299
FXUS63 KLBF 141750
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1250 PM CDT Sat Jun 14 2025

.KEY MESSAGES...

- The threat for strong to severe thunderstorms continues each
  day Saturday through Tuesday with a Slight Risk (Level 2 of
  5) in effect each day.

- In addition to severe weather, the threat for heavy rain will increase
  by early next week with probabilities of exceeding 1.0" for a
  72-hour window ending Wednesday morning in the 50-70% range.

- Well above normal temperatures appear probable for the latter
  half of the week with probabilities of exceeding 90F daytime
  highs reaching 75%+.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 406 AM CDT Sat Jun 14 2025

Early morning satellite shows expansive upper-level cloud cover
across much of western Nebraska. This is the remnants of strong to
severe thunderstorms that moved through far western Nebraska late
Friday night. Radar analysis shows lingering stratiform
precipitation over southwest Nebraska tied to a passing MCV. Further
north, isentropic lift will helping produce scattered showers and
general thunderstorms along and north of Highway 20. Modest lift
should continue over the next few hours before waning around
daybreak Saturday.

For Saturday...south to southeasterly flow will continue through the
day which should promote increasing low-level moisture advection
into the area as a warm front lifts north out of the Sandhills and
into far southern South Dakota. Off the surface, warming low and mid-
level temperatures will maintain an appreciable capping inversion
across the region and keep the afternoon hours dry. Eventually,
increasing convergence invof of the frontal boundary extending south
and west towards the increasing upslope forcing will promote
scattered thunderstorm development by early evening. Similar to
Friday, daytime highs will range from the middle 80s to lower 90s
with ample low-level moisture as dew points climb into the middle
60s. This will allow for strong destabilization with most unstable
CAPE values likely exceeding 3000 j/kg for most locations west of
Highway 83. With westerly mid-level flow of 20-30 knots, deep layer
shear should again be adequate for organized strong to severe
thunderstorms. Forecast soundings suggest MU parcels rooted around
h7 with large LI values nearing -10C. This suggests fairly strong
updrafts capable of large hail. What appears likely, however, is the
window for discrete storm mode appears to be quite brief. Storm
mergers from a growing cold pool should foster quick upscale growth
with storms moving into an environment supportive of damaging wind
gusts yet again: Downdraft CAPE values exceeding 1200 j/kg and 0-3km
max theta-e differences falling below -30C. Latest HRRR and NAM Nest
suggest storms developing 4-6pm CDT well west of the forecast area
and propagating east-southeast. Timing appears to favor arrival as
early as 7-9pm CDT for our western zones and quickly shifting west
to east through the area by late evening and early Sunday morning.
Leaned on NAM Nest/HRRR/HREF blends for PoPs which paint expansive
20%+ across the forecast area and highest amounts of 60-65% across
the northern Sandhills during the evening. Expectation is severe
hail up to 1.75" possible with damaging wind gusts up to 70 mph
being the main concerns. While a tornado cannot be fully ruled out,
weak 0-1km shear with increasing surface based CIN should preclude
greater concerns. While heavy rain will again be possible, the quick
progression of activity and lack of training storms should limit
rainfall to 0.50-1.00" with locally higher amounts closer to 1.50".
Expect dry conditions to return swiftly to most locations by early
Sunday morning. Low temperatures should fall into the upper 50s to
lower 60s.

For Sunday...a near identical setup is expected for Sunday as seen
Saturday with precipitation chances increasing through the late
afternoon but peaking in the evening. This is again likely as mid-
level ridging continues to build in, leading to increasing
subsidence aloft and increasing low and mid-level temperatures favor
a strengthening cap. Storms will likely develop invof a warm front
stretching west to east across South Dakota as well as southeastern
Wyoming as moist upslope flow again yield orographic lift strong
enough to overcome the lack of stronger synoptic forcing. Given
afternoon highs in the middle 80s to lower 90s yet again with rich
low-level moisture characterized by dew points in the lower 60s,
moderate to strong destabilization is again likely. Storms should
largely favor late afternoon development west of the area and
eventually track into the forecast area for the evening hours. Deep
layer shear will approach 25-35 knots which should support
supercells capable of large hail and damaging winds but quick
upscale growth again appears probable. Large hail and damaging winds
will again be the main concerns with the time frame of concern
generally being 8pm-2am CDT.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 406 AM CDT Sat Jun 14 2025

Active weather continues into the early part of the work week. Ridge
axis appears set to arrive onto the High Plains by early Monday with
ridge breakdown taking place through the day. Broad troughing
arrives onto the West Coast and will quickly translate east into the
Central Rockies by early Tuesday. At the surface, a frontal boundary
will stall across northern Nebraska and steady southerly flow across
the warm sector will promote rich moisture advection into the
boundary. While some discrepancies remain regarding magnitude of low-
level moisture, NAM/ECWMF output suggests dew points climbing into
the low 70s. This coincides with PWAT anomalies of nearly 125-150%.
Strong instability will again develop with mid-level flow largely
parallel to the surface boundary. Deep layer shear will support
organized convection with fairly expansive thunderstorm coverage as
upper-level forcing increases ahead of the approaching trough. This
will likely lead to the potential for training storms along the
boundary and the threat for heavy rain. Early in the storms` life
cycles, large hail and damaging wind gusts appear to be the main
concerns but heavy rain will likely to fairly prevalent across the
area. NBM higher percentile output suggests heavy rain potential
Monday evening into early Tuesday with EPS/GEFS probabilities of
seeing > 0.50" rain around 40-60%. Convection should push the
frontal boundary south towards Interstate 70, placing much of
Nebraska within the cooler easterly flow under expansive cloud cover
and precipitation chances. While steep mid-level lapse rates with
enhanced mid-level flow remains in place, it appears that the
greatest magnitude of instability will remain south across Kansas
and it`s here that I expect the greatest severe weather threat to
reside. Will need to monitor this potential going forward. Heavy
rain potential continues Tuesday into Wednesday but by now, the
favored areas will reside across eastern Nebraska with decreased
probabilities of seeing > 0.50" for the 24 hour period Tuesday into
Wednesday. ECMWF Extreme Forecast Index (EFI) values continue to
highlight greater anomalies for Tuesday than Wednesday and I don`t
see anything to support straying from this thinking. For the whole
event spanning 72 hours ending Wednesday morning, probabilities of >
1.0" rainfall peak 60-70% east of Highway 83 and probabilities of >
2.0" reach 30% for these same areas. The WPC highlights the area in
Marginal Risk excessive rainfall outlooks and believe potential
exists to see this category increased with subsequent forecasts.
Following the cooler days Tuesday and Wednesday with highs in the
70s and 80s, temperatures look to quickly rebound by late week. This
is due to amplifying ridging returning to the Central and Southern
Plains. EFI values for temperatures, both daytime and overnight,
surpass 0.5 suggesting slight anomalies for mid-June. Shift of Tails
values are negligible across the local area with non-zero values
limited to the Plains across eastern Colorado. The current forecast
with highs returning to the 90s hugs the lower range of the NBM
forecast envelope so further increases in the coming days appears
possible. Even so, forecast highs for both North Platte and
Valentine appear set to reach higher percentile values in their
respective climatology`s (75th percentile or higher by Thursday).
The return to abnormal warmth appears likely to persist through the
end of the month with the latest CPC outlook suggesting fairly high
warm biases in the latest 6-10 Day and 8-14 Day Outlooks.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1239 PM CDT Sat Jun 14 2025

High clouds will gradually thin from the west this afternoon.
Thunderstorms are likely to move into western Nebraska this
evening, then weaken as they move into southwest Nebraska
after midnight. Seeing some signal for potential low clouds and
MVFR/local IFR across portions of the southern Sandhills and
southwest Nebraska Sunday morning. Confidence is not high enough
to include in the TAF at this time due to the potential
thunderstorm activity tonight.

&&

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

&&

$$

SHORT TERM...NJ
LONG TERM...NJ
AVIATION...BT