788
FXUS63 KLBF 020929
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
429 AM CDT Thu May 2 2024

.KEY MESSAGES...

- A break from the rain today, before precipitation chances
  return tomorrow, late this weekend, and into early next week.

- Very gusty winds this afternoon, especially across the Sandhills,
  where gusts could exceed 40 miles per hour. Elevated fire
  weather conditions expected across the western Sandhills and
  Panhandle this afternoon.

- Temperatures remain near seasonal through the weekend into
  next week.

&&

.SYNOPSIS...
Issued at 425 AM CDT Thu May 2 2024

Upper air analysis and satellite imagery show a upper level trough
over Wyoming, with another shortwave off the coast of Washington. A
line of showers and thunderstorms are observed over eastern
Nebraska and eastern Kansas. At the surface, a low pressure system
is located over north central Kansas, with a warm front extending
along the Kansas-Nebraska state border and a cold front sweeping back
across the Oklahoma Panhandle. A second low pressure system is
located over western South Dakota, with a cold front extending
through the Nebraska Panhandle to near Denver, Colorado.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 425 AM CDT Thu May 2 2024

The cold front across the Panhandle will continue to push east this
morning and afternoon. The cold front is relatively dry in nature,
which will contribute to lowering relative humidity this afternoon
as well as clouds clearing out behind the front. Not expecting too
much impact to temperatures with this front, as temperatures are
generally expected to be in the 60s across the region this
afternoon. As the cold front passes through the region, winds will
shift from the northeast, and have potential to become quite gusty.
In fact, the environment looks very similar to Tuesday this week,
where strong gusts were observed across western and north central
Nebraska. BUFKIT soundings this morning show a very strong potential
for deep mixing this afternoon, with potential for winds around 600
mb to mix down to the surface. This will also help contribute to the
dry out behind the front, as much lower humidities in the upper
levels are mixed down. Given the very similar set up to Tuesday,
went ahead and trended up winds and wind gusts this afternoon. The
prime locations for strongest mixing appear to be over the Sandhills
and portions of north central Nebraska, where gusts could very well
exceed 40 miles per hour this afternoon. Further to the east,
roughly along a line from Hayes Center to O`Neill, the forecast
soundings still show prolific mixing, but not quite to the
extent across the Sandhills. Expect that in these areas, gusts
could exceed 30 miles per hour.

With the combination of low relative humidities and strong wind
gusts this afternoon, elevated fire weather conditions are possible
across the Panhandle and western Sandhills this afternoon. Of most
concern will be areas that have not received as much rainfall in the
past few storms. As the evening sets in, the boundary layer will
begin to decouple, allowing surface winds to calm.

For Friday, the shortwave currently off the coast of Washington will
have trekked eastward over Wyoming, generating another low pressure
system and associated cold front. As this system forms, a plume of
moisture advection is expected ahead of the system, setting the
stage for another round of rain and thunderstorms.  Latest CAM
guidance is in generally solid agreement for storms to form in the
afternoon across the Panhandle and sweep across Nebraska  throughout
the day. As for the severe weather potential, there is still a bit
of uncertainty in the models, particularly in how much CAPE will be
available in the environment. For now, the Storm Prediction Center
has southwest Nebraska in a Marginal risk for Friday, with wind and
hail being the primary concerns at this time. This is likely to be
further refined as models come into better consensus on fine details
in the environment. Additionally, the Weather Prediction Center has
placed a Marginal risk for Excessive Rainfall across southwest
Nebraska. Given the decent plume of moisture ahead of the storm
system, these storms could be prolific rain producers, so locally
heavy rainfall is also expected with these storms Friday afternoon
into Saturday morning.


&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 425 AM CDT Thu May 2 2024

As the storms move out to the east Saturday morning, a low amplitude
ridge is expected to set up over western Nebraska. This will provide
another slight break in the rain over the weekend. However, the
break is not a long lasting one. A deeper upper level trough begins
brings another low pressure system, generating more chances of
showers and thunderstorms Sunday afternoon.

As the upper level low deepens, the main question will be where the
low and upper air dynamics set up on Monday. There is general
agreement in the low being over Wyoming/western Nebraska, but some
variation remains in the placement of the upper level jet streaks.
However, with the upper level support and expected track of the
surface system, Monday looks promising for additional rain and
thunderstorms. The Storm Prediction Center is already highlighting
portions of north central, central, and eastern Nebraska in a 15
percent chance for severe weather on Monday. At this time, there
remains some question on the type of severe threat, as a lot depends
on how the models begin to resolve some of the finer scale features.
Given the potential set up, though, it will be well worth keeping an
eye on how this system develops.

Beyond Monday, the upper level low is expected to track over the
Dakotas, bringing the area under the influence of an upper level
trough. Precipitation chances are not looking too robust at this
time, generally less than 20 percent on Tuesday. Ensemble guidance
does suggest potential for some showers Wednesday into Thursday,
around 30 percent, but those numbers drop off to around 10 percent
for amounts greater than one tenth of an inch. Temperatures for this
period look to remain around seasonal, with highs generally in the
60s and to low 70s.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1240 AM CDT Thu May 2 2024

Poor flight conditions early, then improving to VFR Thursday
morning with potential for gusty winds.

Low pressure passing by to our southeast will pull the lingering
precipitation eastward with it. KVTN is already on the backside
of the precipitation and expect KLBF will also be in about
another 2 hours. However as the precipitation ends, the boundary
layer will stratify and low clouds/fog will develop with
IFR/LIFR conditions expected at TAF sites thorugh daybreak,
though improvement will be rapid with a return to VFR later
Thursday morning. VFR conditions will then persist through the
end of the valid period.

Winds will generally be light overnight, then become
westerly/northwesterly by midmorning with gusty conditions
developing. There is a lot of wind at the top of the mixed layer
that may reach the surface if mixing is deep enough, so will be
watching closely to see how the clearing and heating develop
this morning. For now will keep gusts at 30kt for KLBF and 35kt
at KVTN this afternoon, but if mixing is robust and allows
winds to reach maximum potential, could be looking at gusts 10kt
or more above the current TAF values this afternoon especially
at KVTN.

&&

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

&&

$$

SYNOPSIS...Richie
SHORT TERM...Richie
LONG TERM...Richie
AVIATION...MBS