968
FXUS63 KOAX 022102
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
402 PM CDT Sun Jun 2 2024

.KEY MESSAGES...

- Strong winds and a line of storms is still on track to move
  into the area after 9 PM this evening. Wind gusts potential is
  decreasing to only as high as 70 mph, especially going east.

- Some flooding is possible overnight, but will be limited by
  faster storm speed.

- Storm chances continues Monday and Tuesday, with the highest
  potential for additional severe weather being Tuesday.

- Mostly dry Wednesday into the weekend with highs in the mid
  70s through mid 80s.

&&

.DISCUSSION...
Issued at 357 PM CDT Sun Jun 2 2024

Today:

Water vapor imagery this afternoon continues to feature out messy
zonal pattern with a shortwave embedded in the zonal flow moving
into the the High Plains. Taking a look at a recent surface
analysis, a strengthening frontal interface stretches from
southeast Colorado northward into northwest South Dakota, with
falling surface heights, and as a result, increasing surface
moisture advection being seen along it. To the east,
temperatures generally in the 70s are in place across eastern
Nebraska and southwest Iowa, largely due to morning and early
afternoon convection that persisted. Gusty winds of 20 to 30 mph
are making for a breezy afternoon as well, with the strongest
winds being in eastern into central Nebraska. Weak showers and a
few sprinkles continue to waft across areas southeast of
Norfolk, but should not pose any severe threat due to the
limited instability in place.

The forecast for a potential line of storms or MCS to move into the
area this evening continues to stay on track, with impressive
instability and sufficient shear held in a narrow corridor just to
the east of the aforementioned frontal interface up the High Plains.
Supercells will continue to develop in those areas, eventually
growing upscale into a cluster of storms or an organized bowing
segment. RAP forecast soundings in central Nebraska show impressive
downdraft CAPE (DCAPE), which CAMs seem to be locked onto while
producing wind gusts over 80 mph in central Nebraska. The main
caveat for it`s progression into our area will be the
morning/afternoon`s influence on the convective parameters. Weaker
shear that will be less than 30 kts and a capped 2000-2500 J/kg of
CAPE will make the stronger wind gusts a lower probability as
it moves eastward. Additionally, a weaker gradient of
instability may also guide the bow southeast rather than
straight east. The weaker shear in our local area will provide
resistance to MCS maintenance, as it will trend closer and
closer to being outrun by it`s gust front (and subsequently
lowering the wind speed potential of the system). Regardless, we
still are expecting strong winds to move into eastern Nebraska
around 9 PM, before exiting/dissipating by 4 AM. The weaker
nature of the bowing segment should limit rainfall intensity to
go along with it`s fast movement, but soils in parts of
northeast Nebraska and into Iowa are still saturated and
flooding remains a possibility (though rainfall amounts
generally should stick below on inch).

Monday and Tuesday:

For Monday most of the area is expected to stay dry, with a few
pop-up showers and storms that many of the CAMs depict
developing during the afternoon, dissipating by sunset. Very
weak shear will make any severe weather unlikely, with coverage
of storms depending on how the residual inversion will be and
how strong storm outflows will be colliding.

Our next best chance at showers and storms come Tuesday afternoon
and evening, as deeper trough interrupts the zonal flow aloft and
drags a cold front through the region. Global deterministic models
indicate that ML instability will be hard to come by anywhere
outside of southeast Nebraska and Iowa, and those areas will
represent our best chances for and severe weather. On the bright
side, the sweeping front is expected to set the stage well for a
nice end to the week.

Wednesday and Beyond:

Behind the departure of Tuesday`s system, swift northwesterly flow
will find itself entrenched over the central CONUS. The main axis of
the mid/upper jet streak will be bisecting the forecast area,
guarding us from any of the better moisture return. Instead, we`ll
enjoy highs in the upper 70s to low 80s and afternoons with gusts of
20 to 25 mph to enjoy while we dry out a bit and give rivers and
soils some recovery time.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1224 PM CDT Sun Jun 2 2024

Shower and storm activity from this morning continues to
complicate the aviation forecast through the early afternoon,
with continually developing storms in central Nebraska wafting
near the KOFK and KLNK vicinity, becoming weaker over time. This
activity is expected to continue through 20 to 22z, with it
being currently unclear how long into the afternoon these
chances will extend. What is clear, lightning chances diminish
as you go east, VFR conditions are expected through the
afternoon, and gusty winds will be in place through the evening
hours.

A line of storms is still on track to move into the area from
the west this evening, with continued refinements expected for
its timing in the TAF. KLNK currently has the best chance to see
higher-end wind gusts, with the strongest of which expected on
the front side of the arriving line of storms. Weaker winds out
of the south are expected to replace the system overnight into
tomorrow morning.

&&

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

&&

$$

DISCUSSION...Petersen
AVIATION...Petersen