Inland Northwest Hay Weather

A low pressure system off the California coast will slowly move into our area by Saturday, bringing a chance of some light rain.  Here’s the weather map for today (Thursday) showing the cool low off the west coast, with a ridge of hot high pressure over eastern Washington and Idaho. By Saturday morning, the low will move up to the Washington coast.  We’ll have two chances of rain with this system.  The first will be on Friday night and early Saturday morning.  Most of the computer models are betting against this scenario.  But the European and UK models (two of the better performers) are in favor of some Saturday morning rain for our area.  Here’s the European rainfall forecast for that time: The European model suggests this morning round of rain won’t bring any lightning.  I wouldn’t entirely rule it out though. But by Saturday afternoon, thunderstorms are expected to develop over the Cascades and northern mountains of Washington and Idaho.  This...

Summertime rain is getting hard to come by in these parts. But we do have another chance coming up at the end of this week. After a chance of some mountain showers across the north Sunday afternoon and evening, we’ll have some warmer temperatures, for those who like that sort of thing. This is the forecast weather map for Friday morning. Hot high pressure extending from the Four Corners region up into western Canada. This will push temperatures into the 90s by Thursday and Friday. But a fairly decent low pressure system is approaching the coast.  This is typically a really nice pattern for severe thunderstorms in the Northwest. But the models don’t see it that way. They are rather unimpressed. One missing ingredient is atmospheric moisture.  Also the timing has to be just right, so that the low arrives during the afternoon   So we’ll keep an eye on the Friday and Saturday forecast.  Here’s the rainfall forecasts from the US, Canadian and European models.  After ...

The chances of rain are increasing a bit for Wednesday through Thursday. Rather than just showers developing over the mountains, the weak weather system aloft is starting to look a bit stronger.  As a quick demonstration of this, here is the rainfall forecast for Wednesday through Thursday morning that was made by the European model on Sunday.  Only gray shading (i.e. less than 0.10”) for the valleys. Other models showed even less than this.  Now here is the same forecast made by the model today.  Notice that there’s more green shading (rainfall amounts above 0.10”) over a greater area, all the way down to Spokane and Moses Lake.  The rainfall predicted for the north Cascades is right where the two largest wildfires are located.  The timing is still about the same. Showers and thunderstorms will form over the northern mountains by mid-afternoon Wednesday.  But instead of shutting down in the evening, the strength of the storm could keep them going all ...

  Things have changed a little in the forecast, enough to warrant an update.  And we’re actually talking about rain showers. The first chance is coming up later this week.  A weak atmospheric wave will form over our area on Wednesday afternoon. The weather map below shows this small area of blue over Washington.  This, along with some moisture coming in from the west, will lead to the formation of showers and thunderstorms over the mountains of northeast Washington.  Yes, I did say thunderstorms unfortunately.  Here’s the lightning forecast from the European model on Wednesday afternoon   The winds aloft will be out of the north. This could bring the remnants of the thunderstorms southward to near Spokane on Wednesday evening.  Probably only few hundredths at best for lower elevations. The same scenario plays out on Thursday afternoon and evening. After a dry weekend, the weather pattern is looking a little more promising for rain showers and thun...

After a bone dry July, I think most folks would like to see some August rains. Any chance of that?  Unfortunately there’s only a very small chance.  In the meantime, we’re looking at a week or more of dry days. Here’s the chance of rain over the next 10 days at Deer Park.  Only a 10% chance of something around the 14th.  And nothing heavy. In the meantime, we’re going back into a warm and breezy pattern. Friday will be the hottest day, and then a gradual cooling trend. The gradual cool down means that we probably won’t see a strong windy event. But we will still see breezy afternoons for the next week as a westerly jet stream sets up overhead. This is the wind forecast for Spokane.  Gusts to 20 mph each day for the next week.  Our atmosphere will continue to be very dry.  Drier than August usually is, with dew points in the 30s. This will allow our nighttime temperatures to continue to fall into the 40s.  But with such low dew points, it will cont...

Some may not have noticed, but it’s been a very dry July.  Officially at the Spokane Airport, they haven’t measured anything more than a sprinkle. Has there ever been a July with no rain at all?  Technically it’s happened only once in Spokane, and that was way back in 1883.  There’s been 15 Julys like this year where only a sprinkle fell the entire month. The same happened in 2017, 2013, 2008 and 2003. To be fair, other locations in the Inland Northwest did receive rain. But mostly it was less than 0.10”. The exception was in the Colville area. I showed this chart a couple of years ago at the Northeast Washington Hay Growers meeting. The blue line is the July rainfall each year at Spokane, while the green line sort of a moving average. Between 1975 and 2000 there were several wet Julys.  But since that time, July rainfall has really fallen off to the point where it’s pretty much nonexistent.  In case you’re wondering, August shows the same thing. You may have no...