842
FXUS63 KOAX 201103
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
603 AM CDT Wed May 20 2026

.KEY MESSAGES...

- Cooler weather continues with the potential for morning frost
  for northeast Nebraska on Wednesday.

- Shower/thunderstorm chances return Wednesday night into
  Thursday continuing on/off through Friday.

- Trend back toward warmer temperatures over the weekend.

&&

.DISCUSSION...
Issued at 1214 AM CDT Wed May 20 2026

Surface high pressure was building in late this evening with clouds
slowly, but surely starting to clear out of the area. Winds will
also become quite light as the high passes over, setting up what
looks to be a chilly night. Latest guidance suggests fairly
widespread 30s, with portions of northeast NE and west-central IA
dipping into the lower to mid 30s. Expect frost development in much
of this area with potential for a few spots getting below freezing.
A Frost Advisory remains in effect through 8 AM.

The surface high will push to our east through the day on Wednesday
as some weak shortwave energy currently over the Desert Southwest
ejects eastward toward the area. This will lead to increasing cloud
cover and perhaps a few sprinkles or showers in portions of
northeast NE, but they likely won`t amount to much more than a few
hundredths of an inch. Otherwise, temperatures remain on the cooler
side, with highs in the lower to mid 60s. Another bit of shortwave
energy will slide through southern portions of the forecast area
late Wednesday night into Thursday. Guidance is in better agreement
that we see some showers and perhaps an isolated storm with this,
mainly near and south of I-80 (30-50% chance).

Meanwhile, a trough will be digging into the western CONUS out of
Canada and eventually push east into the forecast area late Thursday
night into Friday. Guidance is in fairly good agreement that we`ll
see widespread rainfall with this system on Friday (60-80% chance),
but still some differences on exact track and resulting rainfall
amounts. Consensus currently suggests most places see a few tenths
at most.

Warmer, drier air will move in behind this system as it departs on
Saturday, allowing temperatures to climb back into the upper 60s to
lower 70s. We`ll warm further on Sunday and Monday as the trough
axis pushes to our northeast and ridging starts to build in. Expect
upper 70s to mid 80s Sunday followed by widespread 80s Monday into
next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 601 AM CDT Wed May 20 2026

VFR conditions are still expected to hold for the next 24 hours,
with shallow fog near the KOMA terminal that will last for an
hour before dissipating. Winds are very light and generally out
of the north, but will become increasingly easterly, then
eventually southeasterly towards the end of the TAF period at
less than 10 kts.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Frost Advisory until 8 AM CDT this morning for NEZ011-012-
     015>018-030>034-042>044.
IA...Frost Advisory until 8 AM CDT this morning for IAZ043.

&&

$$

DISCUSSION...CA
AVIATION...Petersen