Climate Summary for December 2012

December 2012 Weather Highlights for West-Central Texas

...6th Warmest December for San Angelo... 

The monthly precipitation was below normal, most noteably across areas of the Big 
Country, northern and western Concho Valley, and southeastern sections of west-central 
Texas. These locations received less than 10 percent of normal precipitation for the 
month. 

Temperatures averaged well-above normal for the month. 

At Abilene Regional Airport, the average temperature for December was 49.4 degrees. 
This was 4.1 degrees above the normal average temperature of 45.3 degrees. Total 
precipitation for Abilene in November was only 0.04 inches. This was 1.19 inches below 
the normal of 1.23 inches. 

At San Angelo Regional Airport, the average temperature for December was 51.7 degrees. 
This was 5.0 degrees above the normal average temperature of 46.7 degrees. This marks 
the 6th warmest December on record for San Angelo. Total precipitation for San Angelo 
was 0.18 inches. This was 0.67 inches below the normal of 0.85 inches. 

Total snowfall for December was 0.1 inches at Abilene. No snowfall was recorded at San 
Angelo. 


Weather Highlights for December 2012... 

Record warmth occurred during the first few days of December, with south-southwest 
winds which were gusty at times. Low clouds expanded north in coverage across much of 
west-central Texas during the late night to mid-morning hours, with generally clear 
skies during the afternoon hours. A record high temperature of 83 degrees was set at 
San Angelo on the 1st. Record high minimum temperatures were set at San Angelo and 
Abilene on the 2nd. The low of 63 degrees at Abilene (on the 2nd) tied for the highest 
December minimum temperature on record. This record has also occurred on 6 previous 
occasions. A record high minimum temperature was tied at San Angelo on the 3rd. 

Despite a weak cold frontal passage the 3rd and 4th, above normal temperatures 
continued through the 8th. A record high temperature of 81 degrees was tied at San 
Angelo on the 6th. 

Dense fog (with visibilities of one quarter of a mile or less) occurred across roughly 
the southern third of west-central Texas during the early morning hours of the 8th and 
9th. 

A strong cold frontal passage on the 9th was followed by gusty north winds and much 
colder temperatures. An upper level disturbance moving into the southern Plains brought 
a brief period of light snow to the northern Big Country, during the overnight hours of 
the 9th and 10th. Snowfall amounts were less than one inch. Highs on the 10th were 
mostly in the 40s. A high pressure system settled southeast into west-central Texas 
during the overnight hours of the 10th and 11th. With clear skies and light winds, 
temperatures dropped into the teens to lower 20s for early morning lows on the 11th. 
These were the coldest temperatures observed in nearly one year. 

Gusty south to southeast winds occurred on the 14th, out ahead of an upper level storm 
system over the southwestern states. A peak wind gust of 41 mph was recorded at the San 
Angelo Regional Airport. 

With the approach of an upper level disturbance and cold front, a line of showers moved 
rapidly east across the northern Big Country on the evening of the 15th. Later in the 
evening, a band of showers and a few thunderstorms developed along the cold front, as 
it moved across southeastern sections of west-central Texas. Rainfall amounts were 
mostly less than one tenth of an inch where the showers occurred, but a few locations 
received between one tenth and one quarter of an inch. 

Dry and breezy conditions with west winds occurred on December 15-17, as a couple of 
strong upper level disturbances tracked east across the central and southern Plains. 
Temperatures during this time averaged 10-15 degrees above normal, for the middle of 
December. Well-above normal temperatures continued on the 18th and 19th, until the 
arrival of a strong cold front. 

As an upper level storm system moved across the southern Plains on the 19th, strong 
west winds developed across west-central Texas during the evening hours. The winds 
shifted to northwest as a strong cold front advanced south across the area. Peak wind 
gusts reached 51 mph at Abilene, 44 mph at San Angelo, and 40 mph at Junction. With the 
strong winds, blowing dust was carried into much of west-central Texas, with 
visibilities occasionally dropping to 3 miles or less. 

Temperatures were much cooler on the 20th, when highs were mostly in the lower 50s. 
A high pressure system settled southeast into west-central Texas during the overnight 
hours of the 20th and 21st. With clear skies, light winds and very dry air in place, 
temperatures dropped into the teens to mid 20s for early morning lows on the 21st. The 
coldest readings occurred in the low-lying areas and river valleys in the central and 
southern parts of west-central Texas. 

Temperatures were well-above normal on the 23rd. Highs were in the 70s across central 
and southern sections of west-central Texas. 

Showers occurred across the eastern Concho Valley and Heartland areas during the pre- 
dawn hours of Christmas. Rainfall amounts of one quarter to one half inch occurred at 
scattered locations. The highest amounts (one half to three quarters of an inch) 
occurred in a small part of northern Brown County. 

A quick change to much colder conditions, along with some wintry weather, occurred 
during the day on Christmas. A strong cold front advanced south across west-central 
Texas, with gusty north winds and falling temperatures following its passage. A peak 
wind gust of 41 mph was recorded at Junction. As an upper level storm system 
intensified over Texas, some light snow developed across the Big Country. Accumulations 
were around 1 inch in the northern Big Country, and less than one inch farther south 
across the Big Country. The cold airmass remained over west-central Texas on the 26th, 
before moderating on the 27th. Highs on the 26th were in the upper 20s to lower 30s 
across the Big Country, in the 30s across the Concho Valley and Heartland, and in the 
40-45 degree range across southern sections of west-central Texas. 

Another cold air intrusion followed a cold frontal passage on the 28th. Early morning 
lows on the 29th ranged from the teens to lower 20s. 

Light rain occurred on the 30th and 31st, with the approach of an upper level storm 
system from the southwestern states. Rainfall amounts of one tenth to one quarter of an 
inch occurred across parts of the Heartland, Concho Valley, and Northern Edwards 
Plateau regions. Elsewhere the amounts were mostly less than one tenth of an inch. 

Warmer temperatures on the 31st were accompanied by gusty south-southwest winds. A peak 
wind gust of 40 mph was recorded at the Abilene Regional Airport.