392
FXUS63 KLBF 061724
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1224 PM CDT Thu Jun 6 2024

.KEY MESSAGES...

-  Dry conditions persist again today, with temperatures
   slightly cooler than yesterday with the area behind a cool
   front.

-  Scattered thunderstorms are expected to form along a frontal
   boundary Friday afternoon, with a threat for large hail and
   damaging winds. Though the threat appears low, a tornado
   cannot be ruled out as well.

-  Additional thunderstorm chances will persist into the
   weekend and early next week, though the threat for any severe
   weather is uncertain.

-  Increasing temperatures are expected for the middle of next
   week and beyond, with widespread 90s and increased heat
   concerns possible.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 407 AM CDT Thu Jun 6 2024

For today and tonight, the area will remain under the influence of
an upper ridge, centered over the southwestern CONUS. Height rises
and increasing subsidence aloft should keep skies clear again today
across the area. Today has the markings aloft of another very warm
day (H5 heights ~90th percentile climo), though the area will remain
post-frontal this afternoon with a backdoor cool front draped across
northeast CO into northern KS and southeast NE. Weak cold advection
behind this boundary will keep highs in the low to middle 80s this
afternoon, as much as ~5 degrees cooler than yesterday. By this
evening, a surface high will begin to migrate eastward across
western Nebraska, dropping into eastern KS/western MO by late
tonight. As this surface ridging exits the area, southerly flow will
quickly redevelop across the area in its wake. Increasing warm
advection overnight will keep lows more mild tonight, in the middle
to upper 50s across southwest Nebraska.

The southerly flow continues into tomorrow, with increasing lee
cyclogenesis noted across the high terrain to the west into tomorrow
afternoon. During the morning hours tomorrow, a warm front is
expected to lift through the area, with a threat for scattered
showers and thunderstorms primarily north of HWY 2. These showers
and thunderstorms are expected to exit the area through late
tomorrow morning and pose little to no severe threat.

By tomorrow afternoon, a surface low will slide into northern
Nebraska and will need to be monitored for redevelopment of
convection. Though subtle differences remain in guidance solutions
with respect to precise placement, the majority show the same basic
evolution. This evolution drapes a warm front across the northern
Sandhills by mid-afternoon, with a triple point somewhere in the
vicinity of HWY 27/HWY 61 across the western Sandhills. A surface
trough then extends southward from the surface low through southern
Panhandle and into northeast Colorado. In the warm sector across
much of southwest and central Nebraska, continued southerly flow
will advect richer boundary layer moisture into the area through the
afternoon, with dewpoints expected to climb into the upper 50s to
low 60s. Aloft, a subtle shortwave trough will progress around the
northern periphery of the upper ridge axis, crossing southwest
NE/northeast CO during the late afternoon. This will both augment
the mid-level wind fields (lengthening hodographs) and steepen lapse
rates aloft. This will both increase deep layer shear (to
~40-45kts) and instability, with more bullish solutions
suggesting MLCAPE values >2500 J/kg. As convergence increases
along the aforementioned surface boundaries (especially
near/ahead of the surface triple point), at least scattered
convective initiation is anticipated by mid/late afternoon.
Winds fields support an initial supercellular storm mode, albeit
somewhat high based given large T/Td spreads and resultant high
LCLs. This could lead to some propensity for storms to become
more outflow dominant, though confidence in this is low
initially. The exception to this would be in vicinity of the
surface warm front, where moisture pooling could lead to more
favorable T/Td spreads and lower LCLs locally. Additionally,
backed east- southeast surface flow could lead to a narrow
corridor of increased tornado potential, and the positioning of
this boundary will need to be monitored closely. The main
hazards for much of the area looks to be large hail initially,
with ample instability below 0C, straight and long hodographs in
the mid- levels, and somewhat favorable mid-level storm
relative winds to limit updraft seeding. The longevity of the
hail threat will be determined on how quickly storms can form
cold pools, where after damaging winds will become more common.
Forecast soundings show good inverted-v thermodynamic profiles,
suggesting ample sub-cloud layer evaporation and more than
adequate DCAPE for strong outflow winds. At least some threat
for significant damaging winds would exist should cold pool
formation occur through late afternoon. Storm scale interactions
will likely drive the corridor of greatest damaging wind threat,
and this will remain low confidence until tomorrow afternoon
more than likely. That said, a growing number of high-res
guidance solutions suggest this threat would be maximized across
central Nebraska as storms initiating along the triple point
and warm front grow upscale and drop southeast.

Storms will quickly exit the area through sunset, ending the threat
for severe weather locally. Lows tomorrow night fall into the 50s
again in the post-frontal airmass.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 407 AM CDT Thu Jun 6 2024

The area will remain post-frontal Saturday, with the threat for
strong to severe storms largely remaining off to the south. Still,
some threat for showers and thunderstorms could exist Saturday
afternoon as post-frontal low level upslope flow could lead to
thunderstorms off the high terrain. Near daily thunderstorm chances
will then continue through the weekend and into early next week.
Placement of mesoscale boundaries and associated instability will
drive the degree of threat each day, and confidence remains low for
this reason in severe weather. BY midweek, upper ridging will begin
to amplify across the southern Plains, leading to much warmer
temperatures and a lesser threat for thunderstorms locally. In fact,
widespread highs in the 90s look to enter the forecast for
Wednesday, and persist towards the end of next week. This could also
lead to the first round of heat concerns this season, and will need
to be monitored closely for potential impacts.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1223 PM CDT Thu Jun 6 2024

Across western and north central Nebraska, skies will remain
mostly clear through the overnight hours. Some higher clouds
will develop over northern Nebraska late tonight into Friday
morning as isolated thunderstorms are possible over northwestern
Nebraska. ATTM, this activity is expected to remain west of the
terminal. More organized thunderstorm activity is expected to
develop Friday afternoon and may impact both terminals after 20z
Friday. Some of this activity may be severe with large hail and
damaging wind gusts.

&&

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

&&

$$

SHORT TERM...Brown
LONG TERM...Brown
AVIATION...Buttler