198
FXUS63 KLBF 020535
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1235 AM CDT Sun Jun 2 2024

.KEY MESSAGES...

- Storms are anticipated to move into the area late this
  afternoon and evening, with potential for very large hail,
  damaging winds, and an isolated tornado.

- Confidence in potential for a high impact event is increasing
  for late Sunday afternoon/evening, for a line of severe
  thunderstorms capable of producing widespread wind gusts at
  or above 70mph across central and western Nebraska.

- Additional threats for thunderstorms exist Monday and Tuesday,
  though the threat for any severe weather remains uncertain.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 414 PM CDT Sat Jun 1 2024

Showers and thunderstorms that brought some large hail to portions of
western Nebraska before daybreak have moved off to the east and
dissipated. Visible satellite shows that an earlier well defined bubble
high over central Nebraska and a lingering outflow boundary have
started to erode under strong diurnal mixing, but anticipate hints of
the boundary will linger for a bit. Further upstream thunderstorms have
started to develop over the higher terrain in Wyoming and Colorado with
a dry line extending from southeast WY down through eastern Colorado.

Anticipate the dry line will push eastward and generate new convection
that will grow upscale as it encounters more moisture and surface based
CAPE values at or above 2500J/kg. The environment is well sheared with
0-6km bulk shear values at or above 40kt and long hodographs that
develop better curvature as the convection moves into western and
southwest Nebraska early this evening, along with lapse rates at least
moderately steep surface and aloft. Initial mode of convection looks to
be supercells that will build southeastward sliding along the ribbon of
unstable air from the western sandhills through southwest Nebraska into
northeastern Kansas. Initial storms closest to where the dry line moves
into the axis of unstable air from about Hwy 61 westward will be
capable of producing large to very large hail, damaging winds, and an
isolated tornado. Later this evening into early tonight as storms move
thorugh southwest/south central Nebraska generally along/south of I-80
there may be some clustering of storms into a loose MCS as outflows
consolidate with primarily wind/hail threats before diminishing and
moving off to the east before Midnight. With the expected slow movement
of storms there will also be potential for locally heavy rainfall and
flooding. Lingering elevated instability and an amplifying low level
jet will maintain an opportunity to for isolated/widely scattered
storms going overnight but with the axis of the jet shifting east any
activity before sunrise may be confined to Hwy 183 eastward or possibly
even Hwy 281 east.

We get a break in convection Sunday morning but the break will be
brief as a cold front approaching from the west. The airmass will
rapidly destabilize ahead of the front with surface based CAPE values
at or above 2500J/kg and steep lapse rates aloft. Some mid level
drying and a small inverted-v evident in model soundings near the
surface will boost DCAPE values to around 1500J/kg and present
a good signal for potential of significant winds. Anticipate
convection will develop ahead of the front entering the western
sandhills mid to late afternoon, then rapidly grow upscale into
a linear MCS that will cross the entire region through Sunday
evening before exiting to the east before Midnight. The majority
of mesoscale guidance is in good agreement depicting potential
for a high impact event with potential for winds at or above
70mph over a fairly large area, along with large hail, late
Sunday afternoon through Sunday evening. This bears close
watching, especially for anyone traveling or with outdoor plans.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 414 PM CDT Sat Jun 1 2024

Progressive flow regime with a series of shallow trofs moving
through the northern tier of states will keep active weather
across central and western Nebraska into the first part of next
week before a large ridge starts to build over the western US.
Additional thunderstorm threats will persist into Monday and
Tuesday, though confidence is not high with respect location and
timing of best thunderstorm potential. Drier conditions are then
expected into midweek as the western ridge builds. Differences
in guidance locations of features creates uncertainty late week
and beyond, but will have to watch for potential of thunderstorm
development late next week in northwest flow aloft depending on
exactly where the upper ridge becomes established.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1234 AM CDT Sun Jun 2 2024

A couple aviation weather concerns exist through the forecast
period for western and north central Nebraska terminals.
Scattered thunderstorms will continue to cross the Sandhills
overnight before fair conditions resume during the day. A more
organized complex of storms is anticipated this evening, likely
taking the form of a line with high winds and heavy rain. Gusts
of 50+ kts are possible for the southern terminals (LBF). In the
meantime, ambient surface winds will gust to 20 kts from the
south.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Brown/MBS
LONG TERM...Brown
AVIATION...Snively