Plattsmouth, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

803
FXUS63 KOAX 150340
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
940 PM CST Thu Nov 14 2024

.KEY MESSAGES...

- Above normal temperatures (highs in the upper 50 and 60s) and
  dry conditions are expected through Sunday.

- Precipitation chances return Monday and Tuesday (50-80%
  chance) as a low pressure system approaches. As of now, all of
  the precipitation is expected to fall as rain.

- Uncertainty grows for the remainder of the end of the week,
  but a rain/snow mix is possible with much cooler temps
  forecast.

&&

.DISCUSSION...
Issued at 330 PM CST Thu Nov 14 2024

Another day of relatively benign weather continues with sunny
skies and negligible winds. Temps have surpassed 60F in a
couple of locations under southwest flow on the backside of a
ridge. With quiet winds forecast tonight and temps plummeting
under starry skies, expect temps to approach dewpoints. Patchy
fog is likely in western Iowa and Nebraska river valleys. Dense
fog doesn`t seem likely, but will warn the evening forecasters
to keep an eye on obs.

Over the course of the weekend, our temperatures will slowly
climb thanks to the influence of that continued southwest flow
over the mid-Missouri Valley. Saturday will serve as the week`s
warmest day with maximum temps in the lower to mid-60s under
clearing skies and southwesterly winds gusting up to 30 mph.

As a cutoff low digs down the California coast on Saturday
night, southwest flow at H5 will stretch from Baja through the
arrowhead of Minnesota. A lee trof developing in Colorado will
be caught up in the H5 flow and drive northeast along the
surface front that will be sagging south. A cold front will sag
through the area with little change beyond a wind shift and a
loss of about ten degrees Fahrenheit. We will remain dry
through the weekend. That will change for the work week.

The Cali low ejects east Sunday night and hits climatological
minimums for H5 heights and mean SLP as it traverses Texas
(NAEFS).

.MONDAY AND TUESDAY...

The center of the cutoff low pushes north through the Central
Plains Monday, but with an anomalous high over the Canadian
maritimes and a low south of it over the Atlantic, that low is
going to have a hard time making it much farther east (blocking
pattern). That slow but powerful system will advect
climatologically anomalous moisture from the GoMex through
eastern Nebraska and Iowa (and farther north). The NAEFS mean
PWAT ranges from 0.75 to 1.3 inches across the area by mid- day
Monday.

PoPs begin along the KS/MO state lines after midnight Sunday
night and grow to likely (60-95%) by Monday afternoon. Mid-
range machine learning models (CSU) suggest a 5-15 probability
of excessive rainfall for Monday. Current NBM QMD 24hr precip
probabilities of 1" of rain range from about 20% at Norfolk to
about 70% at Falls City. Thinking at this point is that the dry
slot will bring an end or a major diminshment of precipitation
(drizzle?) on Tuesday. Clustering of low pressure centers of
GEFS and ECE members is pretty good by Monday night (NE Kansas).

.WEDNESDAY AND BEYOND...

Model solutions begin to diverge by Wednesday, though both
deterministic EC and GFS produce a second low dropping south on
the heels of the first low. It looks breezy or windy behind the
ejecting system with about 10% of ensemble members producing
50mph gusts in the area. Current NBM PoPs of 30% look reasonable
with a rain/snow mix possible for the western tier of counties
on Wednesday night. Max temps on Wednesday and Thursday peak
near 40F and lows fall solidly into the 20s.

For those itching to get out a sled or a shovel, the NBM 90th
percentile (only a 10% chance of this actually happening)
produces about one inch at Lincoln and Omaha and up to 4-5"
north of Norfolk. But to be clear, this is unlikely...
especially considering the warmth of the ground this time of
year. But there is certainly a chance that some Nebraskans will
see their first snowflake of the season. It`s less likely for
those of you reading this from the 712 area codes.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 940 PM CST Thu Nov 14 2024

VFR conditions through the period. Winds at TAF issuance from
the southwest to southeast at 6 knots or less. Southeasterly
winds increase to 12 to 14 knots by 18z, with gusts up to 24
knots thereafter. LLWS likely develops at all sites toward the
end of the TAF period by 16/04-06z, but too far out to include
in this package.

&&

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

&&

$$

DISCUSSION...Nicolaisen
AVIATION...DeWald