Freeze Warning 13, NWS Medford, OR

426 
WWUS76 KMFR 171656
NPWMFR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MEDFORD OR
856 AM PST SAT DEC 17 2016


ORZ021-171800-
/O.EXP.KMFR.FZ.W.0013.000000T0000Z-161217T1700Z/
/O.EXP.KMFR.FR.Y.0016.000000T0000Z-161217T1700Z/
SOUTH CENTRAL OREGON COAST-
INCLUDING THE CITIES OF...COOS BAY...NORTH BEND...BANDON...
PORT ORFORD
856 AM PST SAT DEC 17 2016

...FREEZE WARNING WILL EXPIRE AT 9 AM PST THIS MORNING...
...FROST ADVISORY WILL EXPIRE AT 9 AM PST THIS MORNING...

TEMPERATURES ALONG THE COAST ARE RISING AND THOUGH SOME SPOTS MAY 
REMAIN BELOW FREEZE WARNING AND FROST ADVISORY CRITERIA PAST 9
AM...MOST WILL CONTINUE RISING.

$$

ORZ022-171800-
/O.EXP.KMFR.FR.Y.0016.000000T0000Z-161217T1700Z/
CURRY COUNTY COAST-
INCLUDING THE CITIES OF...BROOKINGS...HARBOR...GOLD BEACH
856 AM PST SAT DEC 17 2016

...FROST ADVISORY WILL EXPIRE AT 9 AM PST THIS MORNING...

TEMPERATURES ALONG THE COAST ARE RISING AND THOUGH SOME SPOTS MAY 
REMAIN BELOW ADVISORY CRITERIA PAST 9 AM...MOST WILL CONTINUE
RISING.

$$

Area Forecast Discussion
National Weather Service Medford OR
941 AM PST Fri Dec 16 2016

.UPDATED MARINE AND AVIATION DISCUSSION.

.DISCUSSION...A few minor updates will be made this morning. The
flood warning for the Coquille and Coquille will be extended later
this morning since it is still well above flood stage and,
historically, flooding there recedes very slowly. The Rogue at
Agness has dropped below flood stage and will be expired shortly.
All other flood products have already been taken down.

The frost advisory along the coast will be allowed to expire at 9
AM. It looks like some locations were cold enough for frost, but
the north coast had clouds, so there probably wasn't much frost
there. At any rate, tonight should be a much colder night, so the
remaining frost/freeze products look on track for tonight.

I also raised pops a little on the east side, in particular, over
the Lake and Modoc County mountains. The satellite shows pretty
solid cloud cover as the remainder of an upper trough swings
through. Webcam and radar coverage is sparse, but at the very
least, it's still snowing in the Warner Mountains as shown on the
Cedar Pass camera. This will gradually diminish today as the
trough moves away, but there will be some light accumulations in
the east side mountains. -Wright

&&

.AVIATION...17/18Z TAF CYCLE...CIGS are expected to gradually
increase during the day and clouds will gradually become scattered
as drier air moves into the region. VFR CIGS are expected to be the
predominate condition into this evening. However could not rule out
partial mountain obscuarations east of the Cascades through at least
22z. The one exception for VFR CIGS is in Roseburg where MVFR CIGS
could persist for most of the day. Current TAF shows Roseburg going
to VFR around 0z, but conditions could improve an hour or two
earlier. Low clouds and fog are almost certain in the Umpqua Basin,
Illinois and Rogue valley later this evening through at least 18z
Saturday. -Petrucelli

&&

.MARINE...Updated 941 AM PST Friday 16 December 2016...Current
observations show seas have diminished below 10 feet, thus have
cancelled the small craft for seas. Weak low pressure will move
through the waters today, then offshore high pressure sets up
tonight and will persist through the weekend. a frontal system will
approach the northern waters Monday and winds will become south and
increasing to small craft and perhaps briefly to Gale Force early
Tuesday. Longer period swells between 14-17 ft near 15-17 seconds
should impact the waters Tuesday into Wednesday.

&&

.PREV DISCUSSION... /Issued 507 AM PST Fri Dec 16 2016/

UPDATE...Updated to add new Aviation and Marine discussions.

DISCUSSION...16/00Z NAM/GFS/EC in.

The hemispheric view shows a wave number of 3 around the globe
with two strong blocking highs over the Pacific Ocean and Western
Europe. That usually means a stagnant or regressive pattern.

However, that will not be the case initially over the U.S. west
coast as a long wave trough now over the area will move off to the
east Friday...and dry and cold northerly flow aloft will move into
the area. Any straggling showers will end Friday and clearing
skies and a cold air mass will allow temperatures to plunge Friday
night. The highs Friday will be 5 to 10 degrees below normal over
most of the area...and 10 to 15 degrees below normal over Lake
County and northern California. The lows Friday night will be
below freezing everywhere but most of the immediate coast...but it
will be close even there. Lows will be below zero over many
locations east of the Cascades.

The flow aloft will turn northwesterly Saturday and this is when
the pattern will stagnate over the Pacific Northwest. The ridge
will hold in place offshore into Monday morning. So the weekend
will be dry with a gradual warming trend. Inland highs will warm
to around 5 degrees below normal over most of the area Monday.

A short wave riding over the ridge will flatten it Monday. The
Medford CWA will catch the weak southern end of the associated
surface front...and this will bring the next chance of
precipitation to the area. At this time it looks to be a weak
system with the bulk of the precipitation falling along the
coast...Coast Range...Umpqua Valley...and adjacent Cascades.

At this point the pattern will change to a progressive one with
low amplitude upper troughs and ridges moving through fairly
quickly. This pattern will persist through Thursday with cold
fronts moving onshore Tuesday and Wednesday night.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Frost Advisory until 9 AM PST this morning for ORZ021-022.
     Frost Advisory from 1 AM to 9 AM PST Saturday for ORZ021-022.
     Freeze Watch from late tonight through Saturday morning for
     ORZ021-022.

CA...None.

Pacific Coastal Waters...none.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
807 AM PST FRI DEC 16 2016

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

0807 AM     SNOW             1 S ADIN                41.19N 120.95W
12/16/2016  M1.0 INCH        MODOC              CA   TRAINED SPOTTER

            .

&&

NWS MEDFORD OR
IRIS SYSTEM