935
FXUS63 KOAX 190341
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1041 PM CDT Thu Jul 18 2024

.KEY MESSAGES...

- An extended stretch of cooler-than-average temperatures will
  persist into next week.

- Next widespread rain chances will be Friday evening into Saturday.
  There are additional spotty rain chances into next week.

&&

.DISCUSSION...
Issued at 302 PM CDT Thu Jul 18 2024

.Late this afternoon through tonight:

Surface high pressure over central IA is contributing to mild
weather (by July standards) across the region today with
temperatures in the upper 70s to lower 80s as of 2 PM. The high
will shift east tonight in response to a deepening low pressure
system over southeast MT into western SD. Low/mid-level warm
advection developing downstream from the low across central SD
into north-central NE may support isolated to widely scattered
showers and thunderstorms, a few of which could reach portions
of northeast NE toward daybreak Friday.


.Friday and Friday night:

A shortwave trough located over southern Alberta and northern MT
as of early afternoon is forecast to track from eastern MT
Friday morning into the mid MO Valley by late Friday night, in
tandem with the above-mentioned surface low. Increasing moisture
and forcing for ascent ahead that system will support a
general increase in showers and thunderstorms during the
afternoon across central/eastern SD into northern NE with that
activity spreading southeast through our area Friday night.

While mid-level lapse rates are not expected to be particularly
steep, the increasing moisture and strengthening mid/upper-level
winds may yield sufficient amounts of instability and vertical
shear for a few strong to potentially severe storms during the
late afternoon and evening hours, mainly across northeast NE.
Hail up to quarter size and/or wind gusts up to 60 mph are the
primary hazards, along with locally heavy rainfall.

Highs on Friday will be in the low to mid 80s.


.This weekend:

The 12z global models suggest that a high-latitude omega
blocking pattern will become established, which will
effectively maintain mid-level troughing across the mid MO
Valley into early next week. As such, we will see continued
shower and thunderstorm chances with the highest PoPs (50-70%)
on Saturday morning. Areas of rain and associated cloud cover
will result in seasonably cool conditions with daytime highs in
the 70s.

Another item of note is the potential for smoke from Canadian
wildfires to filter into the region. Model forecasts suggest
this would be mainly aloft, so it`s currently not expected to be
an impactful occurrence to sensitive groups.


.Next week:

As mentioned above, the large-scale blocking pattern will
maintain mid-level troughing across the region early in the
week with periodic 20-30% PoPs on Monday and Tuesday. It does
appear that we will see gradually warming temperatures with
highs in the 70s on Monday warming back into the low to mid 80s
by mid-week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1041 PM CDT Thu Jul 18 2024

Main forecast concern will be timing and location of
thunderstorms Friday. Guidance is in decent agreement we see
some develop in northeast Nebraska from 11-15Z, but is split on
how far southeast those persist. Most likely scenario is that
only OFK sees storms, but if they hold together OMA and LNK
could see something toward 18Z. Then a more widespread line of
storms looks to move through Friday evening, though there
remains large spread on timing ranging from 23Z to after 04Z at
OFK. Once again, questions remain on how far southeast they`ll
make it, but expect them to at least weaken quite a bit prior to
reaching OMA and LNK. Outside of storms, expect VFR conditions
with FEW to SCT clouds around 4000 to 7000 ft and southeast to
south winds around 10 kts, with a few gusts near 20 kts at OFK.

&&

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

&&

$$

DISCUSSION...Mead
AVIATION...CA