Small Craft Advisory 27, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
1235 PM PDT Wed Mar 22 2017

Updated Marine and Aviation sections...

.UPDATE...The current forecast for today looks to be on track with
showers currently occurring over the Cascades and east associated
with the dissipating front. A few more showers are currently
positioned over the coast. These showers will continue this
morning with rain chances decreasing from west to east as the day
goes on. Although instability and thunderstorm indicies are a bit
weaker today than yesterday, a isolated rumbles of thunder can't
be ruled out well east of the Cascades and in Modoc and Southeast
Siskiyou Counties in California. Have not made any changes to
today's forecast. -Schaaf

&&

.AVIATION...22/18Z TAF CYCLE...Today will be an unstable and showery
day. MVFR will be possible in showers throughout the day, but,
generally, VFR will prevail. Terrain will be partially obscured
throughout the day. A slight chance of thunderstorms exists mainly
in Modoc and Southern Lake Counties later this afternoon and early
this evening. Showers diminish this evening, and with some
increasing stability, expect the chance for MVFR/IFR ceilings to
develop in some valley locations tonight. Incoming mid and high
clouds and increasing winds Thursday morning are likely to disrupt
and break up these lower ceilings mid-late morning. BTL/SK

&&

.MARINE...Updated 920 AM PDT Wednesday 22 March 2017...Steep seas
will continue today through early Thursday morning. A strong front
is likely to bring widespread gales, strong in the Cape Blanco
convergence zone area, and very steep seas Thursday afternoon into
Friday morning. Latest model trends continue to indicate the
potential of storm force gusts late Thursday afternoon. Winds will
decrease Friday night into Saturday...but seas should remain steep.
Another strong front is due to arrive on Sunday. BTL/SK

&&

.PREV DISCUSSION... /Issued 545 AM PDT Wed Mar 22 2017/

Updated aviation discussion.

DISCUSSION...Two bands of rain will affect our forecast area this
morning. One band extends from Klamath Falls SW into Mount
Shasta. This band is expected to move into Lakeview and Alturas
area late morning. The second band of rain is moving into the
Illinois Valley and western Siskiyou County. Short term models
bring this band into the Medford area around morning commute hours
then into the Cascades by mid morning.

Another front will move ashore this morning. This front is
expected to move into the Cascades by late this morning with
scattered showers west of the Cascades. The front will shift area
of instability east of the Cascades and this is where we expect
afternoon thunderstorms to occur this afternoon. The most
unstable area this afternoon appears to extend from the Medicine
Lake area of SE Siskiyou Co to Lakeview and the Warner Valley.
Snow level is expected to lower behind the front to around
3000-3500 feet from the Cascades west and 3500-4500 feet east of
the Cascades but precipitation is expected to taper off to
showers.

High pressure will keep the area dry Thursday morning. A warm
front is expected to spread light rain to the coast and the Umpqua
Basin Thursday afternoon. Rain is expected to be widespread
Thursday night with snow levels lowering to around 5000 feet by
Friday morning. Friday appears to be a wet day with widespread
valley rain and higher mountain snow.

Medium range guidance shows shower activities will continue into
Saturday with possible break Sat afternoon into Sunday morning
before the next front inland Monday. This is consistent on both
the GFS and ECMWF. Tuesday could be dry per GFS but not per the
ECMWF. /FB

&&

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

CA...None.

Pacific Coastal Waters...
- Gale Watch from Thursday morning through late Thursday night for
  PZZ350-356-370-376.
- Small Craft Advisory for hazardous seas until 5 AM PDT Thursday
  for PZZ350-356-370-376.

BMS/FJB/NSK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
1152 AM PDT WED MAR 22 2017

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

0800 AM     HEAVY RAIN       4 WSW KLAMATH FALLS     42.19N 121.84W
03/22/2017  M0.88 INCH       KLAMATH            OR   TRAINED SPOTTER

            8AM TUESDAY TIL 8AM WEDNESDAY. ELEVATION
            4366 FEET. SOME SNOW ALSO OCCURRED,
            CURRENTLY <0.50" ON THE GROUND. THE DURATION
            OF THE HEAVY RAIN EVENT WAS 24 HOURS.

&&

BTL