New Mexico Weather: 12/14/15

In Rio Rancho this morning, the weather is cool, partly cloudy, and still. There is a blanket of altocumulus clouds about the metro area this morning, and there is still some remnant snow on the ground.

The National Weather Service (NWS) in Albuquerque forecasts a 10% chance of rain today, with a high temperature of 44 F. This evening, there is a 50% chance of snow, dwindling to 20% by late evening, with a low of 23 F. New snow accumulation of 1-2″ is possible.

The visible satellite imagery shows the light cloud cover over the northern half of the state.

The enhanced infrared satellite imagery shows that the clouds over Albuquerque are thin, though there are some thicker clouds moving into the state from the Four Corners area.

The water vapor satellite imagery shows several bands of moisture moving through the state this morning. Overall, we are in the dry slot behind the cold front, but more moisture and colder temperatures are coming.

The 12Z upper air sounding from Albuquerque shows a drier sounding than yesterday, but damper than this time last week. The dewpoint depressions were relatively low under 500 mb, and there was 0.26 inches of precipitable water present in the column this morning. There was no Convective Available Potential Energy (CAPE). There was a thick but relatively weak inversion in place, dropping the 0-3 km average lapse rate to 3.0 C/km.

There was 67 kts of deep-layer, largely due to speed changes. The low-level shear was 23 kts of mostly directional mode.

The surface observations (from the SPC Mesoscale Analysis Map) show the mostly clear skies, still winds, low temperatures and low dewpoints across the state this morning. There are no major frontal or dryline boundaries present.

The surface pressure map shows a new, 998 mb low pressure system moving in from the northwest. It is currently over central Utah. Over north-central New Mexico, there is a 1012 mb pocket of relatively higher pressure, and between the two systems, a steep pressure gradient. The RAP does show this gradient decreasing throughout the next six hours.

The critical thickness plot shows that a good part of the state is north of the 0C isotherm (magenta), but no other critical thickness lines are near the state. To our west, notice that several of the critical thickness lines dip all the way through Arizona and southern California into Mexico- this is headed our direction later today.

Synoptically speaking, the 300 mb NAM chart (from Unisys) shows the broad trough extending through Utah. This will put New Mexico downstream of some slightly faster southwesterly winds at the 300 mb level.

At the 500 mb level, this trough will bring Positive Vorticity Advection (PVA) to the western half of the state this evening, and to the entire state by tomorrow morning.

Associated with the PVA will be some rapidly-rising air at the 700 mb level that may spawn the snow showers that are forecasted by the NWS this evening.

The 850 mb NAM chart shows a strong thermal gradient, but no strong advection across the gradient. It is worth noting that the temperatures at the 850 mb level are colder over Arizona than they are in Denver or Detroit.

Snow will be quite possible this evening, particularly in areas west of the I-25 corridor. The enhanced PVA and rising air will lead to convection and falling precipitation, and I fully expect the critical thicknesses to favor snowfall by this evening.

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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