Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 222324
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
624 PM CDT Fri Mar 22 2024

.KEY MESSAGES...

- Chance for light snow tonight into Saturday morning. Highest
  chances (30-50%) for accumulations in NE Nebraska.

- Widespread rain expected on Sunday with thunderstorms possible
  during the morning. Strong southeasterly winds gusting to 45
  to 50 mph expected as well.

- Rain turns to snow on Monday, with 60-80% chance of
  accumulation for NE Nebraska. Highest amounts expected in Knox
  and Antelope counties. A Winter Storm Watch has been issued
  for these two counties for Monday into early Tuesday.

- Dry weather returns for Wednesday and Thursday with
  temperatures trending back up.

&&

.DISCUSSION...
Issued at 204 PM CDT Fri Mar 22 2024

Low stratus is hanging on across eastern Nebraska and western
Iowa this afternoon keeping temperatures cooler than expected.
Many areas may struggle to get out of the 30s. We`re also
dealing with gusty northerly winds which is making it feel
cooler with wind chills in the 20s to low 30s across the area.

Tonight, a weak elevated warm front will move across our area,
bringing a chance for light snow, primarily across northeast
Nebraska overnight into Saturday morning. Behind this front,
we`ll see a shift to southeasterly winds, which will still be
sourcing from cooler air with the High to our east, so
temperatures will stay cool on Saturday. The NBM may be a few
degrees to warm again, with widespread cloud cover expected to
hold across the region through the day. Have brought
temperatures down a couple degrees. Saturday afternoon we could
see a few isolated rain/snow showers develop as far south as
southeast Nebraska, but these are not expected to have any
accumulation of snow. The best chance for accumulating snow will
be overnight into early Saturday morning over northeast Nebraska
(30-50% chance), with amounts around a half-inch or less.
Nonetheless, as we saw this morning, this could lead to a few
slick spots on the roads Saturday morning.

Sunday - Tuesday:

Sunday starts the really interesting weather as the surface low
starts to really deepen over eastern Colorado. We start to see
strong moisture advection into the region as the warm front
approaches then moves across our area Sunday morning. With this
surge, I expect elevated instability north of the warm front to
lead to some thunderstorms as early as 7 AM Sunday morning
across southeast Nebraska. As the warm front lifts north, expect
thunderstorm chances to decrease and moderate rainfall to spread
across eastern Nebraska into western Iowa. Meanwhile, southerly
winds behind the warm front will ramp up quickly Sunday morning.
NBM probabilities wind speeds in excess of 30 mph and gusts in
excess of 45 mph are up around 80 to 100 percent, so a Wind
Advisory will likely be needed starting around noon and going
through Sunday night.

The next hazard will the the changeover to snow Sunday night
into Monday morning across northeast Nebraska. A frontogenesis
band looks likely to set up just to our west, with about a 50-50
chance of clipping Antelope and Knox Counties. The 06Z model
runs and ensembles were bringing it right into these counties.
The big question will be the exact track of the surface low
which will play a big factor in how early we see a transition
from rain to snow in these counties. If we see a transition to
snow earlier Monday morning, we could see as much as 8 inches of
snow across Knox and Cedar Counties before the frontogenesis
band exits to the northeast. If we see the Low track farther
west (30% chance), the frontogenesis band may stay just west of
our area, and a later transition to snow Sunday morning could
mean as little as 2 inches of snow. I know no one likes a large
range of snow totals, but I believe there is going to be a sharp
gradient between a lot and a little amount of snow somewhere in
the area. Went ahead and put out a Winter Storm Watch for Knox
and Antelope Counties for early Monday through early Tuesday to
get the message out for potentially up to 8 inches of snow, but
if this shifts farther west, we may only upgrade it to an
Advisory.

The second hazard for northeast Nebraska Monday will be winds.
The NBM is depicting a trend in the ensembles for a deeper
surface low bringing winds gusting to 45 to 50 mph across much
of northeast Nebraska. Stronger winds appear likely for Central
Nebraska, where they could see gusts to 50 to 60 mph. Any area
that sees accumulating snow greater than 2 or 3 inches could see
branches and power lines come down as the snow will be very
moist and heavy in texture, and will likely try to stick to
trees and power lines.

Areas southeast of Knox and Antelope counties in northeast
Nebraska will see a sharp cut-off to less than an inch of snow
expected. Due to the track of the surface low, we don`t see
below freezing temperatures spread southeast across the area
until the cold front moves through Monday night. This will be as
the low and moisture is exiting the area. A dry slot may even
push through southeast Nebraska and southwest Iowa shutting off
precipitation completely as early as Monday morning. Again, if
this low tracks farther west (30% chance), the dry slot will
push through farther north which will reduce the chances for
snow to zero as far north as Lincoln and Omaha.

Tuesday, the system completely exits our area and northwesterly
winds will gradually relax through the day. Temperatures will be
cool, but with clearing skies during the afternoon we will
likely see locations in southeast Nebraska and southwest Iowa
get into the upper 30s to low 40s. Elsewhere will see highs in
the upper 20s (where there is snow) to mid 30s.

Overall, this system should bring some much needed precipitation
to our region. A combination of rainfall and liquid equivalent
(from snow) shows an area of 1 to 2 inches of precipitation
across northeast Nebraska, north of the Platte River, and areas
to the south still see 0.5 to 1 inch.

Wednesday - Thursday:

High pressure slides across the region Wednesday and Thursday,
bringing back dry, sunny weather which will help to melt any
snow on the ground. Temperatures will be trending back up, with
highs on Thursday back up in the 50s to low 60s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 610 PM CDT Fri Mar 22 2024

MVFR ceilings will continue to linger around the area before
gradually breaking and clearing around 02-05Z. Northeasterly
winds will continue above 12 kts before calming for the night
around 02-03Z. Winds will shift to southeasterly behind an
elevated warm front expected to cross the area around 12-15z
Saturday morning. Winds will increase above 12 kts at all
terminals around 16-18z Saturday morning with gusts up to 24 kts
possible through the afternoon.

Light snow is possible Saturday after the frontal passage,
especially at KOFK. KOFK can expect light snow around 10-15z.
Snow may be accompanied by a period of MVFR ceilings. There is
a low chance (20%) of a light rain/snow mix reaching KOMA and
KLNK towards the end of the forecast period (21-00z), confidence
is not high in this occurrence.


&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Winter Storm Watch from late Sunday night through Tuesday
     morning for NEZ011-016.
IA...None.

&&

$$

DISCUSSION...McCoy
AVIATION...Wood


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