-- Discussion containing changed information from previous version are highlighted. --
687
FXUS63 KLBF 130440
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1140 PM CDT Wed Jun 12 2024

.KEY MESSAGES...

-  The heat continues into this evening, before "cooler" air
   filters into the area behind a quick moving cool front.

-  Thunderstorm chances increase Friday, with a threat for
   strong to severe thunderstorms Friday evening. The greatest
   threats will be large hail and damaging winds.

-  Additional rounds of thunderstorms are expected into the weekend
   and early next week. Though confidence remains low for now,
   a threat for severe thunderstorms looks to persist across
   portions of western and north central Nebraska into early
   next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 355 PM CDT Wed Jun 12 2024

Currently, a surface trough is pushing through the area from
northwest to southeast, and is located from near Hayes Center to
Broken Bow to just west of O`Neill. Deep mixing behind this front
has led to temperatures warming into the upper 90s across southwest
Nebraska, with upper 80s to low 90s further north and east. Dry air
is also filtering into the area in the wake of a surface trough,
keeping heat index values limited to the middle to upper 90s. Still,
this will keep concerns for heat related illnesses elevated into
this evening.

By tonight, a cool front will begin to push through the area,
reaching the I-80 corridor near sunrise tomorrow morning. Dry
conditions are expected to persist into this evening, before
convection (currently initiating over the high terrain of
Wyoming) could survive the trek through the Panhandle into far
western Nebraska. This is low confidence, and should any
precipitation survive it will be quickly weakening and also
battling very dry air (dewpoint depressions ~20F). Still, enough
guidance at least suggests this will survive to near the HWY 61
corridor to introduce 15-20% POPs early tonight. Little to no
impacts are expected with this activity. Lows overnight remain
mild in the middle 50s to the middle 60s, with the
aforementioned cool front promoting mechanical mixing of the
boundary layer.

For tomorrow, the cool front will finally clear the area to the
south into early afternoon, with northeast winds expected in its
wake. Will have to monitor the potential for thunderstorm
development in advance of the front, primarily for areas near and
south of HWY 6. However, the front looks to be fast moving enough to
keep the bulk of convection to the south of the area, and confidence
continues to wane in a threat for thunderstorms tomorrow afternoon.
Temperatures will also be cooler in this post-frontal airmass,
with highs in the middle to upper 80s across the area.

&&

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
Issued at 355 PM CDT Wed Jun 12 2024

For Friday, the cool front is anticipated to stall across northern
Kansas Thursday, then lift northward into Friday afternoon as a warm
front. This is in response to an upper shortwave ejecting northeast
across the Northern Rockies, with increasing surface cyclogenesis
noted across eastern Colorado. Convection looks to occur in two
rounds, first Friday morning into the afternoon with the northward
advancing warm front. This will primarily be elevated in nature, and
could pose at least some risk for hail amid steep mid-level lapse
rates and increasing deep layer shear. The next will come by late
Friday evening, as broad southeasterly flow increases dewpoints into
the low/mid-60s. This, combined with warming temperatures should
help to erode lingering CIN across northeast Colorado, where
convection should initiate in advance of the aforementioned
deepening surface low. Guidance continues to hint at quick
upscale growth with this activity as it lifts northeastward into
southwest Nebraska late Friday evening, with a primary threat
for damaging winds. The threat for large hail will likely be
muted somewhat, though cannot be completely ruled out given
given the CAPE/shear overlap. This will likely be maximized on
the southern end of any line segments, where updraft seeding can
be minimized. Some threat of warm sector supercell initiation
does exist as well further northeast, though guidance continues
to trend towards a more diffuse warm frontal zone and less
surface convergence across southern/southwest Nebraska. This
will continue to be monitored, though confidence is waning some
in any convection ahead of any line segments entering the area
from northeast Colorado.

Additional convective chances look to persist into this weekend and
early next week, though confidence remains low due to positioning of
mesoscale boundaries. This will influence the greatest zones of
severe potential, and previous day convection will likely play a
role as well. Still, some guidance solutions point towards a warm
frontal boundary positioned across the area Sunday and into Monday,
which would focus a threat for strong to severe thunderstorms
each day. Will also have to watch for the potential for heavy
rainfall along said boundary, with limited forward boundary
motion possible. To add to this threat, forecast soundings
suggest very slow storm motions, and training thunderstorms
could realize a localized flash flooding threat late this
weekend and early next week. Temperatures look to remain near to
slightly above average into early next week, before a more
substantial frontal passage brings a return of below average
highs into the middle of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
-- Changed Discussion --
Issued at 1139 PM CDT Wed Jun 12 2024

VFR ceilings will continue through Thursday evening with some high
level cirrus being the only concern. Some stronger winds are
possible during the day, though, across the entire region. Gusts up
to 25 to 30 knots will be possible before diminishing by late
afternoon to early evening.
-- End Changed Discussion --

&&

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

&&

$$

SHORT TERM...Brown
LONG TERM...Brown
AVIATION...Kulik