textproduct: Medford

DISCUSSION

We set 4 new records Tuesday and tied one record as the strong ridge settled over northern California and southern Oregon. Various ensemble data continues to point this ridge being unusually strong for this time of year. The Extreme Forecast Index(EFI) is showing widespread values of 1 today through Friday. This suggests the ECMWF ensemble members are all exceeding the model climatology in widespread areas. The 500 mb heights around 586dm are also in the extremes of climatology for this time of year in northern California. This will result in daytime temperatures pushing 15 to 25 degrees above normal for mid March.

Therefore, we'll break or come very close to breaking records at all out climate sites, except for North Bend later today as it will be covered in stratus for part of the day.

Alturas' record of 73 will fall to a high around 80. Mount Shasta City's record of 74 will fall to a high around 83. Montague's record of 77 will probably fall to a high around 81. Medford's record of 80 could be tied or perhaps fall. Klamath Falls' record of 74 will fall to a high around 78. Roseburg's record of 80 could be tied or perhaps fall.

The upper air pattern doesn't change at all heading into Thursday, although troughing in the Pacific will help break down this ridge slightly by Friday. During this time, temperatures will just nudge down a bit in Oregon, although California still seems rather warm during Friday afternoon.

Eventually, a short wave will push through Oregon late Friday night into early Saturday morning. A cold front will accompany this short wave and we do have a slight chance of rain over locations west of the Cascades Friday night and Saturday morning. Conditions dry out to the south and east as this front progresses through Oregon.

The weather around Tuesday and Wednesday is a little more uncertain. ECMWF ensemble members are showing a low of various strengths deepening in the Gulf of Alaska off the BC coastline. About 15% show a low around 950 to 960 mb while about 20% show 960 to 970mb with the others showing something significantly weaker and a minority showing nothing at all. We feel pretty confident the latest GFS is out to lunch as it much closer to shore compared to the rest of ensemble members. Overall, we'll likely see another cold front or perhaps an occluded front push through late Tuesday and Wednesday. The NBM is predicting probability of precipitation around 70 percent along the coast and 30 percent inland during Tuesday with snow levels dropping rapidly down to 4500 feet on Wednesday. The amount of snow could be nothing to a few inches in the Cascades with the weather mid week.

-Smith

AVIATION...18/12Z TAFs

VFR conditions will prevail across most of the area through the TAF period. The exception will be along the coast and over the coastal waters where LIFR conditions in marine stratus will bring persistent low clouds and periods of fog into Wednesday morning. The marine layer should retreat to just offshore late Wednesday morning into the afternoon, but confidence is low on the timing. /BR-y/Smith

MARINE...Updated 200 AM PDT Wednesday, March 18, 2026

West swell builds into this evening, but conditions will remain below advisory levels through Friday. A thermal trough develops early Saturday, bringing gusty north winds with gales possible into Sunday, and steep to very steep seas possible into Monday. The outlook is for conditions to briefly improve Monday afternoon and evening, ahead of a cold front with rapidly building seas. Advisory strength winds are likely, and Gales are possible on Tuesday. The west swell dominated seas that follow may become very high and very steep Tuesday night into Wednesday.

MFR WATCHES/WARNINGS/ADVISORIES

OR...None.

CA...None.

PACIFIC COASTAL WATERS...None.