495
FXUS63 KOAX 222300
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
600 PM CDT Thu May 22 2025

.KEY MESSAGES...

- On and off shower and storm chances Friday through Tuesday.
  Highest PoPs of 40-90% Friday, and 40-70% from late Saturday
  afternoon through Saturday night.

- Storm-total rainfall generally less than a half inch at most
  locations.

- Severe weather chances currently look low (5-10%), and
  confined to the Fairbury vicinity Friday afternoon.

- Seasonably cool temperatures continue through early next week
  with a warmup favored during the latter half of next week.

&&

.DISCUSSION...
Issued at 245 PM CDT Thu May 22 2025

     Tonight through Friday night...

A shortwave trough over the Pacific Northwest into northern
Intermountain Region as of early afternoon is forecast to
gradually weaken as it progresses into the northern High Plains
late tonight into Friday. In the low levels, an associated
surface low will initially develop over eastern WY tonight
before weakening in deference to the formation of a secondary
cyclone over eastern CO on Friday. East of those low pressure
areas, a modestly strong low-level jet will encourage the
poleward flux of an increasingly moist/unstable air mass into
western parts of KS and NE.

Latest CAM data are in good agreement in depicting the
development of showers and thunderstorms this evening into
tonight across portions of western NE; coincident with the
destabilizing air mass. That activity is expected to grow in
areal coverage overnight as it advances into central NE; aided
by warm advection and moisture flux along the low-level jet.
That convection is then forecast to move into our area Friday
morning, with the potential for redevelopment on its western
flank on Friday afternoon. The forecast will maintain the
~40-90% PoPs for Friday with the best potential for > 0.25"
rainfall being across portions of northeast NE into west-central
IA.

Despite the presence of strong cloud-bearing shear, forecast
soundings indicate only modest elevated instability (i.e.,
MUCAPE of 500-750 J/kg) for parcels lifted from around 700 mb,
which should limit the intensity of an convective updrafts.
While some sub-severe hail is possible with the strongest
afternoon storms, the better severe-weather potential is
expected to remain to our west and south.

The showers and thunderstorms may linger into Friday evening
before diminishing in areal coverage overnight.

Widespread clouds and areas of precipitation will limit daytime
heating on Friday with highs in the 50s and 60s.


     Saturday through Wednesday...

The 12z global models have slowed the progression of another
shortwave trough through the Great Basin and lower CO Valley on
Saturday, with that feature now only reaching the central and
southern Rockies by Sunday. That system is then expected to
advance into the Great Plains on Monday, with a closed low
subsequently forming over the northern Plains. That low will
slowly drift east into the upper Great Lakes by Wednesday.
Meanwhile at the surface, the primary frontal zone is forecast
to become established across OK into the Ozark Plateau, with the
strongest instability and severe-weather/heavy-rainfall
potential remaining south of our area.

The slowing of the mid-level trough casts a little more
uncertainty on the specific timing of showers and thunderstorms
that may affect our area this weekend into early next week.
This forecast update will indicate the best potential for
widespread rainfall (highest PoPs of 40-70%) from late Saturday
afternoon through Saturday night, with generally 20-40% PoPs at
other times from Saturday into Tuesday. Storm-total QPF (Friday-
Tuesday) is expected to remain below a half inch at most
locations, due to the displacement of the more moist/unstable
air mass well to our south (as mentioned above). So, while there
is an extended period of rain chances, it appears that there
will be opportunities for people to get outdoors this holiday
weekend. That being said, it will remain seasonably cool with
highs mainly in the 60s through Tuesday. We could see some 70s
by Wednesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 556 PM CDT Thu May 22 2025

VFR conditions are expected to prevail, at least through the
overnight period. Northerly winds will calm and transition to
variable overnight before shifting to southerly-southeasterly
tomorrow morning. Scattered showers move into the area tomorrow
morning, with the highest confidence in impacting KOFK and KLNK
during the morning hours. Towards the afternoon, showers chances
increase at KOMA. Shower chances will continue through much of
the day. MVFR ceilings will be possible with heavier showers,
though low confidence in their coverage has led to VFR
conditions being maintained for the time being.

&&

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

&&

$$

DISCUSSION...Mead
AVIATION...Wood