Cooler Temperatures and Rain Expected in Roseburg Thursday and Friday

Rain and cooler temperatures are on the way for Thursday and Friday of this week. High temperatures could be as low as 68 degrees on Thursday and 67 degrees on Friday in Roseburg. Expected rainfall for the area could be as high as another inch by Saturday morning. Here is the full forecast discussion: There have been some cumulus build-ups this afternoon along the Cascades as well as in the western portions of Siskiyou County. The chance for some showers or thunderstorms remains low (<10%) east of the Cascades through the late afternoon and evening hours. Cooler-than-normal temperatures will persist with this onshore westerly flow. An upper-level trough will eventually push onshore later tonight, with high pressure building in its wake briefly tonight. There could be some patchy fog along the coast tonight, although confidence is not great. Smoke and haze also linger around the Boise fire, as the rain from Saturday didn’t make a huge dent in that fire. The upper-level flow remains from the west to northwest, so most of the smoke should be moving out of our forecast area. By Thursday, another low moving down from Alaska will settle off our coastline, bringing a modest chance of rain showers and perhaps a low probability of some thunderstorms as well. Thursday doesn’t appear as wet since there is some lacking moisture ahead of the wave. However, a cold front will likely push into the coast, which should significantly increase the probability of precipitation on Thursday afternoon and Thursday night. The chance of thunderstorms is about 10 to 20 percent on Thursday ahead of the cold front. The models seem to be targeting the Cascades, so that is where the thunder potential is mentioned. We’re also not expecting any severe storms as the convective available potential energy is really lacking and under 100, although there is a good amount of shear around 30 to 50 knots. Long Term: Friday is a really interesting day as this unusually cold low starts to move farther eastwards and right over our county warning area. Temperatures aloft remain in the 0.5 percentile for this time of year, and the weather that follows really drives that home. We’re currently forecasting some of the lowest high temperatures for August 23rd. In fact, we’ll probably set new records for Medford and Mount Shasta City, with Klamath Falls also being possible. This weather is more like late October than towards the end of summer. Furthermore, the chance of wetting rain (>0.1 inches) is fairly high (50-80%) across our forecast area. Even the chance of 0.5 inches is about 30 to 50 percent over some of the higher terrain in Oregon. There could be some rumbles of thunder as well, although these are usually pop-up showers and storms when very cold air rides over a warm surface in the center of the low. Overall, we’re very confident in a cool and wet Friday afternoon and evening. If anyone reading this has plans during that time, they should plan for a relatively cool and wet period. Heading into Saturday, the forecast dries a bit, although it still remains cooler than normal. The probability of showers lingers, and we still have a 30 to 40 percent chance of rain across the forecast area. After this cool and wet weekend, we jump right back into the summer swing of things, with dry weather and temperatures jumping right back to normal or above normal. -Smith