Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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650 FXUS66 KOTX 111157 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 457 AM PDT Tue Jun 11 2024 .SYNOPSIS... This afternoon and evening will be windy raising concerns of isolated power outages, rough water on area lakes, and the heightened potential for grass fires. Another cold front is expected to bring more breezy conditions Friday and Saturday. The weekend will be cooler along with the chance of mainly mountain showers. && .DISCUSSION... ...WARM, DRY AND WINDY THIS AFTERNOON AND EVENING... Today and Tonight: The passage of a dry cold front this afternoon will produce another windy day for the Inland Northwest. A compact surface low moving through southern British Columbia and deepening over southern Alberta in the afternoon is a favorable pattern for delivering strong winds to our region. Strong subsidence is evident on water vapor imagery this morning (2 AM) off the coast of Oregon/Washington with a distinct darkening along and behind the cold front. Model soundings from the GFS prog a deep layer of 35 to 40kts of west winds from 900mb to 700mb from 4 PM to 9 PM. GFS MOS guidance and wind gust output from the ECMWF ensembles are in decent agreement that several hours of 35 to 45 mph gusts will likely occur over the majority of eastern Washington and north Idaho late in the afternoon and early in the evening. Wind Advisories have been expanded into northeast Washington and north Idaho including Spokane, Coeur d`Alene, Sandpoint, Bonners Ferry, Metaline, Colville, and Republic. It can be tough to measure winds strong enough to satisfy Advisory criteria (sustained 30 mph or gusts of 45 mph) in Ferry, Stevens, Pend Oreille, Bonner and Boundary counties. But even wind events that fall short of criteria frequently produce power outages and tree damage due to the abundance of trees in these counties. In addition to tree damage and scattered power outages, rough water on area lakes will be a hazard this afternoon and evening. The aforementioned darkening on the water vapor imagery is a precursor of deep atmospheric drying. Warm, dry, and windy conditions will raise concerns of rapid spread of new fire ignitions. Dry grasses and brush in places that haven`t gotten rain recently like Grant, Chelan, and Douglas counties will be of particular concern today. Wednesday: Tuesday`s cold front will be well into the Dakotas and Minnesota by Wednesday morning. Winds region-wide will return to more "seasonably appropriate" levels ranging from 10 to 20 mph across north Idaho and eastern Washington with localized gusts to 25 mph in the lee of the Cascades in places like Wenatchee, Waterville, and Vantage. Temperatures will be close to average, too. Highs will range from the low 70s in north Idaho to near 80 in places like Lewiston, Moses Lake, and Omak. I guess we will call it a dry and "wonderfully average" early June day. /GKoch Thursday to Monday: Expect mild and dry conditions Thursday before a pattern shift arrives late in the week across the Inland Northwest. Winds will turn breezy on Friday in advance of approaching low pressure, with cooler temps and chances for showers arriving this weekend. Wind speeds of 15-30 mph, with gusts of 30 to 40 mph will be possible for Friday into Saturday, especially across the Cascade gaps into the Waterville Plateau and Columbia Basin. The best chances for precip look to be across the Cascades, northern WA mountains, and northern Idaho from late Saturday into early next week. After our period of above normal temps, daytime reading are forecast to drop below normal for Saturday through Monday. /KD && .AVIATION... 12Z TAFS: There will be a 20 percent chance of convective showers along the Canadian border around Newport and Bonners Ferry this afternoon. Elsewhere, the most notable weather associated with today`s cold front will be increasing west winds. Sustained 15 to 20kts winds with gusts to 35kts will be common for our TAF sites including Wenatchee, Moses Lake, Spokane, Coeur d`Alene and Pullman. Peak gusts will likely occur between 21-03z. /GKoch FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: A few amendments may be necessary today for the timing of gusty west winds. There is a low chance of visibility reductions due to blowing dust at Moses Lake and Spokane International as winds peak late in the afternoon. Most agricultural field work has been done for the spring season, but there may be a few freshly worked fields capable of gernating dust. /GKoch ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .PRELIMINARY POINT TEMPS/POPS... Spokane 82 43 73 45 80 54 / 0 0 0 0 0 0 Coeur d`Alene 79 43 72 44 79 52 / 0 0 0 0 0 0 Pullman 77 43 69 43 77 52 / 0 0 0 0 0 0 Lewiston 89 52 80 51 86 58 / 0 0 0 0 0 0 Colville 80 38 75 40 78 47 / 10 0 0 0 0 0 Sandpoint 78 43 70 42 76 49 / 10 0 0 0 0 0 Kellogg 76 46 68 47 77 54 / 0 0 0 0 0 0 Moses Lake 85 45 80 46 84 52 / 0 0 0 0 0 0 Wenatchee 79 48 78 50 82 54 / 0 0 0 0 0 0 Omak 84 45 80 48 83 52 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory from 2 PM this afternoon to 8 PM PDT this evening for Coeur d`Alene Area-Northern Panhandle. WA...Wind Advisory from 2 PM this afternoon to 8 PM PDT this evening for Northeast Mountains-Okanogan Highlands-Spokane Area- Upper Columbia Basin. Wind Advisory from noon today to 8 PM PDT this evening for Moses Lake Area-Waterville Plateau-Wenatchee Area. && $$