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587
FXUS63 KOAX 020813
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
313 AM CDT Thu May 2 2024

.KEY MESSAGES...

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- A few stronger to isolated severe storms may linger early
  this morning and produce some 40-50 mph gusts and ponding of
  water on roads.

- An active weather pattern will continue into the weekend and
  early next week with the highest storm chances Friday night
  and Monday. There will be some severe weather potential at
  times, especially Monday, but confidence on details is rather
  low.
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&&

.DISCUSSION...
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Issued at 313 AM CDT Thu May 2 2024

Some strong to isolated severe storms were moving through
southeast NE as of 3 AM, with spotty gusts just on either side
of 60 mph, though the vast majority of obs with these storms
were in the 40-50 mph range. Radar imagery showed an outflow
boundary pushing southeast ahead of these storms, with most
activity to the northwest weakening significantly. In addition,
storms were moving out of the better moisture...out of lower 50s
dewpoints and into 40s dewpoints. As a result, expect these
storms to continue to weaken/become disorganized as the push
east/northeast over the next couple hours, and latest CAMs
continue to suggest this will be the case. Additional storms are
on the way immediately behind the primary line, but these
should be weaker. Will need to keep an eye on wake low wind
potential, with several sites gusting 40-50 mph out of the east
behind the storms. Finally, can`t completely rule out some
localized flooding this morning, but trends have been toward
these storms moving out a little bit quicker with a little less
training over the same areas.

Storms should exit to the east by late morning with perhaps a
few spotty sprinkles/light showers lingering in parts of the
area today. Do expect some storms to re-develop right along the
front early this afternoon, some of which could be strong to
severe, but guidance is in good agreement that this will occur
south and east of the forecast area. That said, any slowing of
the front and portions of far southeast NE/far southwest IA
could see a low end severe weather threat (probably less than a
5% chance of this happening). Otherwise, it should be fairly
quiet with with northwest winds around 15-20 mph and
temperatures topping out in the 60s.

The pattern stays active heading into the weekend and early
next week with mean troughing over the western CONUS and various
bits of shortwave energy/surface fronts sliding through and
bringing additional storm chances. The first will come Friday
night as a cold front pushes into at least a somewhat unstable
airmass bringing a likely MCS across much of Nebraska. Still
some questions as to just how unstable it will be, though, with
overall consensus keeping us below 500 J/kg of MUCAPE, but a few
pieces of guidance (02.03Z RAP and 02.00Z NAM) suggesting some
pockets of 1000-1500 J/kg (most likely to our west and just
clipping some of our southwestern counties
(Saline/Jefferson/Gage). Shear would be sufficient for storm
organization and severe weather, though latest guidance suggests
0-3 km shear vectors look to largely remain parallel to the
front, indicating that storms that do develop would quickly
become outflow dominant. Still, could be just enough for some
gusty winds and perhaps some hail. Again, highest chances for
severe weather will likely mostly be to our southwest, but much
of the area should see at least some rain Friday night into
Saturday morning.

Once this precip exits, should see a fairly nice Saturday
afternoon with decreasing clouds and highs in the 60s with
surface high pressure building in behind the front. As the high
pushes off to the east Sunday, we`ll start to see strengthening
southeasterly flow start to usher in some moisture and slightly
warmer temperatures as the front from Friday night starts to
work back north as a warm front. Still some spread on just how
far north it gets, with some guidance getting it into southern
portions of the forecast area and other guidance keeping it well
south. Wherever it ends up, expect some showers and storms in
vicinity of the front (bottom line, 20- 40% chance in our area),
but severe weather looks unlikely at this time.

Higher severe weather chances look to arrive Monday as a potent
shortwave trough slides through with a surface low spinning
across MT/WY and into the Dakotas. This will drag a cold
front/dry line into the area which will interact with a moist,
unstable airmass and lead to storm development. Being pretty far
out, definitely some questions on details such as exact timing
of those boundaries and potential for morning precipitation
which may limit instability, so confidence remains on the lower
side. Still with several pieces of guidance showing strong deep
layer shear, curvature in low level wind profiles, and SBCAPE
values of 1500+ J/kg, it`s definitely worth keeping an eye on
for severe weather potential.

That precip should exit Tuesday morning, though additional
weaker bits of shortwave energy are progged to move through the
area at times through Wednesday, so keeping 10-20% rain chances
in the forecast for now. Otherwise, expect highs in the 60s and
70s through the weekend, and firmly in the 70s through the
middle of next week.
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&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1144 PM CDT Wed May 1 2024

A large complex of thunderstorms currently from central and
northeast NE into north-central KS will continue east and
affect the terminal locations during the overnight hours. VFR
ceilings will lower to MVFR with a period of IFR conditions most
probable at KOFK and KLNK. Furthermore, visibilities will be
reduced as the strongest storms move through. East or northeast
winds of around 12 kt will switch to northwest on Thursday with
the passage of a front through the area.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...Mead