textproduct: Medford

DISCUSSION

Updated aviation discussion for 12z TAFs.

AVIATION...26/12Z TAFS

MVFR and areas of IFR (south coast) will continue at the coast with rain showers through this morning. Inland, expect rain showers, mountain obscurations, and lower ceilings with areas of MVFR, mainly from the Cascades west, but also locally east of the Cascades. Conditions gradually improve to VFR late this morning and afternoon, though higher mountains probably remain at least partially obscured. There is a slight chance of thunderstorms this afternoon/early evening, but especially in NorCal. Areas of MVFR may redevelop (20-30% chance) late Tuesday evening/night along the coast and into the Umpqua Valley. -Spilde

PREV DISCUSSION

/Issued 248 AM PDT Tue May 26 2026/

KEY MESSAGES...

* Much cooler area wide today compared to yesterday with inland areas about 10-20F below normal. Breezy east side, but not as windy as yesterday. * Showers and thunderstorms continue through the rest of the week with a peak in coverage Wed/Thu. Some storms could be strong (severe?), each of those afternoons. High temperatures range from near normal to about 10F below normal.

* Another trough swings through Saturday with isolated shower/t-storm activity, mainly NorCal and far east side.

* Drier and warmer conditions are likely to follow Sunday into next week.

DISCUSSION...A cold front and well-mixed lower atmosphere brought quite the wind storm to portions of the Rogue Valley yesterday afternoon. It was one of the windiest days that I can remember with winds from a WNW direction. Most of our strongest wind storms are from offshore lows that bring SE winds. The airport here in Medford measured a peak wind gust of 60 mph and there were quite a few power outages reported along with branches and tree limbs down. While it was windy in most areas yesterday, the strongest winds were fairly localized to here (peak gusts over the east side and in NorCal were mostly in the 35-55 mph range).

The remains of the front are pushing well to the east of the Cascades early this morning. Meanwhile, a deep closed, upper low will break away from the main branch of the jet stream and drift southward over the area today. It will settle into the Great Basin around Lake Tahoe tonight, then will sit and spin there for a couple of days (Wed/Thu). This will bring cooler, unsettled weather to much of SW Oregon and NorCal during the next few days with scattered/numerous showers and also isolated/scattered thunderstorms. While the forecast sounds wet (and some places will be - especially from the Cascades eastward), there should be plenty of longer, drier breaks due to the showery nature of precipitation.

Radar imagery this morning is showing a fairly persistent area of rain from western Modoc up into Lake County with precipitation more showery from the Cascades westward. Wetting rain did fall at the coast and over to the Cascades yesterday as well as parts of the East Side (to the north and east of Klamath Falls). But, many valley locations did indeed get skipped over so far with only trace amounts measured at Medford and Roseburg and no rain measured at Klamath Falls. Even so, fire weather risk is much lower today due to higher humidity and lighter winds. Today will be the coolest day since the core of the closed low will be moving overhead (H5 temps of approx -25C). This will bring high temperatures generally 10-20F below normal for areas inland from the coast (50-55F east side and 55-65F west of the Cascades). Instability is greatest over NorCal, but there could be a rumble or two of thunder just about anywhere showers pop up this afternoon/evening.

Multiple short wave disturbances will rotate around the closed low tonight through Thursday and this will keep things active over the area with coverage of showers/thunderstorms greatest from the Cascades south and east. Even so, mid-level flow surrounding the low is fairly strong and will carry convection off to the west, which could traverse the Cascades and move over portions of the west side at times. Models are showing an area of showers rotating through from ENE to WSW tonight, eventually falling apart or dissipating Wednesday morning.

Things destabilize again Wednesday afternoon, as another short wave arrives from northern Nevada. Model lightning probabilities increase Wed afternoon, especially over the East Side with shear (40-50kt) and CAPE values becoming robust (>500 J/KG). Some of the hi-res guidance (particularly HRRR) show cells organizing into a line of storms as it moves westward over the area. It's difficult to assess exactly where and if this will occur, but could result in some strong to possibly severe storms with gusty outflow winds and hail. We'll continue to monitor this potential. As it moves over the west side, it should run into more stable air, so thunder probability decreases farther west. Thursday appears to be the most robust day in terms of CAPE, so we'll probably have another fairly active afternoon/evening.

Eventually, enough energy will move across the north Pacific to cause the low to eject to the ENE into Utah/Idaho/western Wyoming late this week into this weekend (Fri/Sat) with another weaker upper trough moving through the PacNW Saturday into Sunday. Drier and much warmer conditions should develop by early next week. -Spilde

MARINE...Updated 230 AM PDT Tuesday, May 26, 2026...Steep to locally very steep (outer waters beyond 40NM from shore) northwest swell-dominated seas will continue to build into the waters today, peaking at 13 to 18 ft at 14 seconds. While seas will gradually subside tonight into Wednesday morning, they are expected to remain steep and hazardous.

After brief, slight improvement, high pressure offshore and lingering low pressure inland will again bring increasing north winds on Wednesday afternoon with the strongest winds likely to occur south of Gold Beach. The gusty north winds and a long period west-northwest swell will continue steep seas Wednesday night, and possibly during Thursday and Thursday night also. Conditions may briefly improve on Friday. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Thursday for PZZ356-370-376.

Small Craft Advisory until 8 AM PDT Wednesday for PZZ350.

Hazardous Seas Warning until 5 PM PDT this afternoon for PZZ370- 376.