425
FXUS63 KLBF 200605
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
105 AM CDT Mon May 20 2024

.KEY MESSAGES...

- Showers and thunderstorms continue to push through the area
  tonight, with some thunderstorms remaining strong to severe.
  Thunderstorm activity picks up again Monday evening continuing
  through Tuesday morning, bringing another round of
  potentially severe weather.

- Heavy rainfall will be possible with thunderstorms Monday
  night into Tuesday morning, with widespread amounts greater
  than 1 inch likely across most of the forecast area.

- A mid week cool off brings a limited threat for frost, with
  the most likely area for frost across portions of the
  Panhandle.

- The pattern remains active through the week, bringing near
  seasonal temperatures and chances of precipitation throughout
  the week. &&

.SYNOPSIS...
Issued at 349 PM CDT Sun May 19 2024

Upper air analysis and satellite imagery this afternoon place an
upper level shortwave across the Montana-North Dakota border, with a
deeper trough over western Oregon. At the surface, a low pressure
system is located over western South Dakota, with a warm front
extending through the Nebraska Panhandle. On satellite, a few
pronounced thunderstorms are noticed over south central Nebraska
and north central Kansas, with another developing line of
thunderstorms over the Nebraska Panhandle.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 349 PM CDT Sun May 19 2024

Ongoing convection over the Panhandle will continue to push east
through the evening, with the potential for severe thunderstorms
capable of producing large hail and damaging winds. As such, a
Severe Thunderstorm Watch is in effect until 02Z for areas
primarily along and south of Highway 83.

Convection will continue through late this evening, when latest
guidance has storms weakening out around midnight. After the
storms tonight, a brief but relatively calm period settles in
overnight through Monday afternoon. Guidance has cooled off a
bit for Monday`s high temperatures, so have followed suit and
trended temperatures down slightly. High temperatures should
still remain near seasonal, but on the cooler side of
climatology. By Monday afternoon, another round of showers and
thunderstorms is expected to form along the Nebraska Panhandle
and begin pushing eastward.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 349 PM CDT Sun May 19 2024

As showers and thunderstorms progress eastward tomorrow evening,
another round of severe weather will be possible. Current forecast
soundings seem quite supportive of large hail and damaging wind
gusts. The Storm Prediction Center has included most of southwest
Nebraska and portions of the southern Sandhills in a Slight Risk for
severe weather tomorrow. Of concern are the areas along southwest
Nebraska, where the SPC is identifying the potential for 2 inch hail
and 70 mile per hour wind gusts.

On top of the severe weather potential tomorrow evening, heavy rain
will be possible with thunderstorms across the region. Precipitable
Water values continue to be forecast in the 90th percentile across
the region. The heavy rain potential also continues to be
highlighted in the ECMWF Extreme Forecast Index and Shift of Tails,
indicating higher confidence in an anomalously high rain event.
Continued to agree with Weather Prediction Center guidance, which
continues to bring at least 1 inch of rain across most of the
region, with an area across the Sandhills up to 2.5 inches. Given
the convective nature of the expected system and the anomalously high
PWATs, would not be surprised if a few areas reported 3 inches or
greater. WPC continues to highlight an area from southwest Nebraska
to northeast Nebraska with a Marginal risk for Excessive Rainfall,
so will definitely be worth watching.

Another shot of cool air invades the area Tuesday night into
Wednesday morning. Of potential concern will be overnight low
temperatures across the Panhandle Wednesday morning. Guidance
generally maintained temperatures, however some of the lower end
guidance brings temperatures that would be conducive to frost. Still
feel the threat for frost remains on the lower side, but cannot rule
out the potential that frost may be observed in portions of the
Panhandle Wednesday morning.

The upper level pattern remains fairly active, with several
shortwaves forecast to impact the region through the end of the
week. Chances of precipitation remain through the end of the week,
though there may be a bit of a dryer period Wednesday afternoon into
Thursday afternoon, when PoPs do not currently exceed 30 percent.
Temperatures should remain fairly seasonal with the active upper
level pattern.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 101 AM CDT Mon May 20 2024

VFR conditions are likely through the bulk of the valid forecast
period. Main aviation concerns will focus on transient, shallow
fog early in the period followed by gusty winds during the
daytime and then the threat for rain and thunderstorms late.

Shallow fog has floated around the LBF terminal. Forecast
soundings show very shallow moisture near the surface but this
is expected to shift east closer to sunrise as winds increase
out of the north. Winds will gradually veer to easterly during
the daytime with gusts increasing to 25 to 30 knots as they do.
Eventually rain and thunderstorms will move in from the west.
Timing of this is medium confidence at this time with 1-2 hour
difference in various short-term guidance at this time. For now,
will hedge towards the mean value with adjustments possible
later. Convection will likely contain gusty erratic winds and at
least MVFR visibility reductions. Further degraded conditions
are possible but will hold off on including at this time.

&&

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

&&

$$

SHORT TERM...Richie
LONG TERM...Richie
AVIATION...NMJ