028 FXUS66 KMFR 091707 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1007 AM PDT Mon Jun 9 2025 ...New Aviation Section... .AVIATION (18Z TAFs)... A marine layer (IFR) still evident via satellite and observations along and near the coast will persist for a few more hours, but then conditions should go to VFR along with the other terminals already experiencing these conditions. Today will be noted by mostly clear skies, but this afternoon we have a chance for isolated thunderstorms for areas mainly over northern California and the eastside. One or two of which could impact the Klamath Falls terminal; however, not expecting widespread thunderstorm activity today. Otherwise, typical diurnal breezes expected this afternoon with speeds diminishing near/after sunset. -Guerrero && .PREV DISCUSSION... /Issued 856 AM PDT Mon Jun 9 2025/ DISCUSSION...Satellite image shows marine stratus along the coast and offshore and into the Coquille Basin. The marine stratus in the Coquille Basin should burn off in the next 2-3 hours with clear skies there for the afternoon. Elsewhere, it clear at the moment, but as instability increases during the day so to will the building cumulus, first over the mountains, then in other areas in northern Cal and east of the Cascades. The main change to the forecast was to fine tune the timing and coverage area of isolated storms this afternoon and evening. Isolated storms are expected to develop first in southern Siskiyou County and south Warners in southeast Modoc County. Isolated storms will tend to expand in coverage and expand north into southern Lake and Klamath County late this afternoon into early this evening, then storms will diminish and end shortly after sunset this evening. The main event in terms of storms will be Tuesday afternoon into Tuesday evening. Storms will be more widespread and a few of the storms could be strong or even severe. We`ll take a more detail look at this. -Petrucelli AVIATION...09/12Z TAFs...Along the coast, marine stratus will again produce widespread IFR/LIFR conditions through this morning. Conditions will improve to VFR around 18-20z, then will lower yet again to MVFR/IFR this evening and tonight. Inland, VFR is expected through the TAF period. However, there is a potential for thunderstorms this afternoon and evening (mainly 21-06z) across northern California and far southern Oregon, including Yreka, Mount Shasta, Alturas, Klamath Falls and Lakeview. There is a low chance (10-15%) for thunderstorms Monday afternoon at Medford. Gusty outflow winds and locally heavy downpours may occur with thunderstorms. -BPN MARINE...Updated 850 AM Monday, June 9, 2025...As north winds increase over continuing fresh north swell, steep seas will build today across all the waters and persist through at least Tuesday. On Tuesday afternoon and evening, locally very steep seas are possible within 20 nm of shore between Cape Blanco and Gold Beach, but given the limited coverage, a Hazardous Seas Warning does not look necessary right now. Models support continued gusty north winds and steep seas on Wednesday. Then there is a potential for winds to increase further Thursday through Saturday as the thermal trough restrengthens. This will likely result in continued steep seas. We will also monitor for the potential of very steep seas late in the week. -BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Heat Advisory until 8 PM PDT this evening for ORZ023-024-026. CA...Heat Advisory until 8 PM PDT this evening for CAZ080-081. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Tuesday for PZZ350-356-370-376. && $$