294
FXUS63 KOAX 172313
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
513 PM CST Sun Nov 17 2024

.KEY MESSAGES...

- Widespread rainfall is forecast Monday into Monday night
  (90-100% PoPs). Many locations will see amounts of 1.0-1.5"
  with isolated 2"+ readings possible.

- Turning windy and cooler Tuesday and Wednesday with below-
  normal temperatures lingering into next weekend.

&&

.DISCUSSION...
Issued at 300 PM CST Sun Nov 17 2024

Today through Monday...

Clearing skies over northeast Nebraska allowed temperatures to
plummet into the lower 30s and upper 20s this morning. Meanwhile,
southeast Nebraska and southwest Iowa clung onto the low to mid 40s
under a more insulated blanket of clouds. A band of showers within
those clouds traversed our southeastern border this morning.
However, it struggled to produce much, if any measurable rain, given
the dry air it was falling into.

By 2 PM, temperatures had rebounded into the upper 50s to around 60,
with clear skies over northeast Nebraska. Thicker cloud cover held
off the warm sunshine, locking the rest of the region in the lower
50s.

A low pressure system will strengthen as it moves out of the
Southern Plains Monday, punching a deformation zone across eastern
Nebraska and western Iowa. Rainfall will begin to edge into
southeast Nebraska by 09Z tonight, and overspread the forecast area
through the morning hours. Rainfall rates will generally be around
0.25"/hour or less, preventing excessive runoff and mitigating any
flooding concerns. The dry slot will likely impinge on the forecast
area during the afternoon hours, eating into rainfall totals.
Overall, most locations will still see around 1"-1.5" with highest
amounts around 2" possible.

Ample shear of 45-55kts could help sustain strong updrafts with a
cell that take advantage of the few hundred J/kg of MU-CAPE
available as the surface low passes over southeastern Nebraska
Monday afternoon/evening. Therefore, an isolated strong to severe
storm or two still appears possible, but unlikely (<10%) at this
time.

The strongest winds (from the southeast) are expected ahead of the
surface low over southeast Nebraska and southwest Iowa Monday
afternoon where gusts of 30-35 mph are possible. Highs will range
from around 50 over the northwest part of our area to low 60s in far
southeast NE. Rain will come to an end from south to north Monday
night.

Tuesday through Wednesday and Beyond...

Models remain in good agreement that the weakening system will be
overtaken by a mid/upper level low diving out of the northern Plains
Tuesday. This southeastward moving system will bring both gusty
winds and cooler temperatures to our region through the coming week.
A cold front will pass through Monday night and Tuesday, bringing
northerly wind gusts up to 25-35 mph through the day. Afternoon
highs on Tuesday will be in the upper 40s to low 50s.

Isobars tighten further on Wednesday as the upper low passes to our
east. Wind speeds will increase to 20 to 30 mph, with gusts up to 35
to 45 mph, likely necessitating a Wind Advisory for a portion of our
forecast area. Highs on Wednesday will top out in the 40s at most
locations. Far northeast Nebraska will be in the upper 30s, with a
small chance for a flurry or two near the South Dakota border.

Overnight low temperatures will fall below freezing, each night from
Tuesday through the end of the week. High temperatures will remain
in the 40s through the weekend, with dry conditions prevailing.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 506 PM CST Sun Nov 17 2024

Light winds out of the south or southwest start the back-loaded TAF
period, with incoming rainfall expected to break up the initial
VFR flight conditions early tomorrow morning. Lower ceilings
will precede rainfall tomorrow by 2-4 hours, with ceilings
falling into the low-end of MVFR starting around 10z at KOMA and
KLNK while KOFK holds on until 15z. Those ceilings will then
deteriorate into IFR conditions with the initial scattered
showers and mist, before becoming low-end IFR to LIFR through a
good chunk of the day tomorrow as ceilings fall to FL004-FL006,
and visibilities fall to 1-2 miles or even less at times of
heavier rain. On the horizon is the expected increasing ceilings
that reach MVFR around 22z tomorrow afternoon.

&&

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

&&

$$

DISCUSSION...KG
AVIATION...Petersen