Record Hot July, Rain Anyone?

If you are hoping for some rain, we have good news for you!  But before we get there, another heat wave is about to hit the Inland Northwest which isn't good news for the ongoing drought.

Here is the latest U.S. Drought Monitor released today, July 29th.  Exceptional drought (D4) was covering a large portion of Eastern Washington and north Idaho.

U.S Drought Monitor released July 29th, 2021

Much of this drought locally is from very dry weather over the past 6 months which has had significant agriculture impacts to spring wheat, barley, and hay.

Percent of normal precipitation past 6 months

Combining the dry weather with lightning so far this July has led to multiple wildfires across the region.  The maps below show total lightning this month through the 24th.

And here is satellite image from July 23rd showing smoke from multiple wildfires over the region.

Evening satellite - July 23rd, 2021 courtesy of UW

Making matters worse has been the hot July, with temperatures over most areas running 4 to 8 degrees above normal so far this month.

And another heat wave is likely as we close out the month of July.  On Friday many locations will reach the triple digits, with the heat peaking on Saturday with near record high temperatures for the day.   Here the forecast high temperatures for Saturday as of this writing

NWS Forecast High Temperature for Saturday, July 31st, 2021 issued 230 PM July 29th

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These temperatures will equate to many areas nearing, or exceeding their all time warmest July on record.  Here are some locations that have a good chance of the hottest July, with observed average temperatures for July 2021 so far shown.

Spokane Airport (GEG)

Bonners Ferry, ID

Lewiston, ID

Wenatchee Airport, WA

Omak, WA

Changes Ahead!

After all this talk of heat, fires, and drought, let's shift gears and talk about changes this weekend.  Some surfaces may look like this by Monday.

Yes, we have rain to talk about!  Models are pretty consistent in showing an increase in moisture moving up into our region.  This animation below (courtesy of College of DuPage) shows available moisture (also called precipitable water) and is NOT a rainfall forecast.  It's more of an indicator of available moisture for rain.

12z July 29th GFS run of Precipitable Water Standardized Anomaly valid July 29-Aug 3, 2021

Note that as values reach the blue and purple shadings on Sunday and Monday that it corresponds to the highest end of the legend at the bottom of the graphic.  This means there will be close to the highest amount of available moisture over our area as we can get for this time of year.

But the big question is will this lead to an abundance of rain and will there be thunderstorms?  We think most areas will get some rain, but amounts are uncertain.  This is due to the convective hit and miss nature of showers and thunderstorms.  Here is one ensemble forecast for rain totals for Coeur d'Alene, ID.

12z July 29th GEFS forecast of precipitation for Coeur d'Alene, ID through August 3rd, 2021

Note the large spread in possible rain amounts with the solid black line indicating the average values of near 0.25".  One solution gives as much as 1.50", while several show 0.20" or less.  

There will also be a chance for thunderstorms which could lead to new fires.  But the good news is that downpours should reduce the threat of new fires becoming large, and could help current fires with some much needed rain.

And there may be more rain for the middle to end of next week.  Here is the 6-10 day precipitation outlook from the Climate Prediction Center favoring increased odds of wetter than normal conditions.

Climate Prediction Center 6-10 day Precipitation Outlook valid Aug 4-8th, 2021

To summarize, hot temperatures to close out July will give some locations the hottest July on record.  Exceptional drought covers much of the region.  August will start on a different note, with an increasing chance for showers and thunderstorms.   With exceptional drought, don't expect this rain to even come close to ending the drought, but will at least bring a change in the weather and should help out the fire situation over the region.