568
FXUS63 KOAX 150858
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
358 AM CDT Sat Jun 15 2024

.KEY MESSAGES...

- Non severe thunderstorms early this morning, then an
  additional chance of strong and possibly severe thunderstorms
  this afternoon. All modes of severe weather would be possible
  from 4 pm through midnight, mainly along and south of a
  Columbus to Sioux City line.

- Very hot temperatures expected Sunday and Monday with
  afternoon heat index values 98 to 103 each day.

- Daily storm chances exist at least somewhere in our coverage
  area every day from Sunday night through next week, and
  especially north of Interstate 80. Each round of storms will
  have potential for some severe weather and locally heavy
  rains.

&&

.DISCUSSION...
Issued at 357 AM CDT Sat Jun 15 2024

A line of non severe thunderstorms is currently moving through
eastern NE early this morning. Wind gusts have ranged from 40 to
55 mph along with some small hail. This line will continue to
push into western IA before daybreak, with an hour or two of
stratiform rain trailing behind the main line. The rain will end
from west to east with the bulk of it over by 10 am. Then
there will be a few hour break from late morning through early
afternoon, and while most areas will remain dry during this
time, there could still be a spotty shower here or there.

Meanwhile, we will be waiting for the main shortwave to move off
the front range of the Rockies, which will fire strong and
possibly severe storms this afternoon. The CAMs honestly provide
varying locations for the convective development this
afternoon, but the consensus seems to indicate the best severe
threat along and south of a line from Columbus, NE to Sioux
City, IA. There should be enough recovery time to allow the
atmosphere to destabilize before this happens, and when storms
develop, they could be quite strong with supercells possible,
with all modes of severe weather possible. SPC has placed the
area in a slight risk for severe storms, with a 15% chance of
wind and hail, and a 5% chance of for an isolated tornado. WPC
has also placed eastern NE and southwest IA in the area for
excessive heavy rainfall since this area will receive heavy
rainfall this morning. Again though, confidence is somewhat low
where the axis of storms develop. The severe storm threat could
begin by 4 pm and linger through midnight. Any storms that
develop will continue to push east and be east of the forecast
area by daybreak Sunday. Before the severe storms arrive late
this afternoon, high temperatures should the middle to upper
80s, and could even reach the lower 90s along the KS/NE border.

And then hot weather is expected to develop Sunday with mostly
sunny skies and high temperatures in the middle to upper 90s.
Combined with dewpoints in the upper 60s, this will create
afternoon heat index values from 98 to 103, and major heat risk.
These values are just below official heat advisory criteria, but
those with outdoor plans should plan accordingly and stay well
hydrated with water and seek the shade whenever possible.
Southerly winds at 15 to 25 mph will help, but it will be the
hottest day of the year so far.

Storm chances come again Sunday night, mainly north of
Interstate 80, with a marginal risk of both severe storms and
excessive heavy rainfall.

Monday brings continued small storm chances north of I80, but
realistically, it could even be north of our forecast area. It
will be another hot day with high temperatures once again in
the lower to middle 90s, and heat index values 97 to 102. Due to
the prolonged heat, the heat risk will remain elevated, but
again, heat index values remain just below heat advisory
criteria. And rain chances continue north of I80 Monday night,
but again, based on newer models, any storms could also be
north of the area.

Another front moves into the region on Tuesday, which brings
more thunderstorms, and another chance for severe storms along
with heavy rainfall. And storm chances continue every day for
the remainder of the week. Highs Tuesday in the upper 80s to
lower 90s, but that front could bring cooler temperatures in the
upper 70s to upper 80s for Wednesday, but warming back up to the
upper 80s to lower 90s again by the end of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1210 AM CDT Sat Jun 15 2024

A line of strong to isolated severe storms will track through
the area early in the period with TS lasting for about 2 hours
at a given spot with some showers lingering behind. Expect MVFR
to IFR conditions with 30-40 kt gusts as the storms pass
through, followed by some MVFR to IFR ceilings once the showers
exit, most likely at OFK and LNK. Guidance still suggests some
additional spotty storms could form behind the showers from
around 11 to 14Z, but confidence is low in those hitting a TAF
site (highest chances at LNK and OMA).

Additional strong to severe storms are expected to develop
Saturday afternoon/evening as early as 20-21Z, but confidence in
exact timing and placement is too low to include at this time.
Highest chances are at LNK and OMA, but some hints that storms
could remain south of all sites. Otherwise, outside of storms,
expect southeast winds through the period, with gusts of 20-30
kts for most of the period.

&&

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

&&

$$

DISCUSSION...DeWald
AVIATION...CA