National Weather Service Raw Text Product

475 
FXUS63 KOAX 302256
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
556 PM CDT Mon May 30 2022

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 403 PM CDT Mon May 30 2022

Recent surface analysis and satellite observations place a deepening 
surface low north of Yankton, South Dakota, with a southward 
extending dryline that is draped along the Nebraska/Iowa border and 
strong gradient winds have been observed on both sides of the 
feature (with gusts up to 46 kts). Water vapor imagery highlights 
the deepening mid-level support with a strong punch of dry air 
moving northward behind the aforementioned surface low. Strong 
shear, steep mid-level lapse rates, and ample CAPE is in place for 
eastern portions of the forecast area, with the main difficulties 
with storm development being an elevated inversion and strong low-
level shear disrupting any updrafts that do form. The strong winds 
that have been observed over the past several hours are expected to 
largely diminish over the next two hours.

Storms are expected to continue to struggle against the strong shear 
and inversion, with an isolated supercell or two being possible if 
they can sustain an updraft along the dryline. Across northeast 
Nebraska, very high-base storms are still possible as strong forcing 
continues through 7 PM, mainly northwest of a line from Columbus to 
Onawa, with damaging hail and wind. Another area of storms is 
expected to become possible after 9 PM as the cold front catches up 
to the dryline in far southeastern Nebraska and southwest Iowa. The 
collocated forcing mechanisms is expected to allow elevated storms 
to fire up and advect eastward out of the area through 3 AM or so 
with damaging hail and winds once again being the primary hazards. 
This line of storms could stall out in the far southeastern portion 
of the forecast area, and could produce focused flood chances along 
the near stationary line. By sunrise Tuesday morning, a few isolated 
showers may linger for an hour or two in Richardson, Nemaha, and 
Pawnee counties, but quiet weather is expected to fall into place 
once again. 

Slight Rain and storm chances once again return to the forecast area 
as a shortwave trough and associated mid-level jet streak move 
across the area Wednesday as highs fall from the 80's on Tuesday to 
right around 70 for much of the area. Zonal flow is expected to set 
up through Friday evening, while highs creep up to the mid 70's 
Thursday and around 80 degrees Friday afternoon. Friday night 
into Saturday, global model solutions suggest that a weak 
shortwave will move through the continued zonal flow and bring the
area chances for minor rain, extending into Sunday as more 
shortwaves get lobbed through the flow. Overall, the extended 
forecast doesn't look like a washout by any means, but we'll be 
dodging rain and storm chances most every day.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 556 PM CDT Mon May 30 2022

Strong southwest winds will gradually weaken this evening with the
wind direction switching to west and then northwest tonight into 
Tuesday morning. Otherwise, VFR conditions will prevail through 
the forecast period.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory until 8 PM CDT this evening for NEZ011-012-015>018-
     030>034-042>045-050>053-065>068-078-088>093.

IA...Wind Advisory until 8 PM CDT this evening for IAZ043-055-056-069-
     079-080-090-091.

&&

$$

DISCUSSION...Petersen
AVIATION...Mead