chances to the entire area. There are also signs of
some additional shortwave energy sliding through northwest flow
aloft on Monday, bringing another quick round of some showers.
Still some questions on if we`ll see any severe weather during
the weekend, with a fair amount of spread in northward extent of
the warm sector, but highest chances for us currently look to
be Saturday evening/overnight, though even higher chances look
to be to our south and east. You`ll definitely want to check
back on the forecast if you`ll be outdoors this weekend.
Otherwise, expect highs mostly in the 70s with some 80s trying
to work back in by Tuesday/Wednesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 608 PM CDT Wed May 22 2024

VFR conditions through the period. Winds light and variable less
than 6 knots at TAF issuance, but becoming south southeast at 15
to 30 knots 16z and beyond. Any precipitation chances should
hold off until after the end of the TAF period.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...DeWald