Winter Storm Watch 4, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
825 AM PST Sun Jan 8 2017

.DISCUSSION...We made some quick precipitation updates for
Northern California based on observations, trends, and latest
model data. Precipitation is exceeding model output, especially
for the Mount Shasta City area, and we will be considering Flood
Warnings for that area. Communication with Caltrans suggests no
widespread flooding affecting roadways at this time, but
conditions still favor some urban and small stream flooding today,
for much of the forecast area. Areal Flood Watches at FFAMFR
continue through this evening.

The vast majority of temperatures are above freezing this morning,
so we don't expect any wintry precipitation problems with this
system.

Satellite-derived precipitable water (PW) imagery this morning
suggests 1.5 to 2 inch PW values impinging upon the northern
California coast this morning. A steady stream of moderate to
heavy precipitation will continue through this afternoon before
tapering off as a cold front moves inland tonight.

Windy conditions are expected to taper off some over the West Side
later this morning where areas just above the valleys have become
windy overnight. Further east, winds will remain gusty through the
day and it will remain a generally windy period through Wednesday
as strong west to southwest flow at the 700mb level continues.

Last but not least, as cold air arrives behind the front tonight,
an upper low will move in from the northwest and flow will shift
to more southwesterly, bringing moderate to heavy snow to areas
above 3000 feet in Northern California and Southern Oregon. A
Winter Storm Watch at WSWMFR has been issued for this.

Please see the previous discussion below for more details on the
heavy rain and upcoming heavy mountain snow.

&&

.AVIATION...08/12Z TAF CYCLE...From the Cascades west...Light rain
showers with areas of MVFR cigs and local IFR cigs/vsbys early this
morning. Steady rain and widespread MVFR with higher terrain
obscured and strong southerly low level winds will develop between
15Z and 18Z this morning and continue into Monday morning...with
heavier areas of precipitation producing periods of IFR conditions
from this morning into this evening.

East of the Cascades....Light precipitation with a mix of MVFR and
VFR conditions early this morning will become mainly MVFR with
steadier light to moderate rain around 15Z to 18Z and include areas
of higher terrain obscured. Precipitation will taper to light
showers late tonight with snow levels falling to valley floors into
Monday morning.

&&

.MARINE...Updated 500 AM PST Sunday 8 January 2017...A frontal
passage will bring strong southerly winds today including gales this
morning from the southern outer waters to around Cape Blanco. Steep
to very steep seas this morning will reach a peak early this
afternoon but remain high into Monday with a mix of dominant wind
wave and a fresh southwest swell. Another episode of gale force
winds is possible with the next front late Monday morning into
Monday evening. High and very steep seas are likely to reach another
peak late Monday night. Confidence is high that very steep and
hazardous seas will persist through Wednesday. High pressure will
then move in with diminishing seas Wednesday evening into Friday.
-DW

&&

.PREV DISCUSSION... /Issued 309 AM PST Sun Jan 8 2017/

DISCUSSION...Cold ground and all the snow remaining in the west
side valleys has allowed temperatures to drop back to near
freezing this morning, and we've also had dense fog develop.
Reports indicate it is icy in spots out there this morning, so we
hoisted a freezing fog advisory (PDXNPWMFR). As the next front
nears, winds will pick up and mix out both the fog and the cool
temperatures, and this could occur at any moment, but probably by
dawn at the latest. There is some small concern that as rain
arrives this morning, there could be a brief period of freezing
rain in the valleys due to continued cold ground and cold surface
temperatures, but confidence was not high enough to issue any
winter headlines. We did mention this in the freezing fog advisory
as something to be on the lookout for.

Rain can be seen on radar spreading north through northern
California right now as the next frontal system offshore nears
and pulls ample moisture up through the Sacramento Valley. Models
remain consistent in showing widespread moderate to heavy rain
across our area today, and a flood watch remains in effect across
our southern tier of counties. Flood advisories will likely be
needed eventually today, and the most likely location to need a
flood warning today will be over central Siskiyou County where the
rain will be heaviest and snowmelt most efficient. We will also
see gusty winds through the Shasta Valley and across the east
side. Guidance shows winds just short of advisories except across
portions of southern Lake and Modoc Counties where a wind advisory
is already in place.

As the cold front moves in tonight, snow levels will fall to
around 3000 feet. At the same time, plenty of moisture will
continue to stream onshore both in the wake of the departing front
and also in advance of another frontal system Monday night into
Tuesday. The result will be very heavy snow over the coastal
mountains, Siskiyous, Cascades, and in the Shasta area above 3000
feet. Winter storm watches (PDXWSWMFR) were hoisted in these
areas for Monday into Tuesday. Below 3000 feet, we'll be dealing
with more heavy rain and continued flooding concerns.

If all that weren't enough, another extremely wet and mild system
will plow in later Tuesday into Wednesday bringing another round
of heavy rain and high snow levels. Although the breaks between
systems get longer later this week, it looks like the parade of
frontal systems may just keep coming. -Wright

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from noon today to 8 PM PST this evening for
     ORZ030-031.
     Winter Storm Watch from Monday morning through late Monday night
     ABOVE 3000 FEET for for ORZ025-027-028.
     Flood Watch through this evening for ORZ021-022-024-028.
     Flood Watch through this evening for ORZ023-026.
     Winter Storm Watch from late tonight through Tuesday morning
     ABOVE 3000 FEET for for ORZ024.

CA...Wind Advisory from noon today to 8 PM PST this evening for
     CAZ085.
     Flood Watch through this evening for CAZ080.
     Flood Watch through this evening for CAZ081>083-085.
     Winter Storm Watch from Monday morning through Tuesday morning
     ABOVE 3000 FEET for for CAZ082-083.
     Winter Storm Watch from late tonight through Tuesday morning
     ABOVE 3000 FEET for for CAZ080.

Pacific Coastal Waters...Hazardous Seas Warning until 10 PM PST Wednesday for
     PZZ350-356-370-376.
     Gale Warning until 10 AM PST this morning for PZZ370-376.

NSK/TRW/DW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
1218 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1218 PM     HEAVY RAIN       1 S ADIN                41.19N 120.95W
01/08/2017  M0.64 INCH       MODOC              CA   TRAINED SPOTTER

            SINCE MIDNIGHT. MINOR FLOODING IN AREA.

&&

SBN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
1228 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1227 PM     HEAVY RAIN       GLENDALE                42.74N 123.43W
01/08/2017  M1.38 INCH       DOUGLAS            OR   TRAINED SPOTTER

            1.38 INCHES PAST 12 HOURS.

&&

NSK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
124 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 PM     HEAVY RAIN       3 SSE MOUNT SHASTA      41.28N 122.30W
01/08/2017  M3.20 INCH       SISKIYOU           CA   TRAINED SPOTTER

            TOTAL SINCE MIDNIGHT PST.

&&

MND

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
125 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1245 PM     HEAVY RAIN       5 E WINCHESTER          43.29N 123.25W
01/08/2017  M0.72 INCH       DOUGLAS            OR   TRAINED SPOTTER

            MEASUREMENT WAS AT 8 AM PST.

&&

MND

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
126 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1225 PM     HEAVY RAIN       5 NNW BROOKINGS         42.12N 124.32W
01/08/2017  M1.20 INCH       CURRY              OR   TRAINED SPOTTER

            TOTAL SINCE 1 AM PST.

&&

MND

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
211 PM PST SUN JAN 8 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0210 PM     HEAVY RAIN       2 SSW OBRIEN            42.05N 123.71W
01/08/2017  M2.13 INCH       JOSEPHINE          OR   TRAINED SPOTTER

            SINCE MIDNIGHT.

&&

SBN