Scientific Forecaster Discussion
fxus66 kmfr 222123
Area forecast discussion
National Weather Service Medford or
223 PM PDT Fri Jun 22 2018
Discussion...sunny skies prevail over the entire forecast area,
with one exception. The Umpqua basin has been a bit slower to
clear out than expected, but clouds have been burning off quick
over the last hour and expect the rest to clear by early evening.
Tonight, expect another round of low stratus along the coast,
likely reaching inland to the Umpqua basin. Mild weather with
temperatures around 5 to 10 degrees above normal will continue
today across the area today. Tomorrow's weather will be will be
similar to today, though confidence is high that Brookings will
see the Chetco effect, bringing temperatures to at least the mid
80s, possibly near 90 tomorrow afternoon.
Outside of Brookings, main story for heat will be Sunday. A
potent ridge will bring essentially a one day heat wave.
Temperatures will be in the upper 90s in west side valleys south
of the Umpqua Divide, and expect some locations to hit 100. East
side valleys will likely reach into the upper 80s or low 90s.
Confidence is high that Sunday will be the hottest day thus far
this year...for reference, the last time kmfr cracked 100 degrees
was sept 11. The heat will be short-lived; a cold front will
sweep through Monday, and highs will be near normal (mid 80s over
most of the cwa). The front looks to be dry, so some light
precipitation is possible along the coast, but otherwise the main
impacts of the front will be relatively cool, breezy conditions.
Expect a few days of uneventful zonal flow, then mid to late next
week, models have started projecting a trough developing, bringing
potential precipitation. -McAuley
Aviation...for the 22/18z tafs...once the marine layer stratus
producing MVFR ceilings along the coast and the Umpqua basin erodes
today, VFR will prevail across the region for the remainder of the
day. However, MVFR/IFR conditions are expected to return to the
Coats north of Cape Blanco tonight, including at koth, and may also
return to a small section of the coastal water south of Brookings.
The remainder of the area will remain VFR, with gusty winds expected
this afternoon and evening, especially east of the Cascades and
along the coast. -Bpn
Marine...updated 200 PM PDT Friday 22 June 2018...with the
intensifying thermal trough to the south, north winds are increasing
today, along with steep wind-driven seas. Most affects will be felt
south of Cape Blanco today, but winds and resulting seas will spread
north to most areas by Saturday afternoon, with very steep and
hazardous seas and occasional gale force gusts expected south of
Gold Beach. Have upgraded the hazardous seas watch to a Gale Warning
to account for both the expected gale gusts and the likely
hazardous sea conditions.
The thermal trough pattern will be temporarily disrupted late Sunday
into Monday as an upper level trough moves just north of the area.
Conditions, however, are likely to remain hazardous to small craft
into next week as the upper level trough will maintain tight
pressure gradients and resultant moderate to strong northerly winds.
Very steep wind driven seas look to continue into midweek with the
thermal trough strengthening Tuesday Onward. -Bpn/petrucelli
Fire weather...warmer than normal temperatures and breezy winds
are expected east of the Cascades for this evening. A thermal
trough will setup along the coast on Saturday. Winds and
temperatures will then increase along the southern Oregon coast
Saturday. The thermal trough will retreat eastward on Sunday with
temperatures increasing about ten degrees across the region.
Sunday will also be the warmest day with high temperatures 15 to
possibly 20 degrees warmer than average. Daytime humidities will
fall to the mid and lower teens in valleys. Breezy and much cooler
conditions are expected Monday with a marine push in the west
side in Oregon. -Smith
Pacific coastal waters...Small Craft Advisory until 5 PM PDT Monday for pzz356-376.
Gale Warning from 2 PM Saturday to 11 am PDT Sunday for
Small Craft Advisory from 2 PM Saturday to 5 PM PDT Monday for