Inland Northwest Hay Weather

The first seven days of September have been unusually cool and wet. Typically the warm dry summer weather extends until at least the Labor Day weekend, and often longer. But not this year. Fall came on suddenly. But will it last all month?  It’s safe to say that we’re done with the 90s for the summer, but we might still eke out a few 80s.  First, here’s a graph showing the first week of September rainfall at Spokane going back to 1881. Yes, this has been wetter than recent Septembers. But historically, the first seven days of this month have been a lot wetter over the years.  The culprit?  Could be El Niño. Could be tropical cyclone Lala. We’ll never know.  Here’s the weather map for last Friday. That’s an impressively large, cold low over the western US.  By Wednesday of this week, the low will be gone and high pressure will make a brief appearance. But there a storm up in western Canada, just east of Alaska, waiting to drop into our area.  This ...

I mentioned in the last blog that sometimes the remnants of hurricanes get ingested into the jet stream. And this usually causes problems for the numerical forecast computers. Well, in this case, it’s possible that the remnants of Lala (which struck Hawaii last week) could play a role in our upcoming weather.  I’ll show you 4 weather maps of atmospheric moisture. I’ve added a red L to show you Lala remnants. The first map is from Friday morning. Lala is way out by the dateline, on the far upper left edge of the image.  By Sunday, Lala’s remnants have been picked up by the jet stream and are located at the tip of the Aleutian Islands.  On Monday, the remnants of Lala will be nearing Alaska. Another low pressure system over Alaska will drop southward at the same time.  By Tuesday, the Alaskan low has rapidly deepened as in ingested Lala’s moisture. It’s forecast to be located by the Queen Charlotte Islands at that point, heading for the Pacific Northwest. Here’s a diff...

Labor Day is often viewed as the unofficial end of summer. Meteorologically, September can still be rather warm, despite the shortening days. It looks like the Northwest will see cooler weather that will last into early September, along with some chances of rain.  After a couple of days in the 90s, a pattern change will take place in the atmosphere. Cooler low pressure will set up in the West with hot high pressure being pushed into the Midwest.   Temperatures here will drop into the 70s. Sunday and Monday mornings low temperature could be in the upper 30s.  Time to keep an eye out for frost.  How long will this last?  At least into the middle of next week. After that, the computers diverge a bit. Some say warm weather will reappear for Labor Day weekend. Others say that the cooler weather will persist through the holiday weekend.  Part of the disagreement could be caused by tropical cyclone Lala.  After it hit Hawaii it re-strengthened in the north ce...

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 ...