textproduct: Medford

DISCUSSION (Today through Wednesday)

Key Points:

* Minor/low impacts continue the next several days

* Well above normal temperatures through Sunday - Cooler temperatures early next week - Below normal on Tuesday

* No strong signal for precipitation until early next week - Small (10%-25%) indications for isolated showers Fri-Sun - Mainly for northern California and eastside areas - Could have isolated thunder if anything develops - More widespread rainfall chances (30%-90%) Mon-Wed

* Elevated fire weather concerns this week - Combination of low RH and breezy winds - Isolated areas of both critical RH & wind Monday afternoon - Fuels fortunately keeping the overall fire threat low/moderate

Further Details:

A ridge of high pressure remains over the Pacific Ocean through Friday night/Saturday morning, which will result in an overall dry and stable airmass. As the high shifts west, this will allow for more of a zonal flow to set up over the PacNW with weak embedded PVA. There is at least some semblance of a potential for isolated convection each afternoon Friday and Saturday as we reach convective temperatures. Saturday may see more isolated to scattered coverage. Upper level features are less than desirable both days resulting in low confidence, but there is enough overlap of parameters to warrant at least a mention of showers/thunderstorms during peak heating. MUCAPE values vary but are generally around 200-500 J/kg. CAMs are indicating this potential as well each afternoon for northern California, but Saturday could see these chances spreading to eastside areas as well. The NBM has started to show this potential (10%-25%) in the PoP field. May continue to see these chances increase for Saturday in subsequent runs.

By Monday, as the ridge of high pressure becomes displaced out of the region, a strong trough is progged to develop and dig south over the west coast early next week. This is a much stronger signal for precipitation across our entire forecast area than we have seen in well over a week (outside of isolated rainfall). That said, there are discrepancies between global models on the timing/location of said trough (height fields out of phase from one another) and hence coverage of precipitation chances Mon-Wed. The takeaway here is we have a better signal for widespread precipitation compared to what we've seen in recent weeks. In other words, confidence is increasing for potential widespread precipitation Monday through Wednesday, but exact details on amounts and timing are still unclear.

-Guerrero

AVIATION...22/06Z TAFs

Along the coast, areas of IFR ceilings will continue overnight into Friday morning north of Cape Blanco. Stratus will clear by late Friday morning as gusty winds develop along the coast. Areas of IFR are then expected to redevelop Friday evening for areas north of Cape Blanco.

Inland, expect VFR levels with clear skies through the TAF period.

MARINE...Updated 100 PM PDT Thursday, May 21, 2026

A thermal trough is bringing gusty north winds and steep to very steep seas over the coastal waters through Friday night. Winds will be strongest and seas will be highest during the afternoons/evenings. Through this stretch, very steep seas of 10-13 ft are most likely south of Cape Blanco with steep seas (6-9 ft) north of Cape Blanco. Gale force gusts (~40 kt) are possible across portions of the southern waters, especially from around Gold Beach south.

The pattern will ease some this weekend as an upper trough pushes in from the NW. This should bring lighter winds and lower seas (still at least Small Craft Advisory), especially by Sunday. Could be a brief break Sunday night, but models continue to show another trough moving through on Monday (Memorial Day). The strength and timing of this trough are still somewhat uncertain, but it could bring periods of rain, gusty W winds that shift back to N and steep seas. This one should be followed by a larger WNW swell.

-Spilde/Hermansen

FIRE WEATHER

As we maintain the dry airmass and breezy afternoons, there will be at least an elevated threat for fire weather conditions each day. Monday in particular will see the strongest winds. In fact, wind speeds may reach wind advisory criteria for eastside areas. Lake County in particular could see isolated areas of critical wind and critical RH, but timing of precipitation could alter the RH field leading to uncertainty. With that said, fuel conditions per fire agencies reveal the overall fire weather threat remains low to moderate. Given the low RH values each afternoon and breezy winds, people should exercise caution with any outdoor activities that could cause sparks or flames, especially eastside areas with Lake County in particular. Bottom line is that fire season was declared early this year, so these precautionary actions should already be in place, but its especially important when we have these elevated concerns.

-Guerrero

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Hazardous Seas Warning until 11 PM PDT Friday for PZZ356-376.

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