textproduct: Medford

Updated AVIATION Discussion

AVIATION...03/12Z TAFs

VFR conditions prevail across most of the region with mid and high level clouds streaming in from the south. Along the coast, LIFR conditions in fog will persist through much of the morning. Marine stratus will be rather persistent today, but should lift to at least IFR during the afternoon hours. Patchy fog is also developing in the Umpqua Basin this morning, and is expected to impact Roseburg for a few hours this morning before clearing to VFR.

Another round of shower/thunderstorm activity is expected this afternoon and evening. Storm motion will be from east to west today with guidance showing the focus of activity occurring across northern California into Jackson/Josephine Counties, and even possibly as far north as Roseburg. Expect gusty and erratic winds in the vicinity of thunderstorms today.

PREV DISCUSSION

/Issued 259 AM PDT Sun May 3 2026/

DISCUSSION...Low pressure off the coast of California continues to bring mid and high level clouds to the region. Radar activity is fairly minimal this morning, with just a few isolated showers moving northward into Modoc and Lake Counties. Marine stratus is less extensive this morning compared to recent days, still blanketing the marine waters and immediate coast, but has only pushed into the Coquille Basin. Easterly flow over the region should keep the marine layer from making any further inland progress this morning.

The thunderstorm pattern continues today. Low pressure will continue to wobble southward today while high pressure to the west, amplifies and closes off to the north of this low pressure for a brief time today. This upper level pattern will bring some warmer temperatures to the West Side today, most notably in the Umpqua Basin where afternoon highs are expected to reach into the mid 80s. That won't feel too much different compared to recent days for the remainder of the West Side, but it will be warmer by a few degrees today. Regarding thunderstorm potential today, the overall atmospheric set up is similar to yesterday (-3 to -5 LI, 1000-1500 J/kg CAPE). The main difference is storm motion will be east to west today instead of south/southeast to north/northwest. This will shift the focus of highest chances for lightning (60-80%) to Siskiyou/Jackson/Josephine Counties with lower chances (30-50%) as far north as Roseburg this afternoon/evening. Once again, we don't expect any severe weather today, but there could be a few stronger cells at times. The main threats will be gusty outflow winds, lightning, and brief downpours directly under storm cores.

Tonight into Monday, the low is forecast to elongate and shift eastward - moving onshore into California just south of SF Bay during this time. By Monday, we'll be decidedly on the northern periphery of the low with upper ridging to the north and mid-level flow around the low from the northeast. Most areas will be cooler, especially west of the Cascades after the expected warmth of today, but also across NorCal where clouds/showers will be most persistent. There's still a chance of thunderstorms along the Cascades and eastward, but the best chances shift to south of the OR/CA border.

Tuesday into Wednesday, the upper ridge to the north will win out as the closed low settles into the Great Basin and Desert Southwest. This will keep shower/thunder chances mostly to our south and east, and bring another period of above normal temperatures. Afternoon highs will peak about 10 to 15 degrees above normal (mid-upper 80s West/upper 70s-low 80s East), feeling more like late June than early May. Subtle cooling is possible Friday as a weak trough passes to the north of the forecast area. The vast majority of ensemble guidance maintains dry conditions with this trough, though about 15% of the solutions bring some light precip to the region.

MARINE...Updated 100 AM PDT Sunday, May 3, 2026....North winds have weakened, but fresh swell dominated seas will remain steep into early this morning. The fresh north swell will slowly diminish later today into Monday, while a longer period northwest swell builds and becomes dominant. Relatively quiet conditions are expected for much of the upcoming week.

BEACH HAZARDS...Updated 100 AM PDT Sunday May 3, 2026...A short period northwest swell and a building long period northwest swell will combine their energy and may produce very large waves washing up on area beaches late tonight through Sunday morning. The risk will be highest around sunrise this morning.

Sneaker waves can run up significantly farther on beaches than normal, including over rocks and jetties. These waves can suddenly knock people off of their feet and sweep them into the ocean. The waves can also move logs or other objects which could crush or trap anyone caught underneath. Never turn away from the ocean!

MFR WATCHES/WARNINGS/ADVISORIES

OR...Beach Hazards Statement until 11 AM PDT this morning for ORZ021- 022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT early this morning for PZZ350-356-370-376.