552
FXUS63 KLBF 310522
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1222 AM CDT Fri May 31 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 SATURDAY/...
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 NIGHT THROUGH THURSDAY/...
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 /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1222 AM CDT Fri May 31 2024

The latest CAMS develop some thunderstorms from the panhandle
east into the Sandhills and southwestern Nebraska overnight. Not
sure how this will materialize given the ongoing convection
across southern Nebraska. For now, decided to handle the
thunderstorm threat with a vcts group for the KLBF terminal from
09z to 15z. For the remainder of today, scattered to broken
ceilings ranging from 2000 to 4500 FT AGL are expected at KLBF.
For the KVTN terminal: Expect scattered to broken clouds today
with ceilings generally ranging from 6000 to 8000 Ft AGL.

&&

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

&&

$$

SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Buttler