825
FXUS63 KOAX 270838
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
338 AM CDT Sat Apr 27 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 330 AM CDT Sat Apr 27 2024

Multiple violent tornadoes scoured the forecast area yesterday,
leaving a path of devastation in their wake. Multiple damage surveys
will be conducted on Saturday in order to begin to determine the
number and intensity of each tornado. Overall, the surveys will
take days, if not weeks to complete, with 2 more days of severe
weather waiting on our doorstep. Our hearts go out to all of
the people that have been impacted by Friday`s event.

We had a brief reprieve tonight to catch our breath, as storms
festered off to our east, over eastern Iowa. A frontal boundary
attendant to the surface low associated with Friday`s storms has
sagged south of forecast area overnight. Quiet weather will prevail
through the morning hours on Saturday, before that boundary lifts
north as a warm front ahead of the next low pressure system. Round
two of severe weather will ignite along this boundary near the
Nebraska/Kansas border by around 2 PM Saturday. Large hail,
strong winds, and potentially a strong tornado or two will be
possible once again as these storms lift north toward I-80. The
boundary will eventually stall, bisecting our CWA Saturday
evening. With PWATs approaching the 90th percentile,
climatologically, we could see some heavy rain production from
these storms. While it depends on how far north the front is
able to travel, should these storms overlap the location of
Friday`s heavy rainfall/saturated ground, areas of flooding
would be likely. Therefore, we opted to hoist a Flood Watch from
locations along and north of a line from Seward, NE to Red Oak
IA for Saturday afternoon through Sunday morning.

Our third and final round of severe storms (at least for the
immediate future) arrives Sunday as the surface low passes over
eastern Nebraska and southwest Iowa. The greatest chance for severe
storms looks to be just to the south east of our forecast area
SUnday afternoon and evening. however large hail, strong winds, and
perhaps a few tornadoes could clip far southeast Nebraska and
southwest Iowa.

Storms finally exit the region late Sunday night/early Monday
morning. Overall, our pattern remains active through next week, with
multiple chances for showers and storms beginning Tuesday and
persisting through next weekend.

&&

.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...Flood Watch from this afternoon through Sunday afternoon for
     NEZ015>018-030>034-042>045-050>053-065>067.
IA...Flood Watch from this afternoon through Sunday afternoon for
     IAZ043-055-056-069-079-080.

&&

$$

DISCUSSION...KG
AVIATION...Darrah