Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 262302
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
602 PM CDT FRI AUG 26 2016

.SHORT TERM...(tonight through Monday)
Issued at 312 PM CDT FRI AUG 26 2016

Manual 12z upper-air analysis showed a long-wave trough from the lee
of the Canadian Rockies into the southern Rockies with a downstream
sub-tropical high centered over the southern Appalachians.  Between
these features, water vapor imagery indicates a short-wave trough
moving into the northern and central High Plains with a weaker
vorticity lobe located over northeast Kansas. At the surface, 18z
mesoanalysis placed a low over northeast Kansas -- coincident with
the upper-air system-- with an associated warm frontal segment
extending northeast through northwest Missouri into south-central
Iowa.

Showers and thunderstorms now developing over northeast Kansas in
association with the above-mentioned impulse are expected to
spread northeast along the warm front with portions of southeast
Nebraska and southwest Iowa being impacted by this activity. An
isolated strong to severe storm could affect far southeast
Nebraska later this afternoon into evening with the more organized
severe weather threat likely remaining to the south of our area.

Farther to the northwest, a short-wave trough emerging into the
northern and central High Plains has focused a band of
precipitation from central South Dakota to western Nebraska as of
early afternoon. This short-wave trough is forecast to undergo
rapid weakening as it ejects northeast into the upper Great Lakes
ahead of a more substantial polar-branch short-wave trough
amplifying over the northern Plains. This will likely result in
the decay of the precipitation band as it approaches northeast
Nebraska this evening into tonight, as suggested by a consensus of
model guidance. As such, we have lowered POPs considerably.

Mid-level heights will rebound on Saturday into Saturday night
with the passage of the polar-branch trough (mentioned above) to
our northeast. There could be some lingering showers across
eastern and southern counties early Saturday with decreasing
clouds allowing temperatures to warm into the upper 70s to lower
80s.

Sunday into Monday, a weak southern-stream trough will edge east
from the Rockies into the central Plains, supporting slight
chance to low-chance POPs. We will see warmer daytime temperatures
during that time frame with readings in the mid 80s.

.LONG TERM...(Monday night through Friday)
Issued at 312 PM CDT FRI AUG 26 2016

The 12z medium-range models continue to indicate the
amplification of a mid-level ridge next week from the north-
central U.S. into central Canada. The passage of a mid-level
trough through Ontario and the Great Lakes early next week will
drive a surface front into the mid Missouri Valley. This boundary
will begin to lift back north of the area during the middle to
latter part of the work week. The presence of this feature will
support a continued chance (albeit low) of storms. Daytime highs
are expected to remain in the lower to mid 80s.

&&

.AVIATION...(00Z TAFS for KOFK...KLNK and KOMA.)
Issued at 600 PM CDT FRI AUG 26 2016

General model consensus is for deteriorating conditions overnight
with low ceilings and fog. Trended TAFS downward starting this
evening with MVRR conditions, then IFR late tonight until a little
after sunrise Saturday. Confidence on timing and conditions is
fairly good, but just exactly how low visibilities will go is
uncertain. Did not go below 1 mile at this point.

&&

.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&

$$

SHORT TERM...Mead
LONG TERM...Mead
AVIATION...Miller



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