857
FXUS63 KOAX 310751
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
251 AM CDT Fri May 31 2024

.KEY MESSAGES...

- Thunderstorms will linger into tonight. If storms repeat
  over areas that received heavy rainfall last night, some
  localized flooding could occur.

- Additional storms could move in by late Saturday
  afternoon/evening (20-40% chance) with daily chances
  continuing into at least Wednesday. The highest chances for
  strong to severe storms look to be Sunday and Tuesday.

- Slightly warmer through next week with highs in the upper 70s
  and 80s.

&&

.DISCUSSION...
Issued at 251 AM CDT Fri May 31 2024

Watching a couple areas of showers and storms leading to
perhaps some localized flooding early this morning. The first
being along a surface boundary basically splitting NE from
northeast to southwest and the second on the nose of some
moisture transport pointing into far southeast NE and southwest
IA. Guidance suggests the precip associated with the boundary
should taper off toward sunrise as shortwave energy pushes off
to the east and moisture transport into the area weakens.
However, the latter area of precip does look to continue with
persistent moisture transport through much of the day. The good
news is that instability in that area is rather minimal so rain
over the last few hours has been rather light, and this looks to
continue. So while there is some concern with localized
flooding in that area just given 4+ inches of rain already in
that area, rainfall rates should remain on the lighter side at
least through early this afternoon.

Unfortunately, the surface boundary looks remain relatively
stationary today and with some additional shortwave energy
sliding in by this afternoon and MUCAPE values approaching 2000
J/kg, expect storm redevelopment in vicinity of the boundary and
in areas that received heavy rainfall last night. While weak
shear will limit storm organization and overall severe weather
threat once again, this will lead to slow storm movement and an
increased flooding threat, especially with precipitable water
values of 1.25-1.50" and increasing moisture transport into the
boundary by mid to late afternoon into this evening.

Most short term guidance puts an end to storms by midnight
tonight, with only a few spotty showers perhaps lingering into
the overnight hours. Expect most of the area to remain dry for
much of Saturday, but yet another bit of shortwave energy is
progged to slide east into the area by late Saturday
afternoon/evening, bringing yet another chance for showers and
storms. For what they`re worth this far out, CAMs suggest we`ll
see a weakening cluster/broken line of storms moving in, but
still could be just strong enough to produce some gusty winds.
Still plenty of details to work out there, though.

A few of those storms could linger into Sunday, potentially
playing a role in strong to severe storm chances for the evening
hours. The general idea is that they should dissipate by the
afternoon with continued southerly flow ushering in a warm,
moist, and unstable airmass ahead of a somewhat stronger
shortwave trough and surface cold front approaching from the
west. Guidance is in fairly good agreement that we see a line of
strong to severe storms form, but the early day
convection/clouds could limit destabilization. In addition,
shear still looks to be rather disorganized and on the weaker
side, so would think any line of storms that does form should
weaken as it pushes southeast into the area. However, relative
to previous days, the shear does look to be a bit stronger
Sunday evening so in turn, the severe weather threat should be
at least a little higher.

Expect a few lingering showers and storms Monday as the
boundary stalls in/near the forecast area and southerly flow
ushers in more moisture. This will eventually lead to a setup on
Tuesday similar to that of Sunday with a stronger shortwave
trough and surface cold front sliding through at some point
(still a fair amount of spread on exact timing). This would be
our next highest chance for severe weather, but once again, lots
of details and rounds of storms to get through between now and
then.

So overall, the pattern looks to remain active with daily
shower and storm chances and occasional severe weather chances
(especially Sunday and Tuesday), though relatively weak shear
should somewhat limit those chances. Temperatures will be on a
slight upward trend, with highs largely in the upper 70s and 80s
Saturday through next week, though precipitation will almost
certainly impact those temperatures some days.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1126 PM CDT Thu May 30 2024

A frontal boundary has stalled across northeast Nebraska and
will continue to train storms near KOFK through the overnight
hours leading to occasional showers and storms moving near or
into the terminal through the next few hours. This could last as
long as through 12Z, but for now have it in the TAF through 09Z.
Other than that, the next concern is MVFR/IFR cigs spreading
across the area overnight. These cigs will hang around through
the morning hours with occasional showers or drizzle reducing
visibility. Cigs will lift to VFR by Friday afternoon, but we`ll
see additional scattered showers and storms develop which may
impact the terminals through Friday afternoon and evening. Winds
will main primarily out of the southeast, apart from
occasionally becoming variable near stronger showers and
thunderstorms.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...McCoy