459
FXUS63 KOAX 280831
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
331 AM CDT Thu Aug 28 2025

.KEY MESSAGES...

- Areas of fog this morning will burn off after sunrise. Expect
  a mix of clouds and sun today with highs in the low 80s for
  most, and upper 70s over far west and southwest areas.

- 20-40% PoPs gradually overspread portions of northeast
  Nebraska Friday afternoon and evening. Severe weather is not
  expected.

- 50 to 70% PoPs expected Saturday afternoon over northeast
  Nebraska, and again Sunday morning for much of eastern
  Nebraska.

&&

.DISCUSSION...
Issued at 331 AM CDT Thu Aug 28 2025

.SHORT TERM.../TODAY THROUGH FRIDAY NIGHT/

0811z GOES-19 Nighttime Microphysics imagery shows stratus entering
our western service area this morning. The stratus is riding along a
plume of low to mid 60s dew points on the far western periphery of
the 1022 mb sfc high. Just ahead of the low stratus, latest METARs
show a few sites having low temperature and dew point spreads.
Combined with the light wind speeds, expect to see areas of patchy
fog primarily over eastern Nebraska this morning.

Fog will burn off after sunrise, with a mix of cumulus clouds and
sun expected for most areas the rest of today. CAM guidance tries to
develop scattered showers over our far south during the late morning
hours, and while BUFKIT forecast soundings show some low level
saturation (likely from the lingering stratus), forcing remains weak
throughout the column. For this afternoon and evening, CAMs continue
to develop scattered showers and storms along a sfc pressure
trough/boundary, but latest guidance and trends show most of this
activity remaining northeast of OAX and moreso over the FSD and DMX
forecast areas. BUFKIT soundings across our far northeast show poor
low level saturation, so have taken out PoPs for these areas. Highs
today will be in the low 80s for most, with upper 70s across our far
west/southwest where thicker clouds may linger. Lows tonight will be
in the upper 50s to near 60F. Western areas may see patchy fog
redevelop early Friday morning.

By early Friday, a well defined shortwave over Wyoming will track
east into South Dakota as the H5 ridge begins to dampen and weaken.
The shortwave will induce sfc cyclogenesis, tracking a low across
western South Dakota and western Nebraska. Low to mid level Q-vector
convergence will overspread portions of northeast Nebraska by the
afternoon hours. With increasing 1000-850 mb low level moisture
transport along and ahead of the low, will see 20-40% PoPs gradually
overspread portions of northeast Nebraska by the evening hours.
BUFKIT soundings from the RAP and HRRR suggest very limited
instability, around 100 to 200 J/kg and with poor 0-6 km bulk shear,
not expecting to see severe weather. Highs Friday will be in the
upper 70s to low 80s for most, while lows will be in the upper 50s
to low 60s.

.LONG TERM.../SATURDAY THROUGH WEDNESDAY/

By Saturday, model guidance suggests the sfc low will be located
somewhere over south central  South Dakota into north central
Nebraska. At H8, will see the resultant baroclinic zone race east
resulting in increased warm air advection and low level moisture
transport, and with a stronger H5 shortwave ejecting southeast into
Nebraska, will see quite a bit of synoptic scale forcing. So, expect
a gradual increase in PoPs from west to east across the forecast
area for Saturday. PoPs peak Saturday afternoon across northeast
Nebraska at 50 to 70%, and again late Saturday night into Sunday
morning for much of eastern Nebraska at 50 to 70%.

By Sunday morning, the H5 shortwave matures into a closed low,
stalling somewhere over the Nebraska/South Dakota vicinity, before
finally ejecting southeast on Monday. With ample forcing and
lingering moisture, expect the PoP chances to continue Sunday (40-
50% chance areawide) and Monday (15-20% chance). Obviously,
differences in model guidance still exist at this point, so expect
further refinements and adjustments to the forecast as we get closer
to the weekend. Repeated passage of storms could lead to areas of
localized flooding, particularly over northeast Nebraska where QPF
amounts could be around 1 inch by early Monday morning.

Highs during the extended will remain cool, especially for Saturday
and Sunday with highs in the low to mid 70s. Temperatures warm to
the 80s for most on Tuesday before cooling to the 70s by Wednesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1030 PM CDT Wed Aug 27 2025

VFR conditions continue overnight. Expect low stratus to develop
across south-central Nebraska and expand eastward into KLNK by
12Z Thursday morning. Meanwhile, north we`ll see areas of fog
develop, likely to impact KOFK for at least an hour or so. Good
news for KOMA is that models tend to keep this terminal clear
Thursday morning, but there is still a 20% chance we see fog or
low stratus impact the terminal around 13-15Z. Expect VFR
conditions to return as fog/low stratus clears around 15-16Z.

Winds overnight will start out of the south, becoming light and
variable for several hours overnight before shifting to
southeasterly Thursday morning.

&&

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

&&

$$

DISCUSSION...Castillo
AVIATION...McCoy