706
FXUS63 KOAX 280439
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1139 PM CDT Thu Jun 27 2024

.KEY MESSAGES...

- Moderate flooding is ongoing or expected to begin along the
  Missouri River the next day or two. It`s forecast to last into
  next week for Omaha and points south.

- 5 to 15 percent chance of strong to severe storms tonight into
  Friday and again Friday afternoon into Friday night. Both
  rounds of storms could produce heavy rain and localized flash
  flooding, along with damaging winds, hail, and perhaps a
  tornado or two.

- Quiet and cooler for the weekend, with highs in the mid 70s to
  mid 80s. Then warming back up and becoming more active for the
  holiday week.

&&

.DISCUSSION...
Issued at 349 PM CDT Thu Jun 27 2024

A weak shortwave was moving through early this afternoon and
leading to some some scattered showers and a few isolated
storms, though overall not amounting to a whole lot with some of
the returns seen on radar likely not even reach the ground.
These will continue to push east through the afternoon and then
attention will turn to additional storm development for this
evening and overnight as strong low level moisture transport
starts pointing toward the area. Model soundings do reveal a
very stout cap to contend with, but steep lapse rates above said
cap (especially in northeast NE) and decent shear suggest some
of these storms could be on the stronger side if they do get
going. In addition, we`ll have to watch storms that form over
western NE and approach our area around or just after midnight.
They will be moving into a less favorable environment, so should
generally weaken as they push in, but still could last long
enough to give portions of eastern NE some strong to damaging
winds and hail. In addition, precipitable water values
approaching 2 inches and warm cloud depths of 4+ km suggest any
storm that does move through will be an efficient rain-producer
and potentially lead to some localized flash flooding.

A few showers may stick around during the day Friday as
additional shortwave energy moves through. In addition, a
surface low will slide across the Dakotas and drag a cold front
through our area bringing higher chances for stronger storms by
late afternoon/evening. With the daytime precip (or clouds at
the very least) instability may struggle to build as much as
models suggest so storms could initially struggle to get going
as the front moves through. However with strong southerly flow
through the day, far southeast NE and far southwest IA will have
more time for warm, moist air to move in so think those areas
would have the highest chances for any strong to severe storms.
In addition, those areas will see the strongest low level shear
as the low level jet ramps up in the early evening, indicating
at least some tornado threat. However, the environment will be
conducive to at least some stronger storms almost area-wide if
things are able to initiate earlier in the day (more likely if
we see more sunshine during the day). Finally, once again the
environment will be ripe for efficient rain- producing storms
with continued increasing precipitable water values (2+ inches
for some), leading to a localized flash flooding threat. All
that said, overall a fairly low confidence thunderstorm forecast
for Friday afternoon/Friday night. Otherwise, also of note
Friday will be the warm, humid conditions with a few spots
perhaps reaching triple digit heat index values with highs in
the 90s and dewpoints in the mid 70s.

Surface high pressure and upper level ridging will push in
behind the front setting the stage for a pretty nice and mostly
dry weekend. Expect temperatures in the mid 70s to mid 80s with
dewpoints back down in the 50s to lower 60s. Some hints at a few
spotty showers by Sunday evening, but those should be few and
far between with ridging dominating.

The break in heat and storm chances looks short-lived, however,
as the ridge pushes east Monday with broad upper level
troughing/zonal flow building in across the western and central
CONUS Monday through the rest of the week. Various bits of
shortwave energy look to slide through while a slow-moving
surface boundary pushes south Monday and Tuesday (could even
stall at times). The general setup would suggest potential for
some training thunderstorms along that boundary which would
bring a risk for heavy rain and additional flooding, but still
lots of details to work out between now and then. Still, very
much a time period to keep an eye on. Otherwise, we`ll see
continued storm chances through the week with temperatures
getting back into at least the mid 80s to lower 90s. With the
potential for repeat rounds of thunderstorms, ongoing flooding
may end up lingering a little bit longer than currently
forecast, or rivers may remain elevated for longer at the very
least.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1136 PM CDT Thu Jun 27 2024

VFR conditions at TAF issuance with southeast winds at 15 to 25
mph, with LLWS at all three TAF sites, southerly winds around
190 degrees with winds at 2000 feet around 45 knots. LLWS
diminishes by 12z, and that there could be showers or thunderstorms
at KOFK 15-18z, and KLNK/KOMA 18-22z. Winds shift to the
northwest after the rain chances, with speed less than 12 knots.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...DeWald