National Weather Service Raw Text Product

063 
FXUS63 KOAX 061402
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
802 AM CST Sat Mar 6 2021

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 254 AM CST Sat Mar 6 2021

.Today and Sunday:

A shortwave trough moving onto the CA coast early this morning
will move into the northern/central Rockies today with a
downstream ridge overspreading the adjacent plains. The shortwave
trough is forecast to deamplify while traversing the northern 
plains and mid MO Valley late tonight into Sunday morning with
rebounding mid-level heights forecast by Sunday afternoon.

A deepening surface trough in the lee of the Rockies will
encourage the development of a low-level warm advection pattern
over the mid MO Valley today with afternoon temperatures warming
into the mid to upper 60s at many locations. The lee trough will
move off the high terrain tonight in response to the approach of
the mid-level disturbance with that boundary weakening over our
area on Sunday. Southwest winds will increase ahead of the
boundary on Sunday with substantial warming/drying occurring within
the warm-sector air mass. Highs on Sunday will be in the upper 
60s to lower 70s with lowest relative humidity values 25 to 30 
percent. While the expected humidity values don't meet red-flag 
warning criteria, much of the area will fall within the very high
rangeland fire danger category.

.Monday and Tuesday:

A broad southwesterly mid/upper-level flow regime is forecast to
evolve over the Great Plains early next week ahead of a prominent
mid-level trough located along the West Coast. The models continue
to suggest that an embedded disturbance will move through the
central plains on Monday night and Tuesday morning. However,
forecast soundings indicate that capping at the base of an EML in
conjunction with marginal moisture content will limit
precipitation potential. Otherwise, a cold front developing over 
the northern High Plains on Monday night will move southeast with 
that boundary potentially reaching northeast NE on Tuesday 
afternoon. 

Above-normal temperatures will continue with highs on 
Monday in the mid 60s to around 70. Tuesday is expected to be 
warmer with afternoon readings in the upper 60s to mid 70s.

.Tuesday night through Friday:

The 00z global models are all in general agreement in the movement
of the above-mentioned mid/upper trough along the West Coast into
CA or the southwestern deserts by Friday. However, the models
differ on the amplitude and movement of a polar-branch shortwave
trough over central Canada and the north-central U.S., as well
with the timing and intensity of a separate disturbance moving 
through the central plains on Wednesday. Those differences could
have implications on how quickly the surface cold front moves 
through our area, and by extension, the precipitation chances 
associated with the frontal passage.

Currently, it appears the best chance for showers and perhaps a
few thunderstorms will be on Wednesday with any heavy-rainfall
potential setting up to the southeast of our area. With regard to
temperatures, there will be a fairy large range (50s north and
60s/low 70s south) across the front on Wednesday. Readings will 
then fall back into the 50s on Thursday and Friday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 759 AM CST Sat Mar 6 2021

After MVFR vsbys in fog lift at KOFK early this morning, VFR 
conditions are forecast through Sunday morning. South winds 5 to
15kt are forecast through the period. Low level wind shear is
likely at all sites after 04Z as a south to southwest low level 
jet increases to 40 to 50kt.

&&

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

$$

DISCUSSION...Mead
AVIATION...Dergan