colorado snow forecasting 101
DESCRIPTION
Slides often used by meteorologist Joel Gratz in his presentations about Colorado snowfall.TRANSCRIPT
![Page 1: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/1.jpg)
Colorado SnowForecasting101
Photo: Connor Walberg ActionPhotoSchool.com
Meteorologist Joel Gratz
![Page 2: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/2.jpg)
1) Remove mystery ofColorado weather.
How this presentation will help you:
2) Find the most snow.
![Page 3: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/3.jpg)
Hi, I’m Joel Gratz.
I grew up in Pennsylvania,ski raced and instructed, then moved to Colorado after college.
![Page 4: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/4.jpg)
And I started to miss powder days due to inaccurate forecasts.
![Page 5: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/5.jpg)
And it made me mad!
![Page 6: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/6.jpg)
Dec 2007 28 people email list
2008-2009 500 people email list
2009-2010 245,000 pageviews
2010-2011 1,315,000 pageviews
2011-2012 3,330,000 pageviews
2012-2013 12,000,000 pageviews
So I learned how to forecast in Colorado, and started to share.
![Page 7: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/7.jpg)
![Page 8: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/8.jpg)
Big Weather(primary care doctor)
(knee surgeon)
![Page 9: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/9.jpg)
Actual Storm Track
![Page 10: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/10.jpg)
16 Day Forecast
![Page 11: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/11.jpg)
15 Day Forecast
![Page 12: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/12.jpg)
14 Day Forecast
![Page 13: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/13.jpg)
13 Day Forecast
![Page 14: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/14.jpg)
12 Day Forecast
![Page 15: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/15.jpg)
11 Day Forecast
![Page 16: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/16.jpg)
10 Day Forecast
![Page 17: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/17.jpg)
9 Day Forecast
![Page 18: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/18.jpg)
8 Day Forecast
![Page 19: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/19.jpg)
7 Day Forecast
![Page 20: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/20.jpg)
6 Day Forecast
![Page 21: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/21.jpg)
5 Day Forecast
![Page 22: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/22.jpg)
4 Day Forecast
![Page 23: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/23.jpg)
3 Day Forecast
![Page 24: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/24.jpg)
2 Day Forecast
![Page 25: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/25.jpg)
1 Day Forecast
![Page 26: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/26.jpg)
Actual Storm Track
![Page 27: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/27.jpg)
When to trust the forecast
10 days+ storm or no storm+ cold, hot, dry, moist
3-5 days+ details becoming clearer
1-2 days+ details are as clear as possible
![Page 28: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/28.jpg)
How to plan
7-10 days 4-5 days 2-3 daysToast to
possibilitiesClear yourschedule
Pretend you’regetting sick
![Page 29: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/29.jpg)
Weather is not magic. It’s physics.
Forecasts are rarely perfect, but they are getting better every year. Study them, don’t dismiss them.
![Page 30: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/30.jpg)
Long range forecasts stink!
We cannot reliably predict snow accumulationsbeyond about two weeks. Seasonal outlooks are even worse.
![Page 31: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/31.jpg)
Weather happens when moist air
gets high
1 2 3
![Page 32: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/32.jpg)
Where’s the moisture?
Lots of moisture(ocean source)
Less moisture(land source)
OK moisture(ocean + plants)
![Page 33: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/33.jpg)
Orographics get air high
![Page 34: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/34.jpg)
Mountains = Precipitation
Indian Peaks / RMNP
Sangre deChristo
Park Range
Flattops
GrandMesa
ElkMtns
EastSan Juans
N&SSan Juans
Sawatch
Gore
Ten Mile &Mosquito
![Page 35: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/35.jpg)
Favorable wind directions
Wolf Creek
Silverton
Telluride
Powderhorn Crested Butte
AspenVail
Summit Co.
SteamboatRMNP
![Page 36: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/36.jpg)
Breckenridge: NW to N winds
Gore Range
VailPass
![Page 37: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/37.jpg)
Vail: Northwest winds
BeaverCreek
Vail
Gore Range
VailPass
![Page 38: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/38.jpg)
Beaver Creek: West winds
Vail
Gore Range
VailPass
BeaverCreek
![Page 39: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/39.jpg)
Telluride: West winds
![Page 40: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/40.jpg)
VailJanuary 31, 2013
![Page 41: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/41.jpg)
![Page 42: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/42.jpg)
http://www.its.caltech.edu/~atomic/snowcrystals/primer/primer.htm
![Page 43: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/43.jpg)
Moi
stur
e in
the
air
Temperature >> colder
10F 0F
![Page 44: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/44.jpg)
The best snow requires...
• Lots of moisture
• Mountain top temperatures between about 0-10F
• Not too much wind
![Page 45: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/45.jpg)
Wind directions?Complicated.What about radar?
Nope. There’s a problem...
![Page 46: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/46.jpg)
Jamming the Radar
![Page 47: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/47.jpg)
Overshooting the Snow
0.5 deg
![Page 48: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/48.jpg)
http://www.ncdc.noaa.gov/nexradinv/
Denver Airport
PuebloGrandMesa
![Page 49: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/49.jpg)
http://www.ncdc.noaa.gov/nexradinv/
RMNP
Steamboat
Telluride
Wolf Creek
Aspen
Vail
Summit Co.
Crested Butte
![Page 50: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/50.jpg)
Colorado is a state of extremes
Joe Ramey, National Weather Service Grand Juntion, Slide #8 2009-2010 Winter Outlook for Colorado
The difference between a wet year and a dry year can come down to the presence or absence of just a few major storms.
![Page 51: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/51.jpg)
Colorado is a state of extremes
Joe Ramey, National Weather Service Grand Juntion, Slide #8 2009-2010 Winter Outlook for Colorado
More than half of the total annual precipitation falls in only 20% of the days when precipitation occurs.
![Page 52: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/52.jpg)
Example: Schofield Pass
![Page 53: Colorado snow forecasting 101](https://reader034.vdocuments.us/reader034/viewer/2022051611/54b651ce4a79590b4a8b4720/html5/thumbnails/53.jpg)
Example: Schofield Pass
2 of 60 storms created
25% of the total season snow