Blog - Page 40 of 62 - Meteorologist Chris Tomer

Weekend events: Small Monsoon surge

Post author By christomer
Post date August 18, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, Meteorology, Trail Running

Tomer’s Take:

A small Monsoon surge hits Colorado 8/19-8/22.
Bulk of moisture stays in the Southern and Central Mountain Zones.
LT100 run and Triple Bypass are 8/20.

Current Setup

Water vapor satellite shows a large wedge of drier air moving into Colorado. The next Monsoon plume is forming to our West in Arizona and Nevada. Orange/reds = drier air aloft.

Flash Flooding

Excessive rainfall outlook valid 8/18.

Excessive rainfall outlook valid 8/19.

Forecast

Massive-Elbert	AM	PM
8/18	Dry	10%
8/19	Dry	80%
8/20	10%	80%
8/21	10%	60%
8/22	10%	60%

Hourly forecast valid 8/20 in Leadville:

8/20	4am	10am	Noon	4pm	9pm
%	Dry	10%	80%	80%	30%
Sky	Overcast	Cloudy	Storms	Storms	Clearing

Triple Bypass valid 8/20

Air temps over Loveland Pass and Vail Pass (High/Low): 54°/31°F

8/20	4am	10am	Noon	4pm	9pm
%	Dry	10%	70%	70%	20%
Sky	Overcast	Overcast	Storms	Storms	Clearing

Both events on 8/20 straddle a sharp line between the Monson surge and drier air to the north. Mid-atmospheric relative humidity valid afternoon 8/20:

Aurora possible tonight: Geomagnetic Storm Watch issued

Post author By christomer
Post date August 17, 2022
Categories In Forecasting, Meteorology
4 Comments on Aurora possible tonight: Geomagnetic Storm Watch issued

Tomer’s Take:

The Space Weather Prediction Center (SWPC) issued a Geomagnetic Storm Watch for a “G3” level storm intensity late 8/17 into 8/18.
A G3 is categorized as “strong”.
This generates a KP Index of 7. Generally, this brings the Aurora Borealis viewing line south to about 50° latitude. Sometimes locations a little further south of 50° might catch some low horizon viewing.
Seeing the Aurora Borealis in Colorado is not a lock.
If it happens, best viewing occurs in Northeast Colorado.
Colorado Timing: 11pm 8/17 through 5am 8/18.

Forecast overnight 8/17 into 8/18:

Denver: Clear Skies
Greeley: Clear Skies
Sterling: Clear Skies
Fort Collins: Clear Skies
Fort Morgan: Clear Skies
Stoneham: Clear Skies
Holyoke: Clear Skies
Limon: Clear Skies

This is a photo from June 2015 in Northeastern Colorado taken by photographer Dusting Price.

Small Monsoon surge this weekend in Colorado

Post author By christomer
Post date August 17, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, Meteorology, Trail Running

Tomer’s Take:

In Colorado, two drier days ahead 8/17-8/18 for the Central and Northern Mountains (& Front Range). Most afternoon t-storms 8/17 stay in Southern Colorado.
The next Monsoon surge is smaller but lingers: 8/20-8/23. Afternoon rain/t-storms are more likely on these days.
LT 100 run and Triple Bypass bike are 8/20.

Current Setup

Water vapor satellite shows drier air filtering into the Northern Colorado as this current surge comes to an end. The bulk of remaining moisture stays in Southern Colorado on 8/17. Orange/red colors = drier air aloft.

Flash Flood Potential

This is the excessive rainfall outlook valid 8/17. There is at least a 15% chance of flash flooding in the yellow shaded areas.

This is the excessive rainfall outlook valid Friday 8/19 (8/18 is dry). Notice the Monsoon plume moving back into Colorado from the West. There is at least a 15% chance of flash flooding in the yellow shaded areas.

Forecast

Forecast humidity in the middle of the atmosphere valid afternoon 8/20. There is a sharp dividing line between drier air (from the North) and moist air (from the Southwest) with the next Monsoon surge. Leadville is caught in-between. The Triple Bypass is caught in-between but slightly on the drier side.

Massive-Elbert Zone	AM	PM
8/17	Dry	50%
8/18	Dry	10%
8/19	Dry	70%
8/20	Dry	60%
8/21	10%	70%
8/22	10%	60%

Hourly forecast for Leadville on 8/20:

Hour	4am	10am	Noon	4pm	9pm
%	Dry	Dry	60%	60%	30%

Triple Bypass 8/20:

Air temps on Loveland Pass and Vail Pass (high/low): 55°/30°F.

Hour	4am	10am	Noon	4pm	9pm
%	Dry	Dry	50%	50%	20%

Total Precip

Forecast total precipitation between 8/17-8/20. Notice the bulk of accumulation is I-70 and South.

Monsoon season continues in Colorado

Post author By christomer
Post date August 16, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running

Tomer’s Take:

This is one of the most robust Monsoon season’s in Colorado in recent memory.
It stays active through the end of August.
Two events upcoming on 8/20: LT 100 run and Triple Bypass bike race.
Two Monsoon surges: 1) Now-8/17 (medium intensity), 2) 8/20-8/22 (Lower intensity).

Current Setup

Water vapor satellite shows the current Monsoon surge in NM, AZ, UT, and CO. Orange/red colors = drier air aloft.

Flash Flood Potential

The excessive rainfall outlook for 8/16/2022. The yellow shaded area has at least a 15% chance of flash flooding.

The excessive rainfall outlook for 8/17/2022. The yellow shaded area has at least a 15% chance of flash flooding.

Forecast

The LT100 run is 8/20.

Massive-Elbert	AM	PM
8/17	10%	70%
8/18	Dry	10%
8/19	Dry	70%
8/20	Dry	80%
8/21	Dry	70%
8/22	Dry	60%

Hourly forecast 8/20:

Leadville	4am	10am	Noon	4pm	9pm
Precip%	Dry	10%	80%	80%	40%

Triple Bypass 8/20:

High/Low air temps over Loveland Pass and Vail Pass: 54°/31°

Loveland-Vail	5am	10am	Noon	4pm	9pm
Precip%	Dry	Dry	70%	70%	30%

Total precipitation between 8/16-8/20:

Here’s my mountain weather forecast video 8/16.

Rain chances this week in Colorado

Post author By christomer
Post date August 15, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running
4 Comments on Rain chances this week in Colorado

Tomer’s Take:

Two Monsoon surges are on Colorado’s horizon.
The first is a medium intensity surge 8/15-8/17.
The second is a small surge 8/20-8/22.
The LT100 run takes place on 8/20.
In Colorado, the seasonal Monsoon normally runs July through August.

Current Setup

Water vapor satellite shows the Monsoon plume moving north through New Mexico, Arizona, Utah, and Colorado. Red/orange colors = drier air aloft.

The San Miguel County Sheriff says the Bridal Veil area and Black Bear Pass remain closed due to recent flash flooding and rockfall.

Flash Flood Potential

Excessive Rainfall Outlook valid 8/15/2022. Yellow indicates at least a 15% chance.

Excessive Rainfall Outlook valid 8/16/2022. Yellow indicates at least a 15% chance.

Forecast

Massive-Elbert Zone	AM	PM
8/16	30%	100%
8/17	20%	80%
8/18	Dry	50%
8/19	Dry	60%
8/20	Dry	80%
8/21	10%	80%

Breakout hourly forecast for 8/20 in Leadville:

8/20	4am	10am	Noon	4pm	9pm
LT 100	Dry	20%	80%	80%	20%

Bonus Forecast: Crestone Peak

Crestone Peak	AM	PM
8/16	30%	100%
8/17	30%	100%
8/18	Dry	40%
8/19	Dry	60%
8/20	Dry	70%
8/21	20%	80%

Here’s my 8/15 mountain weather forecast update video:

Monsoon surge this week

Post author By christomer
Post date August 14, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running
2 Comments on Monsoon surge this week

Tomer’s Take:

Two surges are lined-up.
Peak surge in Colorado occurs 8/14-8/17. This is a medium intensity surge.
A second smaller surge occurs 8/20-8/21. This coincides with the LT100 trail run in Leadville on 8/20.
Monsoon surges make rain/t-storms more likely. Sometimes the precipitation can start before Noon and last late into the night.

Current Setup

Water vapor satellite shows the southerly wind flow escorting this Monsoon surge north through AZ, UT, WY, and into CO. Red/orange colors = drier air aloft.

Forecast

Massive-Elbert Zone	AM	PM
8/15	10%	100%
8/16	30%	100%
8/17	10%	70%
8/18	Dry	50%
8/19	Dry	50%
8/20	Dry	90%
8/21	10%	80%

Specific forecast for 8/20 LT100 run:

Elbert-Massive Zone	5am	10am	Noon	5pm	9pm
Precip Chance 8/20	0%	20%	90%	90%	40%

Bonus: Longs Peak

Longs Peak	AM	PM
8/15	20%	100%
8/16	30%	60%
8/17	Dry	60%
8/18	Dry	60%
8/19	Dry	70%
8/20	Dry	90%
8/21	10%	90%

Total Precipitation

This is total rainfall by the night of 8/20. 1-3+ inches possible in the mountains south of I-70. The San Juan Mountains could see flash flooding.

Here’s my 8/14 mountain weather forecast video:

Mountain weather update 8/12: Monsoon timing

Post author By christomer
Post date August 12, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running
1 Comment on Mountain weather update 8/12: Monsoon timing

Tomer’s Take:

LT 100 Mountain Bike Race: 8/13
LT 100 Run: 8/20
The events will straddle a Monsoon surge 8/14-8/19.
Bonus: Elk Range 14er forecast is also below.
Monsoon season in Colorado normally runs July and August.

Current Setup

Water vapor satellite shows the current Monsoon surge brushing Las Vegas, Arizona, Utah, Wyoming, Idaho, and Montana. This weekend, the high pressure moves east and opens the door for the surge to swing east through Colorado and New Mexico. Red/orange = drier air aloft.

The Full Sturgeon Supermoon made an appearance over Colorado:

LT 100 Forecast

Massive-Elbert Zone	AM	PM
8/13	Dry	50%
8/14	Dry	90%
8/15	Dry	100%
8/16	30%	100%
8/17	20%	80%
8/18	Dry	70%
8/19	10%	80%
8/20	10%	70%

Bonus: Elk Range 14ers

Elk Range 14ers	AM	PM
8/13	Dry	60%
8/14	Dry	90%
8/15	20%	100%
8/16	10%	90%

Leadville events next two weekends: Weather

Post author By christomer
Post date August 11, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running

Tomer’s Take:

LT 100 Mountain Bike Race: 8/13
LT 100 Run: 8/20
A Monsoon surge occurs in-between plus a cold front. The LT 100 Run on 8/20 is looking cooler than normal with possible residual Monsoon moisture. Details below.

Current Setup

Water vapor satellite shows the plume of Monsoon moisture being directed south to north through Utah, Idaho, Wyoming, and Montana. By afternoon 8/14, this plume begins to pivot and swing across Colorado through 8/19. Red/orange colors = drier air aloft.

Leadville Events Forecast

Massive-Elbert	AM	PM
8/13	DRY	50%
8/14	DRY	80%
8/15	DRY	90%
8/16	DRY	100%
8/17	30%	90%
8/18	30%	80%
8/19	20%	80%
8/20	10%	80%

Additional note: Air temps by 8/20 may run cooler than normal behind this Monsoon surge. There is also a cold front involved.

Here’s a look relative humidity mid-atmosphere and it’s running abnormally high on 8/20.

LT 100 MTB: Here’s the NWS digital point forecast for about 13,000ft valid afternoon 8/12 through 8/13.

Monsoon on vacation but returns late this weekend

Post author By christomer
Post date August 10, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running
4 Comments on Monsoon on vacation but returns late this weekend

Tomer’s Take:

Hot and drier across Colorado through 8/13 with normal afternoon thunderstorm chances.
Moisture starts to increase afternoon 8/14.
This equates to a large window for FKT’s, high altitude loops, and big outings.
Bulk of next Monsoon surge in Colorado occurs 8/16-8/18.
Colorado is currently isolated and protected by the position of the key high pressure. Monsoon moisture is being sent into UT and all the way north into ID and parts of the PNW.

Water vapor satellite shows the high protecting Colorado. Notice how far north the current Monsoon surge is traveling. Orange/red = drier air aloft.

Timing

In Colorado, here’s my precipitation forecast for the Central Mountain Zone:

Central Mountains	AM	PM
8/11	DRY	10%
8/12	DRY	20%
8/13	DRY	20%
8/14	DRY	50%
8/15	DRY	70%
8/16 SURGE	DRY	90%
8/17 SURGE	DRY	90%
8/18 SURGE	DRY	80%

Next Surge

Atmospheric moisture increases to 200% of normal over parts of Colorado 8/16-8/18.

Monsoon surge trending weaker this weekend

Post author By christomer
Post date August 5, 2022
Categories In Exercise, Forecasting, Hiking/Mountaineering, La Nina, Meteorology, Trail Running

Tomer’s Take:

Overall intensity of this surge is trending a notch weaker in Colorado. Call it a low to medium intensity surge.
The location of most precipitation accumulation is also changing. Overall it’s shifting East/Southeast. It favors the Southern Mountains, Continental Divide and East. Lower precip chances across the Western Slope.
Saturday and Sunday mornings start mostly dry.
Watch for weather by 11am on Sunday and Monday in a few locations including the Sangres and Front Range high peaks.

Current Setup

The key area of high pressure is starting to move east and that opens the door to the next Monsoon surge.

Precip Placement

The bulk of precip through the weekend falls in the Southern Mountains, Continental Divide and East. Less across the Western Slope.

The wettest mountain ranges through the weekend are the Sangres and Wet Mountains.

Forecast

Crestone Peak	AM	PM
8/5	Dry	60%
8/6	Dry	90%
8/7	20%	90%
8/8	30%	90%

Longs Peak	AM	PM
8/5	Dry	80%
8/6	Dry	40%
8/7	20%	90%
8/8	20%	60%

Quandary Peak	AM	PM
8/5	Dry	80%
8/6	Dry	50%
8/7	10%	90%
8/8	Dry	30%