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Area forecast discussion 
National Weather Service Medford or
905 PM PDT Tuesday Sep 2 2014

Discussion...the cold front is marching south and northwest winds are
picking up behind the front in the Umpqua basin. Expect the front
to move past Mount Shasta by late tonight. The water vapor imagery
shows a very dry airmass behind the front. This will present a
fire weather concern with low humidity and breezy conditions.
Offshore flow will also present fire weather concerns at night
with poor recovery at the upper slopes and ridges. Overnight lows
for Thursday morning are expected to be in the 30s at many valley
locations east of the Cascades. Patchy frost is possible in the
Tulelake basin as well as areas from Chiloquin north. Right now we
are not forecasting frost temperatures for Klamath Falls or
anywhere west of the Cascades. /Fb

&&

Aviation...based on the 03/00z taf cycle...patchy IFR ceilings/visibilities
will develop along the north coast late tonight...persisting through
middle-morning Wednesday. Koth will likely not be affected. Areas of
reduced visibilities will continiue in western Siskiyou County and
over the southern Cascades due to smoke from wildfires.
Otherwise...clear skies will persist for the next 24 hours. /Jrs

&&

Marine...updated 200 PM PDT Tuesday 2 Sep 2014...north winds will
increase into this evening with Small Craft Advisory winds and steep
to very steep wind wave dominated seas of up to 15 feet. Winds and
seas will be highest over the outer waters south of Gold Beach...but
very steep seas will cover the area south of Cape Arago and beyond 5
nm from shore through Thursday night. The north winds will reach a
peak at gale force during Wednesday afternoon and evening. Winds
along the coast out to 5 nm are not expected to be as strong...
however wind driven seas from the outer waters will move towards the
coast causing them to be choppy. The thermal trough will shift west
Friday which will result in decreasing winds and seas. /Jrs

&&

Fire weather...humidity recoveries will continue to be moderate
to poor through the week. A dry cold front will produce breezy
northerly winds on the west side and westerly winds on the east
side of the Cascades this evening. Behind the front, rh's will drop
quickly..especially at the ridge level with increasing offshore
winds from the Cascades westward tonight. The offshore will
develop across the east side by Thursday morning. Cooler air aloft
will move in Saturday...bringing increased instability. However
the preceding flow is from the east and there will not be enough
moisture to allow any deep convection to form. /Sbn

&&

Previous discussion... /issued 234 PM PDT Tuesday Sep 2 2014/

Discussion...the weather will remain relatively quiet through
the week, on the public side anyway. There will be numerous fire
and marine issues through this time, and these will be discussed
further below. The thermal trough continues to be the primary
driver behind the forecast for the next week. Models are in good
agreement with the general progression of both the strength and
northward expansion of the trough, therefore, confidence remains
high in a dry and very warm week with nearly no indication of
precipitation anytime soon. Smoke and haze will also continue to
be an issue through the week, especially over northern California
and in the vicinity of and downwind from any other fires that
continue to burn in the area.

A dry cold front will approach the region tonight, however
the cooler air will not be able to penetrate very far into the
forecast area. The major impact of the front will be to increase
the temperature difference between the thermal tough to the south
and the cooler air to the north. The result will be increased
offshore winds through Thursday and very dry air over the area.
The thermal trough will then expand northwards through the
week, resulting in temperatures across the area that are more
Akin to early August than early September. In fact, most areas can
expect to see day time high temperatures of 10 to 15 degrees above
normal by the weekend.

There may be some relief by early next week, as models are
producing a stronger, and more importantly, wetter system entering
the Pacific northwest. However, the system has been trending
dryer and slower over the past several runs. Uncertainty is very
high, so have left mention of probability of precipitation out of the forecast at this
time. -Bpn

Aviation...based on the 02/18z taf cycle...areas of IFR ceilings/visibilities
will develop along the north coast and in the Coquille Valley late
tonight...persisting through middle-morning Wednesday. Areas of
reduced visibilities will continue in western Siskiyou County and
over the southern Cascades due to smoke from wildfires.
Otherwise...clear skies will persist for the next 24 hours.

Marine...updated 200 PM PDT Tuesday 2 Sep 2014...north winds will
increase into this evening with Small Craft Advisory winds and steep
to very steep wind wave dominated seas of up to 15 feet. Winds and
seas will be highest over the outer waters south of Gold Beach...but
very steep seas will cover the area south of Cape Arago and beyond 5
nm from shore through Thursday night. The north winds will reach a
peak at gale force during Wednesday afternoon and evening. Winds
along the coast out to 5 nm are not expected to be as strong...
however wind driven seas from the outer waters will move towards the
coast causing them to be choppy. The thermal trough will shift west
Friday which will result in decreasing winds and seas.

Fire weather...humidity recoveries this morning are poor to
moderate at ridge tops and that will continue to be the case through
the week. A dry cold front will produce breezy northerly winds
on the west side and westerly winds on the east side of the Cascades
this afternoon and evening with warmer and drier conditions compared
to Monday as a thermal trough moves inland. Behind the front,
rh's drop quickly..especially at the ridge level with increasing
offshore winds from the Cascades westward tonight. The offshore will
develop across the east side by Thursday morning. Cooler air aloft
will move in Saturday...bringing increased instability. However the
flow preceding it is from the east and there will not be enough
moisture to allow any deep convection to form.

&&

Mfr watches/warnings/advisories...
or...Fire Weather Watch from Wednesday evening through Thursday
afternoon for orz617-622.
Red flag warning until 11 PM PDT Wednesday for orz619>621.
Red flag warning from 10 am to 11 PM PDT Wednesday for orz623.
Fire Weather Watch from Wednesday evening through Thursday
afternoon for orz623.

California...red flag warning until 11 PM PDT Wednesday for caz280.

Pacific coastal waters...Small Craft Advisory for winds until 5 am PDT Friday for
pzz350-356-370-376.
Small Craft Advisory for hazardous seas until 5 am PDT Friday
for pzz350-356.
Gale Warning until 8 am PDT Thursday for pzz356-376.
Hazardous seas warning until 5 am PDT Friday for
pzz350-356-370-376.
Small Craft Advisory for hazardous seas until 2 PM PDT Wednesday
for pzz370.

$$

Fjb/fjb/jrs

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