733
FXUS63 KLBF 201124
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
624 AM CDT Sat Jul 20 2024

.KEY MESSAGES...

- An isolated shower or thunderstorm cannot be ruled out in
  portions of the area today, but most if not all locations
  likely remain dry.

- Similar low-end rain and thunderstorm chances exist Sunday for much
  of the forecast area.

- After cooler temperatures this weekend, forecast highs
  moderate towards the middle of next week with a return to 90s
  likely.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 329 AM CDT Sat Jul 20 2024

Meridional flow remains in place across the central and northern
Plains. This is due to deep troughing across the Hudson Bay
extending southwest through the western Great Lakes. Meanwhile,
strengthening ridge upstream across the Great Basin. The latter of
these features will play prominently in the extended forecast.

Saturday...Extended trough continues to slowly shift south and east
across the upper Mississippi Valley. While modest height falls will
continue through the morning hours Saturday, forcing will continue
to shift south as dry air fills in within the northerly flow behind
the feature. Increased low-level moisture thanks in part to rainfall
from Friday has led to patchy fog across central Nebraska. This fog
has been locally dense in a few spots, but appears to be transient
enough to preclude any Dense Fog Advisories at this time. Mid-level
flow remains fairly meager with lack of any appreciable disturbances
to hone in on. While lapse aloft will remain fairly modest,
northeasterly surface flow will remain breezy and promote mixing
This should also help remove most low-level capping and potentially
introduce the potential for widely isolated thunderstorms during the
afternoon. As mentioned before, the majority of forcing for ascent
remains south and east of the local area and so have kept PoPs
limited to 20% or less (Slight Chance category). HREF ensemble
paintball of > 40 dBZ reflectivity remains fairly muted and recent
extended runs of the HRRR remain mostly dry. Will lean on ARW, FV3,
and RAP solutions for areas of these low PoPs. Latest SPC Day 1
severe weather outlook has also introduced a Marginal Risk (level 1
of 5) for areas west of an Oshkosh to Lamar line. Overall thinking
is the threat for anything strong to severe is quite low and this
outlook generally lines up with the latest RAP solutions 1000 j/kg
MUCAPE contour. Even so, shear is quite weak at less than 25 knots
so should any storm strengthen it`s unlikely to persist long.
Surface height rises will accompany high pressure backing in from
the east. This should help promote some cooler temperatures in our
eastern zones. Forecast highs range from the upper 70s to low 80s
east of Highway 83 to low to middle 80s to the west.

Sunday...surface high pressure will continue to shift west and
arrive into eastern Nebraska by early Sunday morning. Central high
pressure should move into central Nebraska around sunrise. Cooler
temperatures are likely as a result given fairly calm conditions
with the lingering cloud cover precluding a truly radiational
cooling night. Lows should fall into the 50s for most with afternoon
highs only reaching the upper 70s to lower 80s. A weak wave from the
north should bring showers and a few thunderstorms into the area
from South Dakota. This would favor the afternoon and evening hours
when instability peaks. Winds aloft remain very weak, so no severe
weather is expected. A few storms may be capable of producing a few
tenths of an inch of rain, but pinpointing who sees what at this
point in time is difficult at best.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 329 AM CDT Sat Jul 20 2024

Monday and beyond...upstream ridging continues to build north into
Alberta with purely meridional flow locally by early Monday. A few
weak perturbations within the flow should be enough to introduce low-
end PoPs Monday, but with h5 flow remaining around 10 to 15 knots,
support for severe weather continues to appear quite limited. Upper
ridging appears set to further encroach on the area by Tuesday, with
quickly moderating temperatures and dry conditions likely through
the end of the forecast. Latest EFI shows a flip from negative to
positive anomalies for Maximum Temperatures around the middle of
next week, suggesting we`ll quickly return to above normal
temperatures during this time frame. Latest forecast values quickly
return to upper 80s and eventually the lower 90s for the second half
of the week. Even NBM 25th percentile values suggest a run at the
upper 90s by Friday and Saturday for southwest Nebraska up through
the Panhandle. With that in mind, attention will need to focus on
the prospect of this heat wave. Dew points east of Highway 183 may
push the middle 60s so some concern exists about forecast heat
indices. For now, they fall short of Advisory criteria (100 degF or
greater) but trends will need monitored. A pattern change
appears likely for late next week as upper troughing returns to
the Pacific Northwest. This will promptly lead to ridge
breakdown and usher in more active weather. Precipitation
returns to the forecast as early as Friday night with the
potential for additional rain and thunderstorm chances lasting
into the weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 623 AM CDT Sat Jul 20 2024

Patchy dense fog is observed across southwest and north central
Nebraska this morning, bringing MVFR to IFR conditions to areas east
and south of a KIML to KTIF to KONL line. By mid morning, fog should
rapidly decrease and ceilings should also rapidly return back to VFR
conditions across the region. Outside of some brief wind gusts this
afternoon, winds will remain mostly light throughout the TAF period.
Although a few isolated thunderstorms are possible this afternoon,
no impacts are currently expected at the terminals.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM CDT /8 AM MDT/ this morning for
NEZ006>010-025>029-036>038-057>059-069>071.

&&

$$

SHORT TERM...NMJ
LONG TERM...NMJ
AVIATION...Richie