2010 New Mexico Hydrologic and Drought Review
The 2010 hydrologic story for New Mexico began with very heavy precipitation starting in mid January under a strong El Niño influence, and ended the year with a significant drying trend for most of the state under a strong La Niña influence.

The January 1, 2010 snowpack ranked as tied for the 6th best of the past 16 years in the New Mexico portion of the Rio Grande Basin (going back to 1995). In the Colorado high country headwaters of the Rio Grande Basin, snowpack water content as of January 1, 2010 was 94 percent of normal. The snowpack totals from the southern Colorado mountains to the southern mountains of New Mexico were about to get much better from mid January into early February.

Drought conditions during the first two weeks of 2010 reflected the very dry conditions that had persisted through the fall of 2009 and into the end of the year, with moderate and severe drought along the far western border of New Mexico.

NM drought on January 12, 2010
The Oceanic Niño Index (or ONI, used for monitoring sea surface temperatures anomalies in the tropical Pacific) for the winter of 2009-2010 peaked at a three month running mean of +1.8, indicative of a strong El Niño event. A moderate to strong El Niño episode is usually associated with above average winter precipitation for New Mexico.

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January 2010 precipitation, from mid month on, was well above normal nearly statewide as a series of potent winter storms impacted much of the state after January 17. A few spots in southwest New Mexico reported record or near record precipitation for the month of January.

The Beaverhead Ranger Station in southeast Catron County received 4.12 inches of precipitation during the first month of 2010, which was a new January record. The previous precipitation record had been 3.17 inches set in 2005. Both Glenwood and the Luna Ranger Station reported their second highest precipitation totals for January with 4.46 inches and 5.33 inches respectively. The 5.33 inches of precipitation during January at the Luna Ranger Station in west central Catron County was just 0.12 inches shy of the January record 5.45 inches set in 1916!

As of February 1, 2010 the snowpack (snow water equivalent) was above normal to well above normal in all mountain regions of New Mexico.

The Sierra Blanca SNOTEL, northwest of Ruidoso at 10,280 feet, set a February 1 record for snow water equivalent with 19.8 inches of water content in the snowpack. The previous February 1 record was set in 1992 when the water content was 15.2 inches. Snow measurements at the Sierra Blanca site started in 1987.

Much of the precipitation from mid January through early February that fell over northwest New Mexico fell as snow. Heavy snowfalls lead to a Governor’s Disaster Declaration for five counties and the Navajo Nation in northwest New Mexico.

The storm track for the winter of 2010 (December 2009 – February 2010) favored the southern tier U.S. The storm track is depicted as green and blue shading on the figure to the right.  The position of the storm track helped to steer winter storms over New Mexico.

Winter precipitation totals (Dec-Jan-Feb) for locations in northwestern and western New Mexico are shown in the table below.


Station Winter Precipitation Percent of Normal
Farmington Ag Center 3.37 inches 226 %
Navajo Dam 6.19 195
Fruitland 2E 4.10 248
Aztec Ruins N M 3.61 156
Chaco Canyon N M 2.38 145
Gallup Airport 3.75 158
Zuni 4.73 193
Quemado R S 2.71 164

The statewide average for winter 2009 - 2010 precipitation was 168 percent of normal. The Southeastern Plains climate division was wettest at 245 percent of normal, while the Central Valley climate division (from Jemez Dam south through Albuquerque to Socorro and the Bosque del Apache Wildlife Refuge) was 118 percent of normal.

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Heavy precipitation in southwest New Mexico during the night of January 21, 2010, and the following morning, caused small stream and arroyo flooding in parts of Catron County. The San Francisco River near Glenwood crested (around Noon 1/22/10) just below the established bankfull stage of 12 feet. Flooding was reported on the middle fork of the Gila River near the Gila Cliff Dwellings National Monument Visitors Center in extreme southern Catron County during the morning of January 22.

El Niño conditions of warmer-than-normal sea surface temperatures in the equatorial Pacific were about to have a profound influence on the storm track, with both numerous winter storms and abundant sub tropical moisture headed for New Mexico.

Precipitation for the first three months of 2010 was well above normal nearly everywhere in New Mexico as the storm track provided timely rain and snow events through March. As of April 1, 2010, statewide average precipitation was 170 percent of normal. The eastern plains climate division had recorded 225 percent of normal precipitation, while the Northwest Plateau received about 140 percent of normal precipitation. The abundant precipitation of 2010 through March was a stark contrast to the first three months of 2009 which saw only 45 percent of normal precipitation and was one of the driest starts to any calendar year on record.

NM precip for January through March 2010

By early March, the wet start to 2010 had alleviated much of the drought conditions across the state as depicted by the U.S. Drought Monitor map for New Mexico.  Only abnormally dry conditions lingered in the west.

NM drought map for March 9, 2010

The El Niño episode of late 2009 and early 2010 was the strongest El Niño event since 1997 -1998. However, El Niño began to weaken rapidly during the spring of 2010 and was forecast to return to a neutral state during the summer of 2010.


The wetter than normal conditions in the north central New Mexico Mountains during the first three months of 2010 lingered into April. As of April 1, the snowpack water content in the New Mexico portion of the Rio Grande Basin ranked as the third best of the past 18 years at 122 percent of normal. In the Colorado portion of the upper Rio Grande Basin the snowpack water content was 115 percent of normal as of April 1, 2010.

The Sierra Blanca SNOTEL, northwest of Ruidoso at 10,280 feet, set an early April record for snow water equivalent with 29.4 inches of snow water content. The previous early April record was set in 1993 when the water content was 23.4 inches.

The prospects for a much better than normal snow melt runoff were looking very good for rivers and streams that originate from the north central New Mexico mountains and from the mountains of southern New Mexico as well.

A strong back door cold front moving westward from northeast New Mexico and an upper level disturbance in the westerly flow aloft combined to threaten north central New Mexico with heavy showers and thunderstorms in mid April. A Flood/Flash Flood Watch was issued on the morning of April 16 for an expected moderate to heavy rainfall event on the mid elevation mountain snowpack. Later that evening, reports of flooding on the west side of Chama due to overbank flooding along the Rio Chamita were received. A Flood Warning was issued for north central Rio Arriba County. Subsequent reports indicated that the overbank flooding occurred on the Rio Chamita, and outbuildings, a county road, residential yards, and a foot bridge were flooded, but no homes were affected.

The weather pattern turned drier and breezy (occasionally windy) from late April through May. Runoff from snow melt was generally higher than average, but did not result in flooding.

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Water storage at the end of June 2010 averaged 62 percent of the 30 year normal for the eight Rio Grande Basin reservoirs in New Mexico, despite the near normal snowpack that had accumulated in the mountains during the previous winter and spring of 2010. Water storage at the end of June 2009 had averaged 69 percent of normal in the eight Rio Grande Basin reservoirs in New Mexico.

Spring precipitation (March through May) turned sparse from late April through May for most areas of the state, but averaged 95 percent of normal for a statewide average. The driest area was the far northwest where the Northwest Plateau climate division reported only 67 percent of normal spring precipitation. 

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Dry conditions persisted through mid June from northwest and west central New Mexico to the northeast highlands, so that moderate drought conditions were depicted by mid June from west central New Mexico into the northeast highlands of San Miguel, Guadalupe and Mora Counties.

While northwest New Mexico continued to experience dry weather during the latter half of June and the first half of July with unusually hot daytime temperatures, the eastern New Mexico plains received periodic bouts of showers and thunderstorms. One such shower and storm episode during the evening of June 24 resulted in flooding near the village of Bernal in San Miguel County. Fast flowing water damaged culverts, gravel roads and low water crossings in the Bernal area, resulting in a state disaster declaration which provided for up to $250,000 in state funding for repairs.

Slow moving showers and strong thunderstorms moving through the northwest corner of the state during the afternoon and evening of August 2 resulted in localized flash flooding in parts of San Juan County and McKinley County. A motorist was rescued from her car in Farmington by firefighters as her car filled with water after driving into a flooded section of Hubbard Street. An auto dealership in Farmington sustained property and auto damages from local flash flooding as did culverts and drainage ditches, mostly on the east side of the city of Farmington and the Country Club area. A number of roads, mostly dirt roads, on the Navajo Reservation in San Juan and McKinley Counties were reportedly washed out. A bridge near Church Rock just east of Gallup was washed out (again) and rendered impassable by raging flood waters in a normally dry arroyo. One unofficial rainfall report from that evening measured 2.5 inches in Crestwood Estates near Farmington, with most of the rainfall having occurred between 730 and 815 pm.

Heavy rain from showers and thunderstorms struck portions of Jemez Springs and Jemez Pueblo during the late afternoon and evening of August 3. Parts of NM Highway 4 were flooded and covered by mud and rocks washed down normally dry arroyos.

During the afternoon and early evening of August 23, parts of Rio Rancho in Sandoval County experienced flash flooding of arroyos and streets due to heavy rainfall.

Cloudcroft in the south central Sacramento Mountains received nearly 18 inches of rain during July and August, and nearly 20.2 inches for the June through August summer period.

Summer precipitation (June through August) was 110 percent of normal for a statewide average. The Northwest Plateau climate division had the highest percent of normal summer precipitation at 126 percent of normal, while the Northern Mountains climate division averaged 97 percent of normal.


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Precipitation across New Mexico during September 2010 ranged from well above normal in a few spots such as Navajo Dam, Gallup, Clayton and parts of the Albuquerque Metro Area to generally below normal elsewhere. The rain event on September 22nd accounted for almost all of Albuquerque’s monthly precipitation total. The heavy rain, more than 2.25 inches in the far northeast Albuquerque Metro, resulted in fast flowing water in the drainage ditches and arroyos across the city during the afternoon of September 22nd. One man who had been walking in a main drainage channel was swept away when the flow of water increased during mid afternoon. The man’s body was retrieved from the Rio Grande River two days later.

Water Year 2010 precipitation (October 2009 through September 2010) was 110 percent of normal for a statewide average. The Central Highlands climate division, from Cloudcroft and Ruidoso north to Estancia and Moriarty, received 125 percent of normal water year precipitation while the Central Valley climate division, from Jemez Dam south through the mid Rio Grande Valley and Socorro, was the driest climate division at 94 percent of normal water year precipitation. Water Year 2010 was the third wettest water year for New Mexico since 2001.

The El Niño that had brought significant winter precipitation to the state via an active storm track quickly faded away during the spring and early summer. By early fall, La Niña conditions had developed in the equatorial Pacific Ocean. In October, La Niña had become moderate to strong and was expected to persist through the end of 2010. NM drought map for December 14, 2010

The storm track and the associated Pacific moisture had finally found the northwest half of New Mexico starting December 16 resulting in significant snow pack increases for the southern San Juan Mountains that comprise the headwaters of the Rio Chama Basin. A second much colder winter storm brought much needed snow to all of the mountain regions of northern New Mexico as calendar year 2010 came to a close.

Despite the return of winter-like storms to parts of the state during the latter half of December 2010, the snowpack in the mountains of New Mexico lagged far behind what had already accumulated in the southern Colorado Mountains. The mountains in the southern half of New Mexico were particularly moisture starved during their La Niña influenced fall and winter of 2010.



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