267
FXUS63 KOAX 221050
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
550 AM CDT Fri Aug 22 2025

.KEY MESSAGES...

- Cold front moves through today from northwest to southeast resulting
  in PoPs of 30 to 45%. Some storms may be strong to marginally
  severe in the afternoon and evening with gusty winds or hail.

- PoPs exit far southeast Nebraska after sunrise Saturday,
  leading to a rather pleasant day with highs reaching the mid
  70s to low 80s.

- Cooler temperatures continue Sunday through Tuesday with highs
  in the 70s. Temperatures warm to the upper 70s to low 80s
  beyond Tuesday.

&&

.DISCUSSION...
Issued at 350 AM CDT Fri Aug 22 2025

.SHORT TERM.../TODAY THROUGH SATURDAY NIGHT/

A quiet morning is observed across OAX as 08z RAP objective analysis
shows a 1016 mb sfc high extending into portions of the forecast
area. Looking aloft, the H5 pattern shows ridging centered across
the Four Corners area, while a low continues to deepen over eastern
Saskatchewan into western Manitoba. A few shortwaves can be seen
riding the zonal flow across South Dakota. 08z METARs show a cold
front draped over south central South Dakota northeastward into west
central Minnesota and originating from a parent low across
northern Manitoba. Convection has developed just ahead of the
frontal boundary in the FSD forecast area and appears to be
rooted aloft where MUCAPE is around 2,000 J/kg, and forced by
some of these subtle shortwaves in tandem with H8 WAA. Latest
CAM guidance seems to suggest that this convection should weaken
or even fizzle out by the time it gets closer to our northern
tier of counties early this morning.

The frontal boundary is expected to track southeast into northeast
Nebraska after 13 or 14z, while an H5 shortwave across southwest
South Dakota moves along the Nebraska/South Dakota border. While Q
vector convergence is observed in the vicinity of the front, forcing
looks rather nebulous and weak. Despite this, CAM guidance suggests
some threat of scattered showers or storms along the front in
northeast Nebraska during the late morning hours.

As we head into the afternoon hours, instability will pool along and
ahead of the front, with BUFKIT forecast soundings showing anywhere
from 1,000 to 2,000 J/kg of skinny CAPE. 0-6 km bulk shear of around
30 to 40 kts along and ahead of the front will support a threat for
a few strong to marginally severe storms. The main hazards appear to
be strong wind gusts (some DCAPE of around 900 J/kg) and hail. The
SPC currently has a marginal risk (level 1 out of 5) for severe
weather for eastern Nebraska and western Iowa this afternoon into
the evening hours. PoPs increase from northwest to southeast
throughout the day today at around 30 to 45%.

Highs today will be dependent on the location of the frontal
boundary, with northeast Nebraska seeing highs in the low 80s, while
areas along and south of I-80 will see highs in the upper 80s to
near 90F. Lows tonight will be in the low to mid 60s.

A few showers or storms will linger early Saturday morning (15-30%
PoPs) but should exit after sunrise as the front finally pushes off.
Will see sfc ridging across much of the Northern and Central Plains
Saturday. This will make for a rather pleasant day as highs reach
the mid 70s north of I-80, and low 80s along and south of I-80.
Winds will be slightly breezy from the northwest, owing to the
subsidence/CAA observed behind the front and mixing into some 20 to
30 kt 850 mb winds. Skies may have a milky appearance as some
smoke is expected to linger aloft. Lows Saturday night will be
in the mid to upper 50s across eastern Nebraska, and upper 40s
to near 50 in western Iowa.

.LONG TERM.../SUNDAY THROUGH THURSDAY/

H5 pattern in the extended has the low over Manitoba eventually
pushing east and stalling out over Ontario on Sunday into Monday,
deepening the longwave trough across the eastern CONUS. 1000-500 mb
thicknesses will lower across much of the Northern Plains and
Midwest, resulting in a nice cool down. NBM extended currently
suggest highs Sunday and Monday in the low to mid 70s across the
forecast area. Temperatures do warm after Tuesday but to the upper
70s to low 80s. The CPC 6-10 day outlook does suggest temperatures
remaining likely below normal for much of eastern Nebraska and
western Iowa.

PoP chances in the extended appear limited and are likely driven by
the cyclonic flow at H5 from the deepening low. NBM shows a 15-30%
chance of PoPs in southeast Nebraska Sunday morning, and areawide
Thursday morning.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 550 AM CDT Fri Aug 22 2025

VFR conditions are expected for the start of this TAF cycle.
Will see a front swing through from northwest to southeast
across the terminals today. Have tried to time out wind
direction shifts, but winds should stay below 12 kts for the
period. A few scattered showers and storms may develop along
the front as it moves southeast today (30-40% chance at
terminals), but confidence still remains less than 50% for
inclusion in TAF at this time. If storms develop, a few could
have strong wind gusts as well as locally reduced visibilities
and ceilings to MVFR. Trends will continue to be monitored with
amendments and adjustments made as needed. Showers and storms
may linger across the far south toward the end of the TAF cycle.

&&

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

&&

$$

DISCUSSION...Castillo
AVIATION...Castillo