textproduct: Medford

KEY POINTS

* Thunderstorm activity is developing along and east of the Cascades. Slight chances for thunderstorms are present over Modoc, Siskiyou, and southern Jackson County as well.

* Generally unimpactful weather is expected through the weekend, with some fire weather concerns east of the Cascades towards the end of the week.

* In the long term, a pattern change may bring monsoonal moisture and atmospheric stability. In this outcome, east side thunderstorms are possible early next week.

DISCUSSION

Upper flow from the southwest is keeping forecast daytime highs about 5 degrees above normal levels. Areas of cloud development over terrain east of the Cascades show that moisture and instability remain in the area. This supports 25-35% chances of afternoon and evening thunderstorms over northern Lake and Klamath counties. This area has the highest modeled CAPE values (300-500 J/Kg) as well as where the most moisture is expected to be. Thunderstorm chances drop to 20-25% in the southern halves of these counties, while 5-10% chances linger in Modoc, Siskiyou, and southern Jackson County. Thunderstorms look to decrease into the evening hours.

A late morning weather balloon launch indicates elevated instability over an atmospheric inversion over the Rogue Valley. If development can break through that inversion, thunderstorm activity over the Rogue Valley could follow. As we saw on Sunday night, an outflow boundary can also contribute to additional activity. Thunderstorms are sensitive to these conditions that may not show up in global weather models. Awareness of your local conditions is highly encouraged, given how impactful thunderstorms can be.

Drier air and less instability significantly reduce thunderstorm chances for Tuesday, with only single digit chances over northernmost Lake and Klamath counties. On Wednesday, a dry front precedes a slight shift to zonal/slightly northwest flow pattern into Thursday. This will bring temperatures down to normal levels into the weekend, with highs west of the Cascades in the high 80s to low 90s. To the east, temperatures in the mid to high 80s are expected.

On Friday and Saturday, an upper low approaches British Columbia from the Gulf of Alaska. While we're not expected to see any precipitation from the trough around this low, tightening pressure gradients may bring stronger afternoon/evening winds east of the Cascades. When combined with ongoing dry conditions, fire weather may become a concern towards the end of the week (Please see the FIRE WEATHER discussion below for additional details on these concerns through the forecast period).

For Sunday and beyond, the low off of Canada's west coast weakens and moves to the east while high pressure swings over the north- central United States. In this case, southwest flow could develop and bring both monsoonal moisture and pockets of instability to the area and fuel afternoon and evening thunderstorm activity early next week. Global model clusters show good agreement for this overall pattern, with some variation on where the high pressure is located. ECMWF and GFS model ensembles add some confidence to this general forecast, with seasonal warmth for area forecast points and agreement for light shower chances over Klamath Falls and Lakeview while west side areas stay drier. -TAD

AVIATION...06/18Z TAFs

Marine stratus remains in place along the Oregon coast, keeping LIFR levels at Brookings and IFR ceilings at North Bend. Brookings may see a brief period of clear skies and North Bend may see ceilings rise to MVFR heights before IFR/LIFR conditions return this evening.

Inland terminals are at VFR levels, with mostly clear skies west of the Cascades. East of the Cascades, cloud development indicates the presence of instability and moisture in the atmosphere. This supports thunderstorm chances remaining in the forecast, especially over northern Lake and Klamath counties this afternoon and evening. Those chances may be impacted by lingering cloud over in the area, although those clouds look to be moving away to the northeast which would allow for a period of surface warming. Any thunderstorms that develop tonight could bring lighting, moderate to heavy rainfall, and erratic gusty winds. Activity chances decrease into nighttime hours. -TAD

MARINE...Updated 200 PM PDT Monday, July 6, 2026

Gusty but unimpactful winds remain south of Cape Blanco and within 30 nm of shore. Lingering fresh swell and a slight increase in westerly swell will keep steep seas in all waters into early Tuesday morning. Steep seas look to be limited to waters south of Cape Blanco for Tuesday through Wednesday morning.

Currently, northerly winds start to increase on Wednesday morning. This may bring additional areas of unsettled seas to area waters into the end of the week. -TAD

FIRE WEATHER...Updated 1200 PM PDT Monday, July 6, 2026

Warm and dry conditions will continue for the next week, with typical afternoon breezes each day. There will be a few periods of concern: the first this afternoon east of the Cascades, where abundant lightning is expected, and the second being two dry frontal passages that will bring gusty winds and low RH to portions of the area.

Yesterday, we saw convection across much of the East Side and the eastern slopes of the Cascades, with over 300 cloud-to-ground lightning strikes observed. The storms began on the dry side over eastern Modoc and Lake counties, but became wetter as they moved west through the evening. Some locations received wetting rains, particularly around Beatty, where over an inch of rain was measured (some of which was melted hail).

There is again a chance of afternoon and evening thunderstorms along and east of the Cascades, focused mainly over northern Klamath and Lake counties, with isolated storms possible elsewhere east of the Cascades, and over northern California, including the Klamaths, Siskiyous, and Warners. A few model runs even place an isolated thunderstorm in the Rogue Valley, so despite a very low chance of this occuring, we cannot rule that out. Storm motion should be to from southwest to the northeast, at roughly 20 mph. Along with plenty of lightning, hail, and gusty and erratic winds of up to 45 mph will be a concern for any storms that develop. These storms should also be wet, given the increased moisture in the area, but lightning will likely strike outside those wet cores. Fortunately, the upper level impulse responsible for triggering these storms is expected to move out of the area quickly this evening, so convection should not linger as late as we saw yesterday. A Red Flag Warning is in effect for this afternoon, and details can be found at PDXRFWMFR.

Otherwise, high temperatures remain around 5 to 10 degrees above normal, and afternoon breezes remain typical to slightly enhanced during the next week. This will result in very dry conditions, generally just shy of critical wind and humidity thresholds, especially Tuesday and Wednesday as a dry cold front passes through the area. Tuesday looks to be a windier day, while Wednesday appears drier, so we may get through without see critical conditions develop. This weekend, another dry cold fronts passes through, and at this time, it looks to have even less moisture and stronger winds. Thus, there is a much higher likelihood of reaching critical conditions, primarily over east of the Cascades, but also potentially in the Shasta/Scott and Rogue valleys. Updates will be made as necessary over the coming days.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning until 8 PM PDT this evening for ORZ624-625.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Tuesday for PZZ350-356-370-376.