Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 222003
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
303 PM CDT Sun May 22 2022

.DISCUSSION...
Issued at 303 PM CDT Sun May 22 2022

.Forecast Summary:

Cool with periodic rain chances from Monday through Wednesday.
Trending warmer during the latter half of the week with rain
chances returning by the weekend.

.Monday through Wednesday:

A shortwave trough over the northern Intermountain Region this
afternoon will continue east through SD/NE on Monday before
weakening over the upper Midwest on Monday night. Meanwhile,
mid/upper-level jet streaks developing from the Pacific Northwest
into southern Plains will promote the deepening of a more
prominent midlevel trough over the High Plains on Tuesday. That
trough will then progress east across lower elevations of the
Great Plains on Wednesday. That secondary trough will be linked
with a surface low which is forecast to develop from the southern
High Plains on Tuesday morning into the lower-MO Valley by
Wednesday morning.

Latest CAM data indicate that forcing for ascent associated with
the lead disturbance mentioned will promote the development of a
loosely organized, northwest-southeast-oriented shield of rain
showers that will move through the area from mid-morning into
early-evening on Monday. The ambient air mass isn`t expected to
overly moist (i.e., PW values at or below 0.75") with highest
precipitation amounts of 0.10-0.25" forecast across portions of
northeast NE.

By Monday night into Tuesday, the low-level mass response to the
secondary trough evolving over the Rockies into High Plains will
promote the maturation of a warm-conveyor airstream from the Ozark
Plateau into lower-MO Valley, ahead of the aforementioned, migratory
surface low. Low-level warm advection/isentropic upglide in the
northwestern quadrant of that regime will support a good chance of
showers across the southern and eastern part of our area into
Tuesday night.

The models suggest the trough could form a closed midlevel
circulation as it moves through the mid-MO Valley on Tuesday night
into Wednesday with an associated deformation band/TROWAL-like
precipitation structure lingering over the area through Wednesday.

This should end up being a widespread rainfall event with highest
totals of 1.5 to 2.0" forecast across far southeast NE and extreme
southwest IA. The precipitation should be well-tolerated by the
soil and no flooding is expected.

In regard to temperatures, anticipated clouds and areas of rain
will limit daytime heating with highs remaining below normal, and
in the upper 50s to lower 60s.

.Thursday through the weekend:

The 12z ensemble and deterministic models continue to indicate
that a midlevel ridge will deamplify while progressing from the
Interior West into the Great Plains on Thursday into Friday. The
GEFS remains more progressive than the EPS and CMCE with the
movement of another trough from the northern Intermountain Region
into the northern Plains on Saturday. The EPS and CMCE suggest a
slower, but more significant trough, which would impact the region
on Sunday. These differences lead to uncertainty in precipitation
potential and timing. However, it does appear that temperatures
will trend warmer with highs in the 70s on Thursday, and in the
80s from Friday into the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1155 AM CDT Sun May 22 2022

VFR conditions will prevail through much of the forecast period
with increasing mid- and high-level clouds tonight into Monday
morning. A weather disturbance will bring scattered showers to the
region from late Monday morning through the afternoon with some
visibility restrictions possible at KOFK and KLNK prior to the end
of the forecast period. Northwest winds of less than 12kt will
become southeast by Monday morning.


&&

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

$$

DISCUSSION...Mead
AVIATION...Mead


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