Area Forecast Discussion
Issued by NWS Medford, OR

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FXUS66 KMFR 290531

Area Forecast Discussion
National Weather Service Medford OR
1031 PM PDT SAT MAY 28 2016

.AVIATION...For the 29/06Z TAF cycle...Stratus with MVFR cigs has
reached the Coos coast (including KOTH) and will proceed inland
through the Umpqua Basin (including KRBG) overnight. It is unlikely
to proceed much south of Gold Beach. We may see IFR cigs with
drizzle by dawn Sunday at the coast, but the chance was low enough
not to include in TAF yet. Elsewhere, VFR conditions will continue
through the TAF period. -Wright


.PREV DISCUSSION... /Issued 823 PM PDT SAT MAY 28 2016/

Discussion...No updates necessary this evening. A weak upper
trough and associated cool front will move into northwest Oregon
this evening and then dissipate over our area overnight. This will
enhance the marine layer and drive clouds into the coast and
across the Umpqua basin tonight. Some drizzle is possible as well,
but most areas will see little to no impact. This will affect
temperatures tomorrow, mainly in the Umpqua basin where it will be
cooler due to increased cloud cover. The thermal trough along the
south coast will strength, however, and as a result, places like
Brookings will probably be warmer tomorrow. -Wright

Marine...Updated 815 PM PDT Sat 28 May 2016...North winds will
continue over the waters tonight, but speeds will decrease as a
weak frontal system disrupts the pressure field. However, small
craft conditions will continue over portions of the southern
waters. The thermal trough will strengthen again later tomorrow
resulting in an increase in winds and seas, especially south of
Gold Beach. -Wright

PREV DISCUSSION... /Issued 232 PM PDT SAT MAY 28 2016/


A pretty quiet weather pattern continues across the Pacific
Northwest for the short term. We`ll have a very weak cold front
sag towards the coast Sunday evening and produce some drizzle
given the moist air in the boundary layer, but it won`t push
inland and dissipate before the umpqua valley.

After that, we`ll have a thermal trough build with some weak off
shore flow into the start of next week. As a result, look for
anomalously warm conditions for daytime highs pushing into the
80`s and eventually the mid 90`s on Wednesday. Given the very dry
air aloft, we`ll efficiently loose heat during the night time.
Therefore, lows should still drop below 60 degrees in the
valleys, and stay around the lower 60`s on the ridges Tuesday
night. -Smith

LONG TERM...An upper level ridge is forecast to shift inland
slightly and remain over the region next Wednesday and Thursday.
Meanwhile a broad upper trough is forecast well offshore with a
closed low off the central and southern California coast. The
surface thermal trough is forecast to move inland during the day
Wednesday. This pattern will bring hot temperatures across inland
areas on Wednesday. Highs in the mid to upper 90s are expected on
Wednesday for inland valleys west of the Cascades, with highs in the
mid to upper 80s for eastern valleys. High temperatures are expected
to lower slightly on Thursday. Both Wednesday and Thursday, there is
also a slight chance for thunderstorms across inland areas as
southerly mid level moisture is also forecast to move into the area.
This moisture combined with weak instability and some weak
shortwaves is forecast to bring a slight chance for thunderstorms.
This pattern with a ridge over the area continues into Friday.
Instability is weaker on Friday though, so kept thunderstorms out of
the forecast and only have a slight chance of showers in for central
and eastern portions of the CWA.

Models differ on how quickly this ridge will shift eastward and the
strength of a Pacific low moving towards British Columbia and the
PACNW late Saturday into Sunday. The GFS transitions the ridge
eastward faster and is stronger with the low than the ECMWF. Given
the strength of the ridge, have leaned towards the slower ECMWF
solution. Of note, the low to the south may, bring another chance
for thunderstorms next weekend as it moves inland over southern and
central California. There is low confidence in the forecast track of
this low at this time.  /CC


.MFR Watches/Warnings/Advisories...


Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT Monday
     for PZZ356-376.
     Small Craft Advisory from 2 PM Sunday to 11 PM PDT Monday for
     Hazardous Seas Watch from Monday afternoon through Monday
     evening for PZZ376.
     Hazardous Seas Warning from 2 PM to 11 PM PDT Sunday for PZZ376.

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