FXUS66 KMFR 070957 AFDMFR Area Forecast Discussion National Weather Service Medford OR 257 AM PDT Tue May 7 2024 .SHORT TERM... Showers remain ongoing this morning with some surface stations reporting light rain along the coast and the Umpqua Basin this morning. Upper level energy will pass through this morning and sinking motion in the mid levels will become more widespread today. As a result, the probability of precipitation will gradually decrease, although may linger in the Cascades into the early afternoon. Temperatures will trend slightly warmer compared to the last few days with plenty of solar heating towards the afternoon. By Tuesday night, we'll have mostly clear skies with temperatures dropping down into the lower and mid 30's west of the Cascades and lower 20's east of the Cascades. The main concern here is temperatures approaching freezing in valleys west of the Cascades, although the duration of freeze should be fairly brief. -Smith .LONG TERM.../Issued 240 PM PDT Mon May 6 2024/ Upper level ridging will continue to build into the region from the eastern Pacific on Wednesday, with a thermal trough developing over California and far southwestern Oregon. The thermal trough will then strengthen and extend northward along the coast through Thursday night, creating generally east winds through the remainder of the week. Meanwhile, the upper level trough that passed over the area earlier in the week will retrograde, moving back to the west and setting up over the Great Basin, just south of the ridge, which by this time will extend across the Pacific Northwest and into the northern Rockies, creating east winds aloft that will correlate and enhance the east winds at the surface. All of this will result in very warm temperatures through at least the first part of the weekend, with a strong Chetco effect likely along the southern coast near Brookings. This pattern begins to break down over next weekend, which may allow a weak trough to enter the area early next week. With all of this in mind, many changes were made to the forecast to adjust temperatures and winds to fit the expected pattern. The Chetco Effect will begin Wednesday ,then peak on Thursday, with highs in Brookings expected to reach the 80s (and a few models even suggest 90 degrees is possible) Thursday afternoon and perhaps Friday as well. When the thermal moves inland, the south coast will begin to cool as the marine layer regains control, while temperatures for most inland areas will reach their warmest Friday afternoon or Saturday afternoon. For these areas, high temperatures will be more in line with early July than early May. Forecast temperatures were adjusted to fit this thinking, while also considering the strong inversions and warm ridgelines that this pattern typically produces during the overnight and early morning hours. Once the thermal trough moves inland, the prevailing flow will take on a more westerly onshore component, and temperatures will begin to gradually cool Sunday and Monday. Some models suites suggest the possibility of a weak front arriving around this time, but given the warm and dry conditions ahead of it, any frontal passage will most likely remain dry. -BPN && .AVIATION...07/06Z TAFs...VFR conditions are expected throughout this cycle. The chances for MVFR conditions to develop are around 30- 40 percent through this cycle. This would be for mainly ceilings, and really any of the terminals have this chance. Skies will generally start to clear late tomorrow afternoon and furthermore through the evening hours. Conditions may be breezy tomorrow afternoon as well. -Guerrero && .MARINE...Updated 245 AM Tuesday, May 7, 2024...A thermal trough will strengthen Tuesday afternoon; as a result, north winds will become gusty and steep wind-driven seas will develop--highest south of Cape Blanco. Wind speeds will peak during Wednesday afternoon/evening, but gusty northerly winds will persist into Thursday night. During this stretch (Wed-Thu), gale force winds are likely (85% or greater) across our southern waters. Given these conditions, a Gale Warning for areas from roughly Coos Bay southward is in effect. The strength of the thermal trough has trended stronger as new data comes in. Consequently, a Hazardous Seas Warning is in effect for all remaining areas north of the Gale Warning. The thermal trough will weaken Friday into next weekend resulting in weaker north winds and lower seas. -Guerrero/Hermansen && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM this afternoon to 11 AM PDT Wednesday for PZZ356-376. Gale Warning from 11 AM Wednesday to 5 AM PDT Thursday for PZZ356-376. Hazardous Seas Watch from Wednesday morning through late Wednesday night for PZZ350-370-376. && $$