Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 121121
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
621 AM CDT Tue Mar 12 2024

.KEY MESSAGES...

- Well-above normal temperatures through Wednesday.

- Next precipitation chances are on Wednesday and Thursday, with
  a chance (5-15%) for severe storms in southeast Nebraska and
  southwest Iowa Wednesday afternoon and evening.

- A cooler pattern will move into the area Thursday with highs
  expected in the 40s and 50s through the weekend.

&&

.DISCUSSION...
Issued at 158 AM CDT Tue Mar 12 2024

The upper level ridge that brought well-above normal temperatures to
the area continues to slide off to the east. Simultaneously, an
upper level trough is beginning to dig into the western CONUS. A
weak shortwave trough between these two features will move across
the Central Plains today. This is expected to bring a slight
decrease in temperatures compared to previous days. However, highs
will still remain in the upper 60s (well-above normal) for much of
the area today. CAM guidance displays some weak reflectivity
features sliding across this area in the late morning and early
afternoon as the shortwave and an associated weak front moves
through the area. However, model soundings show considerable dry air
in the low-levels, bringing low confidence that any precipitation
will reach the ground.

The aforementioned upper level trough will continue to traverse
across the western CONUS into Wednesday. An associated shortwave
trough is expected to eject into the Central Plains and spin up a
surface low along the eastern CO/NM border late Tuesday. This
feature will progress northeast across KS on Wednesday while an
associated warm front pushes north throughout Wednesday afternoon.
00z guidance from the deterministic GFS brings the front up into far
southeast NE and southwest Iowa with the deterministic ECMWF
continuing to lag further south with the front struggling to
penetrate past the NE/KS and MO/IA border. This will keep the better
moisture (mid 50s dewpoints), CAPE (MUCAPE 750-1000 J/kg), and
veering low-level winds just south of our CWA with the potential to
creep into the far southeastern corner of our CWA. Guidance is also
displaying 45-50 kts of 0-6 km shear in this area, sufficient for
supercells in northeast Kansas and possibly into southeast NE. This
has prompted the SPC to issue a slight risk for severe thunderstorms
in northeast KS and reaching into southeast NE. Steep mid-level
lapse rates (7 to 7.5 C/km) will bring the possibility of large hail
to any organized storms that do develop. A close eye will have to be
kept on these details as the system approaches.

Severe potential aside, this system looks to bring the possibility
for some much needed widespread rainfall to the area. A heavy rain
band is expected to push into the area late Wednesday evening and
continue into late Thursday/early Friday. The heaviest rain is
expected in northeast NE with values decreasing further south.
Several GEFS ensemble members display up to 1" in northeast NE with
values decreasing to 0.5" by the NE/KS and MO/IA borders.
Precipitation type looks to remain rain as Thursday highs reach the
50s and 60s. However, guidance is displaying snowfall in central NE
Thursday night into Friday. Currently, this looks to only creep into
our far northwestern counties for a brief period Friday morning.
Highs will take a dip into the 50s on Friday and Saturday. As the
upper level trough passes by this weekend, a cold front and strong
northwesterly flow will continue to drop temperatures into the 40s
on Sunday and Monday.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 610 AM CDT Tue Mar 12 2024

VFR conditions prevail through the TAF period. Expect the strong
winds at FL014 to continue east and no longer affect TAF sites.
Otherwise, expect light surface winds with variable direction
over the course of the day. A weak boundary shifting southeast
across the area will slowly replace southerly flow with
northerly flow over the course of the next 24 hours.

Some elevated rain/sprinkles are possible over the area mid-day
today. They are expected to evaporate before reaching the
surface, but may be found at FL040.

&&

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

&&

$$

DISCUSSION...Wood
AVIATION...Nicolaisen


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