070
FXUS63 KOAX 171943
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
243 PM CDT Tue Sep 17 2024

.KEY MESSAGES...

- Daily chances of showers and storms will continue through the
  weekend, with the highest likelihood occurring at night. Peak
  chances (50 to 70%) are expected from Friday night through
  Saturday.

- Temperatures remain above average through the work week, with
  highs in the 80s. Cooler conditions are anticipated this
  weekend.

- Significant rainfall accumulation of 1-3" is possible over the
  weekend.

&&

.DISCUSSION...
Issued at 237 PM CDT Tue Sep 17 2024

...TODAY AND TONIGHT...

The current upper level pattern consists of troughing over the
western CONUS with an area of low pressure ejecting northeast
towards MT/WY over the next few days as an additional area of low
pressure moves onshore over the west coast. Lingering morning rain
showers continue to decay across the area with clouds breaking from
west to east. This will bring a mostly clear afternoon with highs
expected in the mid- to upper-80s. Breezy southerly winds will
persist through the afternoon with gusts exceeding 30 mph in
northeast Nebraska.

Another round of AM rain showers will move in late tonight into
Wednesday morning, gradually decaying as they must east. This chance
will be forced by a moist LLJ being met with a weak shortwave
trough. PoPs of 30 to 60 percent will be present over our western
counties with the remainder of the area left with less than 20
percent.

...WEDNESDAY...

Morning showers are expected to break up by noon, bringing another
afternoon of mostly clear skies and highs in the upper 80s. As the
aforementioned low progresses northeast, it will help to push a
dryline through the area Wednesday evening and bring a marginal risk
for severe weather. Instability remains meager (CAPE of 1000-1500
J/kg) with 30-35 kts of bulk shear. This should be sufficient for
hail up to 1" and wind gusts up to 60 mph with any strong updrafts.
The scattered nature of this event brings PoPs in the 25 to 40
percent range.

...THURSDAY...

Thursday looks to be the warmest day of the week with highs in the
upper 80s/low 90s. These highs are a good 10 to 15 degrees above the
climatological average for mid-September (though still a few degrees
below record values). Another severe weather risk will be present
Thursday evening as the aforementioned low remains centered over
North Dakota/Saskatchewan/Manitoba and drops a trailing cold front
over the region. The severe weather threat remains focused over our
Iowa counties at this time as the better instability resides over
central IA/MN. We will still have 750-1000 J/kg of CAPE and 25-30
kts of bulk shear to work with. This should be sufficient for a
marginal wind (gusts up to 60 mph) and hail (up to 1") risk. PoPs
remain in the 20 percent range, increasing just east of our CWA.

...FRIDAY AND BEYOND...

Towards the end of the work week, the aforementioned secondary low
pressure system over the western CONUS will progress northeast from
southern California towards the Four Corners region. Friday looks to
be our last day with highs in the mid- to upper-80s as a ridge sits
over the southern/central CONUS. A chance for more widespread
precipitation moves into the area Friday night into the weekend.
Precipitation onset timing will depend on how quick the slow-moving
western low makes it towards the region. Recent guidance has slowed
down its arrival, bringing the start of precipitation late Friday
evening into Saturday morning. This arrival will need to be
monitored for anyone attending outdoor football games Friday
evening.


Although long range guidance becomes a bit more indecisive over the
weekend, there is confidence that this weekend will be wet. PoPs
peak at 55 to 70 percent through Saturday with PoPs generally
remaining above 40 percent through the entire weekend. Potential for
1 to 3 inches of rainfall is present with locally heavy rainfall a
possible hazards. Precipitation chances taper off into the start of
next week. Breaking down of the ridge and extended cloud cover will
bring highs in the mid 70s on Saturday and upper-60s/low-70s
Sunday into next week. This comes just in time for the autumn
equinox on Sunday.

Though we will have a chilly and wet start to next week, the CPCs 8-
14 day outlook is expecting temperatures to lean above average with
near normal precipitation chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1135 AM CDT Tue Sep 17 2024

VFR conditions are expected to prevail. Currently, a line of
decaying light rain showers is pushing across eastern Nebraska.
Showers should push past KLNK by 17Z and decay before impacting
KOMA. A brief period of -SHRA may be needed at KOMA from 18-19Z
if showers hold together. Otherwise, southerly winds will
continue above 12 kts with gusts up of 22-26 kts possible this
afternoon. Another round of morning showers will move through in
the 9-14Z timeframe with the highest confidence of impacting
KOFK.

&&

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

&&

$$

DISCUSSION...Wood
AVIATION...Wood