New Mexico Weather: 8/20/15

In Rio Rancho this morning, the weather was cool and still. When I left the house, the temperature was 58.8 F, according to my backyard weather station. The skies are mostly sunny, with some high cirrus clouds in most directions. There are a few thin cumulus clouds, all of which have very limited vertical development.

The visible satellite imagery shows more uniform cloud cover east of the mountains, just like yesterday. Some of the cumuloform clouds are visible over the west and southwestern part of the state.

The enhanced infrared satellite imagery shows that there are a few thicker, cooler-topped clouds northeast of the Albuquerque Metro area, but otherwise, the clouds are thin, with low, warm tops.

The water vapor satellite imagery shows that there is still moisture present in New Mexico, though there is dry air over Texas, and potentially a dryline near the southeastern corner of the state.

The 12Z upper air sounding from Albuquerque shows a mostly-dry atmosphere, except for a strong moisture peak at 300 mb. This is why we have so many high clouds about. There was 0.64 inches of precipitable water present, and almost no Convective Available Potential Energy (CAPE). There was a lot of Convective Inhibition (CIN), which is calculated at 527 J/kg, so morning convection will be severely limited. The near-surface lapse rate was 5.8 C/km, so nearly the moist adiabatic lapse rate.

In terms of shear, we still have 34 kts of deep-layer shear available and 19 kts of low-level shear, which is enough to support rotating storms and tornadoes, if all other parameters were in place.

The surface observations (from the SPC Mesoscale Analysis Map) show decreased wind speeds, lower temperatures and slightly higher dewpoints as compared to yesterday morning. The back door cold front that was shown on the map yesterday has pushed southwest and has mixed out.

The surface pressure map shows that the thermal low has weakened and decreased in size. It is up to 1008 mb near Farmington. To the east, the high pressure system over Colorado has moved east, so the pressure gradient has decreased across the state, meaning the winds will decrease as compared to yesterday.

Synoptically speaking, the 300 mb NAM chart (from Unisys) shows the trough moving farther east, leaving nearly-zonal (but slightly northwest) flow across New Mexico.

At the 500 mb level, there is no significant vorticity advection across the state. I have excluded the chart from this post.

At the 700 mb level, the model forecasts show rising air, especially in the northern half of the state. This must be in response to daytime heating and orthographic lift, as there are no other major synoptic forces at work to generate this lift.

The 850 mb chart is showing no significant thermal advections, though there is a sharp temperature gradient that runs parallel to I-25. The winds are not strong across this gradient, however.

Overall, I expect a precipitation-free day for most of the state. The moisture and the lift are just no present today. There may be some rising air later this afternoon, but with limited moisture and no forcing, any storms that form will be weak and short-lived. Winds will be slower than yesterday in the eastern half of the state, due to the weakened pressure gradient.

Thank you for reading my forecast.

The upper air soundings and mesoscale analysis plots are from the Storm Prediction Center website.
The forecasted upper air soundings are from TwisterData.com.
The surface observation and upper level charts are from Unisys Weather.
The satellite data is from NASA – MSFC

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About highplainschasing

This blog is about my tales in storm chasing. My name is Seth Price and I am an instrumentation instructor at New Mexico Tech. My amateur radio call sign is N3MRA.
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