647
FXUS63 KLBF 230520
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1220 AM CDT Sun Jun 23 2024

.KEY MESSAGES...

- Some potential for isolated strong to severe thunderstorms
  late Sunday and again late Monday along/east of Highway 83.

- Hot on Monday with potential for hazardous heat index values
  across central and western Nebraska.

- Thunderstorms with increasing potential for locally heavy
  rainfall mid to late week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 440 PM CDT Sat Jun 22 2024

High pressure building down into eastern Nebraska tonight will bring
quiet weather to the region with lows generally around 60. As
the high quickly moves off to our southeast return flow on the
back side of the high will allow southerly winds to usher hot
air back into central and western Nebraska by tomorrow as
afternoon readings peak well into the 90s but a bit cooler to
the northeast. As a dry line starts to push in from the west
during the afternoon unstable air will pool along and east of
Hwy 83. There is some capping in the core of the greatest
instability along the Hwy 183 corridor, lapse rates aloft are
not overly steep, and the synoptic environment is not
particularly robust in this conditional environment but forcing
from the dry line and a low level jet starting to nose into the
region from the south early Sunday evening look to be enough to
support at least isolated thunderstorm development despite most
mesoscale guidance showing reluctance to develop convection.
Storms that do manage to form will have 0-6km bulk shear around
30kt and modestly curved hodographs aid organization with enough
chunky CAPE aloft to support a large hail threat and DCAPE
values of 1500J/kg with steep low level lapse rates in a hot
boundary layer will aid efficient wind production for a damaging
wind threat. SPC Day 2 Marginal Risk centered on south central
Nebraska seems about right and will have to monitor outflow
boundaries capable of initiating convection as the propagate
away from this area. The convective threat will wane early
Sunday night with loss of diurnal heating, some dissipation of
elevated instability, and the dry line retreats westward. Lows
Sunday night will generally be in the middle 60s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 440 PM CDT Sat Jun 22 2024

Monday is shaping up to be hot with EFI/SoT guidance showing a
trend for well above normal heat across central and western
Nebraska. Anticipate triple digit highs along and south of
Interstate 80 with readings well into the 90s further to the
north, potentially elevating heat index values to hazardous
levels. Will monitor heat potential closely to see if headlines
become warranted.

The convective environment remains conditional on Monday due to
some capping, though the dry line pushing eastward again during
the afternoon followed by a cold front moving through late may
provide enough forcing to trigger convection. There will be a
substantial pool of instability mainly east of Highway 183 with
CAPE values approaching 4000J/kg along with steep low level
lapse rates and substantial DCAPE values around 2000J/kg but
shear is not as robust with small hodographs and 0-6km bulk
shear generally in the 20 to 30kt range. Anticipate widely
scattered storms will develop with best potential for severe
storms east of Hwy 83 from south central up toward northeast
Nebraska with primarily a wind/hail threat with loss of diurnal
heating and passage of the cold front bringing an end to
convection overnight.

Thereafter, the High Plains will remain under a mean ridge with
a series of waves moving through the northern tier of states
periodically suppressing the amplitude of the ridge. Ensemble
guidance shows an increase in precipitable water values during
the latter portion of the workweek with values rising above the
90th percentile as moisture with a tropical connection streams
up from the southwest. This will continue our warm temperatures
and bring potential for diurnally biased showers/thunderstorms
each day from midweek onward, along with potential for excessive
rainfall working up form the southwest by the end of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1218 AM CDT Sun Jun 23 2024

VFR is generally expected across wrn/ncntl Nebraska overnight,
Sunday and Sunday evening.

Isolated showers and thunderstorms are possible along and east
of highway 83 from 20z Sunday through 03z Sunday evening. There
are no other flight concerns.

&&

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

&&

$$

SHORT TERM...MBS
LONG TERM...MBS
AVIATION...CDC