Ralston, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

347
FXUS63 KOAX 302029
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
329 PM CDT Sun Mar 30 2025

.KEY MESSAGES...

- Showers and drizzle (15-30%) come to an end late this
  afternoon and evening.

- Monday will be pleasant with light winds as high temperatures
  reach the 40s to 50s under partly cloudy skies.

- Next storm system arrives Tuesday (30-60% PoP chances) and continues
  into Wednesday (widespread 60-90% PoP chances). A slight risk
  of severe weather (15% chance) across south central into
  eastern Nebraska and western Iowa.

- Benign weather returns for Thursday with next round of PoPs
  late Friday into Saturday (15-30% chance).

&&

.DISCUSSION...
Issued at 328 PM CDT Sun Mar 30 2025

.SHORT TERM.../Today through Monday Night/

A dreary day continues this afternoon as periods of drizzle, light
rain, and even some snow showers persist. 20z upper air analysis
shows the 850 mb low now positioned over northeast Iowa, with north
northwesterly flow behind the low across eastern Nebraska. Weak
omega between the sfc to around 800 mb or so within a saturated
layer is driving much of the aforementioned shower/drizzle activity,
as seen from RAP cross sections and soundings. The RAP and NAM Nest
seemed to be the most aggressive with these light showers/drizzle
early this morning, keeping them in our forecast area through the
late afternoon hours before exiting east, while other CAMs seem to
be more muted with the showery output. As the sfc low pushes farther
east toward the Great Lakes area late this afternoon and evening, it
will drag along the remaining wrap around moisture with it. Sfc
ridging will set in behind this low during the evening hours, which
will help scour out any remaining moisture and limit shower/drizzle
coverage. Did slightly lower highs today from NBM guidance, given
that stratus will linger today during peak heating time with weak
cold air advection behind the low, resulting in highs in the upper
30s north to mid 40s across the south. Winds will be breezy today
from the northwest at 15-20 mph with some gusts up to 30 mph. Lows
tonight reach the upper 20s north to near freezing across the south.

With the sfc ridging trekking eastward, expect to see pleasant
conditions during the daytime Monday. Winds will be light and
variable with high temperatures reaching the upper 40s to mid 50s
under partly cloudy skies. Ridging will depart the area by Monday
evening ahead of our next system.

.LONG TERM.../Tuesday through Saturday/

A 500 mb shortwave is expected to deepen and amplify Monday evening
across the Colorado/Rockies area. As the trough strengths, it will
induce a sfc low over eastern Colorado. By early Tuesday morning,
synoptic scale forcing for ascent coupled with low level warm air
advection and a 40-50 kt LLJ pumping in additional Gulf moisture
will lead to widespread PoPs (30-60% chance) for the forecast area.
At this time, rain appears to be the most likely precipitation type,
but a brief rain/snow mix cannot be ruled out across our far north
again given low temperatures are forecast to drop to the low to mid
30s there early Tuesday morning. Winds Tuesday will be gusty, given
the tightening pressure gradient associated with the deepening sfc
low and the potential to mix up to 850 mb where the 40-50 kt LLJ is.
Have collaborated with neighboring offices to slightly boost wind
speeds Tuesday with blend of NBM/NBM90th.

By Tuesday afternoon and evening, the sfc low is expected to be
located somewhere along the central Nebraska/central Kansas border.
Model discrepancies are evident at this time, however, as the
NAM and GFS tend to push the low center into south central
Nebraska, while the ECMWF shows the low center farther south
into Kansas by 00z Wednesday. Instability will be on the
increase as well, with models showing a stream of MUCAPE around
1,000-1,500 J/kg entering eastern Nebraska. How far north this
stream of instability will travel will be highly dependent on
where the low tracks and how far north the warm sector may make
it. BUFKIT soundings show much of this instability remaining
elevated, but with 0-6 km shear being at 50 kts or greater and
decent directional shear seen from hodographs, severe weather
with a few elevated supercells is certainly plausible. The 12z
NAM Nest is already hinting at severe convection forming towards
the end of its model run with a few UH tracks.

For this forecast package, the Storm Prediction Center has outlined
portions of south central into eastern Nebraska and western Iowa in
a slight risk of severe weather. At this time, large hail appears to
be the main threat, although a strong wind gust isn`t totally out of
the question owing to the presence of the aforementioned 40-50 kt
LLJ and downdrafts pushing this momentum downward. NBM currently has
PoPs Tuesday evening into early Wednesday morning at 60-90%, with
PoPs exiting the area by Wednesday evening. Potential rainfall
totals for this system are anywhere from around a quarter inch
across northeast Nebraska to as much as an inch across our far
southern service area.

Thursday will see a sfc high move from the Saskatchewan/Manitoba
area southward toward South Dakota. This will result in fairly
benign weather Thursday with partly to mostly cloudy skies. A weak
shortwave passing through late Thursday leads to some very low end
(less than 15%) chances for precipitation. Model consensus begins to
diverge as we head into Friday with differing solutions on the
placement and timing of mid to upper level features. The NBM tries
to bring in some PoPs (15-30% chance) across our far south late
Friday through Saturday night, but confidence in occurrence and
placement is low at this time due to the diverging model
solutions.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1205 PM CDT Sun Mar 30 2025

MVFR conditions will gradually improve through they day. Light
rain/drizzle/flurries will be possible, primarily at KOMA and
KLNK through about 20Z, before precipitation completely exits
the forecast area. Expect winds to diminish to 12 kts or less
shortly after 00Z this evening, with VFR conditions returning by
06Z tonight.

&&

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

&&

$$

DISCUSSION...Castillo/Mead
AVIATION...KG