637
FXUS63 KLBF 301949
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
249 PM CDT Thu May 30 2024

.KEY MESSAGES...

- Locally heavy rainfall may develop in a few areas of swrn and
  ncntl Nebraska tonight. Isolated severe wind gusts are also
  possible.

- Severe weather is possible Friday, Saturday and Sunday but the
  chances Friday are mainly across far swrn Nebraska and the srn
  Panhandle. The chances Sunday are across far ncntl Nebraska.
  Saturday will be the most likely day for severe storms,
  potentially affecting a good portion of wrn Nebraska from
  about 4 pm CDT onward.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 238 PM CDT Thu May 30 2024

Winds aloft are very weak this afternoon, 10-20kts at h500-300mb.
Meanwhile, moisture is pooling ahead of a cold front across
ncntl/swrn Nebraska leading to PWAT above 1 inch. The CAMs are
signaling asynoptic southwest storm development with storms firing
across ncntl Nebraska this afternoon and building, or developing
southwestward into swrn Neb this evening. The southward moving cold
front will be close behind marking an end to sfc based storm
development.

In a nutshell, locally heavy rainfall is possible in spots. The
NANnest is showing a 4-inch total near Sargent by 00z with several 3
inch totals further south, all localized, by 06z tonight. Given the
4.3 inch total reported in Sherman county this morning by WFO GID,
discrete southwestward developing storms producing locally heavy
rainfall would appear to be operative storm mode late this afternoon
and tonight.

A check on BUFkit shows a plume of dry air in the midlevels moving
in from the west. This could lead to the demise of a thunderstorm
and cause damaging wind gusts at the same time. Such was the cause
near KVTN last night with a recorded gust to 79 mph.

The POP forecast tonight leans toward the aggressive CAMs but
limits POPs to 50 percent.

The aforementioned cold front will be located across nrn KS Friday
morning and then lift north as a warm front Friday and Friday night.
Most model solutions offer little opportunity for rain during
this time but the RAP and HRRR sense upper level support moving
through the Rockies and moisture at the lower levels. The result
is at a minimum, periods of drizzle or light across wrn
Nebraska Friday into early Saturday morning with the potential
for showers and thunderstorms associated with the upper level
support.

SPC suggested severe weather concerns late Friday for an upscale
thunderstorm complex emanating off the Colorado Front Range and
the Cheyenne Divide. The slight severe weather risk brushes a
small portion of southwest Nebraska.

Given the wide range of model solutions Friday and Friday night, the
POP forecast leans on SPC and WPC for guidance. POPs are less than
40 percent.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 238 PM CDT Thu May 30 2024

Additional opportunities for severe weather are Saturday and
Sunday. Forecast solutions, in terms of storm coverage Saturday,
range from the potential for upscale growth in the NAMnest to a
more singular severe storm complex in the NAM12 to nearly
nothing in the ECM. The ECM shows the storms remaining mostly in
Colorado. Western Nebraska will be in the warm sector so it is
likely the model differences are a result of differences in the
location of the low level focus and upper level support shown in
the models. Later forecast will resolve this. As it stands now,
the NAM shows 40-50kt h500-300mb winds pushing into wrn
Nebraska Saturday afternoon, effective shear 40 to 60kts and 21z
MLCAPE around 2500J/KG. This would certainly support severe
storm development with swrn Nebraska and the srn Panhandle the
favored location.

The situation Sunday becomes more uncertain as the models focus
convection as far north as ND and MN in the NAM to cntl Nebraska in
the ECM. Regardless, winds aloft will be strong, 30-40kts at h500-
300, effective shear is 40-50kts and MLCAPE 1500-2000 J/KG,
according to the NAM. This would support an isolated severe storm
potential; the BRN is 35 or less.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1243 PM CDT Thu May 30 2024

A low pressure system and slow moving cold front are working across
western and north central Nebraska this afternoon. Along the front,
lower ceilings are observed, though most remain VFR to some MVFR
locations. Showers and thunderstorms will also be possible along
this front, though the greater concern seems to be along a line east
of KVTN back through KLBF. For that reason, will omit thunder from
KVTN for now, and leave VCTS mention at KLBF as thunderstorms will
be likely in the vicinity of the terminal overnight. Expect that
around thunderstorms, ceilings may drop into IFR conditions, with
lower ceilings lingering through tomorrow afternoon at KLBF. Winds
become northeasterly behind the frontal passage, and may see swings
of greater than 30 degrees, though primary direction will be
northeasterly.

&&

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

&&

$$

SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Richie