North Platte, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

273
FXUS63 KLBF 202321
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
621 PM CDT Fri Sep 20 2024

.KEY MESSAGES...

- Cold front will bring cooler temps to the area beginning Saturday.

- Decent threat for precipitation across southern portions of the
forecast area Saturday afternoon into Saturday night.

- Cooler temps will persist into next week with possible frost
potential Monday morning in the western Sandhills.

- Mainly dry conditions expected next week with near seasonal
  temps.

&&

.SYNOPSIS...
Issued at 319 PM CDT Fri Sep 20 2024

H5 analysis this morning had high pressure anchored over
south central Texas. A ridge extended north into southern Nebraska.
Further west, a closed low was located over Los Angeles while over
New England, a second low was located off the coast of Maine.
Further north, a broad trough of low pressure was noted over western
Canada. Within this trough, a couple strong shortwave troughs were
noted. The first over eastern British Columbia and a second over
northeastern Manitoba. At the surface this afternoon...Low pressure
was located over southeastern Saskatchewan. A surface trough
extended to the south of this feature into far western North Dakota.
A second surface trough was present over northwestern Nebraska into
northeastern Colorado. Along and west of this surface trough, winds
were from the west and were on the order of 10 to 15 MPH. East of
the trough, winds were southerly and southwesterly and were gusting
up to 35 MPH at Valentine and 25 MPH at North Platte. Current RH over
northwestern Nebraska was around 20 percent attm, however winds were
fairly light at Gordon and Alliance. Further east at Valentine and
Ainsworth, RH was in the 20 to 25 percent range as of 2 PM CT. Given
the wind speeds in these areas, near critical fire weather
conditions were present. If dew points in these areas hold in the
lower 40s, and believe this will continue, we would have to see air
temps in the mid to upper 90s for critical RH values. ATTM, believe
strongly, the current temps will be the high for today in the before
mentioned areas. Elsewhere, temps were generally in the middle to
upper 80s under mostly clear skies.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 319 PM CDT Fri Sep 20 2024

In the short term, precipitation chances Saturday night into
Sunday morning is the main forecast challenge. The shortwave
trough over eastern British Columbia, will migrate east into
Saskatchewan tonight. This will force a cold front into
northwestern Nebraska overnight-clearing the forecast area by
mid morning Saturday. The inherited forecast had an abundance of
precipitation chances beginning as early as Saturday morning,
continuing into the afternoon hours on Saturday. This is not
supported by the latest NBM ensemble QPF guidance which has a
near zero probability of QPF>0.01" across the area through 7 PM
CT Saturday evening. Further support for a dry forecast Saturday
lies with the latest deterministic NAM12 and GFS solns which
demonstrate, little to no isentropic lift at the 310K layer
through 00z Sunday. Lift for precipitation initially lies along
the frontal boundary, which by Saturday afternoon is off to the
south and east of the area. That being said, with the exception
of a small area of slight chance pops hugging the eastern
fringes of the forecast area, most location will see dry
conditions Saturday. It will be much cooler however as highs
will range from the upper 60s in the northwest, to the lower 70s
in the eastern forecast area. On Saturday night, the upper
level low will migrate from the Four Corners into eastern
Colorado. Isentropic lift will begin to increase, most notably
over the southern third of the forecast area Saturday night or
along and south of Interstate 80. The NBM probabilistic forecast
has a 75% chance of 0.01" of QPF for North Platte Saturday
night. This continues to trend downward from the previous
forecasts. If you look at a tenth of an inch the probability
drops off to around 60 percent. With this in mind and looking at
the latest deterministic NAM12 and GFS solns, will confine
likely pops to areas south of a line from Chappell to Broken
Bow. For areas north of this line, pops were trended downward
quickly with the northern tier of counties now being dry. This
was based on the probabilistic forecast, a sharp cutoff in
isentropic lift and much drier air pushing into northern
Nebraska from South Dakota ie. dew points in the 30s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 319 PM CDT Fri Sep 20 2024

Weak isentropic lift will persist, roughly along a line from
Ogallala to O`Neill during the day on Sunday, shifting into
northeastern portions of the forecast area early evening. Low
precipitation chances will persist on Sunday roughly along and
south of this line. In addition, cloud cover combined with
northeasterly winds, will make for a raw cool day across the
area. Highs will struggle to get out of the middle 50s in the
south with some lower 60s possible in the northern forecast
area. Skies will begin to clear off Sunday night with drier air
pushing into the forecast area from the north. this will lead to
lows in the middle to upper 30s in the west, to lower 40s in
the east. The latest probabilistic NBM forecast indicates a 30
percent chance of temps below 36F Monday morning across the
western Sandhills. ATTM, would like to see a better than 50
percent chance before inserting a mention of frost in the
forecast. FWIW, if we are forecasting areas of frost for Monday
morning in subsequent forecasts and fore confidence increases,
would probably issue frost headlines, given this would be ahead
of the climatological normal. We have also seen unseasonably
warm temps across the area over the past couple of weeks so
sensitive vegetation remains susceptible to frost. A second
shortwave and northern stream trough of low pressure will impact
the area Monday night into Tuesday morning. This will bring an
increased threat for showers to the west. Beyond Tuesday
conditions will be dry with temperatures gradually warming back
into the upper 70s to lower 80s by the end of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 625 PM CDT Fri Sep 20 2024

VFR conditions are expected to prevail through tomorrow evening
across western and north central Nebraska. Lowering CIGs are
expected near the end of the valid period for southwest Nebraska
terminals, as a system approaches the area into tomorrow night.
Additionally, winds strengthen from the north tomorrow morning,
with gusts of 30 to 40kts tomorrow afternoon.

&&

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

&&

$$

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Brown