147
FXUS63 KLBF 240521
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1221 AM CDT Mon Jun 24 2024

.KEY MESSAGES...

- Dangerous heat mainly across eastern and south central Nebraska on
  Monday as afternoon heat index values rise above 100 degrees.

- Potential for strong to severe thunderstorms Monday across
  central and western Nebraska from late in the afternoon into
  the evening.

- Unsettled weather mid to late week with potential for showers
  and thunderstorms, some with locally heavy rainfall,
  especially along and south of Hwy 2.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 355 PM CDT Sun Jun 23 2024

Satellite imagery shows little in the way of cloud cover across
central and western Nebraska this afternoon as the convective cap
holds firm over unstable air east of Highway 83 and the approaching
dry line lacks enough forcing to break the cap. Behind the dry
line low level moisture is not sufficient to support significant
instability in the well mixed hot, dry boundary layer. While an
isolated thunderstorms is not out of the question across south
central Nebraska this evening, anticipate we will remain dry
through tonight as deep convection firing over Kansas slides by
to our southeast. Will monitor radar trends closely and adjust
the forecast if convection to our south pushes further north
than expected. Lows tonight will generally be in the mid to
upper 60s.

We start off the workweek tomorrow with hot temperatures as
afternoon readings rise well into the 90s with some triple digits
along and south of I-80. The heat and humidity will create dangerous
heat index values over 100 degrees late in the day mainly from
near Imperial,through North Platte and Broken Bow, to Stuart and
Naper eastward, so heed the Heat Advisory and stay cool,
hydrated, and be alert for signs of heat illness.

The convective environment appears to be slightly more conducive
to thunderstorm development tomorrow as a trof moves across
southern Canada and helps push a weak cold front into Nebraska
during the afternoon. Ahead of the front, the dry line will make
a bit more progress than today limiting the best instability
further east toward the Hwy 183 corridor. While the cap will be
weaker expect the more pronounced dry air will keep convective
coverage sparse especially west of Hwy 83, with potential for
better coverage in the more moist unstable air to the east. The
question in the east is how far east will any convective
initiation take place before activity moves off further to the
southeast and out of our area. Mesoscale guidance currently
paints a picture around the edges confining the sparse
convection to locations generally along/east of Hwy 183,
along/south of I-80, and along/west of Hwy 61 with little over
the heart of the sandhills. Not taking these solutions literally
but the overall flavor looks to be on target for late tomorrow
afternoon into the evening.

Any storms that do manage to form will be in a hot and deeply
mixed boundary layer with a notable inverted-v evident in
Bufkit model soundings indicative of efficient wind production
and potential for strong wind gusts. Better potential for large
hail looks to be confined further to the northeast where
moisture and instability will be greater and 0-6km bulk shear
around 40kts will help organize cells though shallow angle of
flow relative to the boundaries points to a rapid transition
from any discrete storms to clusters/segments as they exit to
the southeast. Any lingering convection will dissipate early
Monday night with dry conditions for the overnight and
temperatures by daybreak Tuesday generally in the low to mid
60s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 306 PM CDT Sun Jun 23 2024

The High Plains will remain downstream from an amplifying upper
ridge over the Rockies. Ensemble guidance shows high pressure at
the surface settling down into the Great Lakes region with
southerly flow helping to increase moisture during the latter
portion of the workweek. Precipitable water values will rise
well above the the 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 mainly south of Hwy 2 ahead of
a cold front expected to cross the region Thursday night into
Friday.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1220 AM CDT Mon Jun 24 2024

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

The main flight concern will be isolated to perhaps scattered
SHRA/TSRA development 21z-03z Monday aftn/evening and this storm
activity is most likely to develop across areas of scntl
Nebraska east of highway 83. Isolated convection may develop
elsewhere.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM CDT /noon MDT/ this afternoon to 8 PM
CDT /7 PM MDT/ this evening for NEZ007-010-027>029-038-059-
069>071.

&&

$$

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