FXUS66 KMFR 202143

AFDMFR



Area Forecast Discussion

National Weather Service Medford OR

243 PM PDT Sun Sep 20 2026



.KEY MESSAGES...



* Warm and dry weather continues.



* There is a 40-60% chance of rain Thursday night into Friday.



* Temperatures trend cooler by the weekend.



&&



.DISCUSSION...



Coastal stratus and some higher clouds are the main weather

features this afternoon as high pressure remains in control.

Temperatures are just a tad warmer than normal as we're

forecasting a high of 91 here in Medford and 85 is the normal high

at MFR around mid to late September.



Otherwise, more coastal clouds and fog will cover the coast

tonight with a strong marine push. Temperatures will trend

slightly lower on Monday as the 500 mb ridge weakens a bit. A 

closed low will also move into central California on Monday 

afternoon. Some upper level energy will rotate into northern 

California from the east by Monday afternoon. We'll probably see 

some cumulus build ups and there is a very low chance for a shower

or two.



Heading into Tuesday and Wednesday, we'll be under zonal flow 

with a deep trough in the gulf of Alaska. Temperatures should 

trend slightly lower into the upper 70's within valleys west and 

east of the Cascades. By Thursday, the evolution of the weather 

pattern becomes a little more uncertain.



About 30 to 40% of ensemble members have a weaker surface low

spinning up along a baroclinic zone in the Pacific. That low and

upper level trough will probably move into the Pacific Northwest

around the Thursday to Friday time period. However, another 30 to

40% of ensemble members keep things quite dry from Thursday into 

Friday. It seems like there is less available moisture in this 

set of ensemble members. There are also questions where the bulk 

of the rain could fall. Some ensemble members target Washington 

and areas well to our north versus southern Oregon. In any case, 

still a lot to sort out around Thursday night into Friday.



After Friday, conditions will dry out with temperatures moving

notably cooler with fall like temperatures.



-Smith



&&



.AVIATION...(18Z TAFS) IFR ceilings will likely persist for the 

TAF period along the coast as high pressure remains in control. 

Periods of LIFR ceilings will also be possible overnight along the

coast. VFR conditions are expected away from the coast through 

the TAF period.



-Smith



&&



.MARINE...Updated 230 PM PDT Sunday, September 20, 2026...Gusty 

north winds will maintain steep seas south of Cape Blanco into 

tonight. Winds and seas will increase further into Monday evening.

Models are ambitious with some high and very steep wind waves 

around 8 to 9 feet, which should push us into hazardous seas 

criteria. Winds ease some on Tuesday and conditions should improve

north of Cape Blanco as seas become less steep and transition to 

swell dominated. Steep to very steep seas persist south of Cape 

Blanco through Tuesday, with conditions likely improving for the 

latter half of the week.



-Smith



&&



.MFR WATCHES/WARNINGS/ADVISORIES...

OR...CA...None.



PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Monday 

     for PZZ356-376. 



Hazardous Seas Watch from Monday afternoon through Monday 

     evening for PZZ356-376. 



     Small Craft Advisory until 11 PM PDT Monday for PZZ350-370. 



&&



$$