2012 New Mexico Hydrologic and Drought Review
 

The 2012 hydrologic story began with extreme to exceptional drought conditions persisting in the southeast quarter of New Mexico with severe drought in the Rio Grande Valley and northeast plains. 

Only the northwest corner of the state was not in some degree of drought to start 2012.

NM Drought Status Jan 2012
December 2011 had featured a very active storm track that provided significant snow for the central and southern New Mexico Mountains and resulted in a near normal snowpack for the headwaters of the Rio Grande Basin to start 2012.  The Jemez Mountains reported above normal snowpack as did the east slopes and high peaks of the Sangre de Cristo Mountains in New Mexico.  Snowpack in the southern New Mexico Mountains was far above normal to start 2012.  However, reservoir storages were well below normal in the Rio Grande Basin, Canadian Basin, and Pecos Basin. 
 SNOTEL percent of normal Jan. 1, 2012

Unfortunately the storm track would abandon New Mexico in favor of areas to our north during the first three months of 2012 while spring warmth arrived well ahead of schedule, resulting in an early start to the snow melt runoff season across New Mexico.  By the first of March, snowpack in the headwaters of the Rio Grande Basin had slipped to 84 percent of normal.

A drier than normal March also featured a mid-month five day episode of unusually warm temperatures, followed by a final ten day stretch of near record-breaking warmth to end the month.  This early stretch of warm weather served to crush any hopes of a normal snow melt runoff season for New Mexico, both by forcing an early start to the snow melt process, and depriving most northern New Mexico mountain regions from accumulating much needed late season snow.

Warm dry winds during March also helped reduce the snowpack through sublimation, so that a snow storm that produced a foot or more of snow in the north central New Mexico Mountains from April 2nd through the 3rd only covered up bare ground rather than add new snow to what should have been a seasonally near-peak snowpack.  By the first of April, snowpack in the headwaters of the Rio Grande Basin was a disappointing 44 percent of normal.

 SNOTEL percent of normal snow for April 1, 2012

As dry conditions returned to far northwest New Mexico during the first three months of 2012, so did the drought. 

No longer was any portion of the state exempt from some sort of drought designation while southeast New Mexico remained in extreme to exceptional drought.

NM drought April 3, 2012
The NOAA National Climatic Data Center reported that the first three months of 2012 had been the tenth driest start to any year on record for New Mexico.  For the first three months of 2012, statewide average precipitation was only 48 percent of normal. Jan through Mar NM precipitation
The last three weeks of April and all of May were a dry and warm period for the northern half of New Mexico which accelerated an already earlier than normal snow melt runoff process in the mountain regions.  Peak snow melt runoff occurred four to eight weeks earlier than usual for most northern New Mexico Rivers.  Due to the poor snowpack, total flow volumes were also significantly well below normal, as shown in the river gage data below.  2012 streamflow values, depicted as blue, are well below the long term average values (gold) during the May/June period.
stream flow gages for Jemez River, Pecos River, and Rio Grande
By the first of June, average statewide precipitation for the year was 56 percent of normal and ranked as the 20th driest start to any year on record.  Much of the state saw little or no measurable precipitation during June, with only a few locations in the northeast plains receiving near normal precipitation for the month.  As of the June 19th U.S. Drought Monitor map depiction, more than 80 percent of New Mexico was in severe drought or worse. NM drought status June 19, 2012

July is the first full month of the New Mexico summer monsoon season and is generally one of the wettest months of the year for many locations.  However, July 2012 was a disappointingly dry month for nearly all of northeast New Mexico, for the lower Rio Grande Valley, and for the east central plains as well.  However, above normal July precipitation was fairly widespread from the southern San Juan Mountains in central Rio Arriba County through the Jemez Mountains in northern Sandoval County and west into parts of McKinley County and San Juan County (with another dry exception being the immediate Four Corners).

The first seven months of calendar year 2012 were much drier than normal for all climate divisions within the state.  Statewide precipitation of 58 percent of normal through July ranked 2012 as the 8th driest start to any year on record.  This follows 2011 where the January through July period was the driest on record at 42 percent of normal.

The first half of July 2012 did see several flash flood episodes. 

Heavy rainfall resulted in flooding and debris transport in the Little Bear Wildfire burn scar area of Lincoln County from July 5th through July 7th and also filled Bonito Lake with enough ash and sediment to render the water as unfit to serve as a supplemental water supply source for the City of Alamogordo.

Heavy rainfall caused flash flooding in Santa Clara Canyon (in the Las Conchas Wildfire burn scar area) on July 11th while minor flooding from the canyon occurred downstream in Santa Clara Pueblo.  The four ponds/small dams in Santa Clara Canyon were either overtopped or completely refilled with ash and debris.  Debris flows also impacted traffic on NM Route 501 through and near Los Alamos Canyon and along Camp May road.  A few days later, a temporary foot bridge at Bandelier National Monument along Frijoles Creek was washed out by heavy rainfall and resultant flash flooding on July 16th.

South Fork Above Bonito Lake following Little Bear Burn Scar flooding in early July

August 2012 precipitation across New Mexico was generally below normal with only a few areas receiving near normal rainfall, such as the Angel Fire/Eagle Nest region and parts of the west central mountains from Zuni and El Morro National Monument south through Quemado to Reserve.  

Again, despite the lack of widespread precipitation, a few instances of flash flooding occurred.  Heavy thunderstorm rainfall during the afternoon of August 5th resulted in flash flooding in parts of western Cibola County and eastern McKinley County.  Flooding was reported in and near Thoreau.  The primary rail line of the Burlington Northern Santa Fe was affected and freight trains and an Amtrak passenger train were stopped in Cibola County from approximately 4 pm to 930 pm.  Various local and county roads were blocked due to standing water.  

Heavy rainfall from showers and thunderstorms resulted in localized flooding in east central Sandoval County on August 16th in and near the Santa Domingo Pueblo.  High water levels in Galisteo Creek forced the New Mexico Rail Runner commuter train between Albuquerque and Santa Fe to stop due to concern for the stability of the railroad bridge over Galisteo Creek.  Train passengers were bused to Albuquerque.  The rail route was re-opened on August 18th.

Even as our summer Monsoon season drew to a close, more than 60 percent of New Mexico remained in severe drought or worse as depicted by the U.S. Drought Monitor map of September 11, 2012. NM drought status on September 11, 2012
The 2012 fall season would be even more unkind to New Mexico than the disappointing summer monsoon season was in the way of withholding widespread beneficial moisture and in worsening our drought conditions.  At the end of water year 2012 (September 30, 2012), New Mexico had experienced the driest (and second warmest) consecutive two water years on record. 

 

Average statewide 24-month precipitation ending in September

October and November combined brought only about 25 percent of normal precipitation to the state for the two month period.  Conchas Lake in northeast New Mexico received less than 0.20 inches of precipitation during October and November, while Albuquerque and Los Lunas in the mid Rio Grande Valley both recorded less than 0.15 inches.  In addition to the widespread dry conditions, temperatures remained well above normal during most of October and November.

By the end of November, statewide average precipitation was slightly less than 60 percent of normal for the year, and 2012 ranked as the second driest 11 month start to any year on record.

Through the end of November, 2012 also ranked as the warmest start to any year on record.

 
The 24 month period ending November 30, 2012 was both the driest and the warmest 24 month period (ending in November 2012) on record for New Mexico.

Average statewide 24-month precipitation ending in November

Reservoir storage as of the end of November ranged from 14 percent of normal in both the Canadian River Basin of northeast New Mexico and the Pecos River Basin, to 73 percent of normal at Navajo Reservoir in the far northwest.  Of the eight reservoirs in the New Mexico portion of the Rio Grande Basin, average storage was about 30 percent of normal at the end of November.

In south central New Mexico, water storage at Elephant Butte Lake at the end of November was only about 10 percent of normal (122,000 acre-ft), while Elephant Butte Lake can store  more than two million acre-ft.  An acre-ft of water is approximately 326,000 gallons.  The water level was at an eight year low.

Photo courtesy of Ed Polasko

The 2012 - 2013 snow accumulation season in the mountains of New Mexico got off to a slow start, such that by December 9th, snowpack was barely 25 percent of normal.  Several timely winter storms brought much needed snow to all mountain regions from December 10th through the 19th and again on the 24th into the 25th, so that by the end of the year, snowpack in the northern New Mexico Mountains ranged from 46 percent of normal in the Pecos River Basin to near 80 percent of normal in the Rio Chama Basin. Snowpack in the southern New Mexico Mountains ranged from near 80 percent of normal in the Gila River Basin to more than twice the norm over the high peaks of the northern Sacramento Mountains.

 

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