909
FXUS63 KOAX 031951
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
251 PM CDT Fri May 3 2024

.KEY MESSAGES...

- Thunderstorms are expected this evening into the overnight
  hours with a 5 to 10% chance of damaging hail and wind.

- There is a chance of severe thunderstorms (15 to 30 percent
  chance) Monday afternoon and evening.

- Additional chances for showers and storms possible through the
  end of the week, but no organized threat for severe storms.

&&

.DISCUSSION...
Issued at 251 PM CDT Fri May 3 2024

This afternoon - Saturday:

There are still some high clouds around the area this afternoon,
causing some echos to show up on radar, but we`re not seeing
anything reach the ground. Winds are out of the southeast and
temperatures are in the upper 60s to around 70 here around 2 PM,
and should rise into the low 70s for highs this afternoon. We`re
watching a cold front associated with a low pressure system out
over the Nebraska Panhandle this afternoon which will move
through overnight tonight. This will bring a line of showers and
thunderstorms through around 10 PM to 6 AM. We are under a
marginal risk for severe weather from the Storm Prediction
Center. The environment out ahead of the cold front does have
up to 500 J/kg of MUCAPE indicating enough instability for
thunderstorms, and combined with 50-60 kt of 0-6 km Bulk Shear
indicates a threat of up to quarter-size hail and damaging
winds. This line should move through fairly quickly, but we
could see up to an inch or more of rain in places. Once the main
line moves through, expect a post-frontal rain shield to trail
the main line, tapering off an hour or two later.

Low clouds will hang around through the morning on Saturday,
with the sun coming out Saturday afternoon. Temperatures will be
a bit cooler with highs only in the low-to-mid 60s with breezy
winds out of the north gusting to 25 mph in the morning,
dropping off during the afternoon.

Sunday-Monday:

Another upper-level trough will start to dig into the Four-
Corners region on Sunday, approaching our area. Sunday should be
a fairly nice day with light winds in the morning becoming
southeasterly and starting to increase during the afternoon
ahead of the approaching system. Temperatures will stay on the
cooler side with highs in the mid-to-upper 60s.

We`ll see the surface low start to develop on the lee side of
the Rockies Sunday evening with a surge of moisture lifting
north out of the Gulf of Mexico associated with the Low-Level
Jet across central and eastern Nebraska. We probably won`t see
precipitation start Sunday night, but we`ll see increasing
clouds with chances for rain starting Monday morning.

We`ll want to watch Monday evening for potential severe weather
as the main upper-level wave pushes the dry-line across our
area. This is our best opportunity for severe weather, with
large hail, damaging winds, and tornadoes all possible. There is
some possibility that stronger storms developing to our south
cut off a lot of our moisture which could limit our severe
potential, as the greater severe weather threat does appear to
be to our south. We do still want to monitor this time frame,
though. Storms do appear likely to be out of our area by Tuesday
morning.


Tuesday-Thursday:

No other notable severe weather risks to mention through the
rest of the forecast. We do see a shortwave move through Tuesday
night that could bring another round of more modest storms
through Tuesday night into early Wednesday. Through the end of
the week we see a broad trough set up across much of the central
CONUS with a fairly baroclinic pattern that could bring
additional low chances for showers and storms, but no organized
threat for severe weather. High temperatures stay in the 60s and
70s and lows in the 40s and 50s.


&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1207 PM CDT Fri May 3 2024

VFR conditions this afternoon with some high clouds over
northeastern Nebraska and winds out of the southeast. We`ll see
a line of thunderstorms move across eastern Nebraska overnight
tonight along a cold front with winds shifting to northwesterly
behind the line of storms. I have given a good estimate of
timing for storm arrivals at each of the terminals but this
timing may need to be adjusted as we see the complex develop
this evening and we get a better idea of timing. Models are
fairly confident in MVFR cigs developing behind the line of
storms with a shield of light rain. Cigs could lower as low as
700 feet, but more confident in MVFR cigs at this time. Will see
how models trend ahead of the next TAF package to see if we need
to change post-frontal cigs to IFR (20 percent chance at this
time). Expect low cigs to break out by Saturday afternoon.

&&

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

&&

$$

DISCUSSION...McCoy
AVIATION...McCoy