633
FXUS63 KOAX 031125
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
625 AM CDT Mon Jun 3 2024

.KEY MESSAGES...

- A few spotty thunderstorms possible (10-15% chance)
  this afternoon in far southeast Nebraska and far southwest
  Iowa.

- Higher storm chances Tuesday afternoon (60-90%) with a
  15-20% chance of severe storms, mainly in southeast Nebraska
  and southwest Iowa. Large hail and damaging winds are the
  primary threats.

- Mostly dry Wednesday into the weekend with highs in the mid
  70s to mid 80s.

&&

.DISCUSSION...
Issued at 349 AM CDT Mon Jun 3 2024

As of 3 AM, remnants of the strong to severe line of storms that
tracked through Nebraska last evening were still sitting over
eastern NE/southwest IA, but were just mainly showers at this point.
The responsible shortwave trough will continue to push eastward this
morning and should leave us with mostly dry conditions by 8-9 AM.
This should set the stage for a fairly nice, but maybe somewhat
humid day for most of the area with temperatures topping out in the
lower to mid 80s and dewpoints in the mid 60s to around 70. Will
need to keep an eye out for storm development in far southeast NE
and far southwest IA toward peak heating this afternoon, but overall
confidence in storm coverage is rather low with weak forcing and a
bit of a cap to overcome. For what they`re worth, CAMs suggest just
a few spotty storms in the area, and most likely just to our
southeast, but they can often struggle in these weakly forced
situations. If we end up warming up more than forecast, coverage
could be a little higher. Also, there is plenty of instability to
work with for a few stronger cells (3000+ J/kg of SBCAPE), but shear
will be very weak, suggesting disorganized and short-lived
individual storms, and thus low potential for severe weather.

Higher storm chances will arrive Tuesday as a shortwave trough
currently over the Pacific Northwest arrives while a surface slow
spins across the Dakotas and drags a cold front through the forecast
area. It does look like a somewhat similar setup to what we saw on
Sunday with suggestions we see some early day convection with some
weaker shortwave energy moving through before the main wave and
surface boundary slide through at some point during the
afternoon/evening. The big question will be how much instability is
available due to the potential early day convection, as well as
questions on front timing (later afternoon would mean more
instability, earlier afternoon would mean less). The strongest deep
layer shear looks to remain behind the front so storms could be
somewhat disorganized and 0-3 km shear looks boundary-parallel,
suggesting storms that do develop could become outflow dominant
somewhat quickly. One are this setup differs from that of Sunday is
that storms are expected to initiate near or over the forecast.
Therefore, could see an initial large hail threat when storms are
more discrete, but expect a fairly quick transition to a wind threat
as storms congeal into a line and push southeast. Finally, storms
could once again be efficient rain producers with precipitable water
values around 1.50 inches, but latest guidance suggests the line
should move through fairly quickly.

Behind the front, northwesterly flow aloft will settle in with
surface high pressure helping to keep us mostly dry through the
weekend. Guidance does hint at a few weak bits of shortwave energy
sliding through at various times (highest chances Friday night and
Saturday night), but the best moisture should largely remain to our
south and west, so any precip we do get should be on the lighter
side. Otherwise, temperatures will be seasonable, with highs in the
mid 70s to mid 80s.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 607 AM CDT Mon Jun 3 2024

VFR conditions will prevail throughout the day. A few showers
and storms could pop up over southeast Nebraska this afternoon,
however they are not expected to impact the TAF sites. Variable
winds this morning will become southerly and should remain below
12 kts through the period.

&&

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

&&

$$

DISCUSSION...CA
AVIATION...KG