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267
FXUS63 KOAX 292104
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
404 PM CDT Wed May 29 2024

.KEY MESSAGES...

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- Shower and storms are expected to develop tomorrow morning,
  with a 5 to 15% chance for damaging wind and up to quarter-
  sized hail from 3 to 8 PM.

- Showers and storms tomorrow will be slow-moving, and could
  rain heavily on locations and result in flooding.

- There will be daily chances for rain/thunderstorms starting
  tomorrow and lasting through Tuesday.

- There is increasing potential for strong to severe storms
  during the Sunday-Monday time frame.
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.DISCUSSION...
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Issued at 403 PM CDT Wed May 29 2024

This Evening through Tomorrow:

Water vapor imagery this afternoon features two troughs sitting on
either side of the Great Plains region, with the trough to the west
beginning to tilt negatively despite its general shallow nature.
Over the High Plains, upscale growth of showers and storms is
beginning, but should not sustain itself and make it to easter
Nebraska due to the generally poor moisture and shear in place
locally. A surface analysis depicts a dryline/surface trough
that the aforementioned storms are initiating from with a broad
moist sector and thermal ridge to the east that gets more and
more restricted spatially to the north by a leftover and now
stationary front extending from western North Dakota to the
southeast towards the Mid- Atlantic. Deep mixing has been
ongoing today with the expectation that the shallow cumulus
cloudcover that has developed to disappear shortly after sunset
with lows expected to fall into the upper 50s tonight. With the
front and trough to the northwest expected to begin approaching
the area, stronger winds are expected to slowly creep into the
area overnight, with gusts to 20 kts possible despite a healthy
nocturnal inversion.

By tomorrow morning moisture transport and warm air advection is
expected to be in full force, roughly when the dying convection and
its associated shortwave to the west drifts into eastern
Nebraska. The combination of these elements are expected to
result in increasing shower and weak storm chances by mid-
morning, while daytime heating will further increase surface
instability and as a result lightning activity. During the
afternoon hours, those thunderstorms that do develop in the warm
sector have storm motions on the order of less than 10 kts due
to the weak shear and ambient wind speeds in the lower 5 km.
Restricting the warm sector to the west will be a slow-moving
cold front that will serve as the focus for more organized
convection. While low-level hodographs feature good curvature,
weak shear and large temperature/dewpoint spreads will limit
tornadic potential. What seems more likely are spotty strong
wind gusts of over 60 mph thanks to drier low-levels and pockets
of severe hail through around 9 PM. Beyond that, chances for
storms generally transition to sub-severe levels.

Saturday and Beyond:

For the weekend and beyond, storm chances are expected to continue
well into next week as we fall into a summertime mid/upper pattern.
With the mid/upper flow transitioning into a generally zonal
pattern, southerly moisture will gradually creep northward along
with warmer temperatures thanks to southerly winds being present at
least for some part of each day. One signal that is being picked up
on by several of the forecast models is the chances for a larger MCS
to develop out of the western Nebraska Panhandle region and into
eastern Nebraska/Iowa overnight Sunday into Monday. Aside from that,
temperatures well into the 80s are set for the weekend into next
week with each day playing host to additional rain and storm
chances, including increasing chances for severe storms
Monday/Tuesday as shear increases.
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&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1231 PM CDT Wed May 29 2024

Southeasterly winds are in place this afternoon with speeds
generally hanging around 10 kts with an occasional gust over 15
kts. Some lower-level clouds at FL070 can be seen faintly on
satellite imagery but should remain sparse this afternoon.
Overnight, wind gusts are expected to increase in northeast
Nebraska first and then spread southeast to KOMA and KLNK by 13z.
Also of note for tomorrow will be increasing shower and weak
storm chances that will begin developing in northeast Nebraska,
but have been left out for this issuance for KOFK due to
inconsistent timing and coverage in short-term models. Better
chances are expected to move into the region after 18z through
06z, but will only affect any one location for a fraction of the
time.

&&

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

&&

$$

DISCUSSION...Petersen
AVIATION...Petersen