505
FXUS63 KOAX 270439
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1139 PM CDT Fri Apr 26 2024

.KEY MESSAGES...

- Severe thunderstorms Today and Saturday with strong tornadoes,
  large hail, damaging winds, and flash flooding possible.
  Greater flooding threat on Saturday night.

- Severe thunderstorms possible on Sunday as well, to a lesser
  degree, but brief tornadoes possible as well.

- Storms wrap up by Monday, with warmer temperatures arriving
  next week. Another round of showers and storms possible
  Tuesday/Wednesday.

&&

.DISCUSSION...
Issued at 1224 PM CDT Fri Apr 26 2024

Skies are clearing from the southeast this afternoon as storms
are starting to develop near the center of the surface low
across central Nebraska. There`s already one supercell that has
developed west of Grand Island. We`re watching towering Cu start
to develop across north-central Kansas and south-central
Nebraska out near Hebron which will be our line of strong to
severe thunderstorms for this afternoon. We have a primed
environment with 2000-2500 J/kg of MLCAPE, 150-200 m2/s2 of 0-1
km helicity that increases to 200+ across southeast Nebraska.
Seems like this could be a day where any individual storm will
be capable of producing a strong tornado. Storms will be moving
into the Lincoln area around 3 PM, the Omaha Metro around 4 - 5
PM, making it to the Missouri River around 5 PM, and out of our
area by around 7 to 8 PM. Some of the CAMS show the potential
for an additional storm or two trailing behind the main line,
but the severe window for each area will center mostly around
the main line of storms.

Once storms clear the area this evening, we`ll see clearing
skies across most of our area. We will have low clouds spread
south out of South Dakota overnight tonight into Norfolk, but
probably won`t make it as far south as Omaha.

Saturday morning we`ll be between systems, dry with light
winds. We`ll see a warm front lift north during the afternoon
with the approach of our next low pressure system. We`ll see
initial storm development along and ahead of the warm front
around 6-7 PM with several rounds of storms developing and
training along the warm front which stalls somewhere along I-80.
With training storms, we add the significant potential for flash
flooding in addition to large hail, strong tornadoes, and
damaging winds Saturday evening, with the significant severe
threat possibly not ending until after midnight.

We`ll see a third chance for severe storms on Sunday as the
center of the surface low passes over our area Sunday afternoon.
This will be a lower threat, but should not be overlooked. This
will be similar to what we saw about ten days ago where we had a
couple brief tornadoes that popped up from low-topped supercells
that developed in a similar environment as the surface low again
passed right over our area. We could also see hail up to
quarter-size and damaging winds up to 60 mph. All storms should
finally exit our area after midnight Monday.


For the extended forecast, we just don`t have time right now to
do an in-depth analysis beyond day three. See previous
discussion below:

We finally receive a break from the active weather pattern on
Monday and into early next week, with just a few minor showers
and storms possible Tuesday and Wednesday. Temperatures will
generally top out in the 70s next week, with a few locations
reaching the low 80s on Tuesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 649 PM CDT Fri Apr 26 2024

Winds will be generally out of the west at 10 to 20 knots for
the next hour or so. Overnight tonight, winds will diminish to
under 10 knots and veer with time to become more northerly through
the TAF forecast period. Increasing cloud cover from the south
beginning tomorrow morning will bring periods of MVFR ceilings
to all TAF sites (by 15Z for portions of northeast Nebraska,
including KOFK, and after 00Z for the rest of the area including
KLNK and KOMA). There will be the potential for scattered rain
and thunderstorms after 19Z along and south of the I-80 corridor
(KLNK and KOMA), but coverage and timing uncertainties preclude
inclusion in TAFs at this time. Winds south of I-80 after 19Z
are expected to prevail out of the south. Some storms may be
strong to severe south of I-80 with all modes of severe weather,
including flash flooding, possible.

&&

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

&&

$$

DISCUSSION...KG/McCoy
AVIATION...Darrah