464
FXUS63 KLBF 112318
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
618 PM CDT Sun Aug 11 2024

.KEY MESSAGES...

- A Slight Risk (Level 2 of 5) for severe weather across
  western Nebraska this evening, mainly west of Highway 83. A
  Marginal Risk (Level 1 of 5) remains for north central
  Nebraska. Primary threats remain wind and hail, though a
  tornado cannot be ruled out.

- Near daily risk of showers and thunderstorms across the area
  through Thursday, with the potential for beneficial rainfall.

- Temperatures gradually warm and return to near seasonal
  normals by mid week.

&&

.SYNOPSIS...
Issued at 346 PM CDT Sun Aug 11 2024

Upper level analysis and water vapor satellite imagery reveal a
shortwave trough south central Wyoming, providing upper level lift
for this afternoon and evening`s severe storm threat. At the
surface, a low pressure system is located in southeast Wyoming, with
a warm front through the Nebraska Panhandle. A large area of stratus
has slowly moved eastward, mostly along and east of Highway 83. This
stratus deck has limited daytime heating potential, keeping
temperatures on the cooler side for daytime highs and also limiting
the build up of CAPE across western Nebraska.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 346 PM CDT Sun Aug 11 2024

Convective initiation is underway across portions of southwest South
Dakota and southeast Wyoming this afternoon. Although the persistent
stratus today limited the building of CAPE, recent clearing has
allowed for some build up of MUCAPE values around 1000 J/kg across
portions of the Panhandle. Effective shear values remain quite
supportive of severe weather this afternoon and evening. The
environment continues to ripen for supercell activity later this
afternoon and evening. While the primary threats remain for large
hail and damaging wind gusts, the low level helicity may be enhanced
enough in vicinity of the warm front to the point that a brief
tornado cannot be ruled out. Another thing worth keeping an eye on
with thunderstorms this evening will be the rain potential. PWAT
values around 1.25 inches fall between the 75th and 90th percentile
for early August, so storms could be quite efficient rain producers.
Expecting the higher rain amounts will be across north central
Nebraska this evening with more training and clustering cells moving
in from South Dakota. In general, expecting between half an inch to
one inch, though locally heavier amounts are possible.

As storms move out tonight, stratus clouds return overnight, keeping
overnight lows in the mid to upper 50s. With recent rainfall and
fairly light winds, there is a decent chance for patchy fog to
develop overnight, mainly along and south of Interstate 80.

For Monday, an upper level ridge will attempt to push in from the
west and attempt to settle over western Nebraska. A shortwave
pushing through the upper level flow may provide enough upper level
support for a surface boundary to generate storms across eastern
Wyoming and Colorado. Storms should continue to push eastward into
southwest Nebraska, bringing another chance of precipitation.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 346 PM CDT Sun Aug 11 2024

Upper level ridging is expected to be fully settled over western
Nebraska by early Tuesday morning. Guidance picks up on a few
embedded shortwaves tracking through the upper level flow throughout
the week. This will keep a near daily chance of showers and
thunderstorms across western and north central Nebraska through
Thursday. This is further reinforced by decent low level moisture
advection through the week, so certainly could bring beneficial
rainfall across the region. By late week, another ridge begins to
set up, which begins to limit the rain chances to around 20 percent.
Also worth mentioning, as the shortwaves continue to push through
this week, this should help limit temperatures a little bit under
the ridging. Expecting that temperatures will warm up, but only to
near seasonal average through the end of the week.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 607 PM CDT Sun Aug 11 2024

Early TAF concerns center around ongoing convection and how it
will impact TAF sites. Expect clouds over KLBF will limit
potential for severe storms but still may see some convective
remnants during the first couple of hours. KVTN is more unstable
but severe convection has made a right turn and is diving south
of the airfield. However additional thunderstorms are still
upstream and will affect the airfield during the next couple of
hours.

Following the early convection, anticipate a brief period of VFR
conditions before stratus/fog develop with IFR expected to
persist through daybreak and into Monday morning. A return to VFR
conditions is expected through the latter portion of the valid
period as the low clouds/fog dissipate by mid morning.

Winds will generally be light at 10kt or less, though strong/erratic
wind gusts can be expected near any thunderstorms.


&&

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

&&

$$

SYNOPSIS...Richie
SHORT TERM...Richie
LONG TERM...Richie
AVIATION...MBS