FXUS66 KMFR 091137 AFDMFR Area Forecast Discussion National Weather Service Medford OR 437 AM PDT Thu Jul 9 2026 .Updated AVIATION Discussion... && .AVIATION...09/12Z TAFs...Marine stratus will maintain IFR/LIFR conditions along the coast from Cape Blanco northward and Brookings southward through most of the morning. Some some gradual improvement to a scattered layer is expected again later this morning, but will return to similar areas after 03z this evening. All other areas will remain VFR through the TAF period with the typical increase in afternoon breezes this afternoon and evening. && .PREV DISCUSSION... /Issued 239 AM PDT Thu Jul 9 2026/ KEY MESSAGES... * Typical summer weather for the remainder of the week: seasonable temperatures and humidities, gusty afternoon winds. * Pattern amplifies Friday into the weekend resulting in tightening pressure gradients and gusty southwest winds (25-35 mph) Friday- Sunday. Gusty winds combined with low RHs bring heightened fire weather concerns (winds strongest/RHs lowest on Saturday). * Thunderstorm pattern early next week. Best chances east of Cascades and across northern California with lesser, but not negligible chances for the West Side. DISCUSSION...Another quiet summer morning underway today. The marine layer is far less extensive this morning and only blankets the coast from Brookings southward. Skies are clear everywhere else. Westerly flow will prevail today under a mostly zonal flow pattern with flat high pressure to the south and a broad trough extending south over the northeastern Pacific from the Gulf of Alaska. This will result in a more stable air mass with thunderstorm potential remaining well east of the area. There will likely be some cumulus buildups today east of the Cascades and across northern California, but no showers are expected today. Generally cooler temperatures are expected into the weekend, so instead of temperatures being 8 to 10 degrees above normal like recent days, high temperatures through the weekend will hover within a few degrees of normal, equating to low 90s West/upper 80s East. The pattern transitions on Friday with high pressure to the south moving eastward into the Great Basin region, then amplifying on Saturday. Meanwhile, relatively strong low pressure off the northern British Columbia Coast digs southward Friday into Saturday, lingering offshore near Seattle through the weekend. This will turn the flow southwesterly again and southwest OR/northern CA will be wedged between these two systems, resulting in tighter pressure gradients. This pattern will bring multiple days of strong, gusty winds to the region Friday through Sunday when gusts of 25 to 35 mph are expected east of the Cascades and across northern California. The air mass in those areas will be more under the ridge influence, while areas west of the Cascades will be more under the trough influence. This will result in much drier air for areas to the east (daytime humidities in the low teens, possibly single digits), and when combined with those 25 to 35 mph gusts, critical fire weather conditions could be possible east of the Cascades Friday through Sunday, most widespread on Saturday. The parent low pressure to the north pushes northeastward on Sunday, but a frontal boundary/energy gets left behind, maintaining tight pressure gradients. Guidance maintains another day of gusty winds (25-30 mph), and although humidities do tick upward some, it could still be another day of elevated to critical fire weather conditions. Meanwhile, strong ridging gets nudged eastward with that trough and the flow will turn more south to southwest heading into the early part of next week. This pattern will bear watching for thunderstorm potential as south to southwesterly flow could push some monsoonal moisture into the region. Much will depend on when/where shortwaves develop and at this juncture, it's too soon to try to pinpoint details. It's also challenging because our region will remain wedged between strong high pressure to the east and incoming troughs from the northwest. The proximity of those troughs could be enough to keep the flow more southwest or even westerly, and the more westerly the flow, the lower the chances for thunder, especially west of the Cascades. Until further details can be sussed out, it currently looks like the best chances for thunderstorms would be across eastern areas on Monday/Tuesday. We'll continue to monitor model trends to see if the eastward shift in the upper level pattern persists, or if thunderstorm chances shift westward. Stay tuned for updates as models hone in on additional details. MARINE...Updated 100 AM PDT Thursday, July 9, 2026...A thermal trough will maintain gusty north winds and steep to very steep seas today. Hazardous warning level seas are expected south of Gold Beach and generally beyond 5 nm from shore and there could be a brief period of northerly gales in this area this afternoon. Conditions improve tonight into Friday as the thermal trough weakens and winds ease, but steep seas will continue for all areas south of Cape Blanco through Friday evening. Gusty north winds could return again for a brief period on Sunday, but in general, seas will be dominated by a fresh northwest swell this weekend and into early next week, with the thermal trough rebounding more fully during the latter half of next week. FIRE WEATHER...Updated at 200 AM Thursday, July 9, 2026... Seasonable temperatures and humidities are expected for the remainder of the week, with critical fire weather concerns increasing Friday and continuing through the weekend. The region will be wedged between strong high pressure to the east and an upper level trough off the eastern Pacific through the weekend, which will result in increased pressure gradients across the area. Strong gusty southwest to west winds (25-35 mph) are expected Friday through Sunday. Daytime humidities will be in the mid to low teens on Friday, and when combined with these gusty winds, critical fire weather conditions are likely across the Modoc and southeastern Fire Weather Zone (FWZ) 624 for Friday afternoon. A Fire Weather Watch has been issued for this potential. Critical fire weather conditions are expected to peak on Saturday when humidities trend lower (low teens/single digits possible), winds increase some (25-35 mph common, possible up to 40 mph in the windiest locations) and these combined conditions are more widespread across the East Side. Conditions improve slightly on Sunday with wind speeds on the lower end of the spectrum and humidities trend ever so slightly higher. Regardless, critical fire weather conditions are again possible for Sunday as well, so additional watches/warnings will likely be needed through the weekend. A potential thunderstorm pattern is shaping up for the first half of next week as the flow becomes south to southwesterly which could send monsoonal moisture into the region. Latest model guidance has shifted a bit on the overall pattern set up. The region will remain wedged between strong high pressure to the east and incoming troughs from the west/northwest. The proximity of those troughs could be enough to keep the flow more southwest or even westerly, and the more westerly the flow, the lower the chances for thunder, especially west of the Cascades. Until further details can be sussed out, it currently looks like the best chances for thunderstorms would be across eastern areas on Monday/Tuesday. We'll need to monitor the potential for any shortwaves/tropical activity that models try to develop and send our way early next week. On the other hand, however, if models continue this more eastward shift of the incoming troughs/southwest to west flow, we could potentially see an extended period of winds/RH concerns vs thunderstorms. Stay tuned as details become more clear with future model runs. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Fire Weather Watch from Friday afternoon through Friday evening for ORZ624. CA...Fire Weather Watch from Friday afternoon through Friday evening for CAZ285. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Friday for PZZ350-356-370-376. Hazardous Seas Warning until 2 AM PDT Friday for PZZ356-376. && $$