Changes in the Wind for Star Valley

This coming week will see a changing weather pattern as the storm track shifts southward over the Western U.S.  The first storm will be be sending a cold front across Star Valley today accompanied by some precipitation...particularly along and over the mountains.  Precipitation should initially be in the form of rain in the valley, but the snow level should drop to the valley floor by this evening.  Once the cold front moves onto the east, the accompanying upper trough of low pressure will be intensifying as it moves across western Wyoming overnight.  This will continue at least some light snow over the valley through the night with several inches likely falling in the higher elevations of the Salt and Wyoming Ranges.

Even though it will be intensifying, the upper trough should move east of the valley, by mid day Tuesday with a diminishing snow threat and some clearing by afternoon.  The colder air will keep temperatures in the valley in the 30s all day.  Tuesday night high pressure and clearing skies will allow temperatures to drop into the teens.

After a cool but generally fair Wednesday and much of Thursday, a much stronger storm will be developing into the western states by later Thursday.  This storm will spread a much larger area of precipitation in the form of snow across much of the northern Intermountain region including Star Valley.  Heavy snow is likely with this system but at this time the primary threat area is still uncertain.  It is possible it will move far enough to the south to place the area of heavy snow across northern Utah or even further south.  However it is quite likely that at least a few inches could occur in Star Valley beginning late Thursday into Friday.  This storm will be followed by even colder air that the one now approaching and Saturday morning could see single digits in the coldest valley locations if skies clear sufficiently.

Winter Weather Is In Sight

Since the early season heavy snow 3 weeks ago, the pattern for Star Valley has been generally dominated by high pressure and little in the way of active weather. In the wake of the  storm system earlier this week that ushered in the coldest air of the fall, the pattern into the first of the week will be controlled by a storm track remaining north of Star Valley.

However the longer range forecast models are now indicating a major change to the jet stream location  by the middle of the coming week.  Initially a trough of low pressure  will move through the Great Basin by later Tuesday with most of the precipitation moving through Nevada into Utah to the south of  Star Valley.  Then by Thursday a fair but cool day will prevail.  The longer range forecast models are now indicating a much stronger and potentially significant Winter Like Storm will develop across southern Idaho/Nevada into Utah by early Friday.  This storm has the potential for spreading widespread snow to the valley floors...including the lower elevations of Idaho and Northern Utah during the day Friday, impacting travel conditions in most routes out of Star Valley

Cold Air Arrives on Schedule

A cold  front moved across Star Valley early Tuesday as expected with little in the way of precipitation.  The only measurable was .01 at Star Valley Ranch early Tuesday morning.  However there was some snow in the Salt Range as both Willow Creek and Cottonwood Creek Snotel sites recorded about .10 in the form of snow which was visible on the Osmond ES Cam Tuesday morning above about 7500 feet.

Under clear skies and calm winds temperatures this morning dropped to the coldest of the fall.  The lowest reported in the valley was at both Etna ES and Thayne ES with 14 and Star Valley Ranch was the warmest at 19.

While the cold front was generally dry in far Western Wyoming, significant snow has fallen in the east.  As of this morning there has been as much as 9 inches reported in the Cheyenne area.

A generally fair weather pattern will set in across Star Valley the next several days. While nights will continue seasonably cold, daytime temperatures will slowly moderate.  By Friday afternoon will be back into the 50s and likely change little into the coming week.  Little in the way of precipitation is now expected at least through the weekend.

Indian Summer Comes to an End Tuesday In Star Valley

After another unseasonably warm late October Day on Monday across  Star Valley a cold front crossing the Valley Monday night will usher in a markedly cooler air mass on Tuesday.  Daytime temperatures on Monday in the 50s  will have a difficult time of rising above the low 40s  Tuesday and remain in the 30s much of  Wednesday. Most of the rain and snow with this system will likely remain to the north of Star Valley, however some light/snow could occur early Tuesday behind the cold front, most likely from the Narrows north as the cold front moves through.   Any accumulation would likely be confined to the higher Salt and Wyoming Ranges, and even then only amount to an inch or so.

The greatest effect will be the colder air, officially ending the growing season across all of the Valley. By Wednesday morning the coldest regions of the valley will drop into the teens and well below freezing even in the typically milder locations such as Star Valley Ranch.

Later in the week high pressure will provide generally dry but cool conditions with a slow daytime warming trend.

FORECAST

The  FORECAST Section contains not only the latest Star Valley Zone Forecast produced by the Riverton WFO but the AFD(area forecast discussion) which is a meteorological reasoning that the forecast was based on.  The Zone forecast is updated by the Riverton WFO as needed.

There is much more to the FORECAST Section than the products issued by Riverton WFO. Below the  AFD is the latest 72 hour MOS(model output statistics) produced by the GFS(global forecast system) model. Jackson (JAC) is the closet site to Star Valley that the MOS forecast is produced. Additionally an extended GFSX MOS Forecast that extends out for 7 days is also included for JAC.

On the right side of the FORECAST page  from top to bottom are:

--Current Visible satellite loop centered over the Northern Intermountain region. The loop is 2 plus hours long.

--Composite radar imagery loop.  Left clicking on the loop will bring up the latest image overlaid with surface plots.

--Loop of PIH WSR-88D  reflectivity  image.  Loop is around 45 minutes in length.  Left clicking on the loop will bring up the complete radar menu among other options permitting the access of other radars.

--The most powerful diagnostic section available on the Star Valley Weather Page.  Left clicking accesses the Storm Prediction Center(SPC)  Hourly Mesoscale Analysis.  There is a myriad of choices in selecting diagnostic fields which can be used forecasting not only convection including severe thunderstorms, but winter and fire weather conditions..  There is extensive helps  built into the page. Also any questions I will be glad to try and provide an answer through the comment section.

While the area is centered over the Northwestern portion of the CONUS, it can be shifted to other  areas  along with a National area as well.

--This is the sounding section.  Left clicking on the map of available soundings will by default bring up the plot of Norman OK.  However any of the other soundings can be selected  by left clocking on the star over the location. The soundings closest to Star Valley are SLC, BOI, and RIW. Soundings for the previous 7 days can also be selected. Again there is an extensive help menu provided on the page describing all the computed parameters from the sounding.  Additionally any questions can be addressed on the comment section.

Where is the Sun?

The forecast for Star Valley the past couple of days has called for mostly sunny.  Anyone in the valley knows that there has been very little in the way of sunshine on Thursday and so far today.  As with most of the weather that effects Star Valley, the mountains play a big role.  In this case even though Idaho Falls and Pocatello have been enjoying lots of sunshine, the lift from the Caribou and Salt Ranges has continually developed cloudiness.  To see this process in action go to the Web Camera page and build a several hour loop off the first cam looking out over the valley.  The processes that are maintaining the cloud cover over the valley are quite evident.  This can also be seen on the Forecast page and the visible loop over the area.

Current Conditions

There are three options under Current Conditions,  Temperatures, Winds and Rainfall.  The plot is centered over Star Valley.  Sources of the data are varied and in some areas overlap making it difficult to see all the stations.  Rolling the mouse across the data will pop up a source id.  The listing below the graphic is of all the stations that are displayed.

The plot is updated every 15 minutes.  Rainfall totals are for the  24 hours ending at data plot time.

Weather Cameras

The Weather Camera is a link to the site www.halescamvideo.com that was developed by John Hales as a Christmas Gift to me(his father) in 2008.  While John provides any technical needs, I am the site manager and maintain quality control of the Cams on the site.

At any given time there could be as many as 130 web cams displayed.  The criteria used to determine the display of a camera are:

1. Quality of the image.(StarDot Cameras much preferred).

2. Frequency of updates. (ideally every minute)

3. Proximity to Star Valley WY

4. View of the sky.

5. Reliability

Current Features

Left click on the image will provide a  larger current image

The cursor at the top of each cam will open up the control menu for that particular cam.


Left click on the minutes option(30 60 120 180 300) will build a loop of that length in time.

Left click on the info (i) button and it will bring up a google map centered on the webcam location.  Additionally it will display the latest weather observation and identifying the location of the observation.

There is also a radar option which when turned on will display the current composite reflectivity product from the NWS 

Clicking on the + will open up a looping option.  At least 3 days are available in the archive for all cams.  Selecting the date/time and looping length in minutes will rebuild a loop.

There are two options when building a loop.  The Load Loop option will rebuild a requested  time period  and display it.  A much more powerful option is the Create Video.  This will build the requested time period and then display the Download mp4 Video which will then produce a url  that can be copied/sent or saved as a video file.

As an example using this command a video was made of the Star Valley Ranch snow gauge on March 2 2012 when the snow depth was at its deepest point during the past winter.  This video was created on November 3 2012 as the number of archived days for this particular cam extended back that far.

 http://www.camviewing.com/clips/SVH1_2012-11-03-2256MST_300.mp4

While all cams have at least the most recent 3 days archived, additional days can be added to a particular cam upon request.