277
FXUS63 KOAX 100853
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
353 AM CDT Wed Jul 10 2024

.KEY MESSAGES...

- A few storms may produce hail and gusty winds this afternoon
  into this evening. The chance for severe weather is low (5% or
  less), but it can`t be completely ruled out.

- Most should remain dry through the weekend, but like many
  recent days, there could be some spotty showers and storms
  Thursday and Friday (5 to 15% chance).

- Dangerous heat is expected for much of the area this weekend
  into Monday, with heat index readings of 100 to 110 degrees
  likely. Sunday and Monday will be the hottest days.

&&

.DISCUSSION...
Issued at 345 AM CDT Wed Jul 10 2024

Early morning radar imagery showed showers and storms near the
SD/MN/IA border as a shortwave trough continued to push
southeast. These may end up clipping portions of northeast NE
and west-central IA this morning, but overall shouldn`t amount
to much. However, additional storm development is expected this
afternoon as we hit peak heating and a weak surface boundary
slides through. The strongest forcing with the shortwave looks
to stay to our east which should somewhat limit coverage over
our area, but still think we`ll have enough to get at least a
few storms going. Guidance indicates there will be some decent
instability in place (1500-2000 J/kg of MUCAPE), but shear
should remain rather weak and limit overall storm organization.
Still, could see a few stronger storms with hail and gusty
winds, and can`t completely rule out an isolated severe storm
(around a 5% chance). Outside of those higher scattered storm
chances, it should be a fairly similar day to yesterday with
highs in the mid to upper 80s, though maybe a touch more
humidity. Tonight, light winds and clear skies could set the
stage for fog development like the past few nights, though
guidance is a little bit more widespread with it this time,
likely owing to residual moisture from any precip we see today.

Thursday and Friday will be similar with daytime cumulus and
perhaps a few showers and isolated storms. Model soundings
suggest a cap both days, but another shortwave on Friday should
provide just enough forcing for some higher precip chances that
day (still only around 15% at this point though).

Attention then turns to the heat building in for the weekend
into early next week as upper level ridging currently over the
western CONUS edges east into our area. NAEFS guidance continues
to suggest 850 mb temperatures in the 90th to 99th percentile
of climatology, though we may not end up mixing quite that high.
Regardless, should see high temperatures well into the 90s to
possibly right around 100 in a few spots. In addition, southerly
low level flow will be ushering in plenty of moisture which
will combine with the evapotranspiration from crops to make it
feel quite sticky. Expect dewpoints in the lower to mid 70s for
most, though can`t completely rule out an isolated 80 degree
reading in some spots. That said, southwesterly flow may keep
dewpoints a tick lower than they otherwise would be. Still,
expect heat index values in the triple digits Saturday through
Monday. The highest values will be in southeast NE and southwest
IA Sunday and Monday, when we could get into the 105 to 110
range. So it`s looking like another period of dangerous heat for
some and would certainly expect at least a Heat Advisory at
some point. A surface front does look to sag south into the area
sometime late Monday into Tuesday and provide a little relief
along with some precip chances, though still expect highs in the
80s to lower 90s on Tuesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1121 PM CDT Tue Jul 9 2024

Isolated thunderstorms are possible (30 to 40 percent chance of
rain) across portions of northeast and east-central Nebraska
(KOFK and KOMA). Probabilities are too low to include in TAFs at
this time, but the most likely time for precipitation will be
between 18Z and 02Z. Just beyond the end of this forecast
period, there is some signal for patchy fog to develop across
the region. Uncertainties in coverage and timing may preclude
inclusion in TAFs for the next couple forecast cycles if this
signal persists.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...Darrah