Plattsmouth, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

848
FXUS63 KOAX 220348
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
948 PM CST Sat Dec 21 2024

.KEY MESSAGES...

- Above normal temperatures Sunday through next Saturday, with
  Sunday the warmest day of the week.

- Small (15-25%) precipitation chances Wednesday night into
  Saturday. There a very low chances (5-10%) of a wintry mix of
  precipitation Thursday and Friday mornings, with any snow or
  ice accumulations appearing unlikely.

&&

.DISCUSSION...
Issued at 312 PM CST Sat Dec 21 2024

Today...
Southerly low level flow returned across the area under mostly
clear skies except for some cirrus. Afternoon temperatures are
near normal, as thermal trough at H8 lingers across the region,
and a south- to southeast low level wind component is limiting
maximum diurnal mixing. Overnight low temperatures will be
similar to those experienced Saturday morning, generally in the
20s across the region.

Sunday...

Low level pressure gradient increases due to leeside surface low
and frontal system development. A greater southwesterly
component to the wind will allow for better mixing, thus expect
a boost in temperatures by 10 degrees or more for high
temperatures. Trended slightly above NBM 50%, which results in
lower 50s generally west of a Yankton to Wahoo to Nebraska City
line. The rest of the area will be in the upper 40s. A cold
front moves through the area Sunday evening, no precipitation is
expected with better moisture transport to the east of the area.

Monday through Wednesday...

Low level cold air advection and perhaps lower clouds will keep
temperatures cooler for Monday, though still above normal for
late December, with high temperatures 40-45 across western Iowa
and 45-50 across eastern Nebraska. A secondary surge of colder
air moves through the area late Monday, which will keep
temperatures cooler for Tuesday, generally in the 40s.
Christmas Day looks similar to Tuesday, but perhaps a degree or
two warmer.

Wednesday Night through Saturday...

Several more vigorous shortwave features in the mid-levels will
move across the central part of the country Wednesday night into
Saturday. The deterministic GFS has a more robust upper low
moving across Kansas and Nebraska as it reduces the wavelength
between shortwaves moving across the area Thursday into Friday.
The EC and CMC tracking the Christmas Night upper system across
the southern plains, with a more muted shortwave following it on
Friday into Saturday. Several GEFS ensemble members also
depicting a more southern track and muted upstream wave, thus
will trend resulting precipitation forecast toward EC/CMC/GEFS
solutions. Precipitation chances will be low (15-25%). There
looks to be small potential (5-15%) for wintry mix during the
morning hours of Thursday and Friday, with about third of the
superensemble members surface to 925mb wet-bulb profiles at or
below 0C. Little or no accumulation is expected.

Temperatures will be dependent on cloud cover and any cooling
from light precipitation. Trending slightly cooler than 50% NBM
based as there appears to be more of a right or cooler skew to
the individual members.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 948 PM CST Sat Dec 21 2024

VFR conditions expected through the period with passing mid to
high level clouds. Winds overnight will be out of the south
around 10 kts. There will be potential for low level wind
shear, mainly at OMA and LNK, where winds at around 1500 ft will
be out of the southwest at 35 to 40 kts. Then expect some gusts
of 20 to 25 kts during the day before winds become westerly to
northwesterly by late Sunday afternoon/evening.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.

&&

$$

DISCUSSION...Fortin
AVIATION...CA