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000
FXUS63 KOAX 121042
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
542 AM CDT Fri Apr 12 2024

.KEY MESSAGES...

- Fire danger will be in the very high category on Saturday
  afternoon.

- Much warmer temperatures are expected Saturday through Monday,
  with highs in the middle to upper 80s.

- There is a very high (90%) chance of thunderstorms Monday
  evening through Tuesday afternoon. Thunderstorms may become
  severe during this time frame, with the greatest potential
  focused over southeast Nebraska and southwest Iowa.

&&

.DISCUSSION...
Issued at 306 AM CDT Fri Apr 12 2024

After a dry and very windy day on Thursday, Friday`s end-of-
the-workweek weather will be much calmer, and is really shaping
up to be an outstanding weather day. Water vapor imagery
indicates that the long wave trough has shifted a bit to the
east, and the north-to-south train of shorter wavelength troughs
rotating through has also shifted east of the local area.
Meanwhile, broad ridging over the western CONUS has begun its
gradual build overhead. Winds have decreased quite a bit
overnight and will continue to decrease through sunrise,
then persisting as a steady breeze mainly out of the west
northwest, but eventually out of the west southwest late today.
The airmass will be quite dry, but winds will be light enough
that the overall fire danger will be reduced compared to
Thursday. High temperatures will be in the upper 60s to lower
70s under ample sunshine.

Temperatures will drop quickly in the evening as winds become
nearly calm around sunset, but southerly return flow builds in
overnight. The south winds increase on Saturday with the
increasing pressure gradient. The airmass will once again be
very dry with afternoon RH in the 18-28 percent range and winds
gusting 20-28 mph. Currently it appears that most of the area
will just miss red flag criteria, but it will be very close and
forecast soundings (and the current forecast) suggest that RH
will be on the extreme low side of guidance while gusts will be
on the high side with ample mixing. Similar days have tended to
mix deeper than most model guidance indicates, leading to the
drier, warmer, and gustier scenarios. Even with that in mind,
Saturday will be borderline, but something to watch. Speaking of
warmer...the entire area should climb into the mid 80s. Sunday
will be quite warm and dry as well, although not as windy with
high pressure dominating much of the day.

The weather gets quite interesting as Sunday night blends into
Monday and Tuesday. The upper ridge will shift east with a
strong trough developing into the Four Corners region, taking on
a negative tilt as it ejects northeast toward our local forecast
area. While Sunday will be quite dry, moisture return will be
ongoing to our south, and by Monday it appears quite likely that
60 degree dewpoints will make it at least this far north. A
strong jet streak will wrap around the southeast side of the
storm system, overhead by late Monday. While the heart of the
storm system will be over eastern CO on Monday evening, there
are strong signals that there will be sufficient forcing and
instability to initiate convection and move it across the local
area. This may occur in multiple waves during the evening and
overnight hours, continuing into Tuesday morning. The convective
environment is muddled amidst these waves of storms, but it
appears that the warm sector of the system will remain in our
forecast area through mid day Tuesday. If this does occur, the
upper low would appear likely to move overhead which could set
up an interesting scenario for low-topped storms with ample
vertical vorticity. Several ingredients for severe storms will
be in place Monday evening through Tuesday afternoon, but with
great uncertainty surrounding storm mode due to ample forcing
and potential for multiple convective foci. Storm organization
does appear likely with elongated hodographs, and there are
periods of impressive low-level shear as well, so at least for
now will need to keep all hazards in consideration.

The next wave on Wednesday night comes with a bit colder airmass
in place, and could result in a cold rain or even some brief
pockets of snow. Temperatures will cool a bit for Wednesday
through the end of next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 541 AM CDT Fri Apr 12 2024

VFR conditions expected to hold through the TAF period. Winds
out of the north or northwest today will shift to south-
southeasterly around 23-00Z this evening. Winds will hold out of
the south-southeast through the remainder of the TAF period.

&&

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

&&

$$

DISCUSSION...Barjenbruch
AVIATION...McCoy