March 8, 2016 San Jose New Mexico Thundersnow Chase

by John Farley

I had been kind of on the fence this day as to whether to go skiing or keep the day open for a possible thundersnow chase. With a storm system digging southeast from California to (eventually) Mexico City, there was some potential for fairly widespread precipitation with a possibility of thundersnow in New Mexico. Lapse rates would be good, but the storm system would strike a grazing blow to NM rather than moving through head on, and there was uncertainty about how much moisture would be available with the storm taking this track. For the most part the night before, the rain and snow showers that were forming over southwest and south central NM were fizzling out by the time they got near I-40, raising doubts about how much activity would reach the northern part of the state. Checking the radar in the morning, I saw that there was very little precip on the radar, and the surface air was pretty dry (14% relative humidity in ABQ, for example). So I opted to go skiing at Pajarito near Los Alamos, but figured I could keep an eye on the weather and if it got looking really interesting, I could always shift into chase mode. While skiing, I did notice areas of convective snow showers on the west slope of the Jemez to my west, and also on the east slope of the Sangres to my east, but very little anywhere else.

This picture was taken around noon, looking from the Pajarito Ski Area to the west or WNW across the Valles Caldera toward a snow shower on the west slope of the Jemez mountains:

Due to drastic temperature shifts in the past few days, the ski conditions were not great, and I had had enough of that by shortly after 2 p.m. When I got home around 3:15 I went online and checked radar and the lightning tracker. The latter showed a strike or two some time ago near Clines Corners, but nothing recent. The heaviest showers were near Cline's Corners to the SE of Santa Fe and near Tesuque a few miles north. I had driven through the Tesuque one, as it was forming, on the way back from skiing and encountered some fair-sized graupel, but not a lot. So, I went about doing other stuff as nothing seemed chase-worthy, and did not pay much attention to the weather for an hour or so.

Around 4:30, I noticed higher cumulonimbus (CB) towers to the SSE, certainly more developed than anything I had seen earlier. So, I again checked the lighting tracker and radar. The radar was unimpressive, but there was a recent lightning strike south of I-25 between Glorietta and Eldorado. Despite the unimpressive radar, I could tell from the visual appearance of the CB that heavier snow or graupel was imminent or occurring, so between that and the lightning indicator I decided to head out, hoping to intercept the cell near Glorietta Pass. I was confident the precipitation type would be snow and/or graupel (snow pellets), as the forecast was for the snow level to be around 6500 feet and heavy convective bursts could take it even lower.

Here is a picture taken of the storm looking SE along I-25 from between Santa Fe and Eldorado, around 4:50:

I had to go past Glorietta 2 more exits to San Jose, but by 5:15 or so I could see I was coming into some decent precip. The cells were lined up NE-SW between Santa Fe and Las Vegas, now mostly along the east slopes of the Sangres and southwestward over the Glorietta Mesa. After going through some light snow and graupel around Rowe, I could eventually see areas of updraft base along the eastern edge of the line, with new areas of precip starting under them. The upslope flow hitting the east side of the Sangres seemed to be leading to local intensification. Between Rowe and San Jose I began to hit heavier and larger graupel, then saw my first flash of lightning to the NE. A few miles before the San Jose exit, I encountered snow and slush about an inch deep on the road, with traffic down to 40 mph or less. In this area I encountered bursts of heavy graupel and snow, and possibly a little hail. I exited at San Jose and found a place on the edge of a convenience store parking lot. The time now was around 5:05 p.m. Lightning flashed before I could get my video camera going, but once I got it going there were 2 cloud-to-ground (CG) flashes right where I was pointing my camera, as well as some visible cloud-to-cloud (CC) bolts just before the first CG. Here are pictures (video captures):

The CG bolts struck about a mile away, as light snow and graupel fell at my location. (I was just east of the main band of precip.) I also got two other flashes where either the bolts were in-cloud, out of camera range, or obscured by the snow. After 15 minutes or so there did not seem to be any more lightning so I started NW on the frontage road to see if I could get into the area where snow and graupel had accumulated. P-type was all snow now. Then I saw another flash of lightning so I stopped to get more video, but that proved to be the last flash. So, I started back toward Santa Fe around 5:30. Where there had earlier been a lot of snow and slush on the road it appeared to have been treated with salt and the red scoria that is used on NM roads, and was in much better condition, though wet snow or graupel was still falling fairly heavily. Here is a video capture from then:

The elevation of San Jose is about 6,100 ft., and most of the precip while I was there was snow or graupel. It did mix with rain briefly when it lightened up, just before I took the frontage road. Then quickly back to snow when it picked up again, and snow and graupel after that. That night I saw a report and picture on the TV news of a couple of inches of snow around Mora, and I would guess the higher elevations around there got more. However, it seems to have missed all of the ski areas, with none reporting more than a half inch of snow. I think the relative lack of moisture caused to storm to underachieve over all (at one time up to 11 inches of snow had been predicted for the Sangres), but the upslope flow along with the back-door cold front was enough to get the job done locally in the areas west and north of Las Vegas.

Here is my video for the day:

Here is a satellite image showing the storms along the east slope of the Sangre de Cristo Mountains:

Notice the two orange areas over northern New Mexico. I was under the southwestern one of these two areas.

Total chase distance: 82 miles.

Return to 2015-16 Winter Weather Observation Page