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fxus66 kmfr 241034 
afdmfr

Area forecast discussion
National Weather Service Medford or
334 am PDT Sat Jun 24 2017

Discussion...strong high pressure and hot weather is the main
story for today. The upper ridge is shifting inland over the
Pacific northwest today with the coastal thermal trough following.
This transition brings an end to the offshore flow that has
brought hot temperatures and windy weather to portions of the
South Coast over the past few days, and will increase the heat
over the inland areas.

Record highs will be tied or broken in many inland areas with
highs ranging from mid 90s to near 110. An excessive heat warning
and advisory remains in effect the hottest locations today
through Sunday afternoon. Please heed the safety information
regarding hydration, limited outdoor activity, car safety, and
cold water safety.

The upper ridge axis shifts eastward into Idaho on Sunday with a
robust upper low approaching the region from the southwest. With a
slightly cooler airmass in place and increased cloudiness,
temperatures will cool off several degrees, but it will remain
hot.

Thunderstorms are possible as the upper low Ushers in moist and
unstable southerly flow Sunday afternoon and evening, with a
continuing chance during the overnight hours. The center of the
upper low is progged to move across the County Warning Area during
the day Monday with the main threat for storms over the Cascades
and east but uncertainty keeps much of the west side in slight to
chance probabilities mainly east of a line from Roseburg to Grants
Pass to Happy Camp. The timing of the low moving east suggests
better confidence that activity will shift primarily east of the
Cascades through Monday evening.

Considering a fair degree of instability advertised both days and
well above precipitable water values, severe thunderstorms could
occur either day, however Monday looks like the better day as the
upper jet moves in ahead of the main shortwave providing ample
wind shear.

Low pressure and cooler weather prevail over the area Tuesday and
Wednesday with high pressure rebuilding later in the week. Stavish

&&

Aviation...24/00z taf cycle...VFR conditions will continue at all
inland terminals through the taf period. A surge of fog and low
stratus will be working its way north along the coastline over the
next 24 hours, and there appears to be a good chance for MVFR
visibility in light fog to redevelop at oth late this evening or
overnight. Koth should clear for the day, then the southerly
fog/stratus surge is likely to make it to koth by late afternoon.
-Bpn

&&

Marine...updated 200 am Saturday, 24 June 2017...south winds
should reach Cape Blanco by this afternoon, then spread north to
Florence by evening. Until then, residual steep seas will
continue to produce Small Craft Advisory conditions for almost all
areas. Relatively calm conditions are forecast for early next
week, then the thermal trough is expected to return by midweek
with north gales possible again by late week. Mts/cirrocumulus

&&

Fire weather...extremely hot, dry weather conditions today through
the weekend will help to dry fuels and set the stage for possible
fire starts as thunderstorms develop later Sunday into Monday. While
heavier fuels are still wet and do not necessarily support fire
spread or growth, finer fuels are approaching seasonal dryness
levels. Furthermore, there is the potential for considerable
lightning in the mountains and northern east side Sunday afternoon
through Monday afternoon as well as some chance for nocturnal storms
even over the west side Sunday night. In addition, breezy winds are
expected Monday afternoon and Tuesday. A Fire Weather Watch
remains in effect and has been expanded into a few areas
including some of the east side and northern Shasta Valley. Cirrocumulus

&&

Mfr watches/warnings/advisories...
or...Fire Weather Watch from Monday morning through Monday evening
for orz625.
Heat advisory from 11 am this morning to 8 PM PDT Sunday for
orz023>028.
Excessive heat warning from 11 am this morning to 8 PM PDT
Sunday for orz023>028.
Fire Weather Watch from Sunday afternoon through Monday
afternoon for orz621-623.
Fire Weather Watch from Sunday afternoon through Monday
afternoon for orz620-622.
Fire Weather Watch from Sunday afternoon through Monday evening
for orz624.

California...heat advisory from 11 am this morning to 8 PM PDT Sunday for
caz080-081.
Excessive heat warning from 11 am this morning to 8 PM PDT
Sunday for caz080-081.
Fire Weather Watch from Sunday afternoon through Monday
afternoon for caz280.
Fire Weather Watch from Monday morning through Monday afternoon
for caz281.

Pacific coastal waters...Small Craft Advisory for hazardous seas until

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