197 FXUS66 KOTX 271143 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 443 AM PDT Sun Apr 27 2025 .KEY MESSAGES... -A 30% chance of thunderstorms over the Idaho Panhandle today. -Rain for the Cascades, Idaho Panhandle, and eastern third of Washington Monday Night into Tuesday Morning. -Sunday through Tuesday will feature seasonably breezy west winds. && .SYNOPSIS... Showers and thunderstorms will occur this afternoon across the ID Panhandle and northeast WA with a weak weather feature exiting. A weather system moving through Monday Night into Tuesday morning will bring rain to the Cascades, Idaho Panhandle, and eastern third of Washington. Warmer and drier weather returns Wednesday and Thursday. && .DISCUSSION... Today through Monday Night: Low currently in Nevada will move into Utah later today. The backside of the trough will move through eastern WA and north ID as the ridge begins to nose onto the west coast. Models are indicating instability this afternoon across the Idaho Panhandle and portions of northeastern WA. NBM chance of precip seems too low given what other models are showing as well as it has been too low under a similar synoptic pattern just a week or two ago. Have increased the chance of precip for this afternoon across northern WA including Stevens and Ferry counties. Have also expanded thunder chances across NE WA as well as the continuing the threat across the ID Panhandle. Winds will increase later this morning down the Okanogan Valley and onto the Waterville Plateau. Those winds will decrease this evening. The Cascade gaps will see their winds increase late this afternoon and continue through the night. The strongest winds will be from 5 to 10 pm. There is a 35-50% chance of gusts greater than 30 mph for Wenatchee and areas on the Waterville Plateau. The mountains surrounding the area have over an 85% chance of gusts to 30 mph and a 60-75% chance of gusts over 40 mph at the higher peaks. Winds will decrease overnight, but will remain breezy. Given the elevated winds through the night, min temps Monday morning across the Wenatchee Valley and down toward the Moses Lake region will be quite warm with mid 40s to around 50 forecasted. Parts of northeast WA and north ID where winds will be very light overnight will be quite a bit cooler with lows in the 30s. Monday the ridge begins to flop over as the next weather feature approaches. Clouds will begin to increase in the afternoon and the chance of precipitation increases overnight. Daytime temps Sunday and Monday will remain about 5 to 10 degrees above average for the end of April with highs in the mid 60s to low 70s. /Nisbet Tuesday to Saturday: The next frontal wave will be pushing into the region at the start of this period, with rain and breezy conditions and a chance for a few embedded t-storms. Then high pressure briefly builds in before another system bring a chance of rain Friday into Saturday. Tuesday morning a cold front drops in from the northwest, backed by an upper trough, tapping a moisture fetch with PWATs of 175-200% of normal. All but the lee of the Cascades will see good chance of some rain in the morning, then the risk retreats to the Cascade crest and Idaho Panhandle in the afternoon, though some showers will still be possible over the eastern third of WA. Overall chances start to wane throughout the area in the later evening into the overnight. Some convective instability is present, though not impressive at 75-150 J/kg. Still I did include a slight risk for t-storms near the WA/ID border eastward. Models have increased the potential for wetting rain (>=0.10") over the past few runs; the highest chances for that remains near the mountains and secondarily over the east third of WA. It will be another breezy day, with the peak in the afternoon/early evening. Gusts of 20-35 mph are forecast, strongest near the lee of the Cascades to western Columbia Basin and near the Blue Mountains. Winds wane overnight into early Wednesday. For Wednesday to Thursday high pressure dominates, with dry conditions and lighter winds. Skies will be partly cloudy to clear. With the rain moistening the boundary layer prior to this period the forecast continues to show a potential for patchy fog over the sheltered valleys Wednesday morning. Friday remains mostly dry, but another system will be approaching and increasing clouds later in the day. Some rain chances come to the Cascade crest in the morning and start to come toward the Blue Mountains and southern ID Panhandle in the afternoon as moisture increases. Then Friday night into Saturday another good chance of precipitation comes in. There has been some disagreement from run-to-run so PoPs are tempered because of that. However the trend has been toward a higher potential; PoPs have increased in kind since yesterday. And there will be a modest potential for wetting rain, except in the lee of the Cascades/deeper Basin. Overall PoPs between Friday night and Saturday are between 30-70%, highest near the mountains and southeast WA. There is also some instability and a slight risk for t-storms Friday afternoon/evening with the incoming front. Confidence in coverage is low but the risk is there. The system will also come with another increase in winds, with gusts in the 20-35 mph range, again strongest near the lee of the Cascades to western basin and near the Blues. Temperatures will be close to normal Tuesday; however, depending on how quickly the clouds/precipitation shifts out in the afternoon the temperatures could be a bit cooler than forecast. Overall the forecast has 60s to low 70s, with some mid to upper 50s over the Blues, Palouse, Camas Prairie and Idaho Panhandle mountain zones where the rain and clouds hold on the longest. Thereafter look for a warming trend into Friday, before another cool down Saturday. The mildest days will be Thursday and Friday when many areas are forecast to see mid-70s to mid-80s. Then temperatures cool to the upper 50s and lower 60s Saturday, with a few areas forecast to be near the upper 60s in the deeper Columbia Basin. Lows will be in the 30s and 40s Wednesday and Thursday AM, with Wednesday AM the coolest with the continued potential for frost in some of the northern valleys. Thereafter lows will largely be in the 40s. /Solveig && .AVIATION... 12Z TAFS: VFR conditions forecast through the period. This afternoon will a better chance of cumulus buildups, especially over far NE WA and N ID with an incoming front. A few showers and weak thunderstorms possible. Bonners Ferry, Sandpoint, and Couer d`Alene carry the highest risk (30-40%). In Central WA, gusty west to northwest winds will impact the east Slopes of the Cascades and spill into the W Basin. These winds will expand into the Eastern Basin and Palouse Sunday afternoon. Winds and shower chances decline after 03-06Z. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Main uncertainty for Sunday will be westward expansion of showers and weak t-storms. Some cam models indicate cells into Spokane-Colville-Deer Park. Forecast may be adjusted to include a prob30 if future runs trend this direction. HREF calibrated thunder has a 10-15% chance this far west. Erratic wind gusts around 25 mph possible near any convective cells Sunday 20-02z. ----------------------- 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 69 47 64 41 68 / 10 10 0 20 70 0 Coeur d`Alene 67 45 60 39 66 / 30 20 0 30 80 20 Pullman 63 45 57 40 64 / 0 10 0 20 80 10 Lewiston 72 50 66 46 71 / 0 10 0 10 80 10 Colville 70 42 66 36 71 / 30 10 0 40 50 0 Sandpoint 65 44 57 39 65 / 60 30 0 30 80 20 Kellogg 62 47 53 42 62 / 50 40 0 20 90 30 Moses Lake 74 49 72 41 73 / 0 0 0 30 30 0 Wenatchee 72 52 69 44 73 / 0 0 0 20 20 0 Omak 73 47 71 41 75 / 10 0 0 30 20 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$