Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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712 FXUS66 KMFR 192128 AFDMFR Area Forecast Discussion National Weather Service Medford OR 228 PM PDT Thu Sep 19 2024 .DISCUSSION...Upper ridging is building is nudging into the area from the west as the upper low in central/southern California continues to move south. Satellite image shows mostly clear skies with a few high clouds moving in from the northwest as a weak northern branch shortwave zips through northern Washington State. It will be dry with milder temperatures this afternoon. Tonight, marine stratus will make a return along the coast, north of Cape Blanco and into portions of the Umpqua Basin. A thermal trough will set up along the south Oregon coast tonight with offshore flow that will be sufficient enough to keep the marine stratus offshore. Friday through early next week will be dry with afternoon temperatures trending warmer for the interior. The thermal trough will remain in place along the south Oregon coast and the pattern is one where we could see afternoon temperatures at Brookings get into the lower to mid 80s, possibly the upper 80s Friday through the start of next week. Tuesday, the thermal trough will build north and weaken some allowing the flow to become weak onshore at Brookings, therefore it should be cooler. Upper ridging will build over the area Monday and Tuesday with afternoon temperatures maxing out both these days, then the upper ridge will shift east as an upper trough approaches from the west Wednesday. This will result in cooler afternoon temperatures for most of the interior along with gusty afternoon and early evening breezes east of the Cascades. The operational models and ensembles are in similar agreement showing the upper trough moving into the area, with a weak front pushing into the northwest part of the area. However, the ensembles show a dry, stable southwest flow with the upper trough positioned west of the forecast area. -Petrucelli && .AVIATION...19/18Z TAFS...Patchy LIFR will linger at the coast into the early afternoon, from Cape Arago north, and south of Brookings. Then, breezy north winds develop at the coast this afternoon into the early evening (including gusts up to 30 kts at North Bend), with strongest winds south of Cape Blanco. LIFR ceilings and visibilities will return to the coast around 06Z this evening, but with more limited coverage (mainly north of Cape Blanco) and faster dissipation (shortly after 14Z Friday morning) than is occurring today. Inland, areas of MVFR ceilings in the central and southern Umpqua Valley, including at Roseburg, are eroding but will persist in the southern portion of the valley into this afternoon. A few patches of MVFR are expected to return to the southern Umpqua Valley late tonight into the early morning. Otherwise, VFR conditions are expected to continue across the area through the TAF period. -DW && .MARINE...Updated 200 PM Thursday, September 19, 2024...A thermal trough pattern is strengthening today and will likely persist into early next week. This will result in the strongest northerly winds south of Port Orford during the afternoon and evening hours, with very steep seas and occasional gale gusts at least into Saturday evening. Meantime, steep seas and advisory strength northerly winds are expected north of Port Orford. The thermal trough is forecast to move inland with weakening winds and easing seas late Tuesday into Wednesday. -DW && .FIRE WEATHER...Issued 200 PM Thursday, September 19, 2024... Pretty quiet weather will continue into this weekend as the flow remains progressive out of the north west. A Weak disturbances moves through the Pacific Northwest around Saturday before a stronger wave moves through the state of Washington around Sunday. The end result should be a notable north east to south west pressure gradient with some stronger north east winds(15 to 20 knots), especially over the Kalmiopsis wilderness. Looking at some ensemble data and comparing to the climatology to this time of year, nothing jumps out as extreme. There could also be some light east breezes instead of stronger north east winds depending on what ensemble cluster comes to fruition around Monday night. In any case, Monday night is a period to keep an eye on, especially for the fire weather conditions in the extreme southwest Oregon. -Smith && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Saturday for PZZ350-356-370-376. Hazardous Seas Warning until 11 PM PDT Saturday for PZZ356-376. && $$