textproduct: Medford

DISCUSSION

Hot and dry weather continues across the region this afternoon as highs push into the mid 90's yet again. For reference, our 'normal' high here in Medford is 81 and we're forecasting 95 this afternoon. A thermal trough will remain in place along the southern Oregon coast this afternoon as some coastal trapped stratus starts to make it's way up the coast by Thursday.

An upper level low will in the Pacific will shove a short wave into our area by Thursday afternoon and evening. The latest convective allowing models are picking up one isolated thunderstorm activity in northern California by Thursday afternoon. Additionally, the high resolution ensemble forecast(HREF) collective is predicting a 10 to 20 percent chance of thunderstorms within 20km of a point within a 4 hour period. These numbers usually correlate to some thunderstorm activity within our area during the Thursday afternoon. There is a low chance that thunderstorms linger overnight with some lightning activity.

In addition, one could analyze the thermal trough farther inland given the 1000-500 mb thickness values and inverted trough at 850mb east of the Cascades. Temperatures will still be hot and peak in the 90's again even without a stronger ridge overhead.

By Friday, temperatures trend lower as the 500 mb trough over the Pacific moves closer to shore and sporadic cloud cover builds in the afternoon. The thunderstorm threat increases notably by Friday afternoon due to more moisture and favorable lift. Most of the storm activity will be in northern California with storms spreading into south central Oregon by the evening hours. The joint probability of convective available potential energy > 500 and shear >30 knots is about 35% in northern California. Therefore, severe thunderstorms are pretty unlikely, although some stonger outflow around 35 to perhaps 40 mph are possible.

This trough will push eastwards by Saturday with the threat of thunderstorms shifting east to mainly Lake County. Temperatures will trend lower, although still remain above normal for this time of year.

We warm right back up next week with highs moving into the upper 90's here in Medford and 80's east of the Cascades. The extreme forecast index(EFI) wasn't picking up on anything in the extended forecast, so just unusually warm seems like that main theme next week.

-Smith

AVIATION

Stratus will surge up the coast later tonight into tomorrow morning with some LIFR or IFR ceilings at times near KOTH. Eventually, those ceilings could clear up by the afternoon hours. VFR conditions prevail inland through the TAF period. Thunderstorm activity is possible in northern California Thursday.

-Smith

MARINE...Updated 100 AM PDT Wednesday, June 17, 2026

The thermal trough pattern peaks Wednesday, then gradually eases through Friday. North gales will continue south of Cape Blanco today with very steep seas expected as far north as Cape Arago. Winds ease below gales on Thursday as the thermal trough weakens, but steep to very steep seas are likely into Friday. Conditions improve moreso Friday, but steep seas and moderate north winds are likely to persist through the weekend.

FIRE WEATHER...Updated 300 PM PDT Thursday, June 17, 2026

Elevated fire weather conditions will continue this afternoon and again on Thursday due to hot, dry and unstable conditions. Isolated dry thunderstorms are possible in northern California during Thursday afternoon as a thermal trough remains in place. Mixing heights push to 10000 feet, which is high, although not as high as they could be under this weather scenario on Thursday.

Thunderstorm activity will increase on Friday with storms moving to the north at about 20 to 25 mph, which is notable, although not that fast to be really dry. PWATs are also around 0.7 to 0.9, which is just enough moisture to help thunderstorms with deeper convection and keep some dry thunderstorm risk. Overall, we went with a fire weather watch as thunderstorms could produce enough lightning and fire starts to really challenge initial attack. Realistically, this is a lower end fire weather watch event as there are some questions about fuels and storm motion appears a little slow at 20 to 25 mph.

-Smith

MFR WATCHES/WARNINGS/ADVISORIES

OR...Fire Weather Watch from Friday afternoon through late Friday night for ORZ624-625.

CA...Fire Weather Watch from late Thursday night through Friday evening for CAZ280-281-284-285.

PACIFIC COASTAL WATERS...Gale Warning until 8 PM PDT Thursday for PZZ356-376.

Small Craft Advisory until 8 PM PDT Thursday for PZZ350-370.

Hazardous Seas Warning until 8 PM PDT Thursday for PZZ350-370.