Weather for NearSys Station, January 2018

The average low at NearSys Station was 34 degrees F and the average high was 45 degrees F. According to one of our local television meteorologists, this January was 5 degrees warmer than the average.

There was 1.25 inches of rain in January and no snow. No snow is quite an exception. Fortunately, it was cold enough in the mountains that the precip there was in the form of snow.

All Sky Photometer for NearSys Station, 29 January 2018

NearSys Station was foggy and overcast until late afternoon. The sun came out briefly and then promptly passed behind the clouds.

Visibility for NearSys Station, 26 January 2018

The 5:10 PM MST UAVSonde flight indicates visibility at NearSys Station is in excess of 50 miles. Snow is visible on the Owyhee and Boise mountain ranges. The cloud base was higher than 6,500 feet, or the top of Shaffer Butte in the Boise Mountains.

Looking East.

Looking North.

Looking South.

Looking West.

An Observation on Cloud Height as Rains Approach

Starting the afternoon of January 21st, the clouds began building up (from what was originally a clear morning) for a rain shower we were promised. I wondered if the clouds were going to get lower as the "storm" approached, so I measured the temperature of  the ground and clouds with a thermal imager (Seek Reveal) every 30 minutes. When the storm finally arrived at 6:00 PM MST, a light drizzle persisted all night. Here are the results.

The ground temperature dropped only five degrees F over the course of my measurements. The cloud temperatures on the other hand increased 31 degrees F over the same time.

Assuming a dry adiabatic lapse rate of 5.4 degrees F per 1,000 feet, this is the height of the clouds as the rains approached. 

I need to repeat this experiment several more times to see if it remains consistent. This also means making these measurements when I know it''s not going to rain or snow.

All Sky Photometer for NearSys Station, 21 January 2018

What started out as a clear morning turned into a cloudy and eventually rainy night. Below is the photometer's output. You can see at around 1:30 PM MST, the clouds came in pretty heavy.

Ground and Sky Thermal Observation for NearSys Station, 20 January 2018

NearSys Station is partially overcast with altocumulus clouds (I believe). The base of the clouds had a temperature of -12 *F for a temperature between the ground and sky of 31 degrees.

Assuming a dry adiabatic lapse rate of 5.4 degrees per thousand feet, the base of the clouds is at an altitude of 5,700 feet.

Visible image of the clouds over NearSys Station at 3:30 PM MST.

Thermal image of the clouds over NearSys Station.

Visibility for NearSys Station, 20 January 2018

The UAVSonde flight indicates that the visibility from NearSys Station is at least 50 miles. Most interesting is the line of cumulus clouds setting about the Owyhee Mountains. These are most likely created by air moving south and forced to rise over the mountain's higher elevation.

Looking East.

Looking North.

Looking South. Orographically-generated clouds are visible over the edge of the Owyhee Mountains.

Looking West.

Sky and Ground Thermal Observation for NearSys Station, 17 January 2018

It's overcast and dark at 7:30 PM MST, so I can't see the clouds making the sky overcast.

The ground temperature is 15*F. The clouds have a temperature between -8 and -10*F. Assuming a dry adiabatic lapse rate of 5.4 degrees per thousand feet, the height of the clouds is between 4,300 and 4,600 feet.

Colder patches in the clouds have a temperature of -15*F. The makes their height 5,600 feet.

I can't see the clouds, so I don't know if the thermal imager is detecting openings or higher portions of the clouds.

All Sky Photometer for NearSys Station, 17 January 2018

It was an overcast but dry day at NearSys Station. The clouds thinned out briefly around 2:00 PM MST.

Visibility for NearSys Station, 17 January 2018

The UAVSonde flight at 4:30 PM MST indicated the visibility was at least 50 miles.

Looking east

Looking north

Looking south

Looking west

Thermal Images at Oceanside, California

On the way back home, I made a quick stop at the beach in Oceanside to see what the kand, sea, and air looks like I'm clear, sunny skies.

The dark rocks are warmer than the sand and the water is cooler than the beach. The air just above the waves is warmer than the ocean water.

Looking northwest.

The dry sand is cooler than the damp sand. And I can see the air immediately above the ocean is warmer than the water.

Looking west into the Pacific Ocean.

All Sky Photometer for NearSys Station, 7 January 2018

Dense fog all day at NearSys Station, we never saw the sun or sky.

Visibility for NearSys Station, 7 January 2018

NearSys Station is socked in with fog. The visibility is only 1/2 mile.

A drive to town discovered that the overhead clouds were only 400 feet above NearSys Station.

Ground and Sky Thermal Observation for NearSys Station, 5 January 2018

A thermal measurement of the ground and sky was made at 9:15 AM MST. Most interesting was not the height of the cloud bsse, but the variation in the cloud height.

The warmest, lowest portion of the clouds had a temperature of 7 degrees F. The coolest, higher portion of the clouds had a temperature of 0 degrees F.

Assuming a dry adiabatic lapse rate of 5.4 degrees per thousand feet, the variation in the cloud height was 1,300 feet.

NearSys Station is covered in stratocumulus. The inversion is inally being cleared out of the valley.

A higher altitude region between cumulus cloud puffs.

The bottom surface of a cumulus cloud.

All Sky Photometer Data for NearSys Station, 4 January 2018

Since I'm on vacation, I started recording data earlier and let the photometry record data for longer. It was an overcast day, however we did get some weak sunlight starting after the late morning.

Sky and Ground Thermal Observation for NearSys Station, 3 January 2018

According to the Seek Reveal, the ground temperature was 8 *F and clouds were at -12 *F. Assuming a dry adiabatic lapse rate of 5.4 degrees per thousand feet, the clouds base was at 3,700 feet. The sky behind the clouds had a temperature of -28 *F.

It's a little foggy at NearSys Station and we are covered in overcast. A drive earlier today indicated the fog reaches no higher than 425 feet (since that's the elevation of a ridge I need to cross). Above that is clear skies. So I don't know what cloud base the thermal imager is detecting.

This is the appearance of the clouds and for overhead.

A thermal image of the overhead clouds and fog.

Weather for NearSys Station, 2017

Here are the charts for the temperatures and precipitation for NearSys Station covering all of 2017. The year was known for it's unusually heavy snowfall.

Weather Data for NearSys Station, December 2017

We finished off the month with gradually cooling temperatures. NearSys Station had very little rain, but did experience over five inches of snow in five storms.