162
FXUS63 KOAX 281730
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1130 AM CST Fri Feb 28 2025

.KEY MESSAGES...

- Ice jams and lowland flooding will be possible along the
  Platte, Loup, and Elkhorn Rivers today into Saturday, until
  the ice moves downstream and out of the area.

- Extreme fire danger will develop today with northwest winds
  gusting 35 to 45 mph and minimum relative humidity values in
  the upper teens to around 30 percent.

- Widespread rain is likely (60-80% chance) Tuesday into
  Wednesday, with a chance of some snow accumulation Tuesday
  night into Wednesday morning, especially in northeast
  Nebraska. Thunderstorms may even develop into southern NE and
  IA.

- Wednesday will also be quite windy, with gusts of 40 to 45
  mph possible.

&&

.DISCUSSION...
Issued at 330 AM CST Fri Feb 28 2025

     Today and Tonight...

A vigorous clipper system along the MN-Ontario border early
this morning will progress into the Great Lakes today while a
trailing cold front sweeps through the mid MO Valley. Tightening
height and pressure gradients on the backside of the midlevel
system coupled with steepening low-level lapse rates and modest
cold advection will foster the downward transfer of strong
northwest winds within the post-frontal environment, especially
from late morning through this afternoon. The strongest winds of
20-30 mph with gusts up to 45 mph are expected across northeast
NE into west-central IA where a Wind Advisory will be in effect
from 9 AM to 6 PM.

The deep boundary-layer mixing will also lead to relative
humidity reductions into the upper teens to around 30% during
the peak of the diurnal heating cycle this afternoon. While
these RH values are on the high side of those typically
associated with extreme fire behavior, the strong winds have
been observed to compensate in these scenarios. Fine fuels are
likely cured since the recent snowfall, and dangerous wildfire
conditions anticipated. Accordingly, a Red Flag Warning will be
in effect from 10 AM to 8 PM. Northwest winds are forecast to
diminish this evening with RH values recovering to 65 to 75
percent overnight.

Outside of the winds and wildfire concerns, temperatures will
remain above normal with highs in the upper 50s to mid 60s.


     Saturday through Monday...

The primary features of interest during this timeframe are a
shortwave trough and associated surface low, which are forecast
to move out of the southern Rockies into the central Plains
Sunday into Sunday night. The 00z global ensembles are in
generally good agreement in the timing of the system with the
GEFS and the CMCE means depicting a more intense, northern
track of the system across KS compared to the EPS. A more
northern track of the system would result in better
precipitation chances for our area Sunday night, which is what
this forecast update will align more closely with. Precipitation
is expected to fall as rain with some model signal for weak
instability developing across southeast NE where an isolated
storm or two is possible.

Temperatures will be cooler on Saturday with highs in the upper
30s to mid 40s. However, readings are expected to warm on Sunday
into Monday with highs in the 50s to perhaps low 60s.


     Tuesday through Thursday...

A potentially more significant synoptic system is projected to
impact the Great Plains Tuesday into Wednesday. The global
ensembles are in very good agreement in the track and amplitude
of the midlevel system, as well in the clustering of surface low
positions as the cyclone tracks from along the KS-OK border
Tuesday into the mid MS Valley Tuesday night. That system track
would place the mid MO Valley largely in the cold sector with
increasing precipitation chances Monday night, peak PoPs of
60-80% Tuesday afternoon and evening, and then decreasing PoPs
Wednesday morning.

Current indications are that rain will remain the predominant
precipitation type through Tuesday afternoon with the potential
for a rain-snow mix or changeover to all snow occurring from
northwest-southeast across the area Tuesday night into Wednesday
morning. It`s still too soon to get a good feel for amounts,
but the best potential for minor snow accumulations appears to
be across northeast NE. Similar to the Sunday night system, the
models indicate some weak instability developing across
southeast NE and southwest IA where a few thunderstorms are
possible.

Windy conditions are expected to develop on Tuesday night into
Wednesday morning as the synoptic system begins to pull away
from the region.

In regard to temperatures, highs in the 50s on Tuesday are
forecast to cool into the 40s on Wednesday with 40s and 50s on
Thursday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1130 AM CST Fri Feb 28 2025

VFR conditions expected through the period with passing mid-
level clouds. Northwest winds will gust 30 to 40 kts through the
the afternoon and before becoming more northerly right around 10
kts from 02Z through the remainder of the period.

&&

.HYDROLOGY...
Issued at 330 AM CST Fri Feb 28 2025

The Loup River at Columbus remains in minor flood stage early
this morning with recent gauge data indicating a decrease in
water levels. That could indicate that the downstream ice jam
has released. There has been a corresponding increase in water
levels on the Platte River at Schuyler to near action stage with
gauge data from North Bend downstream through Venice showing
in-bank fluctuations, likely due to ice movement. There`s also
ice movement on the Elkhorn River with water levels dropping at
Norfolk and Pilger, and increasing dramatically at West Point.
We`re keeping an eye on that.

Expect continued ice movement today into Saturday. As jams
break free and move downstream, they may re-develop in other
areas. Any ice jamming could lead to a rapid rise in the water
levels of 1-3 feet or more, potentially leading to flooding of
low lying areas. The most at-risk rivers in the next couple of
days for lowland flooding will be the Platte, Loup, and Elkhorn.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory until 6 PM CST this evening for NEZ011-012-
     015>018-031>034.
     Red Flag Warning until 8 PM CST this evening for NEZ011-012-
     015>018-030>034-042>045-050>053-065>068-078-088>093.
     Flood Watch through Saturday evening for NEZ016-017-031>033-
     042>045-050>053-067.
IA...Wind Advisory until 6 PM CST this evening for IAZ043.
     Red Flag Warning until 8 PM CST this evening for IAZ043-055-
     056-069-079-080-090-091.

&&

$$

DISCUSSION...Barjenbruch/Mead
AVIATION...CA
HYDROLOGY...Mead