Summary Of 2011 Here At House

PRECIPITATION - Monthly total (Days with measurable rainfall)

JAN 0.76" (1); FEB 0.29" (2); MAR 0.08" (1); APR 0.36" (1); MAY 0.00" (0); JUN 0.11" (1)

JUL 1.80" (8); AUG 0.83" (4); SEP 2.74" (6); OCT 0.01" (1); NOV 1.71" (6); DEC 2.41" (7)

Annual Total = 11.10" Days with 0.01" or more = 38; with 0.25" or more = 17;
                                    Days with 0.50" or more = 6
                                    A thunderstorm on SEP 10th produced 1.45" here and
                                    Moderate to heavy rains in a DEC storm dropped 1.26" on the 13th

There were two thunderstorms that produced severe winds (my estimate was 60 to 65 mph gusts each day) here at the house. Both were in July and occurred on the 4th and the 7th. The photo above is the dust storm at the leading edge of the storm outflow on the 4th. Davis-Monthan had a gust to 77 mph on July 5th. On September 15th TUS had 2.84" of rain, and Davis-Monthan 1.94", from heavy thunderstorms that stayed on the south side of the city - here at the house there was only 0.01" on that day.

The summer "monsoon" season began June 28th and ended about September 5th - based on my analyses of tropospheric flow at and above 600 mb. After September 5th, winds aloft were southwesterly to northwesterly, and wind shear became quite supportive for severe thunderstorms that moved toward the northeast (i.e., a more typical, central U.S. severe thunderstorm environment). Such storms that can tap residual, low-level moisture at the end of the monsoon are sometimes referred to here as "transitional" storms. Rainfall during the monsoon was quite anemic, totaling only 2.74" here at the house. In contrast, the last part of September and November and December were quite wet, producing 6.86" of rain.

LOW TEMPERATURES

Far and away the most severe weather event of 2011 here in southeast Arizona was the extreme cold, with persistent wind, that occurred from the 2nd to the 4th of February. The damage from frozen water pipes and to  vegetation was very extensive. Here at the house we had consecutive lows of 18, 14, and 11F on these three days. I was still clearing out dead and downed catcus in the northeast corner of the back yard this past weekend. Shown below are a photo of some cactus damage, and the 850 mb chart at 12 UTC on the 2nd, as the massive cold pool was sinking southward across most of the country.

Summary by month of low temperatures at freezing or below here at house goes as follows:

JAN days at or below 32F = 27; at or below 25F = 11; below 20F = 2
FEB days at or below 32F = 20; at or below 25F =  9; below 20F = 3
MAR days at or below 32F = 4
APR days at or below 32F = 1  the last freeze here at the house occurred the morning of APR 11th
NOV days at or below 32F = 5 the first freeze here at the house occurred the morning of NOV 8th
DEC days at or below 32F = 19; days at or below 25F = 12

So there were 76 days here at house with morning temperatures of 32F or colder and 32 days with hard freezes of 25F or colder. Those who follow the blog know that this area along the Rillito is one of the coldest spots inside the city limits of Tucson..