Area Forecast Discussion
Issued by NWS Medford, OR

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS66 KMFR 231306
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
604 AM PDT Thu Mar 23 2017

.Updated aviation discussion.

.DISCUSSION...A frontal boundary will bring gusty winds to our
forecast area this afternoon. Wind advisory continue for the
Shasta Valley and part of east side of the Cascades along with the
Warner Mountains of Modoc County this afternoon through tonight.

Wind forecast at the coast is a little trickier. We generally look
at OTH to ACV pressure gradient and the character of the Low
Pressure as well as how the low level winds align against the
coastal range. In this case, while winds at H925 and H850 hPA are
in the 50-60kt range, the gradient is only 6.0 and the Low is
farther offshore and not deepening. Also H925 wind direction is
more out of the South and Southeast and does not have the SW
direction that forces mass onto the coastal range. I feel that the
coastal headlands and the higher terrain in the coastal range
could see the very strong winds and the High Wind Watch was
canceled. The coast will still be very windy but the strongest
winds will be mainly at the headlands.

The front is expected to spread precipitation into SW Oregon this
afternoon with snow levels around 5000 feet. The front is
expected to move inland tonight and somewhat stalls over the
Cascades not exiting until Friday. Crater Lake, Mt Ashland and Mt
Shasta could see around a foot of new snow by Friday morning.

Precipitation is expected to taper off to light showers by Friday
evening. Scattered showers will continue into Saturday except for
the coast and the Umpqua Basin where precipitation is expected to
be steadier. Saturday night could be dry but both the GFS and the
ECMWF bring another front inland on Sunday. /FB

&&

.AVIATION...23/12Z TAF CYCLE...Outside of some patchy morning
valley fog, mostly VFR conditions exist this morning ahead of a cold
front that`s due to arrive late tonight. Southerly winds will
increase ahead of the front today, so expect increased turbulence,
especially over and near high terrain and east of the Cascades.
Winds at the coast will also become gusty late this afternoon.
Ceilings will gradually lower this evening, from west to east across
the forecast area, and expect mountain obscuration to follow. SK

&&

.MARINE...Updated 300 AM PDT Thursday 23 March 2017...A strong front
offshore will move toward the coastal waters late this morning.
Widespread gales can be expected early this afternoon through this
evening, especially beyond 10 NM from shore, but also closer to
shore near Cape Blanco. A few gusts to storm force are possible.
Seas will become steep to very steep during this time period and
persist through tonight. Winds and seas will decrease Friday into
Saturday...but seas likely remain quite steep. Another strong front
is due to arrive on Sunday. -Spilde/SK

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory from 11 PM this evening to 11 AM PDT
     Friday for ORZ030.
     Winter Weather Advisory from 11 PM this evening to 11 AM PDT
     Friday for ORZ027.
     Wind Advisory from 2 AM to 5 PM PDT Friday for ORZ031.

CA...Wind Advisory from 2 AM to 5 PM PDT Friday for CAZ081.
     Wind Advisory from 2 AM to 5 PM PDT Friday for CAZ085.
     Winter Weather Advisory from 11 PM this evening to 11 AM PDT
     Friday for CAZ082-083.
     Winter Weather Advisory from 11 PM this evening to 11 AM PDT
     Friday for CAZ080.

Pacific Coastal Waters...Gale Warning from noon today to 4 AM PDT
Friday for      PZZ350-356-370-376.      Hazardous Seas Warning from
noon today to 11 AM PDT Friday for      PZZ350-356-370-376.
Small Craft Advisory for hazardous seas from 11 AM to 5 PM PDT
Friday for PZZ350-370.      Small Craft Advisory for hazardous seas
until noon PDT today for      PZZ370-376.

$$

FJB/FJB/TRW


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.