Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 212114
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
414 PM CDT Thu Mar 21 2024

.KEY MESSAGES...

- A round of precipitation is expected to move southeast across
  the region Thursday night into Friday morning. Highest
  rainfall totals are expected in northeast Nebraska and western
  Iowa.

- A storm system will bring widespread rain and snow across the
  region Saturday night through Tuesday morning. Highest
  chances (50- 70% chance) for accumulating snow will be across
  northeast Nebraska Saturday night, and Monday into Tuesday
  morning.

- Heavy rain will also be possible on Sunday, especially across
  portions of east-central and northeast Nebraska. Some
  locations may see over an inch of rain.

&&

.DISCUSSION...
Issued at 412 PM CDT Thu Mar 21 2024

Today and Tonight:

Water vapor imagery this afternoon continues to feature the
shortwave slowly moving further east into the OK/TX region, with a
much faster moving shortwave ejecting ESE across the northern
Rockies. A very dry airmass is in place across the area where
despite highs in the upper 40s and 50s, relative humidity values are
as low as 20 percent thanks to dewpoints in the low teens to single
digits. Despite the dry conditions a weak disturbance has
continued to push eastward, resulting in mid-to-low clouds and a
few sprinkles that have been able to make it to the surface.
These clouds should continue pushing east and diminishing
through midnight, before our next weather maker enters into
northeast Nebraska.

The aforementioned shortwave moving over the Northern Rockies is
expected to begin pushing into eastern Nebraska after midnight,
making the most of meager moisture as light rainfall sweeps
quickly from 1 AM to 8 AM. Temperatures overnight stay
relatively warm with the quick onset of deeper clouds, with lows
only below 32 degrees in far northeast Nebraska. Steeper lapse
in the mid-levels indicate that a few rumbles of thunder will be
heard as the rain falls (perhaps with a snowflake or two closer
to South Dakota.

Friday through Wednesday:

Moving forward towards the weekend, we`ll see a slight cooling trend
in the high temperatures across the area. Highs in the 50s today
will give way to highs in the 40s for Friday and Saturday, joined by
a quick glance of light precipitation Saturday morning.

The main show for the forecast period arrives early Sunday as a
quickly deepening lee cyclone develops over eastern Colorado, aimed
at the Central Plains. Warm sector precipitation will be the primary
source of moisture Sunday when strong vapor transport ramps up
across the forecast area while some severe threat looks possible for
Sunday afternoon and evening, depending on how far east the surface
low gets and how much destabilization can occur despite the
deeper cloud cover.

By early Monday morning, the main surface low will find itself near
the KS/NE border with impressive precipitation just to the north of
it extending northeast, where textbook banded frontogenesis develops
in the deformation zone of the system. The main two snags to
work out from here are how warm we will be during the early
morning hours through noon Monday, and where the
frontogenesis/deformation band trains over the same region as
the main system ejects to the northeast. Areas just to the
northwest of Norfolk are certainly close enough to see 4+ inches
of snow, with higher chances as you go west to see potentially
double that. We`ll continue to watch the differences between the
ensemble members and different forecast systems, but the latest
trend is a slight west shift of the heaviest snow towards
north-central Nebraska. Tuesday and Wednesday will see dry
weather return in the wake of the weekend/Monday system and cool
temperatures on Tuesday will see a 10 degree bump into the 40s
as we move into Wednesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1229 PM CDT Thu Mar 21 2024

VFR conditions are currently in place at all terminals, with
southeasterly winds and a bank of mid-level clouds moving
through with a sprinkle of rain. Winds this afternoon are
expected to gust near 20 kts, which will are expected to drop
off around 00z, followed by low-level wind shear for a few
hours. A quick-moving system is expected to pass through the
area this overnight, affecting KOFK and KOMA for 2 to 3 hours
with MVFR conditions and light rain before winds turn northerly
and gusty for tomorrow morning.

&&

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

&&

$$

DISCUSSION...Petersen
AVIATION...Petersen


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