442
FXUS63 KLBF 171118
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
618 AM CDT Wed Jul 17 2024

.KEY MESSAGES...

- A marginal threat for severe thunderstorms exists later today and
again on Thursday, mainly over far western portions of the forecast
area today and the western half of the forecast area
Thursday/Thursday night.

- Temperatures will be much cooler for the remainder of the week into
the weekend and early next week.

- Thunderstorm chances will continue Friday into the weekend
  with the best chances for precipitation Friday night.

&&

.SYNOPSIS...
Issued at 316 AM CDT Wed Jul 17 2024

H5 analysis tonight had high pressure over the Four Corners
with a ridge extending north into eastern portions of the NW
Territories of Canada. East of this feature, Low pressure was
noted over central Ontario with a shortwave trough axis
extending to the west southwest into southeastern Manitoba.
South of this feature, a line of embedded disturbances extended
from southeastern Colorado, through the Ozarks, into the Ohio
Valley. West of the area of high pressure, a strong shortwave
was noted off the coast of far northern California. Earlier
tonight, a shortwave disturbance, diving south from the eastern
Dakotas, led to thunderstorms over the eastern portion of the
forecast areas. Some of these storms were severe along a
corridor from Brown County, south southeast into Custer and
eastern portions of Lincoln County. At the surface tonight, High
pressure had built into North Dakota overnight, forcing a
frontal boundary well south of the forecast area. Overnight,
this feature was located from central Oklahoma, west into the
northern Texas Panhandle, then north along the front ranges of
Colorado. Overnight, skies were mostly clear across the area.
The exception was some scattered mid level cloudiness over
portions of northern Nebraska. Temperatures as of 2 AM CT,
ranged from 59 degrees at Thedford to 66 degrees at Ogallala.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 316 AM CDT Wed Jul 17 2024

For today into tonight, the main forecast issue will be
precipitation chances which appear to come about in two
episodes. Surface high pressure will track across North Dakota
into Minnesota today. This will keep the before mentioned
frontal boundary well south and, thanks to persistent easterly
flow, well west of the forecast area today and this evening.
Highs today will be much cooler than the past several days with
readings ranging from around 80 in the east to the middle 80s
over SW Nebraska and the southeastern Panhandle. The latest
statistical guidance had a decent spread in highs for North
Platte this afternoon. Incorporating persistence along with the
50th percentile of the NBM was near the middle of the MET and
MAV statistical guidance and was utilized for highs today. Later
this afternoon, the CAMS begin to develop isolated
thunderstorms over the higher terrain of eastern Wyoming and the
western Nebraska Panhandle. This activity will generally be
INVOF the surface frontal boundary which should serve as a focus
for initiation. Once thunderstorms do develop, steep lapse
rates are noted over the panhandle with SB CAPE`s of
1500-2000J/KG this afternoon should sustain convection into the
evening hours. However, if initiation does commence in the
panhandle, south southeasterly mid level winds, should keep the
bulk of activity over the western third of the forecast area
this afternoon and evening. Overnight, as the surface high drops
south into Iowa, an elevated warm front will lift east across
western into central Nebraska overnight. Increased warm air
advection in the mid levels will lead to a threat for elevated
thunderstorms overnight tonight into Thursday morning, mainly
over the western and central 2/3rds of the forecast area. A
decent low level thermal gradient will set up across the area
Thursday afternoon as southerly winds increase on the back side
of the exiting high. By afternoon the latest deterministic NAM
has H85 temps ranging from the middle teens in the east, to the
middle 20s in the west and eastern panhandle. With the increased
temp gradient, highs will range from around 80 in the far east,
to near 90 in the west and southwestern forecast area. By late
afternoon, thunderstorms are expected to initiate over the
southeastern Wyoming, the Nebraska Panhandle and northeastern
Colorado. With the surface frontal boundary further east, the
severe threat will be farther east Thursday afternoon/evening,
impacting the western half of the forecast area. Decent DCAPES
are noted with forecast sb capes of 2000-2500j/kg west of a line
from Broken Bow to Ainsworth Thursday afternoon. Deep layer
shear, along with a good amount DCAPES would support a damaging
wind threat.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 316 AM CDT Wed Jul 17 2024

The strong shortwave, currently off the coast of northern
California, will traverse the apex of the ridge, approaching the
northern plains Friday morning. This feature will dive south
Friday, initiating convection over the Black Hills and NW
Nebraska late Friday afternoon/early evening. As this activity
dives southeast Friday evening, it will encounter decent SB
CAPES of 3000+j/kg across the heart of the forecast area. Deep
layer shear of 30-40 KTS and Capes of 1500-2000j/kg will lead to
a decent damaging wind threat. As the night progresses and
activity pushes into central and eastern portions of the
forecast area, it takes on a more linear mode, and aided by a
decent low level jet overnight, activity should sustain itself
well into the overnight hours. The shortwave will then stall
across eastern Nebraska late Saturday into Monday and there are
some indications of a tut low possibly developing. If this
materializes, cool temperatures will persist Sunday into Monday,
particularly over central and eastern Nebraska, where highs
will struggle to get out of the 70s Sunday and Monday. The low
will try to migrate south and southeast toward the middle of
next week. This will lead to warmer readings back into the 80s
across the area.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 611 AM CDT Wed Jul 17 2024

Pockets of low stratus and fog has developed across portions of
the western Panhandle and Sandhills this morning bringing brief
reductions to visibility and lowered cigs, though remaining out
of vicinity of LBF and VTN. Anticipate this to quickly lift in
the next 1 to 3 hours with a return to VFR conditions across all
of western and north central Nebraska. Mid-level clouds will
increase this afternoon with winds out of the east at 10kts or
less, gradually becoming out of the southeast overnight.

&&

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

&&

$$

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Viken