Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 161732

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1232 PM CDT SUN OCT 16 2016

Issued at 1102 AM CDT Sun Oct 16 2016

Have allowed dense fog advisory to expire at 11 AM. There are
still a couple of sites reporting a quarter mile visibilities at
11 AM...but gradually improving conditions will continue in all
areas as we head toward noon.

UPDATE Issued at 700 AM CDT Sun Oct 16 2016

Dense fog continuing to spread northwestward and expect trend to
continue and last into the late morning. Extended the dense fog
advisory to account for this. Parts of southeast Nebraska should
improve from the south after sunrise.


.SHORT TERM...(today through Tuesday)
Issued at 320 AM CDT Sun Oct 16 2016

The primary forecast concerns are in regards to fog and low clouds,
which may have some impact on high temperatures today.

08z observations and IR fog satellite product show fairly
widespread dense fog in western Iowa and parts of eastern
Nebraska. This should hold most areas into mid morning and may
expand west as suggested by some recent high resolution short
range models (RAP, HRRR, HRRRX). With time, boundary layer and
surface winds should increase from the southeast. HRRR run from
06Z even kept some fog into northeast Nebraska through early
afternoon, so have kept highs coolest there (lower to mid 70s).

Light winds again tonight may lead to fog formation after
midnight. Did not mention dense fog for tonight at this time due
to low confidence on exactly how low visibilities will go. Look
for lows mainly in the 50s, with some lower 60s in southeast
Nebraska and the southern parts of southwest Iowa.

If fog dissipates as expected Monday, it should be a mild day with
southwest low level winds and modest mixing. Guidance suggests high
temperatures mostly in the upper 70s to mid 80s, with some upper 80s
possible near the Kansas border. That scenario seemed reasonable and
was close to the previous forecast.

Cooler air will start to slip in behind a front Monday night,
dropping highs into the upper 60s north and lower 70s south for
Tuesday. Normal highs are in the lower and mid 60s, so Tuesday
would still be considered mild.

.LONG TERM...(Tuesday night through Saturday)
Issued at 320 AM CDT Sun Oct 16 2016

The longer range models are in pretty good agreement with the large
scale pattern in most of this period. A trough will be out in the
Pacific along 160 degrees west longitude Tuesday, which then
moves east to around 140 west by Friday. Also through this period,
a trough will move across the plains (Tuesday through Thursday)
while a ridge develops over the Rockies. The Canadian model
pattern at 500 mb was an outlier, compared to the GFS and ECMWF,
so it was not given any weight. As the ridge expands slightly east
and broadens, our temperatures should moderate slightly toward
next weekend.

Kept some chance of showers going for at least parts of the area
from Wednesday into Thursday, but at this time any amounts are
expected to be very light.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1229 PM CDT Sun Oct 16 2016

IFR cigs/vsbys will lift to MVFR at all eastern Nebraska TAF sites
by 21Z-23Z timeframe. There will likely be a period of VFR
conditions between 00Z and 06Z, however IFR to VLIFR fog is
expected to settle back into all TAF sites after 06Z. KOFK and
KOMA will likely drop to near airport minimums from 10Z to 14Z.
More rapid improvement is expected after 15Z than we saw Sunday
morning as south winds increase more rapidly and turn to the
southwest by 18Z.


.OAX Watches/Warnings/Advisories...


LONG TERM...Miller
AVIATION...Dergan is the U.S. government's official web portal to all federal, state and local government web resources and services.