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fxus66 kmfr 182213 

Area forecast discussion
National Weather Service Medford or
313 PM PDT Wed Sep 18 2019

showers and thunderstorms are going strong across much of the
forecast area this afternoon. The immediate coast, however, is
generally drying out, as the focus of the activity has shifted
inland. Lightning has been increasing over the area during the
last 2-3 hours with the majority of the cloud-to-ground strikes across the east
side and norcal. Thunderstorms will remain possible across areas
inland from the coast through this evening. These storms will be
capable a 30mph wind gusts, small hail, moderate to heavy
downpours, and, of course, cloud to ground lightning. All of this
is courtesy of a -21c 500mb cold pool moving down the coast into
northern California.

Conditions will gradually dry out this evening through Thursday.
Showers will taper off to mostly spits and sprinkles tonight into
early Thursday.

We're still on track for a warming trend back up to near normal
temperatures for Friday and Saturday afternoons, but low
temperatures will be on the chilly side, especially east of the
Cascades where some areas of frost will be possible both Friday
and Saturday mornings. Friday morning is currently expected to be
the coldest morning of the week.

Confidence is increasing in another trough of low pressure moving
in from the northwest with wetting rainfall for Sunday and
Monday. This frontal system does not look as wet as the last 3.
However, the way the models have trended in the last 10 days,
stay tuned for updates. Thereafter, there is a fair amount of
uncertainty, though the majority of the guidance is indicating
another warm-up. Btl


Aviation...for the 18/18z tafs...a slow moving front will exit the
area to the east this morning while the next disturbance reaches the
coast. It will also slowly move across the area through tonight.
This will continue variable conditions with a mix of IFR/MVFR/VFR
ceilings and visibilities, frequent Showers, Mountain obscuration,
and isolated thunderstorms. Btl/dw


Marine...updated 145 PM PDT Wednesday 18 September 2019...
unsettled weather with scattered showers continuing through the
evening. Lingering chances for isolated thunderstorm may possible
through the afternoon, decreasing to non-existent by evening.
Steep seas will build to a peak this afternoon, then gradually
subside tonight into Thursday as high pressure develops offshore.
A thermal trough will develop along the coast Thursday afternoon,
persisting into Saturday morning. North winds will increase in
response to the thermal trough, and conditions may become
hazardous to small craft south of Cape Blanco by Thursday

Conditions will improve Saturday as the thermal trough pattern gets
interrupted when a weak disturbance moves overhead. Another front is
expected to move through the waters Saturday night into Sunday. A
thermal trough is then likely to develop again early next week with
a return of strengthening northerly winds.


Mfr watches/warnings/advisories...
or...Small Craft Advisory until 11 PM PDT this evening for


Pacific coastal waters...
- Small Craft Advisory until 11 PM PDT this evening for
- Small Craft Advisory until 5 am PDT Thursday for

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