229 
FXUS66 KMFR 100047
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
546 PM PDT Tue Oct 9 2018

.Updated aviation discussion.

.DISCUSSION...Current satellite observations are showing some fair
weather cumulus across southern Oregon and portions of Modoc
County in California. Overall, the moisture field is very shallow,
so the rain is pretty much done for today.

High pressure will begin to build in this evening through the
week. Before this occurs, the biggest concern in the short term
forecast is that our windier spots east of the Cascades will see
periods of sustained winds of 15-25 mph with some gusts to 35 
mph. 

The shallow moisture will remain behind the front tonight for 
some low clouds and fog to develop by daybreak in many of the 
valleys. It may get just cold enough for patchy frost to form in 
the Shasta, Applegate and Illinois Valleys, but probably won't 
last long enough to cause damage to vegetation.

Largely, the forecast area will be sunny and dry Wednesday 
through early next week. Northerly flow will transition to 
northeasterly (offshore) as a strong ridge offshore edges closer 
to the coast. This will bring stronger east winds to the ridges 
west of the Cascades during the overnights leading to steep 
morning inversions. This could also result in the first frost of 
the season in some areas west of the Cascades. Despite the cool 
mornings, we'll see a gradual warming trend in afternoon 
temperatures during this time frame.

Additionally, we will see humidity recoveries decrease in the 
coming nights, but currently, we are not expected to reach 
critical fire conditions. -Schaaf

&&

.AVIATION...For the 10/00Z TAFs...VFR conditions are being observed 
in most places this afternoon, and this should continue through 
early evening. There is enough onshore flow to bring MVFR ceilings 
to the West Side valleys and the coast later this evening. MVFR 
ceilings are also possible east of the Cascades, especially in 
northern Klamath and much of Lake County. Conditions should improve 
to VFR by late Wednesday morning as a drier air mass moves in. Keene

&&

.MARINE...Updated 302 PM PDT Tuesday 9 October 2018...A thermal
trough near the coast will bring gusty north winds and choppy seas 
to areas south of Cape Blanco through the remainder of the week. 
Fresh swell from the northwest will also create hazardous conditions 
for small crafts at times, especially south of Cape Blanco. 
Unusually long period southerly swell of 2 to 3 feet at 15-18 
seconds will develop Wednesday, peak Thursday night, then slowly 
subside Friday, and this may bring rough bar conditions at Brookings 
and elevated surf at Port Orford. -Sven

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...None.

CA...None.

Pacific Coastal Waters...Small Craft Advisory until 5 PM PDT 
Thursday for PZZ356-376.      Small Craft Advisory until 11 PM PDT 
Wednesday for PZZ350-370. 

$$