764
FXUS63 KOAX 141124
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
624 AM CDT Sun Jul 14 2024

.KEY MESSAGES...

- Early morning storms entering northeast Nebraska may pack a
  windy punch with gusts of up to 70 mph possible.

- 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.

- More widespread storm chances (20-40%) arrive Monday night and
  linger through Wednesday.

&&

.DISCUSSION...
Issued at 254 AM CDT Sun Jul 14 2024

Today and Monday:

Of immediate concern this morning is the quick southeastern
propagation of what will likely be categorized as a derecho, moving
across south-central South Dakota towards northeast Nebraska.
Despite an increasingly ragged look to the MCS, gusts of over 70 mph
have been reported by mesonet stations within the last 20 minutes
with the HRRR brining 60 to 70 mph wind gusts across Knox and Cedar
counties from 4 to 6 AM, potentially with a gust front well out
ahead of the main storms. As it sits right now, those two
counties are the primary concern and hold the highest chances of
seeing severe gusts while areas to the south and east will
likely only see gusts of 40 to 55 mph with the leftovers of the
system through mid- morning.

Of secondary but more widespread concern is dangerous heat this
afternoon and for parts of the area Monday. The forecast in place
reflects ensemble consensus for high temperatures both days while
we`ve continued to push higher dewpoints, and as a result locations
within the issued Excessive Heat Warning are expected to see heat
indices of 110 to 115 degrees while the rest of the area falls under
a Heat Advisory. Confidence in the heat has continued to be steadied
by the impending thermal ridge moving into the area, while a
leftover boundary or two that linger today in southeast Nebraska may
help temperatures and dewpoints over-perform where it festers.
For Monday, the expected front moving south into the area will
bring some relief to northeast Nebraska, but may make areas to
the south and east of it feel as bad if not worse as moisture is
pooled and compressional heating increases ahead of its slow
movement. Storms will also be possible Monday, but those chances
continue to only graze northeast Nebraska and stay relegated to
Iowa and South Dakota primarily.

Tuesday and Beyond:

We`ll see the patter shift for the rest of the week shift from the
oppressive ridge from the weekend/Monday into
north/northwesterly flow that will keep the heat off to the
western third of the CONUS. The retrograding ridge will amplify
through the rest of the work week and lob shortwaves at the
forecast area, with no end in sight through the first 200 hours
of the global deterministic runs. We`ll enjoy cooler temps and
recurring rain chances for an overall pleasant part of the
summer forecast period.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 619 AM CDT Sun Jul 14 2024

VFR conditions are expected through this TAF period. A decaying
MCS across South Dakota has produced an outflow boundary that
will impact KLNK and KOMA early in this TAF cycle, providing a
wind shift to the northwest with gusts up to 25-30kts. This wind
shift will be short-lived as northerly winds quickly become
southerly by 14-16Z with a few passing mid/high clouds. A few
sprinkles are possible across northeast Nebraska this morning
in association with the above mentioned decaying MCS.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Heat Advisory from noon today to 8 PM CDT this evening for
     NEZ011-012-015>018-030>034-042>045-050-065-078-088.
     Heat Advisory from noon to 8 PM CDT Monday for NEZ015-033-034-
     042>045-050-065-078-088.
     Excessive Heat Warning from noon today to 8 PM CDT Monday for
     NEZ051>053-066>068-089>093.
IA...Heat Advisory from noon today to 8 PM CDT this evening for
     IAZ043-055-056.
     Heat Advisory from noon to 8 PM CDT Monday for IAZ043-055-056.
     Excessive Heat Warning from noon today to 8 PM CDT Monday for
     IAZ069-079-080-090-091.

&&

$$

DISCUSSION...Petersen
AVIATION...Kern