Marine Weather and Tide Forecast for Troy, MT

SYNOPSIS
Broad ridge pattern will bring a warming, dry trend over the region. Wildfire smoke will bring degraded air quality for the Inland Northwest. Smoke could reduce daily highs a few degrees.

DISCUSSION
Monday through Thursday: An upper trough swinging through the region overnight will exit into Montana this morning. As this trough exits a dry northwest flow pattern develops over the region followed by high pressure gradually building into Tuesday and Wednesday and lingering into Thursday. This will allow for a warming trend with low relative humidity each day. Given the north- northwest flow today more rounds of smoke will impact the region from regional wildfires, including smoke coming down from British Columbia. Then with lighter winds and building high pressure the smoke issues will likely continue. Several air quality agencies have issued Air Quality Alerts for several counties across Central and Eastern Washington and north Idaho.
Current temperature forecasts are from the National Blend of Models. Depending on amount of smoke cover, temperatures could not reach potential and end up cooler than forecast.

Friday through Sunday: Ensemble means show high pressure beginning to flatten late in the week, but with dry air persisting. The zonal flow and dry air mass will bring an uptick in wind speeds with ECMWF ensembles showing 15-25 MPH gusts across Eastern Washington each day, and 25-35 MPH through the Cascade gaps. This has the potential to bring elevated to locally critical fire weather conditions. JW

AVIATION
18z TAFs: MVFR conditions have continued across many terminals this morning due to smoke from area wildfires. Pilot reports around eastern WA and north ID indicate a thicker layer around 5000 ft with scattered smoke above, though conditions remain variable as the smoke is transported. Expect continued visibility reductions in smoke for many terminals including KGEG, KSFF, KCOE, KMWH and KEAT through the period. Northerly surface winds across most terminals today, with winds easing overnight.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate to high confidence in winds. Moderate confidence for smoke impacts bringing MVFR to IFR visibilities for area TAF sites.

----------------------- 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 80 50 85 52 90 56 / 0 0 0 0 0 0 Coeur d'Alene 79 50 84 53 89 57 / 0 0 0 0 0 0 Pullman 76 44 83 46 88 50 / 0 0 0 0 0 0 Lewiston 82 54 88 57 94 60 / 0 0 0 0 0 0 Colville 82 42 86 45 91 50 / 0 0 0 0 0 0 Sandpoint 77 45 82 48 88 52 / 0 0 0 0 0 0 Kellogg 75 49 81 52 85 55 / 0 0 0 0 0 0 Moses Lake 83 52 89 53 93 57 / 0 0 0 0 0 0 Wenatchee 84 60 89 63 94 66 / 0 0 0 0 0 0 Omak 85 54 90 57 94 61 / 0 0 0 0 0 0

OTX WATCHES/WARNINGS/ADVISORIES
WA...Air Quality Alert until 5 PM PDT Thursday for Central Chelan County-Lower Garfield and Asotin Counties-Moses Lake Area- Northeast Blue Mountains-Northeast Mountains-Okanogan Highlands-Okanogan Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-Waterville Plateau-Wenatchee Area-Western Chelan County-Western Okanogan County.
ID...Air Quality Alert until noon PDT today for Central Panhandle Mountains-Idaho Palouse-Lewis and Southern Nez Perce Counties-Lewiston Area.