Friday, March 30, 2018

A Bullseye of Dry

The past winter season (December-February) was a little on the weird side. The west coast, which normally experiences it's wet season in the winter, was pretty dry. It was cold across the Plains and Midwest, but snowfall was way below average in many areas. Winter had a late surge in the northeast in late February and March. However, one aspect of the last five to six months that has been interesting to watch is the fairly rapid development of severe to exceptional drought in the panhandle region of Texas and Oklahoma and adjacent portions of Colorado, Kansas and New Mexico.

Here is the U.S. Drought Monitor as of today, showing parts of this area in Extreme Drought, compared to the Drought Monitor in early October.

Dryness expanded and intensified through November and December, and by early January the first depictions of Extreme drought were showing up on the U.S. Drought Monitor. 

By early March an area from the Four Corners region to the panhandles was painted with Extreme Drought, with a small area of Exceptional Drought in northern Oklahoma. That small area has doubled in size in the past two weeks.

The precipitation map for the past 6 months depicts the seriousness of the precipitation deficit.

This map from the Oklahoma Mesonet demonstrates the incredible precipitation gradient across Oklahoma the past four months, ranging from only an inch in the panhandle to more than 25 inches in the southeastern part of the state.

Then there was this note included in the Area Forecast Discussion by the NWS Amarillo office on March 28.

We have some dedicated CoCoRaHS observers that have been submitting daily observations, mostly zeros, throughout the development of this drought. Here is a list of CoCoRaHS rainfall totals under one inch from Texas, Oklahoma, Colorado, New Mexico and Kansas October 1 through March 28 for all stations which had observations for at least 90 percent (161) of the days in this period.
Station Number Station Name Total Precip Total Snow
 CO-BA-27  Stonington 8.6 SE 0.28 1.3
 CO-LA-16  Kim 8.8 SSE 0.58 2.7
 KS-HM-3  Syracuse 14 SSE 0.59 0.0
 TX-LK-24  Ransom Canyon 0.4 ENE 0.64 0.2
 NM-SC-26  Lemitar 0.7 NNE 0.67 0.0
 KS-SV-18  Hugoton 0.6 NNW 0.69 0.0
 NM-SN-39  Rio Rancho 3.3 ENE 0.73 0.0
 NM-SN-62  Rio Rancho 3.0 WSW 0.75 0.0
 KS-WH-9  Leoti 6.8 NNW 0.78 7.4
 TX-LK-14  Lubbock 5.3 SSW 0.79 0.4
 NM-SN-43  Rio Rancho 3.5 W 0.80 0.3
 CO-OT-25 La Junta 1.0 S 0.82 1.8
 NM-SJ-19  Farmington 3.4 WSW 0.83 0.0
 NM-BR-205  Albuquerque 8.9 NW 0.83 0.0
 NM-BR-36  Albuquerque 5.9 WNW 0.86 0.0
 TX-LK-59  Wolfforth 4.6 S 0.86 0.5
 TX-LK-7  Lubbock 6.7 SW 0.87 0.3
 NM-BR-7  Albuquerque 7.1 SW 0.88 0.0
 TX-LK-77  Lubbock 6.4 NW 0.89 0.0
 CO-BN-8 Las Animas 8.1 NE 0.92 3.4
 NM-BR-152  Albuquerque 2.9 W 0.92 0.0
 CO-OT-28 La Junta 1.6 SW 0.93 1.5
 NM-SJ-32  Kirtland 21.7 S 0.95 0.2
 NM-TR-1  Mountainair 1.0 S 0.96 1.0
 TX-LK-81  Lubbock 3.0 S 0.96 0.0
 NM-BR-215  Albuquerque 5.3 W 0.96 0.0
 KS-HM-19  Syracuse 3.1 NNE 0.96 0.0
 KS-FO-23  Dodge City 12.7 S 0.98 1.2

The winds aloft, particularly in December and January, were west-northwest on average in this part of the country. Any moisture heading toward the Texas and Oklahoma panhandle region would get wrung out of the atmosphere as the air was forced up on the west side of the Rockies. Any low pressure systems that developed tended to be steered east before they started to develop. What the drought-affected area needed, and didn't get, were some strong low pressure system developing on the lee side of the Rockies that could tap into moisture from the Gulf of Mexico to produce precipitation.
These maps depict the average 500 millibar height pattern (~20,00 ft) for the months of December, January and February. Winds at this level blow parallel to the contour lines. The arrows show the general direction of the wind at this level.

Although this region did get a little rain this week, the operative word is "little". The latest forecasts keep the drought area dry for at least the next week or so.

Tuesday, March 20, 2018

Are You Up for a Spring Challenge?

Those of you in the Northeast might be saying "We've been challenged enough!" with the recent train of nor'easters passing thought, but this challenge will be less stressful.

NASA's GLOBE (Global Learning and Observations to Benefit the Environment) is running a spring challenge for cloud observations and is encouraging citizen scientists (that's you, CoCoRaHS observers) to participate.

From now until April 15th you can take part in the challenge by downloading the free GLOBE Observer app for iOS or Android. You can also submit you observations online through the web site. However, once you have the app, you can snap and send cloud observation photos directly to NASA using the app.

Participants are invited to enter up to 10 cloud observations per day from now to April 15. GLOBE and GLOBE Observer participants with the most observations will be congratulated by NASA scientists with a video posted on the NASA GLOBE Clouds website.

I spent some time on the GLOBE Cloud web site recently to find out more about what this entailed. There is plenty of training material available on cloud types and cloud observations, including a nice downloadable cloud chart as well as an online cloud chart, and a guide to Observing Cloud Types.

The optimal observation is one that coincides with a satellite pass over your location, and there is a tool on the web site where you can get these. There are at least five orbiting satellites that collect cloud data. you will need your latitude and longitude for this. The app will determine this if you have location services turned on on your phone or tablet. That's also available from your CoCoRaHS account if you don't have it written down somewhere. The app allows you to set an alarm to alert you to upcoming satellite passes.

Clouds are important to Earth's energy balance. They reflect, absorb, and scatter sunlight as well as infrared emissions from earth. The type of cloud, its height, and transparency all are factors that have to be addressed. Satellites can detect clouds, and while they are great tools, they have limitations especially when it comes to the details. For example, satellites see the tops of clouds, but not the bottoms. Satellites may also have a hard time differentiating high, wispy thin cirrus clouds (composed of ice crystals), from deep snow cover on the ground. So while satellites look down on the clouds, GLOBE cloud observers are looking up.

Altocumulus clouds.
Photo: Steve Hilberg

The app (available on iOS and Google Play) walks you through the steps of making an observation. The following information is required for each observation:

Date, time, location
SKY:clear, cloudy, obscured
COVERAGE: what percent is covered
TYPE:  cloud/contrail types
Visual opacity
Surface conditions

One observation is allowed per time stamp, and it's recommended that you wait 10 to 15 minutes between observations so changes in the sky can be recognized.

Also, there is this important reminder:

"Reminder: This protocol includes a category of “No Clouds” which should be reported whenever there are no clouds visible in the sky. A “No Clouds” report is just as important as a “Clouds Observable” report in helping understand our Earth’s system. If “Clouds Observable” is reported, follow the observation hints located in the left navigation column."

Sound familiar, CoCoRaHS observers?? Blue sky (zero) is an observation.

You can also manually observe clouds and then enter the data into the GLOBE observer web site. A printable data entry form is provided for this.

I did try the app out and encountered a couple of hiccups. The data entry part, up to the photos, was quick and easy. However, there seems to be a little bugginess in the photo function. After messing with this a number of times I think I figured out how the app works with respect to taking photos (I could find no directions anywhere on how this works). So, you may want to hold on to these directions if you are going to use the app. I tested this on my Android phone.

 After your last entry of surface observations, you will see the photo screen.

If you want to take a photo using the app, select Take Pictures. A second screen will appear showing your camera view, along with N S E W Up Down on the bottom left, and a circle in the middle of the screen. 

IF the correct direction is showing for the direction you are pointing at (the "W" in this case), move the camera until the direction letter is lined up with the center circle. Once it is it will turn green and a photo will automatically be taken. Click DONE in the lower right of the screen and you will exit to the next screen, which will show your photo(s) at the bottom. this function, if it's working, is actually nice because by lining up the W with the circle it forces you to tilt the camera up at the correct angle

If you want to delete the photo, tap the photo thumbnail and select Delete. If everything looks OK, then click FINISH at the very bottom of the screen (you have to scroll down). The next screen will give you the option of reviewing and submitting your observation.

You can also add photos manually (second option). Selecting will take you to the Take Pictures screen. Tap the direction you are taking your photo. You have the option of taking a photo with your camera or choosing an existing photo from your photo gallery. If you are having issues with the first option the manual option is easier. 

The compass direction showing on my screen was off by 90 degrees for some reason (I was shooting north but it indicated west). There was some message about the phone's compass but it disappeared from the screen when I initially tried this and I couldn't seem to resurrect it. When I checked my phone with an independent compass app it was spot on. I don't know if the direction is determined by the internal compass or the GPS.

Also, once I took the photo in landscape mode the GLOBE screen would not return to portrait mode, and the camera was on in the background behind the menu. Even if I closed the app and reopened it it was still in landscape mode. Unfortunately there is no real app-specific help within the app itself to deal with these functions. Before you use the app to make an actual observations I would go through a few dry runs just to see how it behaves on your phone. None of the data is actually sent until you tell the app to send it. However, editing your observation is clunky. Editing takes you to the start of the data entry and you have to go through each screen again.

Once your observation is in the system, ground observations of clouds are matched with satellite observations. If your observation coincides with a satellite observation, you will received an automatic "match" email, which summarizes both your ground observation and the satellite observation. It takes anywhere from one to seven days to receive the satellite data, depending on the satellite. You can read more about the satellite comparison on this page.

This is a great opportunity to spread your citizen scientist wings in a weather-related way, and the data you collect may be used by NASA scientists for their research on clouds.

While this "spring challenge" only runs until April 15, cloud observations continue year 'round. Despite a few little glitches with the app, this is a worthwhile addition to your observation activities.