390 
FXUS63 KOAX 011104
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
604 AM CDT Sat Jun 1 2024

.KEY MESSAGES...

- Daily storm chances starting by this evening and lasting
  through at least Tuesday.

- The highest chances for strong to severe storms are on Sunday
  and Tuesday, but confidence is low on exact timing and how 
  widespread the severe weather threat will be.

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

&&

.DISCUSSION...
Issued at 311 AM CDT Sat Jun 1 2024

Pretty quiet early this morning with radar showing only some 
light lingering returns in our area following our day of heavy 
rain. To our west, a few storms were going up over in the NE 
panhandle on the nose of some weak low level moisture transport.
CAMs suggest they will push east through the morning and 
gradually weaken, though a few pieces of guidance suggest they 
could make it to portions of northeast NE by late morning 
through mid-afternoon. Shouldn't amount to much more than a 
brief downpour and some lightning if they make it (probably a 
10-15% chance). 

Additional storms are expected to approach from the west late 
this evening into early Sunday, but once again should weaken as 
they push east, with most guidance in good agreement that 
instability quickly tapers off in our forecast area. That said, 
it is worth noting that a few pieces of guidance (various 
GEFS/EPS members and the 01.00Z NAM) give us a little more 
instability and suggest the storms organize into an MCS and push
through Sunday morning on the nose of strong moisture 
transport. Then during the day Sunday, the general idea is that 
we'll see strengthening southerly flow/moisture ahead of a 
surface low in eastern CO and some shortwave energy progged to 
move along the NE/SD border. This looks to usher in a warm, 
moist, unstable airmass with MUCAPE values of 2000-3000 J/kg 
ahead of a cold front approaching from the northwest, suggesting
we'll see a line of strong to severe storms late Sunday 
afternoon/evening. However, there's quite a bit of spread on 
just how much shower and storm activity we'll see during the 
day, likely in large part owing to differences in cap strength. 
This will play a large role in how the evening severe weather 
threat plays out, with any daytime storms likely greatly 
reducing instability ahead of the approaching front. In fact, if
storms do get going during the daytime hours, a few could be 
strong to severe, though deep layer shear does look to be on the
weak side (25-30 kts), suggesting they could be a little 
disorganized. So bottom line, we're highly confident we'll see 
thunderstorms at some point on Sunday (70-90% chance), but lots 
of questions remain on exact timing and the overall severe 
weather threat. Less storms during the day would mean a much 
stronger line of storms for the evening. More storms during the 
day would mean a more prolonged strong to severe storm threat, 
but maybe a little lower end when it comes to coverage and 
strength of severe storms. Flooding is probably the severe 
weather threat we have the highest confidence in seeing simply 
due to the recent heavy rainfall and additional rounds of storms
in an environment with precipitable water values progged to be 
hovering around 1.50 inches.

Additional storms would be possible Monday with a decent amount
of instability remaining in place over at least the southern 
half of the area and some moisture transport continuing to point
into the region. Tuesday looks to be our next best chance for 
severe weather, with a very similar setup to that of Sunday as 
we could see some daytime showers and storms ahead of an 
approaching cold front that could bring another line of strong 
to severe storms Tuesday evening.

Behind that front, model consensus is that surface high 
pressure builds in and keeps us mostly dry, though there are 
some hints that a few bits of weak shortwave energy slide 
through the northwesterly flow aloft and bring us additional 
shower and storm chances through the latter half of the work 
week. However, at this time those chances appear to be 10% or 
less. Otherwise, expect seasonable temperatures for the start of
meteorological summer, with upper 70s to mid 80s on tap through
next week (though daytime showers and storms could lead to 
cooler highs on a couple days).

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 557 AM CDT Sat Jun 1 2024

Patchy fog and areas of MVFR to IFR ceilings will clear out by
16Z this morning, with VFR conditions returning. Chances for
showers and thunderstorms will increase after midnight tonight
and persist into Sunday morning. Winds will be light and 
generally out of the north this morning and gradually veer to 
the southeast by 00Z this evening. 

&&

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

&&

$$

DISCUSSION...CA
AVIATION...KG