River Flood Warning 14, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
308 AM PDT Wed Apr 10 2019

.DISCUSSION...Current satellite imagery is showing some clouds
overhead, but concurrent +0.5 degrees RADAR is showing no returns
as of 2:30 AM. That being said, the -0.2 degree radar are showing
some light returns spilling across the Umpqua Divide from north to
south and in the Cascades. Web cameras are showing some
snow at the Willamette Valley Pass on Highway 58, and on Dead
Indian Memorial Road. Siskiyou Summit appears to have ongoing
rain, but it is difficult to tell with that web camera. These
showers will continue through the night, so travelers should
prepare for potential slippery conditions if traveling in the
mountains, otherwise, things remain quiet.

A few flooding concerns remain in the area, mainly the Coquille
River at Coquille which continues to threaten homes and roads in
low-lying areas near the river from the estuary to Myrtle Point.
The Coquille is still in Moderate Flood Stage, and has remained
near crest for the last 30 hours or so. Flooding impacts from this
river will remain for a few more days before the river returns to
its banks. Please see the FLSMFR for more information.

Meanwhile, the Pit River at Canby and the Sprague River at Beatty
remain near or at bank full, and are continuing to rise. Both
rivers are not expected to reach flood stage, but they will be
close. So will allow the flood watches to continue. Please see the
FFAMFR for more details.

The next system will arrive at the Pacific Northwest Coast today,
but looks to remain north of southern Oregon. This means that the
majority of precipitation will occur north of our area, but the
Coastal Range and the Southern Oregon Cascades north of the Umpqua
Divide could see a little bit of precipitation today. This system
will spread southward on Thursday, but only light rain is
expected, with maybe some moderate rain occurring at the coast
near Coos Bay and Florence. Showers will continue overnight
Thursday and taper off on Friday. Snow levels will be around 4000
to 5000 feet through this entire system. Thus, the precipitation
associated with this system is not expected to be enough to
increase flooding along the Coquille or any of the other rivers,
but it may delay the receding of the rivers at least a little bit.

Meanwhile, the snowfall in the Cascades will be between 5 and 9
inches, with the highest amounts occurring over the highest
elevations (think Crater Lake). Interstate 5 at Siskiyou Summit
may see a dusting of snow, but the higher passes could be the
issue. Regardless, this snow will fall over a long enough time
period that it should remain below advisory amounts.

Friday will have a quick break in the action before the next
system arrives on Saturday. Models are suggesting that this system
will arrive in the late morning to early afternoon for Douglas
County and northern Coos County, spreading into the rest of
southern Oregon and northern California Saturday evening and
night. The showers continue on Sunday as a shortwave reinforces
precipitation chances. Ensemble guidance suggests that this system
won't be as exciting as the last weekend, despite some decent
winds aloft.

Precipitation chances remain somewhat elevated through the rest of
the forecast period, but some of the models are trying to suggest
a ridge of high pressure trying to build in with systems moving
north of the ridge. Have gone with the ensemble guidance here as
picking a deterministic solution here would be strange (the GFS is
strong with the ridge with precipitation remaining north of
Eugene, the ECMWF is a bit weaker with the ridge allowing
precipitation to reach the northern reaches of the Umpqua Divide,
and the Canadian is very weak with the ridge allowing
precipitation to reach the entire area). Regardless, expect this
to get ironed out in future runs; so it's worth keeping an eye on.
-Schaaf

&&

.AVIATION...For the 10/06Z TAFS...Overall, expect a mix of
MVFR/VFR with terrain obscuration with MVFR becoming more
widespread overnight since there'll be plenty of low-level
moisture due to recent rainfall. These ceilings will last through
Wednesday morning. Some IFR is also possible, but confidence is
low in timing and extent of these lower conditions. -Spilde/BR-y

&&

.MARINE...Updated 200 AM PDT Wednesday, 10 April 2019...Swell
dominated seas will ease today with mostly light to moderate north
to northwest winds. A frontal system will push through the area
Wednesday night into Thursday with some showers, but winds and seas
should remain below advisory levels. West-northwest swell will build
to near or just above 10 feet Friday and remain elevated into this
weekend. The next front will move through Saturday or Saturday
night. Models have trended weaker with another front expected to
move in early next week. -Spilde/BR-y

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...None.

CA...None.

Pacific Coastal Waters...None.