Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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522 FXUS66 KMFR 281030 AFDMFR Area Forecast Discussion National Weather Service Medford OR 330 AM PDT Fri Jun 28 2024 .DISCUSSION (Today through Thursday)... Overview: Potential impacts through this forecast include the triple digits next week, in addition to the potential for fire weather given the continued drying trend with further dry/windy conditions possible next week. This stretch may lead to many areas near 100 degrees across our westside locations. During the middle part of next week, this heat may be accompanied by breezy winds and low RH, so we could see fire weather conditions arise Tues-Thurs. Lastly, there is a small chance for thunderstorms Sunday afternoon and evening across the far eastern portions of Modoc and Lake counties. Although widespread severe weather is not expected, lightning will be a concern across far eastern portions of the forecast area. Further Details: We will transition from a mostly zonal flow pattern aloft today to more southwesterly flow by Saturday as a closed low pushes south of the Gulf of Alaska into southwest Canada. Depending on how the moisture and forcing phase together, there is a chance for thunderstorms on Sunday with both the GFS and EC indicating around a couple hundred J/kg of MUCAPE. Its not the best setup, but there was enough evidence to warrant at least a mention of thunderstorms, but more than likely most of the area will miss out on thunderstorms. Depending on how the low develops out of the Gulf of Alaska, we may have a chance for thunderstorms on Saturday as well, but chances are even less compared to Sunday`s potential. Moisture is the limiting factor here for this setup. As the aforementioned low pushes east, an area of high pressure over the southern CONUS will break down and slide east. This will allow for high pressure over the Pacific ocean to slide over the west coast. The high is progged to setup over central California, and this will allow for the heat to settle in for several days starting Tuesday. By Wednesday, and more so Thursday, the probability for 100 degree days will be on the rise, especially for our typical warmer locations like our westside valleys. For example, the Rogue Valley and Shasta Valley will approach a 50-60% chance of reaching 100 degrees or greater late next week through the weekend. In other words, some sort of heat risk is shaping up mid/late next week. Unfortunately, much of the forecast area has not received much--if any--rainfall in quite a while now, and this trend is only forecast to continue. Given the drying trend, fuels are likely to cure further, and the risk for fire danger will likely increase next week. This will be most notable starting Tuesday, as overnight recoveries are not that great, and we will be going into some hot afternoons near 100 degrees. Western parts of Siskiyou county in particular could have critical fire weather conditions arise mid week with RH values around 10 percent in the afternoon coupled with breezy wind speeds. In fact, elevated to critical fire weather conditions look possible for much of mid/late next week. -Guerrero && .AVIATION (06Z TAFs)... IFR ceilings are building into the coast as an inversion builds under some higher cirrus clouds. Models suggest LIFR ceilings are possible later tonight around North Bend. Marine air will push into the Umpqua Basin later tonight with some MVFR ceilings within that valley tonight. These lower ceilings will persist into the morning hours of Friday before skies clear out. VFR conditions are anticipated for most of Friday as a weak area of high pressure builds. -Smith && .MARINE...Updated 1215 AM Friday, June 28, 2024...A return of gusty northerly winds is present today, with steep seas affecting areas south of Cape Blanco. Winds and seas will peak late Friday afternoon and evening, with steep seas continuing south of Cape Blanco into early Saturday morning. Winds and seas lower Saturday afternoon into Sunday for most of the area. However, areas from Pistol River south within about 15 NM of shore could observe brief and isolated advisory level seas as winds peak in the afternoon, generating a steep wind wave. These conditions will likely be too short lived and localized to warrant needing a warning, but you`ll want to watch Buoy 27 to monitor conditions in this area to be safe before heading out. Then, a very strong thermal trough is expected to develop next week beginning on Monday and lingering towards the end of the week. The peak should be either Tuesday or Wednesday evening, but there is some spread in the forecast and uncertainty here. As for the wind speeds expected during the peak of the thermal trough, the chance for gale force wind gusts south of Cape Blanco is 70% or greater (90% plus south of Pistol River) and this will drive very steep waves. There is also a moderate (20-40%) chance that gale force winds develop over the waters north of Cape Blanco. -Miles && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Saturday for PZZ356-376. && $$