12/30: One Last "Afternoon Forecast" of 2013 & the WY Weather Events of 2013

Well tomorrow is the last day of 2013.  For a Complete Forecast of what to Expect through the Rest of the Evening and on Tuesday, click HERE

Otherwise, here's a breakdown of what the Temperatures will be like:

In other Weather-Related News..Quite  BUSY Year it was for many of us in the Cowboy St that Mother Nature was held responsible for :)

This week and next week, I am doing the Top 10 Countdown of the 2013 WY Weather Events.  Here is #10:

<< About this Event, Southwestern WY was on the Dry/Blustery side of the 1st April Snow for Central WY.  A tight pressure gradient developed in Utah/CO and just pummeled the I-80 Corridor.







#9 on the List is back in the Summer time during Frontier Days on a Friday Afternoon in Cheyenne:

<< This was a classic Supercell storm that moved very slow off the Laramies and dropped Southeast toward the City.  







STAY TUNED TO TUESDAY as we Look Back at Events #8 & #7

12/20: Chances of a WHITE CHRISTMAS in WY??

Well Folks, Saturday is the 1st Day of Winter at 10:11AM Mountain Time.

This Weekend, we have a Series of "Moist" Flow sliding into Wyoming.  For a Detailed Forecast click HERE


Now, lets get into the CHRISTMAS EVE/CHRISTMAS FORECAST and what the Weather Model Guidance Showing.

CHRISTMAS EVE:

<< The GFS Model shows a Trough moving into Wyoming that could bring us Breezy Conditions in Central/S'ern WY.

- Does show "Light Snow" Chances for Western WY and the Bighorns.

<< Here is the EUROPEAN Model which is a little more "Moist" than the GFS Model, above.  A Cold Front wants to drop through and bring a chance of Light Snow for much of WY and also along the I-25 Corridor.

** IF This Model holds correctly, this could be enough Snow for a "White Christmas".  Timing looks to be in the Afternoon and Early Evening Hours.

<< Here is the CANADIAN Model.  This shows the same thing as what the EURO Model (Above) is suggesting. A Cold Front wants to drop through dropping our Temperatures and provide Light Snow for much of WY and even Light Snow along the I-25 corridor








CHRISTMAS:

<< Now after Santa passes Wyoming early in the Morning, the GFS Model wants to stay Dry and actually Seasonal with Temperatures in the Middle 30°s for parts of Central WY.

<< EUROPEAN Model is suggesting Cold and Light Snow for the Bighorns/I-90 & Black Hills area.  

* A Clipper wants to dive into MT and Wyoming so it will be a quick hitting burst of Snow Shower activity.

<< CANADIAN Model is suggesting the Same as the EURO Model for Christmas Day. 

* A Weak Clipper wants to drop in around the same spots similar to the EURO and maybe bring light snow into Western WY.






EARLY THOUGHTS:  Right Now, it looks like that Snow chances for WY are in the Favor for the Holiday.  GFS is trending Drier for both days, while the EURO/Canadian Models are Moist with Snow.  As always, we a little under a Week away. Guidance can CHANGE!  Just giving you folks an Idea what "Could" happen.

12/19: Late Thursday SNOWTALK

What a Snowy THURSDAY for Central WY!  It certainly was a Hit or Miss situation as a strong band of over-running moisture set up shop East of Riverton and dumped on top of Casper Mountain and into Douglas/Glenrock.  Upslope Flow also produced some Moderate Snowfall  South of Casper.  

Heres what you can expect for LATE Thursday in the Overnight Hours:

<< Our Cold Front stalled this Afternoon in Central WY as a Developing Low was in a Cyclogenesis stage at 998mb in Northern CO producing that Upslope Flow.  The Low has since faded and now a NEW area of Low Pressure is developing in Southwest WY producing Light Snow.  



The Infrared Imagery is showing the Deeper Cloud Tops of this Snow in the Brighter Yellow and Blue as this Streak continues for a few More Hours in Central WY; until this Low fades away.

SO HOW MUCH More Snow can we see??   

<< Our In-House RPM Run shows about maybe 1-2" more through the Overnight Hours in the Casper area and up to 2-4" in the Southern WY Mountains.

<< The Hi-Res Rapid Refresh Model shows Snow up to an Inch for Casper/Douglas and a stretch along I-80.

** NOTE How you see "Light Amounts" in Western WY?  Well, thats our Next Storm system that will impact that part of WY Friday Night with More Snow.

12/17: Tuesday's SNOWTALK for Thursday

Not going to discuss much this evening for WEDNESDAY. Same setup with Blustery conditions as strong Southwest flow continues to keep us Balmy with Above Avg. temperatures nearing 50° for Central WY & maybe 60° in a couple spots for Southeastern WY!

SNOW TALK Begins now as we Roll into Thursday Morning:

The EURO Model from today agrees with Tonight's Evening Data from NAM/GFS as we start seeing/feeling the Effects of the Cold Front and Snow in Wyoming.
 ** What I am closely watching is a Low wanting to develop ahead of the Front in Colorado that could initiate some Activity before the Front dives in.  BOTH Models (NAM/GFS) shows this by 5AM Thursday.

<< You can see how the Cold Front this evening sort of sped up as it is just North of Casper and Riverton.  The Low could spread Snow into I-80 Corridor and maybe up to Casper; just depends on how "Moist" we are. So the Temps/Dewpoints will be closely watched when the Snow will start to fall.  







THURSDAY EARLY AFTERNOON shows the Time when the Cold Front has now dropped all the way through Wyoming and now just North of I-70 into Colorado.  Snow "Could" get intense during this time along and East of the Laramies so Travel may become Hazardous for Several Hours! 

<<  We'll have to wait and see how much snow is possible cause sometimes you see a Swinging Low lose its Steam as slides from the Pacific and drifts Eastward into NV/UT and approaches the Rockies.  

* NAM shows somewhat of a Trend like this too, so its going to be interesting how the Afternoon plays out. OR, how deep is the Low to produce some Moderate Snowfall Intensity with the Upslope.



SNOW  should continue through the Late Afternoon and Early Evening Hours as it will drop to "Light Snow" Intensity levels for Central/Southeastern WY.  When Late Thursday Evening rolls around, Flurries should taper off past the Midnight Hour for much of Wyoming.

SO HOW MUCH SNOW IS "POSSIBLE" ??

I mentioned this last night as I use the Iowa St Meteogram & "Most" of the Time they are quite accurate with their Snow Range.  Here are a few Cities I've looked at for what they're thinking:
- Casper/Laramie/Rock Springs/Sheridan/Lander: 1-4.5"
- Cheyenne/Gillette/Riverton: 1-2.5"

** I am not Releasing my Amounts until Wednesday Night since we have another 18-24hours for the Wednesday Data to be released but here are what the GFS/NAM Shows; This is NOT my Forecast. **

NAM Model for SOUTHEASTERN WY

NAM Model for CENTRAL WY

** HERE are the GFS Runs.. These go out through 120 Hours and some of the Light Snow amounts  this upcoming Saturday could be included on these Amounts **

GFS Model for Central WY

GFS Model for SOUTHEAST WY

THOUGHTS:  So we are now about 36 Hours until this Storm starts to move into WY.  Wednesday Night will be the last Blog Post discussion for the Pre-Christmas Storm.  I'm confident on the Timing of the Event based on the Evening Guidance AND feel that I-80 and North of Cheyenne along I-25 could be Harzardous as the spots I think the Heavier Snows could drop. We will see!

12/16: Monday SnowTalk for Late Week

What a BALMY Afternoon Central & S'Eastern WY experienced with Above Average Temperatures and breezy weather.  This pattern will persist through Tuesday and Wednesday ahead of our next Storm System sliding into Wyoming on Thursday. To preview the next two days:  what you experienced Monday is what you'll see for the next 48 Hours.


THURSDAY MORNING will be the initial start of the Snow System sliding from Montana into Northern WY.  Now, latest model guidance continues to show Light to Moderate snowfall for Montana but the Moisture decreases in Activity as it approaches the Bighorns and much of Northern WY. 

NAM at 5AM THURSDAY

<< You can see that the NAM has the Cold Front right on top of Riverton/Casper as the wind is shifted to the North. Light Snow is possible for the Bighorns & I-90.

** However, the GFS shows the Front a little farther North along the I-90 Corridor by 5AM with Snow likely in Southern MT.






THURSDAY LATE MORNING shows the Cold Front blasting through Central and now into S'Eastern WY as it slides in the Cheyenne area.  BOTH Models (NAM/GFS) show Snow breaking out with Accumulation likely.

NAM at 11AM THURSDAY

<< NOW, what I am closely watching is the potential for Light-maybe "Moderate Snowfall from Casper to Cheyenne along the Laramies.  A weak 1004mb Low in Northern CO could provide some "Weak Upslope Flow" for a couple Hours.  Moderate Snowfall is when you have Snowfall Rates up to 1"/HR.

** GFS shows the Same burst near Goshen/Platte Co's, so this will be a critical timeframe of who could see the HEAVIEST Snow.





THURSDAY EARLY EVENING shows a Broad swath of Light Snow all along Central & Southern WY.  Light Accumulations should continue to pile up along I-25 & I-80.

NAM at 5PM THURSDAY

<< NAM/GFS both show the same placement on the Snow.  What will occur later in the Evening is High Pressure building from the North into MT/Dakota's will slide into WY for the Overnight dropping our Temperatures after the Snow and Skies clear up.









LATE THURSDAY/EARLY FRIDAY shows different signs as our Confidence grows Weak.  NAM wants to move any Snow Chance away and clearing us out Faster.  However, the GFS is different in their Guidance as our Front stalls along I-70 in Colorado. A weak impulse forms and here's what I see (IMAGE BELOW)

<<  A weak Low forms in Northern UT/CO providing weak Upslope Flow along I-80.  Snow could continue longer from Evanston-Rock Springs-Rawlins so we have to "closely" watch this Feature with the Morning Data









SNOW AMOUNT FORECASTS:
 ** THESE ARE NOT MY FORECASTS; These are Model Guidance Snow Forecasts. However, these Models give me an Idea who/how much snow is possible **

1) Here is the Iowa St Meteogram showing the "Range" from Weather Models

Casper: 1-3.5"

** MANY Spots show Snow from the Meteogram of 1-3" such as: Laramie, Cheyenne, Sheridan, Rock Springs, Lander & Worland
-Riverton only has up to an Inch

NAM SNOWFALL MAP:

<< NAM paints a broad area of 6-8" just South of Casper/Alcova and along the Northern Laramies into Eastern WY.  However, an Isol'd 8-10" near Glendo & Guernsey.












GFS SNOWFALL MAP: 

<< GFS has that swath of 6-8" along I-80 from Rock Springs to Rawlins but light snow amounts along I-25.












THOUGHTS:  We are still over 2.5 Days away until the main event and still lots of questions remain from the Guidance that I'm not Sold On yet.  Hopefully the Morning Data and EURO data shows better guidance, but a New Post will be up Tomorrow Evening.

12/13: METEOR Shower and SnowTalk for Next Week

EVENING FOLKS!

We are talking Meteors late Tonight!  The GEMINID Meteor Shower will occur during the Overnight Hours and up to 50 Meteors/HR are Possible!  For more Info click  HERE. 

WEEKEND & EARLY NEXT WEEK looks to be Mild, Breezy & Dry.  A Ridge begins to develop and I won't be surprised if we'll see a few 50°s along the Laramies from Glenrock towards Cheyenne.

SNOW THREAT does Increase when we roll into Thursday & Friday now.  BOTH Long Range models (GFS & EURO) continues to show the conditions deteriorating by Thursday late Afternoon and early evening for Central WY.  
- Snow could be Moderate in Intensity (1"/HR) with Snow Rates so we have to watch these models very carefully through the Weekend.  

<< 11PM THURSDAY shows a Broad Low of 1008mb in UT/CO and providing Upslope in Central WY and along the Laramies.  

** EURO Model has been inconsistent with the Storm moving in much Faster being a Quick-Hitter and showing not so much on the Snow Chance.  Its been about 6-12HRS Faster than the GFS, so watching how Both of these Guidance Models take it the Storm through the Weekend.



After the Snow, the COLD Air Invades! ARCTIC Air plows in by Friday with High's that could only reach in the Single Digits and Lows likely dropping Sub-Zero once again.  IF we see a decent snowpack, expect COLDER Temperatures than other spots that don't see as much.

GFS did pretty well last week with the Forecast on the Temperatures.

CASPER, by looking at this, could drop down to 
-5 to -15° next Friday Night.







THOUGHTS:  As Always, we are still a Week away from the Start of the Storm and its effects, but the GFS Guidance has stayed consistent this week for the SnowStorm.  The potential is there for another Moderate Snowfall event (6-10") but we will see how Models trend through the Weekend. 

12/10: SOUTHEAST WY Evening Post

Strong winds battered along the Wind Prone spots in Southeast WY, especially from Laramie to Cheyenne this Afternoon on I-80.  ** UNTIL FURTHER NOTICE** I-25 is closed from Cheyenne to Colorado  due to Wintery Conditions.

.
LOOKING AHEAD:  A warmup is near, but just a small one if that.  We will stay Dry but a series of Short impulses will slide into the Northern Rockies.  A Ridge wants to push into Southeast WY to warm us up, but we'll take it; since the Siberian Air last week was brutally Cold.  BLOWING SNOW is still possible off the Laramies if the Wind continues to increase. Safe Travels to all the Motorists.

12/2: Late Monday SNOWTalk

Good Late Evening Folks,

Our COLD FRONT impacting Wyoming is now sliding into Central WY.  As of the 10:45PM Hour, the Front is just North of Casper/Riverton but that will soon change as you wake up in the Morning.

By TUESDAY MORNING, the Front will drop South into CO as a New Low will Transition as it will be the Primary Source of Energy with this System.  The HEAVIEST of Snow should stay in CO/UT for the Ski Resorts. However, some Light-Moderate Snow is possible for Casper and the Mountain and especially on the back side of the Mountain.  Light Snow elsewhere.  Its a Deep Storm so expect lots of Blowing and Powdery-type Snow so safe Travels on the Roads.  (IMAGE RIGHT)



SNOW will stick around all day through Tuesday, though we could see some Breaks in the Activity, so don't be surprised if you don't see snow. COLD Temperatures will settle in as Highs should only stay in the Teens. TUESDAY EVENING looks to be intense as more moisture will wedge to our South in Colorado.  Heavy Snow is possible, but more snow could settle in from Casper-Cheyenne and points Southwest along I-80. Upslope Flow is possible.  

WEDNESDAY will likely see more Snow for parts of Central and Southern WY.  Most places will see Light Snow, however some could see spots of Moderate Snowfall Rates (1"/HR) through the Morning and Early Afternoon Hours.  As we roll into the Evening, the Low drops South as HIGH Pressure drops down clearing out the Skies and ending the Snow.  BUNDLE UP, this is when brutal Siberian Air dives into the Rockies. We will have More on HOW Cold it could get but, it will be Below Zero. Plus we will have Tips on What to Do during these Harsh Conditions if your stranded OR what to do at Home.

Here are the very Latest WINTER WEATHER ALERTS.... 1) Pink Shows "Warnings" 
2) Purple Shows Advisories
3) Blue shows Winter Storm Watches

LATEST COMPUTER GUIDANCE WITH SNOW AMOUNTS:
** These are NOT My Forecasts, but these Models show how much your area could get but I look at these to give me "guidance" of who could see how much. **

EVENING MODEL DATA FROM THE NAM

EVENING MODEL DATA FROM THE GFS

Here are the Amounts I AM GOING FOR at the Moment:

12/1: Sunday's SnowTalk for Early Week

GOOD SUNDAY Evening all!

Happy "Meteorological Winter", but don't worry..that Winter feel will be in full force beginning Monday for Central WY. Officially the 1st day of Winter Solsice begins December 21st.

Okay lets get to the Snow.  AS OF 6PM Sunday, spots in Western WY including Rendezvous Peak has seen over 5"

MONDAY looks to be Blustery for much of Central WY and also along the Laramies & I-80 as winds will Howl through the Day but staying Dry & Mild. However, Moderate to Heavy Snow continues for Western WY. As we head into Early Evening, the Cold Front is forecasted to slide into Western WY and could increase that Snow chance for the Bighorns too along that WY/MT Line

<< A Strong (996MB) Upper Low should move over the I-90 Corridor through the Day and this Map shows the 5PM Time Frame on Monday. Still dry in Central WY, but Blustery. 









LATE MONDAY NIGHT/OVERNIGHT Hours for Central WY shows the Cold Front now blasting through in Riverton/Casper area.  This is where "Light" Snow could start falling after the 11PM Time frame. And with the strong Pressure Gradient, expect any Light Snow to blow around as it will stay breezy. (IMAGE BELOW)

<< Both the GFS/NAM Models show Moderate Snowfall possible for the Bighorns too. This is a Dynamic Storm. Lots of Energy sliding in from the Pacific.










TUESDAY MORNING looks to be quite Hazardous for the Morning Commute. Blowing Snow likely with Light to Moderate Snowfall "Possible" for Casper area.  WHY I think that is because of a Low developing in Northeast CO providing Upslope with North/Northeast winds wrapping around the Low.

As for Southeast WY, the Cold Front should be moving in at this Time, but staying Dry. Light Snow is possible for the Wind River Basin and along I-80.

But for right now, I think CASPER could be seeing the Brunt of the Activity at this Time for Tuesday Morning.





All through the Day on TUESDAY looks Hazardous. Blowing Snow, COLD Temperatures so please SafeTravels if your venturing out.  I do think the Snow could come to a "Lull" in the Activity as Flurries are possible. However, IF you are traveling South of Cheyenne towards Denver, it could be Dicey.  A "New" Low will form in Central CO dumping Moderate Snowfall possible for the Denver area and certainly over the big Ski Resorts in the Rockies to our South! (IMAGE BELOW)

















WEDNESDAY is where the Weather Models begin to vary and Disagree. 1st, lets get to the NAM Model. Maybe a few Flurries or a stray Snow Shower for Central & Southeastern WY as we'll stay Mostly Dry and COLD!  But, lets get to the GFS Model and discuss this.  The BIG Snow in Colorado will have some weak Jet Stream lift and could slide in some Light Snow all along the I-80 Corridor through the Day with another Rd of Snow possible. Light Snow is still possible for Central WY but its pretty much confined down towards Cheyenne area.  As Late Wednesday rolls around, NAM still shows ARCTIC COLD Temps for much of Central & Western WY as we are Dry and maybe a Few Flurries for the Laramies. (IMAGE BELOW)

GFS at 5PM WEDNESDAY

THURSDAY looks to be COLD with Northwest Windflow diving into all of Wyoming.  Most of WY will stay dry, however the GFS paints a few Flurries for the Cheyenne area.  

** IT WILL BE COLD! ** Depending on how much Snow-cover, Clearing Skies & Light Winds will determine How Frigid it will get.  After the Snow passes, EACH Overnight should stay Cold with Below Zero Temperatures from Wednesday and through Friday Mornings. BUNDLE UP.

<< This is the Temperature Map "forecasted" from the GFS showing Below Zero for all of WY and about 5-15° Below Average for much of Central & Eastern WY by Friday Morning.








SO HOW MUCH SNOW?  As Always guys, please keep these Amounts with a "Grain of Salt" from these Models.  The Storm Track can shift these amounts ever so slightly but this is from the NAM Model.

From looking at this, WESTERN WY will and all of the Mountains will likely see over a Foot and a Half, possibly 2' in some spots.  Plus, the Bighorns could get blasted with that wave moving in Monday Afternoon.

Lower Elevations:  The NAM shows very sparse Snow for the Basins, including Lander.

CASPER:  As I showed you earlier, the Upslope Machine could give the "City" Light to maybe Moderate Snow Amounts of 2-5". The Mountain could see 6-10" & north of Glenrock could see some Moderate Snowfall.



The METEOGRAM out of Iowa St shows a "Range" of Snow from various Weather Models and does quite well for Snow Amounts.

<< This is for the "Airport" in Casper. So they show a range of 1.5-3.5" So in the City, I expect more since its closer to that Upslope Effect.


Other Amounts for Cities from the Meteogram:  Riverton/Lander ~ 1-3", Sheridan ~ 2-5", 
Cheyenne ~ 3-7"    DENVER 4-8"


THOUGHTS:  The Monday Morning Data could change so slightly, but its getting close of not Forecasting in advance now with this Storm as its on our Doorstep. I do think this is beginning to take shape a Major Snowstorm for Western/Central CO after it leaves Western Wyoming and the Bighorns. BUT...it could change.  These past few Days with the Storm has been inconsistent so I wouldn't be surprised if it changes once again by Morning with the new Data.  ADVISORIES will likely be Issued for the Snow so Stay Tuned to my Blog/Posts through the next Few Days.

11/30: Late Saturday Snow/COLD Talk

Its a Late-Evening Post but this Read can bring you up to Speed of what the Models showed Saturday for the Upcoming Storm.

<< LATEST Advisories for Wyoming.  Click on the Map to enlarge if needed.  But the Snow Potential for Western WY can vary from 8-20"in some spots.

- BLUSTERY for Central WY in Casper and along the Laramies for Sunday Evening and through Monday in advance of our Front.


WESTERN Wyoming will get blasted with Snow with Moderate-Heavy Intensity through the Day on Sunday and into the Evening as a Trough passes by.  By Monday, the Snow Increases once again, as our Actual Cold Front Arrives from Montana/Idaho.  Central WY will stay Dry/Mild but the winds will be Howling!

-- GFS/NAM takes the Cold Front in Northwest WY by 5PM Monday Evening with Heavy Snow possible in the West as a very Deep 992mb Upper Low rolls into Eastern WY.  









** UPDATE **  Last Post, I mentioned how the Front could impact Wyoming by early-Mid Tuesday Morning, well....  IT has changed.  Since the Storm is gathering more Forward Momentum, the Front has now sped up on the Timing. Right Now, the Cold Front should impact Central WY during the Overnight Hours on Tuesday Morning.  Light Snow should break out and could be Moderate at Times in Casper area if the NAM Model verifies for Tuesday Morning (IMAGE BELOW)

<  Could be a tough travel to Work for Tuesday Morning so make sure you take some extra time as Roads should be slick with the Snow.

Blowing Snow is likely as the Wind Field gets Stronger.  Safe Travels Folks.







TUESDAY EVENING & WEDNESDAY looks to be Hazardous.  I think Snow is possible throughout Central & Eastern WY, but all 3 Models are showing different placement of "Who" will see the Heavier Snow and "When" the Snow will taper off. Right now, the Long-Range EUROPEAN Model has the Snow/Flurries ending by Wednesday Evening; however the GFS keeps Flurries through the Overnight for many of us and Light Snow in Cheyenne/Laramies.

** WHEN the Snow Tapers off, Skies should thin out and Dry out our Airmass. I do think we will go BELOW ZERO for Wednesday & Thursday Overnight. Daytime Highs should stay in the Low-Mid Teens for Central WY. Here is the GFS Forecast for Overnight Lows.

-- Remember, the Bigger our Snowfall Depth on the Ground, the COLDER the Temperatures could get IF the Skies Clear and Winds remain Calm.

-10° is Possible for Casper since we could see more Snowfall than other spots.  You see a lot of White in Western WY.  We could very likely see Temperatures about -30° or Higher!  

*DANGEROUS Temps, so take any precautions if necessary*

SO HOW MUCH SNOW?  I did Say that our Models increased of the Timing with the Cold Front about 12 Hours from Friday to Tonight's Post. That does have some effect to our Snow Potential too. A fast, quick hitting storm reduces a Moderate-Heavy Snow.

<< *THIS IS NOT MY FORECAST*  This is the GFS Snow Potential. Last Night, it showed Casper Over a Foot..now its 1/2 that.  And it pretty much Halved much of Central WY.

Cheyenne and the Laramies could still a Moderate Snowfall event.

- As I said last night, Please Take these Amounts with a grain of Salt as these Totals could change up or down by Sunday.  Snow is one of the hardest variables to Forecast cause its based on 
1)Timing
2)Intensity
3) Storm Track

THOUGHTS: After seeing the Data from the Morning to this Evening, its still that Coin-Flip or Luck of the Draw.  If Models slow down on Sunday, then expect a Moderate-Heavy Snow Potential for Central WY.  However...IF we see a Consistent Faster run like this with our Cold Front arriving Late Monday/Overnight Tuesday, expect a Light to maybe "Moderate" Snowfall of up to 6" in a few Spots in some Cities like South of Casper.  HEAVY SNOW for Western WY is a likely given from what I am seeing.