All posts by Jim Woodmencey

Wednesday’s Wind Gusts

Mountain Weather Blog

Isolated thunderstorms that developed Wednesday afternoon produced some fairly impressive wind gusts in some areas around the valley. These were downdrafts coming down from the base of the thunderstorms, which then spread out horizontally as they come in contact with the ground.
Strong downdraft winds are more common with dry-type thunderstorms, in other words, ones that don’t produce much rainfall.

These storm cells were tracking from the South to the North, tracking right over Snow King Mountain and the Town of Jackson. They formed along a weak cold front that was stalled out over western Wyoming, which gave them an extra boost (see map below).

Sample of Wind Gust Speeds at around 3:30 pm Wednesday May 22, 2013:
Town of Jackson = 41 mph
South Park= 39 mph
Snow King Mountain= 66 mph
Jackson Airport = 32 mph
Timbered Island, GTNP= 48 mph
Teton Pass= 31 mph
Raymer (JHMR-Headwall)= 97 mph

Wednesday Afternoon’s Weather Map (22MAY13)

Last Spring’s Wind Gusts

Wind gusts were not as strong in the valley as they were last Spring with some dry thunderstorms that we had here in Jackson Hole, Those also moved along a similar path, from South to North, passing directly over Snow King Mountain, on June 4, 2012.
Gusts in town were clocked at 59 mph and 51 mph at the airport.
(See blog post from June 18, 2012)

Post by Jim Woodmencey, meteorologist
Map Graphic from MeteoStar

First Day to 70 in Jackson

Mountain Weather Blog

Happy Mother’s Day! And a nice day it should be, with what may be our first “official” day this year with a high temperature over 70 degrees.
At the Jackson Climate Station the high temp the last two days almost made it to 70, with a high Saturday of 67 and the high Friday of 68.
Other thermometers around the area did reach 70 or better, at the Teton County offices that instrument was 70 both Friday & Saturday. The automated station at the USFS office hit 71 Friday and 72 Saturday.
Everyone’s thermometer should get over 70 today.
The reason we are getting warmer is due to a large and warm Ridge of High pressure that is sitting over the Western US. There is some very warm air over California that is pushing north under that Ridge today. For example, it was in the 90’s in Central California yesterday, and 109 degrees in Death Valley, the hottest place in the Country.
That’s quite a change from the weather we had at the beginning of the month in Jackson, with a high around 40 and 5 inches-plus of snow in the valley on May 1st.
If Mom needs it cooler, she could go to Northern Michigan, where it will be cold enough to snow on Mother’s Day. Or, to Pt. Barrow, Alaska where highs will be in the 30’s.
Back to work for me on Monday morning with the Jackson Hole Forecast.
But thought I’d better get updated on what the weather pattern is and prep myself before diving back in tomorrow.
Happy Mother’s Day!

Posted by Meteorologist Jim Woodmencey
Graphics from NWS

                                                          

Maps below shows weather pattern @ 10,000-ft.
And Surface Map for Sunday

Surface Map for Mother’s Day

Mountain Weather Blog

Last week I had the opportunity to work with a group of US Air Force Special Operations guys from the 10th Combat Weather Squadron on an avalanche course here in Jackson. This course was run in conjunction with the American Avalanche Institute. Guide and instructor Christian Santelices (a local Exum Mountain Guide) and Sarah Carpenter (co-owner of AAI) also assisted, as we spent six days working on basic and advanced avalanche topics and skills.

This is the third spring in a row that I have worked with this group, always different guys, but always top-notch. Their ability to absorb and then apply new subject matter constantly amazes me. What I like most about these guys is they are all Air Force trained weather forecasters, some even have degrees in meteorology, as well. And, they are tough as nails when they are out in the mountains. Especially considering they came here from sea level!

We worked on both Teton & Togwotee Passes and had good “winter-like” conditions, for mid April.

This next week I will be going to their headquarters and teaching a Mountain Weather Forecasting Course to this same group. The goal is to provide them with the knowledge and skills necessary to be able to forecast both weather & avalanches in the mountainous regions they are often called to work in.

“Combat-Weather”, I’m glad no one is shooting at me while I’m forecasting! That’s a different level of pressure to be accurate!

Post & Photo by meteorologist Jim Woodmencey

Some of the 10CWS Team on top of Breccia Peak

New Wyoming Weather Page

Mountain Weather Blog

On this first full day of the Spring Season I would like to give you a preview of a new page dedicated to Wyoming’s Weather. I am in the process of making some changes to the mountainweather.com website, and will be doing some re-arranging of the Navigation. A little “spring cleaning”, if you will. As well as adding some other new pages in the coming weeks.

Don’t freak out if the drop down menus change a little, the biggest difference will be combining all the Forecast Tools into the Weather Maps part of the menu, and moving things like the Weather Cams & Road Reports under the “More Weather Pages” drop down.
I’ll be adding a new category to the drop down, called “Mountain States”, where direct links to the Alaska Weather, Wyoming Weather, and other State weather pages will reside, permanently.
I’ll make another announcement when that change is about to be made.
Click here to view: The Wyoming Weather Page
What’s on the Wyoming Page?
This page is designed and arranged to give you a quick overview of the current weather across the State, and a new Weather Access Map for Wyoming, with quick access to the current weather and forecasted weather for most cities, towns, and popular recreation areas. 
More points can be added in the future, if you have a favorite place to hike, climb, ski, bike, fish, etc., then e-mail me and I’ll see if I can add that spot to the map for you.

At the bottom of the page there are a few other weather maps, concentrated over Wyoming.
Let me know how you like it, as you use it for your travels across the State or for planning a weekend to a specific location.
And don’t forget to click on the sponsor’s ads and see what they have going on. After all, it is their support that makes these pages possible, and free for you to use!
Post by meteorologist Jim Woodmencey
 

First Day of Spring?

Mountain Weather Blog


Spring officially began today, Wednesday March 20, 2013 at 5:02 a.m. MDT.  According to the calendar it’s Spring, but our weather the next few days will be more like mid-winter!

Large storm system over the Pacific Northwest and Northern Rockies bringing snow  then cold temps thru the weekend. No sign of warming back up until Tuesday of next week. So, fresh snow and cold temps to celebrate the Equinox in Jackson Hole!
(You can read more about it on the Jackson Hole Forecast page in my discussion).
Forecast Map for Wednesday, March 20.

More about the Spring Equinox
 
Also known as Vernal Equinox, “Vernal” the Latin word for Spring, and “Equinox” meaning equal day and night. The Equinox it is defined as the exact moment that the sun is positioned directly overhead at the Equator. The sun also rises due east and sets due west on the Equinox, which happens twice a year — in March and again in September.
During the days surrounding the Equinox, all locations across the globe, from the equator to the poles, will experience an equal amount of daylight and darkness, about 12 hours of each.
At this latitude in Jackson Hole the sun is now noticeably higher in the sky, 47 degrees above the horizon at noontime, versus 23 degrees above the horizon in December. And, our days are about 3 hours longer than they were back in December.
Post by Jim Woodmencey, meteorologist.
Graphics from NOAA & timeanddate.com

Listen to the Forecast

Mountain Weather Blog

Don’t like to read? You can now listen to MountainWeather’s Jackson Hole Forecast, anywhere, anytime. New audio version of the forecast is now available ………look for the audio button on the Jackson Hole Forecast page on both the main MountainWeather.com site and the mobile version of the website.

Listen on your computer, or your smartphone, when you are ready for your daily forecast!
Find this button at top right corner of the forecast on the main website
Find this button at top of the forecast
on the mobile site
This feature will be available each weekday morning by around 7:30 a.m. Not available on weekends or during my Spring Break period (April 15 to May 15). Sorry about that! But there will still be a local weather forecast posted from the National Weather Service, in its place, just no audio version.
A word about that upcoming Spring Break…..It is not as much of a break as you think, although I still believe in bringing back the off-season! I will be using that time this spring to make more upgrades to mountainweather.com and also teaching some courses to the US Military. If I’m lucky, I might get a few days on my mountain bike in Moab before I come back to forecast the weather for Jackson Hole for the Summer Season.
Enjoy the weather!
Jim Woodmencey, meteorologist

Spring to Winter to Spring: Snow for St. Patty’s Day!

Mountain Weather Blog

Hope you enjoyed the Spring weather this week, back to Winter weather in the Pacific Northwest  & northern Rockies for Saint Patrick’s Day Weekend.
The Ridge of High pressure that brought warm & dry weather this past week to the West & Rockies  gets flattened out and a Westerly flow develops from the Pacific Northwest across the Northern Rockies and into the Plains States, with gradually cooling temps.
A small, but very strong Low pressure system will move across the Pacific Northwest on Saturday, and be over Idaho Saturday night, with a strong cold front passing thru Western Wyoming on Sunday.
This potent little weather system will bring a pretty good shot of snow and much colder temps across the Pacific Northwest .
For the Jackson Hole Area, expect between 6 & 12 inches at higher elevations of the Tetons and 2 to 4 inches at lower elevations from overnight Saturday and thru the day on Sunday. Other mountain areas do pretty well also. (See forecast weather map and snowfall forecast map below.)
Snow showers linger early next week……..then on Wednesday, the First Day of Spring, a larger Low pressure system moves into the NW US with warmer temps initially, then another cold front plows across the Northern Rockies on Thursday. Bringing more snow & colder temps again the end of the week.  Looks like High pressure builds back over us for next weekend, with temps warming again.
Sunday March 17, 2013 Forecast Weather Maps
Surface Map for Sunday
Total Snowfall thru Sunday Evening
Post by meteorologist Jim Woodmencey
Graphics from NWS

March 2013: Lion Rides in on a Lamb

Mountain Weather Blog


As the old saying goes, “If March comes in like a Lion, it will go out like a Lamb”, and vice-versa. In other words, if the weather is winter-like and stormy to start the month, it will end with milder, more spring-like weather. Or, the opposite could be true, if it comes in like spring it will go out like winter.
This year it looks like the lamb will show up on Saturday and then be immediately devoured by the lion on Sunday across the Northern Rockies and at home here in Jackson Hole.
Saturday we should see temperatures in the Jackson Hole Valley topping 40 degrees in the afternoon, and temperatures at 10,000-ft getting up into the lower 30’s, with plenty of sunshine to give us a little taste of Spring. Then clouds increase Saturday night and a storm system that rolls across Montana will bring snow and colder temperatures to Northwest Wyoming on Sunday. 
Northwest Wyoming’s Teton Mountains should accumulate 6 to 9 inches Saturday night thru Sunday night. Northwest Montana & higher elevations in the Cascades of Washington might get a foot or so Saturday thru Sunday. And the Southern Canadian Rockies might score the biggest, topping two feet, but that includes snow from Friday and all day Saturday, as well as Sunday’s snowfall. (See Snowfall Forecast Maps below for this weekend).

Snowfall Forecast Maps Saturday thru Sunday March 2nd & 3rd
Northwest USA
Zoom on Wyoming & Utah

 
The Rest of March 2013

How the month ends weather-wise is no more conceivable than how it started……do we call it Lion or Lamb-like?

Not much change is indicated in the longer range computer models for March, and a “neutral” or No-Nino condition in the Equatorial Pacific that began in January is expected to last through our Northern Hemisphere Spring.
What is interesting about this March is that temperatures are expected to be below normal. Surprising, because the trend over the last couple of decades has been that temperatures in the month of March in the Rockies have been climbing. Oddly, March is the one month of the year that the statistics in Jackson at least have been consistent and indicating the most warming in the long-term climate trend the last 50 years. So, maybe we are starting a trend to even that out a little.
Precipitation Outlooks in March still indicate “equal chances of being above, below, or at normal” for the monthly precipitation (and snowfall) this March, across the Pacific Northwest and Northern Rockies.
You might interpret that to mean that there would also be equal chances of March going out like a Lion or a Lamb.  A wooly one at least, since temperatures are supposed to be below normal.
 (See the 30-Day Outlook Maps below).
30-Day Outlook Maps for March 2013
Temperatures
Precipitation
Post by meteorologist Jim Woodmencey
Graphics from and NWS

Second Half of Winter Outlook

Mountain Weather Blog


The Climate Prediction Center or “CPC” (a division of NOAA and the National Weather Service) is responsible for producing our long-range outlooks. For the next three months they are showing that the Pacific Northwest will be about the only place in the USA that has a good probability of experiencing below normal temps. Nowhere in the western US is expected to see above normal precipitation. The Southwestern US has a higher probability of seeing below normal precipitation February thru April.

Alaska, the Pacific Northwest, Idaho, Montana, and Wyoming will be sitting basically in a climatalogical  no-man’s land during February thru April, as far as our chances of precipitation go.
The CPC determined that this part of the country will have “Equal Chances” of being above normal, below normal, or normal, in the precipitation category.
That pretty much covers it!
So, I could interpret that to mean we’ll either get dumped on, or not not get dumped on, or have something in-between. A very helpful bit of insight. Not.
(See more maps and follow the latest short & long range outlooks on the Long-Range Outlooks Page of mountainweather.com)
3-Month Outlook Maps for February-March-April 2013

Temperatures
Precipitation

El Nino-La Nina-No Nino

While we began the Winter of 2012-13 with a weak El Nino condition in the Equatorial Pacific (that is, slightly warmer than normal sea-surface temperatures off the coast of Peru), indications are that we are transitioning to more of a “Neutral” condition in the Equatorial Pacific as we head towards the Spring Season. What I will call a “No-Nino” situation.

What does that mean for us? Basically,nothing. As you can see from the 3-month outlooks above, the long range forecasters are calling it an even bet on both precipitation & temps for the northern Rockies at least, including Jackson Hole.
You might interpret all of this to mean that we will have a “normal” second half of winter and start to the spring season. If there is such a thing as normal weather in Jackson Hole!
Text submitted by meteorologist Jim Woodmencey
Graphics from NOAA

It’s Groundhog’s Day!

Mountain Weather Blog


Saturday February 2nd, 2013 is Groundhog’s Day! A very important day to a weather person! Groundhog’s Day really has nothing to do with a rodent seeing his shadow, and in the Rocky Mountains it would be rare to not have at least six more weeks of winter. The real significance of Groundhog’s Day is that it marks the halfway point of the “Winter Season”, between the Winter Solstice (Dec. 21st) and the Spring Equinox (Mar. 21st).

Skiing In Grand Teton National Park in late December 2012
The first half of the winter throughout the mountains of the western United States was up and down. In general, it could be characterized by healthy snowfall in December, followed by a long stretch of drought, along with some brutally cold temperatures for a good portion of January. With a period in there when even up at elevation temps were well below zero, before inversions set in.
Jackson Hole Snowfall

In the Teton Mountains, the snowfall and snowdepths we have presently are not too far off of the averages , December’s above normal snowfall in the mountains almost balanced the below normal snowfall of January.
At the at the bottom of Rendezvous Bowl at 9,580-ft. at the Jackson Hole Mountain Resort, 114 inches of snowfall was recorded in December 2012 and 45 inches in January. That’s a total of 159 inches for the two months, and the historical average for the two months is 163 inches.
As of this morning, February 1, 2013, there was another 7 inches recorded and the settled snowdepth at the Rendezvous Bowl site was reported to be at 73 inches. The average on February 1stis 78 inches. Last year we were at 72 inches. (See summary table below).
Total snowfall so far this season at the Rendezvous Bowl site was at 240 inches. The average at this time of year would be 249 inches, and last year we were only at 198 inches.
Just under average, and just ahead of last year.
First Half of Winter Snowfall Summary & Comparison
Total Season’s Snowfall
as of Feb. 1st
Settled Snowdepth
on Feb. 1st
2012-13
240 in.
73 in.
2012-12
198 in.
72 in.
2010-11
306 in.
87 in.
2009-10
265 in.
83 in.
Average  
249 in.
78 in.
What’s Ahead for the Second Half?……………
I’ll put that in a post later this weekend. After I ski Rendezvous Bowl on Saturday and before the Super Bowl this Sunday. (Providing I don’t ski in the morning before the Super Bowl).
Post by meteorologist Jim Woodmencey
Data from Bridger-Teton Avalanche Center