221
FXUS63 KLBF 182034
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
334 PM CDT Wed Sep 18 2024

.KEY MESSAGES...

- Critical fire weather conditions continue this evening across
  northwest Nebraska, where a Red Flag Warning remains in
  effect. Dry and windy conditions across western and
  northwestern Nebraska on Friday may introduce another chance
  of elevated to near critical fire weather concerns.

- A cooler, wet weekend is expected as a slow moving upper
  level system brings potential for a steady rainfall this
  weekend.

- Cooler temperatures Sunday and early next week, with highs
  generally at or below seasonal averages.

&&

.SYNOPSIS...
Issued at 332 PM CDT Wed Sep 18 2024

Upper level analysis and water vapor satellite imagery place an
upper level low over the Montana-North Dakota border, with another
upper level low off the central California coast. At the surface, an
occluding low pressure system is located over eastern Montana, with
a cold front extending through the Dakotas into southwest Nebraska.A
secondary low is located over southwest Nebraska, with another cold
front through the Oklahoma and Texas Panhandles. On satellite,
cumulus clouds are observed along and east of a line from roughly
Hayes Center to North Platte to O`Neill. Some additional high clouds
are observed over the Nebraska Panhandle and the Pine Ridge.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 332 PM CDT Wed Sep 18 2024

Dry, mild, and windy conditions continue across northwest Nebraska
through the evening hours, keeping the Red Flag Warning is place
through 9 PM CDT/8 PM MDT. Overnight humidity recovers to around 50
to 60 percent near the Pine Ridge, but most helpful will be the
calming of the surface winds. As the boundary layer decouples later
this evening, surface winds should calm to around 10 mph, which will
ease fire weather concerns for the night.

The cold front will continue to slowly track east throughout the
night, with temperatures behind the front expected to drop into the
50s overnight. Ahead of the front, overnight lows in the lower 60s
are expected. Similar to last night, there may be the potential for
some patchy fog in the early morning hours in the vicinity of the
front, where moisture is likely to be higher. Forecast soundings
would suggest the possibility, though at this time, it appears to be
generally light in coverage and duration. Probabilistic guidance
suggests at most a 30 percent chance for visibility restrictions
less than half a mile, and mostly east of the forecast area. With
this in mind, will leave fog out of the overnight forecast for now,
but will need to be monitored if conditions become more favorable.

By tomorrow, the front should be out of the area, with temperatures
ranging from the upper 70s to mid 80s across the region. Some
stronger winds across South Dakota may get as far south as the
Sandhills, though the strongest gusts are expected mostly along the
stateline. Current thinking is that wind gusts will remain at or
slightly below 25 miles per hour tomorrow afternoon. The current
upper level trough should continue tracking north and east, with a
slight ridge developing for Thursday. Aside from the winds across
northern Nebraska, tomorrow should be a fairly pleasant day. Skies
should remain mostly clear through the evening and overnight, with
low dropping into the upper 40s to mid 50s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 332 PM CDT Wed Sep 18 2024

The slight upper level ridge continues to build on Friday, ahead of
an aggressive upper level low across the Four Corners region. The
main concern on Friday is the return of elevated to near critical
fire weather conditions, mostly across northwest Nebraska. Under the
upper level ridging, temperatures are expected to climb into the mid
to upper 80s, with potential 90s across portions of northern
Nebraska. Dry conditions are expected, mostly along the Pine Ridge
and into portions of western Cherry County. Forecast soundings
suggest an environment favorable for mixing of upper level winds to
the surface, mainly across southwest Nebraska, the Panhandle, and
the Sandhills. Current thinking is wind gusts during the afternoon
hours could reach 25 to 30 miles per hour, so will be closely
monitoring the conditions heading into Friday.

By Saturday afternoon, the upper level ridging is displaced to the
east, with the upper level low moving across Colorado. The pattern
will set upper level divergence across the region, and a surface low
is expected somewhere along the Colorado/Nebraska/Kansas borders.
The stage will be set for a potential long duration rain event
across southwest into western and north central Nebraska this
weekend. At this time, the severe threat appears fairly low, with
the potential for some embedded thunderstorms. However, the pattern
is more reminiscent of a winter system, that may provide mostly rain
showers and wetting precipitation across the region. Notable, the
ECMWF Extreme Forecast Index and Shift of Tails highlights most of
western and southwest Nebraska as an area supportive of anomalously
high QPF this weekend. At this time, areas further south appear more
favorable. However, there is a slight spread of solutions in the
GEFS Spaghetti plots for the track of the upper level system. A more
northern track could potentially favor bringing precipitation a bit
further north. This is also potentially supported in the ECMWF EFI
and SoT, with little to no EFI, but a SoT marker across northern
Nebraska, meaning there is a chance for anomalously high
precipitation, though confidence is low.

While confidence in the placement of rain this weekend is somewhat
lower, the system does bring with it a pattern change lasting until
at least mid week. Temperatures remain near seasonal to slightly
below seasonal starting Sunday and lasting through at least mid
week. For reference, seasonal temperatures next week are typically
around 76 to 78 degrees. With this pattern shift, we could be seeing
temperatures maxing out in the 60s to mid 70s early next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1210 PM CDT Wed Sep 18 2024

A couple aviation weather concerns exist for western and north
central Nebraska terminals, mainly low stratus clouds and gusty
winds. A stubborn stratus deck is resulting in MVFR ceilings
from near LBF to ONL midday, and will gradually lift through the
afternoon. Across northwest Nebraska are gusty southwest winds,
which will overspread more northern terminals (VTN) today. After
a period of light/variable winds overnight, westerly winds
restrengthen tomorrow midday.

&&

.FIRE WEATHER...
Issued at 332 PM CDT Wed Sep 18 2024

Dry, mild, and windy conditions will continue across northwest
Nebraska through the evening hours, keeping the Red Flag Warning
in effect through this evening. Relatively poor overnight moisture
recovery is expected, with humidity bouncing back to around 65
percent across the Pine Ridge tonight. What will help limit the
fire weather conditions overnight is the boundary layer
decoupling, which will slow wind speeds overnight to around 10
miles per hour. This will also prompt a slight wind shift from
southwesterly to mostly westerly winds tonight.

Tomorrow, afternoon humidity is expected around 25 to 30 percent
across most of the region, with a limited area of higher winds
across portions of northern Nebraska. However, wind gusts are
mostly expected to remain at or just below 25 miles per hour. The
next concern for fire weather conditions is Friday afternoon,
where afternoon humidity is expected to drop to the 15 to 20
percent range across the Pine Ridge and portions of north central
Nebraska. Higher wind gusts up to 30 miles per hour are possible
across the Panhandle and Sandhills, so will be monitoring
conditions of Friday quite closely.

Beyond Friday, a system moving through this weekend may bring some
wide spread and possibly long duration rain across most of western
and north central Nebraska. At this time, heavier rainfall totals
are more likely across southwest Nebraska, but will continue to
track this system as it gets closer. Additionally, temperatures
are expected to trend to near seasonal to slightly cooler than
seasonal temperatures starting Sunday lasting through at least mid
week.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT /8 PM MDT/ this evening for
NEZ204-208.

&&

$$

SYNOPSIS...Richie
SHORT TERM...Richie
LONG TERM...Richie
AVIATION...Snively
FIRE WEATHER...Richie