Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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824 FXUS66 KMFR 291552 AFDMFR Area Forecast Discussion National Weather Service Medford OR 852 AM PDT Sat Jun 29 2024 .DISCUSSION...There are no changes to the forecast this morning. An upper trough will support seasonal temperatures across northern California and southern Oregon through the day. A slight (10%) chance for thunderstorms remains along the northern Klamath/Lake County border area this evening, with those chances fading quickly into the night. Cumulus clouds could develop over other east side areas this evening, but chances for activity are in the single digits. Please see the previous discussion for more details about the short- and long-term forecast. -TAD && .AVIATION 29/18Z TAFS...Stratus at the coast is retreating this morning. The remainder of the area will maintain VFR conditions through the day today, although some mid-level clouds will move into the area. Smoke from a few wildfires could produce some locally low visibility near those fires, otherwise the smoke will not be an issue near terminals. -Miles && .MARINE...Updated 815 AM Saturday, June 29, 2024...Winds and seas will lower this afternoon into Sunday for most of the area. However, areas from Brookings 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 an advisory, 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, and the guidance is trending towards Tuesday; although very little drop off in intensity is expected Wednesday. 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 80% or greater (90% plus south of Pistol River) and this will drive very steep waves. There is also a moderate (20-50%) chance that gale force winds develop over the waters north of Cape Blanco and south of Cape Arago. Confidence is low if these gusts will be frequent enough to warrant any sort of Warning north of Cape Blanco, however. Comparing this event to the past, this is getting into the top end of events, and to summarize, this occurrence of the thermal trough northerlies will not be one to mess with. -Miles && .PREV DISCUSSION... /Issued 419 AM PDT Sat Jun 29 2024/ DISCUSSION (Today through Friday)... Overview: Overall, the forecast is still calling for potential impacts from both heat and fire weather. By middle of next week, the heat will be ramping up across the forecast area, and there is a high likelihood for some sort of heat risk. In fact, there is the potential for some records to be broken as well. Unfortunately, with the heat comes low RH values that could be coupled with breezy winds, so there is at least some risk for elevated to perhaps critical fire weather conditions next week. Lastly, there will be a small chance for thunderstorms both today and tomorrow afternoon for mainly areas on the eastside. Not expecting severe weather, but the threat for lightning will exist. Further Details: Pieces of energy are expected to round the base of a passing trough this weekend. There is a chance for thunderstorms both today and tomorrow afternoon. However, the problem both days are weak variables, and these variables not entirely phasing together correctly, especially the moisture aspect. The vorticity field might phase with moisture today, and this could kick off some showers/thunderstorms over parts of Klamath and Lake counties. Not a great chance, but also not a zero chance. Chances are slightly better tomorrow as we might have an upper level jet streak helping with additional forcing. CAPE is relatively weaker on Saturday, and really only showing up in the NAM (typical with the wet bias), but Sunday we have a few different models suggesting a couple to perhaps a few hundred J/kg of MUCAPE. Again, not expecting severe weather, but lightning may disrupt outdoor activities this weekend on the eastside. The heat is coming! The probabilities for 100 degrees or more have gone up for some of the westside valleys with some areas sitting around a 50-70 percent chance for 100 degrees or more. In fact, the probability for 110 or greater is around 20% for both the Rogue Valley and Shasta Valley. In other words, there is a high probability for some sort of heat related headline come next week to account for this threat. Overnight low temperatures might be in the mid 60s for some areas on the westside Fri-Sun, which would not allow for much relief from the heat overnight. Some Potential Records: -------- July 4th -------- Medford: 103 in 2015 (Forecast: 101) Roseburg: 98 in 2023 (Forecast: 94) Brookings: 96 in 1931 (Forecast: 74) Klamath Falls: 98 in 1981 (Forecast: 94) -------- July 5th -------- Medford: 102 in 1926 (Forecast: 104) Roseburg: 98 in 2023 (Forecast: 99) Brookings: 84 in 1993 (Forecast: 73) Klamath Falls: 98 in 2007 (Forecast: 96) Unfortunately, the heat (above normal temperatures) may continue into parts of mid July as the Climate Prediction Center is forecasting the chance for above normal temperatures to continue with below normal precipitation. This doesn`t bode well for our fire weather conditions as a prolong drying period appears slated for much of the area. -Guerrero && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$