338 FXUS66 KOTX 252146 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 246 PM PDT Wed May 25 2022 .SYNOPSIS... Thursday will be our warmest day of the spring so far with high temperatures in the mid 70s to low 80s. The arrival of a cold front will bring the potential of late afternoon and evening thunderstorms. Some storms may be severe across the central and southern Idaho Panhandle as well as far southeast Washington. The Memorial Day weekend will be showery and cooler than average, and some spots may struggle to reach 50 degrees Sunday with a steady cool rain. && .DISCUSSION... ...STRONG TO SEVERE THUNDERSTORMS POSSIBLE THURSDAY LATE AFTERNOON AND EVENING ACROSS THE CAMAS PRAIRIE Tonight: Clouds across eastern WA and north ID has kept temps today in the 60s while mostly clear skies in central WA has allowed temps to warm into the 70s. Light rain showers are exiting the ID Panhandle and some isolated spots in extreme eastern WA with dry conditions expected tonight. High cirrus will likely persist tonight especially across portions of southern WA and the southern ID Panhandle. Lows will be in the upper 40s to lower 50s which is near or slightly above average. Thursday: As the trough nears the west coast on Thursday, the ridge will buckle with the winds backing bringing in warmer air from the south. This is our one shot for 70 degrees in Spokane with the NBM saying yes, there is a 95% chance of 70 or warmer. Even though there will be substantial cloud cover, the warmer start to the day coupled with 3 or 4 degrees of warming at 850 mb, it suggests Spokane will reach at least 70. By late in the afternoon we will turn our attention to convection firing across northeast Oregon and watch them as they move toward the NE into southeast WA and the southern ID Panhandle. Parameters are such that we could see strong to locally severe storms stretch from the Blue mountains to about Lookout Pass and areas to the south and east, with particular focus on the Camas Prairie. The issue will be the extensive cloud cover and convective inhibition that will need to be overcome to get storms going. Ensembles are showing 150-200 percent of average precipitable water values moving over the area during the evening. Storms will likely have very heavy rain cores in them. Other concerns with these storms will be gusty winds and small hail. The high res models are showing some stronger cores stretching further north toward Spokane/CdA which would likely occur a few hours later, and have mention of slight chance of thunder during the evening. The time frame of strongest storms will be from 5pm to 10pm, with convection possible to continue through the night for portions of the ID Panhandle. The Palouse also has a small threat through the night. Friday: Instability showers will continue through the day and then decrease through the evening and overnight. The best chance for thunderstorms will extend across the northern WA mountains into the ID Panhandle and back towards the Blue Mountains. Winds will increase in the afternoon. Main areas of concern will be the Columbia Basin into the Palouse and West Plains. Have kept the mention of patchy blowing dust. The good news is the strongest winds will not be around the Moses Lake area, but further east across Lincoln and Adams county, and hence that is where the blowing dust is mentioned. Parts of the Waterville Plateau and northern Grant county could see blowing dust, but confidence isn't as high for these areas. Restrictions to visibility down to 3-5 miles will be common for the aforementioned areas, but there could be some isolated spots of down to 1 mile. Saturday through Monday: While the Memorial Day weekend is the unofficial beginning of summer, the weather across the Northwest US won't seem like it. Our holiday weekend will be on par with what we have experienced the last 6 or 7 weeks. The majority of our climate sites were 4 to 6 degrees below average for the month of April. And so far, cool anomalies for May are similar. Just in time for the holiday weekend, a broad upper level trough will set up over the Pacific Northwest. At this time, Saturday looks like a day with scattered mainly afternoon showers. The most concentrated shower activity (30-50 percent chances) look to be over the mountainous terrain of the Idaho Panhandle and the Cascade Crest. Afternoon temperatures are expected to top out in the upper 50s to mid 60s. Saturday night into Sunday has the potential to be quite wet. Ensemble based guidance brings a moist Pacific trough into Oregon coast Saturday night with it stalling over the Beaver State and southern Idaho during the day Sunday. While it is still early to predict the location of rain bands wrapping around the low, this type of pattern has the potential to create an all-day chilly rain for some part of the Inland Northwest with temperatures struggling to reach 50 degrees. Places that remain dry may climb well into the 60s. Folks that plan to camp this weekend anywhere in the Inland Northwest should be prepared for the possibility of a cool and wet Saturday night into Sunday. Memorial Day (Monday) will not be a completely dry day for our region, but precipitation will become more showery in nature with much of it occurring during the afternoon and early evening. The center of our upper low is expected to be over southeast Idaho and Wyoming with wrap around rain mainly over Montana. The small chance of thunderstorms enters the forecast Monday afternoon mainly across north central and northeast Washington. Monday should be the warmest day of the weekend with widespread 60s and a handful of 70s in the Columbia Basin. Tuesday and Wednesday: Look for a gradual warming trend Tuesday and Wednesday. Temperatures near average are currently advertised by our model blend with highs in the mid 60s to mid 70s. In general the ensembles build a weak and flat ridge over the Pacific Northwest, but most models continue to carry enough moisture and instability to carry chances for showers over the mountainous terrain. /GKoch && .AVIATION... 18Z TAFS: Sprinkles or light rain will continue across parts of extreme eastern WA and north ID, potentially brining brief -ra to GEG/SFF/COE/PUW/LWS. Local wind gusts 15-25 mph expected across the Basin, Palouse and West Plains this afternoon, otherwise mainly light winds. && .PRELIMINARY POINT TEMPS/POPS... Spokane 51 76 53 67 44 60 / 0 0 60 50 10 20 Coeur d'Alene 50 76 52 64 43 59 / 0 0 80 60 10 30 Pullman 51 76 52 63 45 56 / 0 0 80 60 20 30 Lewiston 56 82 58 70 51 63 / 0 10 80 70 40 40 Colville 50 76 50 68 40 63 / 0 10 30 50 10 20 Sandpoint 48 72 51 62 42 58 / 10 10 80 80 20 30 Kellogg 50 74 53 61 46 55 / 10 0 90 80 30 40 Moses Lake 51 80 53 72 44 65 / 0 0 10 10 0 10 Wenatchee 52 76 54 68 46 63 / 0 10 40 10 10 20 Omak 51 76 52 72 43 66 / 0 30 30 20 0 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$