On May 9, 2006 , a cold front associated with a weak upper level trough moved east from the Great Basin reaching the Four Corners around noon. This front continued east and south across New Mexico during the afternoon, with the initial wind shift at Albuquerque occurring around 5:00 pm MDT.   A secondary surge of much stronger winds followed an hour later, with wind gusts peaking at 60 mph at the Albuquerque Sunport and 62 mph at Double Eagle airport.  Blowing dust reduced visibilities to near zero across portions of the Albuquerque metro area.

Data from other observation platforms that are routinely monitored during wind events, produced no indication of surface winds exceeding 50 mph.  The wind profiler near Aztec NM showed a shift in the wind direction around noon with an increase of 15 to 20 mph just above the surface. Under an hour before the high wind gusts were reported in Albuquerque, the KABX radar VAD wind profiler and the velocity image did not show evidence of strong damaging winds at or near the surface. 

An initial review of this system indicates that a number of factors contributed to the strong winds noted across the Albuquerque metro area, with speeds exceeding all other official reports across the state.  The timing of the front, weather associated with the upper level trough and extreme drought conditions combined produce a limited area of dangerous winds which uprooted trees, damaged construction sites, knocked out power and lifted a layer of dust across the city.

Reflectivities from the Albuquerque 88D radar showed a band of virga showers, with precipitation evaporating before reaching the ground, moving to the southeast in the wake of the front.  Limited mid level moisture with dry surface conditions resulted in a broad area of virga showers approaching Albuquerque around 6:00 pm.  Downdrafts within and beneath the cloud carried liquid water towards the surface, however the droplets readily evaporated in the dry sub-cloud environment.  This resulted in cooling and an increase in velocity of the downdraft. 

Evaporation below the cloud layer can lead to rapidly accelerating winds near the surface. Beneath a single cell of convection, a microburst can develop (winds extending over an area of 4 km or less). Beneath a larger band of clouds, a macroburst is possible (strong winds affecting an area greater than 4 km and less than 400 km).  This band collapsed as it neared Albuquerque, and the combination of downdrafts, cooling with local pressure increases and downsloping terrain created the strongest winds of the event over the west side of Albuquerque.

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Near Albuquerque, the frontal passage was well timed with the maximum heating of the day. The afternoon sounding taken at the Sunport between 5:00 and 6:30 pm, indicated strong surface heating resulting in an unstable atmosphere and excellent mixing of the atmosphere (up to 450 mb or 20,000 ft). Note the moist layers around 400 mb (around 22,000 ft) with very dry air below. This is the region where the two green lines representing temperature and dew point temperature are close together. Virga showers developed behind the front and as the precipitation descended in the downdraft, it evaporated, cooled the surrounding atmosphere, and increased the downward velocity.  These strong winds from well above the surface were transported through the mixed layer to the surface where they accelerated horizontally.  The downburst winds moved southward behind the front, along an area of decreasing elevations, into the metro area. This downsloping flow of air contributed an addtitional increase to the wind speeds.

The Albuquerque area experienced the second driest November through April period since 1892. The ongoing drought resulted in widespread areas of exceptionally dry surface conditions. The blowing dust, associated with the drought and numerous construction projects on the west side of the city, created more scatterers in the atmosphere for the radar to detect, generally southeast of the radar site.

Note the 60 to 62 mph wind speeds both beneath and ahead of the virga showers. Also of interest is the lack of radial velocities in the area between Albuquerque and the virga showers (30 to 35 miles to the northwest). In this area, there were not enough particulates in the air for the radar to calculate radial velocities.