All posts by Jim Woodmencey

Winter 2022-23 Outlook

We are now past the Autumnal Equinox and for the remainder of the fall season the days will be getting shorter and the sun a little lower in the sky as we roll closer to the winter season. That should come as no surprise, as this happens every year around this time.

The other thing that happens every year around this time is people start asking me, “What kind of winter are we going to have?” The more diehard skiers actually start asking before the end of August. So, every year, I feel obligated to take a look at all of the various outlooks for the coming winter season.

This year I’ll include both the Farmer’s Almanac and the Old Farmer’s Almanac takes on what to expect of this coming winter’s weather, along with the long-range outlook from NOAA’s Climate Prediction Center and a few other less conventional forecast sources.

Old Farmer’s Almanac

The Old Farmer’s Almanac is the yellow-jacketed paperback that has been around for over 230 years and is a treasure trove of all kinds of weather, astronomy, farming and gardening trivia. It is the consummate bathroom book.

This year’s edition just came out and what their weather map shows for western Wyoming and the Jackson Hole area for this winter is, “Mild and Wet” conditions. I suppose you could interpret that to mean above normal snowfall, but not too cold. I know the diehard skiers will read it that way.

The Farmer’s Almanac

The Farmer’s Almanac is the other almanac, the orange covered one, it’s not quite as old as its competitor, but is still chock-full of all kinds of weird folksy information and would also compliment that library within reach of your toilet.

Their outlooks are usually written with a more cryptic flair, leaving the reader to wonder what exactly it means? This year their weather map shows all of Wyoming underneath an area that says, “Hibernation Zone. Glacial, Snow-filled”. Wow! Glacial and snow-filled can only mean one thing, tons of powder skiing for us this winter.

NOAA and ENSO Outlook

The latest forecast maps from NOAA’s Climate Prediction Center, issued in mid-September, are not showing anything out of the ordinary over this part of Wyoming. For December, January and February, they are predicting colder than normal temperatures to the north of us, from Washington State to Minnesota, and warmer than normal temperatures over the Southwestern United States. Wyoming sits in-between and essentially ends up with a 50/50 chance of being above or below normal for temperatures this winter.

NOAA’s outlook also predicts above normal precipitation over northern Idaho and western Montana, with Northwestern Wyoming right along the margin of that above normal zone. Any diehard skier would certainly call that close enough to say we’re likely going to have a snowier than normal winter this year.

As far as the El Nino-La Nina situation is concerned, NOAA is predicting that the current La Nina conditions that we have been in since last winter will continue this fall, with a little less confidence that it will continue through the entire winter.

That is usually good news for us, as the storm track favors the Northern tier of the U.S. in a La Niña. However, every La Nina year is a little different, some have been huge for snowfall here in Jackson Hole and others, like last winter, have ended up more mediocre. Although, we did have a big December and a big April for snowfall last winter, but very little in the middle.

Wooly Worms, Raspberries and Pinecones

There are a few other indicators that I am going to consider this year. One is the wooly worms. It is said that when they are all black, with no stripes, it portends a long winter. Most of the wooly worms I have seen out on the trails this past month were all very black.

The other indicator I learned of this year is the bumper crop of raspberries, like at my neighbor Dave’s house. He’s been told by some Wyoming old timers that a really good crop of raspberries is an indicator of big snow in the coming winter.

The third indicator is an abundant crop of pinecones. Where I live in the trees on Snow King, the local squirrels have been very busy tossing down copious amounts of pinecones on my roof and my yard for the last few weeks. They must know something I don’t. I figure if they are vigorously storing up that many nuts, they must be expecting a huge winter. Call me nuts, but I’m banking on the squirrels and raspberries to predict the weather for this coming winter.

 

Jim is the chief meteorologist at mountainweather.com and has provided a weather forecast for Jackson Hole and the Teton Range for the over 30 years

 

Record Rainfall in Jackson from the Monsoon

Jackson, WY received a record amount of rainfall from Friday morning August 5th to Saturday morning August 6th when 0.80 inches of rain fell in that 24 hour period.

The previous one-day rainfall record on that date (measured on August 6th) was 0.54 inches from August 6th, 1993. The summer of 1993, by the way, was the coldest and wettest summer in Jackson’s weather history.

Rain continued through the day and into the evening on Saturday, adding another 0.74 inches of rain, measured on Sunday morning of August 7th. That one-day total did not beat the old record for that date, which was a whopping 1.16 inches that fell in a 24-hour period back in 2007.

According to the data from the Jackson Climate Station, the total rainfall for the two days was 1.54 inches, all of which fell in about a 36-hour period from this big surge of monsoon moisture.

Courtesy of the Monsoon

On the satellite image below that monsoon moisture stretched across most of Nevada, northern Utah, western Wyoming and Southwest Montana.

That Monsoon flow was aided by a relatively small upper-level Trof of Low-pressure that passed by to the north, across northern Montana this weekend.

Already a Wetter Than Normal August

Total Rainfall in the Town of Jackson so far in August 2022 is 1.94 inches. That is just for the first week. The average monthly rainfall in August is 1.20 inches.
July of 2022 only had 0.06 inches of rain. Average rainfall in Jackson in July is 0.94 inches
So, August has already made up for July’s precipitation deficit.
Jackson would only need another 0.14 inches of precipitation in August to bring the July & August rainfall total up to normal.

 

Posted Sunday August 7th, 2022 by Meteorologist Jim Woodmencey

If it’s so green, how are we in a drought?

We’ve heard a lot in recent months about how bad drought conditions are across much of the western United States.  As of June 30th, 2022 most of Teton County, Wyoming is still listed in the severe drought category. Considering how green everything looks outside on the First of July, and how much rain we had in April. May and June, that might be hard to believe.

Digging in to how drought conditions are determined, gives some insight into how the  U.S. Drought Monitor Map is made each week.

Above Normal Precip

When we talk about drought conditions the first thing that comes to mind is how much moisture, or lack thereof, we have had. Data from the Town of Jackson Climate Station shows that over the 8 month period, between October 1st, 2021 and May 31st, 2022, town had received 11.27 inches of precipitation. By the way, October 1st is when our water year begins.

The long-term average precipitation in Jackson for that same 8-month period is 10.80 inches. In other words, Jackson’s precipitation is above normal right now, by almost half an inch.

Rainbow after heavy rain in the Gros Ventre drainage on June 19, 2022.

Unfortunately, there was missing data at the Jackson Climate Station in mid-June, so June’s precipitation total is not available. But we all know that there was plenty of rain and I suspect that the total was at least near the monthly average of 1.63 inches.

Granted, we had a relatively dry winter, with below average precipitation from January through March. Although we also had a very wet fall, with above average precipitation in October, November and December. This spring it got wet again, with above average precipitation in both April and May.

Despite above average precipitation for five of the last eight months, there are other factors to consider when determining drought conditions.

Drought Indicators

Besides precipitation, things like soil moisture, streamflow, snowpack and the Palmer Drought Index, all factor into categorizing the severity of drought in a particular region. The Palmer Drought Index compares current precipitation amounts to normal precipitation numbers and also considers things like evapotranspiration, infiltration of water into the soil, and runoff.

Locally, the Teton Conservation District monitors the snow water equivalent in the headwaters of the Snake River, which actually peaked later than average this year, due to a snowy April. At the beginning of June,  there was still 4 to 5 feet of snow depth yet to melt at the 9,500-foot elevation in the Tetons.

The Conservation District also keeps tabs on the groundwater depth in the valley, which has been running below normal since January of 2022. At the end of May 2022 groundwater depths remained deeper than the average depth for this time of year.

The last thing that is considered in the calculation of drought conditions is reservoir levels. Locally, both Jackson Lake and Palisades Lake were quite low through most of June. On June 30th, Jackson Lake was at 48 percent full, Palisades was up to 76 percent. Palisades was below 40 percent just two weeks prior.

Since water managers look at stored water when considering how much water will be available for irrigation or agricultural uses, reservoir levels weigh in as a big part of the drought equation.

In the case of the Upper Snake River drainage, the low water levels in the reservoirs began last summer, when both Jackson and Palisades were drawn down to accommodate downstream dam reconstruction. Thus, making our drought conditions some what fabricated or man-made, if you will, by the Bureau of Reclamation.

Clickable diagram of USBR reservoir storage in the Upper Snake River Basin

Drought Monitor Map

The Drought Monitor map is compiled nationally by a number of different entities, including: The National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Department of Agriculture (USDA).

The map is updated every Thursday, identifying areas of drought and rating the intensity of drought on a scale of D0 to D4. On the lowest end of the scale, D0 indicates abnormally dry conditions. D1 is Moderate drought, D2 is Severe, D3 is Extreme, and D4 is Exceptional drought. Earlier in June, Teton County was in the D2-D3 category. Wyoming as a state rarely ever experiences D4 conditions, or exceptional drought.

Each state has their own criteria for what those intensity numbers mean, based on the impact the drought conditions will have on that region of the country. For Teton County, low snowpack in the mountains affects runoff and groundwater, with impacts to streamflow, stream water temperatures critical to fisheries, and vegetation for grazing.

By definition, when you are in the D2 category, pasture conditions are poor, trees and vegetation are stressed, and well levels decline. In D3 category, snowpack is low, and surface water is inadequate for ranching or farming.

I suspect if the Bureau of Reclamation continues to draw down water from Jackson Lake and Palisades this summer, that will put us back into the D3 or severe drought category, no matter how much rain we get n July and August.

Jim is the chief meteorologist at mountainweather.com and has been forecasting the weather in Jackson Hole and the Teton Range for over 30 years.

 

Note: This post was updated from an article that originally appeared in the Jackson Hole News and Guide on June 15th.