814
FXUS63 KLBF 192058
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
358 PM CDT Thu Sep 19 2024

.KEY MESSAGES...

- Warm, dry, and windy again for Friday with near critical fire
weather conditions anticipated for the panhandle and western
Sandhills.

- Much cooler, even windier, and wetter conditions in store for the
weekend. Greatest potential for significant moisture totals
generally lies near and south of Highway 2.

- Moderating temperatures to near normal levels and generally
  drier conditions return next week.

&&

.SYNOPSIS...
Issued at 357 PM CDT Thu Sep 19 2024

A series of upper lows over the central Calif. coast to
No.Dak/Manitoba border to the Eastern Seaboard surrounds a ridge
holding out over the Southern Plains. The main result is very broad
southwesterly or quasi-zonal flow aloft for Nebraska. Despite being
downstream of the Calif. low and underneath the modest upper jet,
forcing overall is quite weak and moisture is lacking. Surface high
pressure located along the lee of the Rockies adds to the low level
subsidence and clear skies.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 357 PM CDT Thu Sep 19 2024

This evening into tonight... Relatively little changes occur in the
upper level dynamics, while the surface high spreads completely onto
the Sandhills. Northerly flow at H85 transitions to southerly
throughout the night, and temperature and moisture advection appear
negligible. Most of the forecast area should remain cloudless, while
some moisture may stream into the southern tier. With winds relaxing
after sunset, conditions are ripe for full boundary layer decoupling
and a relatively cool night. Nudged temps down a couple degrees
using a general consensus of MAV/MET/ECS guidance, which line up
near the bottom quartile of the NBM envelope. Forecast ranges from
mid 40s along the Pine Ridge to lower 50s central Neb. There will
also likely be a period of predominantly south/southeast surface
flow, but the threat of fog appears low. Thinking with dew points
holding steady and really no hint of fog/stratus in SREF probs, kept
all mention out of the forecast package.

Tomorrow... The high pressure keeps trekking east toward the
Missouri Valley, while a lee side low emerges in Colorado. A
boundary will stretch northward, likely through the Neb panhandle to
the surface low corresponding to the upper low along the
NoDak/Canada border. In response to a tightening pressure gradient
and strengthening low/mid level flow, winds will pick up again. The
axis of highest gusts (25+ mph) shifts east throughout the day, but
will generally be concentrated on some portion of the Sandhills.
Meanwhile, plummeting dew points into the 30s will take over the
northern panhandle and Pine Ridge. Near critical fire weather
conditions are anticipated for the panhandle and western Sandhills
where humidity will be lowest (near 15%). However, the overlap
between critical RH and gusty winds appears to be minimal. Cannot
rule out brief or localized critical fire weather, but widespread
and/or prolonged red flag is not anticipated. Nearly full sunshine
again and deep mixing will promote rapid diurnal warming, while
stronger H85 southerly winds hasten warm air advection. Modest 24 hr
temp rises of 3-5C should occur across the Sandhills, so blended in
warmer guidance for max temps. Forecast ranges from mid 80s to
around 90F. A cool front will then cross the area overnight into
early Saturday, resulting in a switch to cool northwest flow. At
this time, moisture appears to be stringent enough to keep PoP
minimal along the fropa.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 357 PM CDT Thu Sep 19 2024

The synoptic pattern really turns active heading into the weekend as
the upper low that is currently over California emerges onto the
Great Plains, possibly directly over Nebraska. In concert with a
split upper jet and surface boundaries in the vicinity, a relatively
long duration precip event appears to still be on track. The
greatest potential for widespread rain and possibly significant
moisture totals lie across the southern half of the CWA, generally
along/south of Hwy 2. Discrepancies still exist amongst the guidance
suite, but the NBM envelope has gradually decreased from previous
peak QPF from a few runs ago. With that said, still think some
locations will measure 1"+ of rain by Sunday night. ECM EFI still
highlights anomalous precip for the southern half of Nebraska with
fairly decent confidence (0.6-0.7/1), and 0-1 for SoT. Along with
the precip will be much cooler temps and blustery north winds. The
last several runs of the NBM keep trending cooler for max temps
Sunday, now suggesting mid 50s to lower 60s. As for wind, higher end
guidance suggests gusts near 50 mph with several members of at
least 40 mph.

After the weekend, the pattern calms a bit with generally drier
conditions returning and temperatures moderating. Highs should hold
near or just below normal for a few days while winds decrease and
fire concerns remain relatively low.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1224 PM CDT Thu Sep 19 2024

VFR conditions will prevail across western and north central
Nebraska through the effective TAF period. Winds will be slightly
gusty out of the west and northwest this afternoon into the early
evening. After the boundary layer decouples, winds will calm to
light and variable throughout the night. After daybreak, winds will
begin to increase again, with gusty conditions starting tomorrow
morning lasting into the afternoon and evening hours.

&&

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

&&

$$

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