September 2011 Climate Summary for Lubbock and Childress
Unlike the summer months, September was much more "typical" as temperatures generally ended up very close to seasonable averages, as Lubbock and Childress were 0.1 and 0.4 degrees above normal respectively. However, given that they ranked slightly above normal, this made September 2011 the 14th consecutive month where "above normal" temperatures were experienced across the region. Unlike what the region observed during July and August, temperatures in September showed much more variability. The month began with extremely warm temperatures as the upper-level ridge of high pressure that dominated the weather during the summer months persisted into the early part of Labor Day weekend, promoting highs in the upper 90s to the lower 100s. However, a significant change occurred on the evening of the 3rd as a strong cold front dropped southward into the region, bringing a significantly cooler airmass into the Southern Plains as daytime and nighttime temperatures dropped about 15-20 degrees from where they has been for the past three months. As a result, the low temperature on the 4th at Lubbock was 57 degrees, making it the first time since May 26th that the mercury failed to remain above 60 degrees overnight. In addition, the high temperature that day was a cool 74 degrees, making it the first time the mercury failed to reach 80 degrees since May 6th, and breaking the streak of 100 straight 90+ degree days. At Childress, the streak for 90+ degree days also came to an end on the 4th at 100 as the high only reached 82 degrees that day. The next morning on the 5th, the temperature dropped to 54, making it the first time since May 28th that the temperature had fallen below 60 degrees there.
The cooler and drier airmass persisted for the next several days as highs peaked in the low to mid 80s and lows in the 50s. A sharp warm-up occurred from the 10th-13th as highs rose back into the mid to upper 90s at Lubbock and the lower 100s at Childress. The Childress set two record highs of 104 and 101 degrees on the 12th and 13th respectively and the 97 degrees set at Lubbock on the 12th was tied for the highest reading of the month. Another sharp cold front dropped through the region on the evening of the 13th, dropping high temperatures back into the 70s and even into the 60s for one day (on the 15th). The reading of 62 degrees at Lubbock and 65 degrees at Childress were the lowest high temperature at readings at either location since May 1st. Though there was some variability from day to day the remainder of the month, the upper-level ridge that controlled the weather during the latter half of September, generally kept highs at or above seasonable averages in the lower 80s to the middle 90s (expect for z brief cool down into the 70s on 22nd) through remainder of the month. Also, given the drier conditions at night, overnight lows remained at very comfortable and seasonable levels in the 50s across the entire region.
NOTE: Some temperature data for Childress exists before 1928 and goes as far back as the 1890s. However it is a very incomplete record as there are many large gaps in the data before 1928 (some as large as 20 years). Therefore, this analysis will only compare the observations from August 2011 to data from the complete temperature record which is from 1928-present.
September 2011 temperature graphs for Lubbock (LBB) and Childress (CDS). The red bars indicate the actual observed daily high and low temperatures and the extended black lines denote the daily record highs and lows. Any record high temperatures set are denoted in yellow. One daily high temperature record was set at Lubbock and two were set at Childress in September! Click on the images for a larger version!
|Average Monthly Temperature||71.8||74.6|
|Normal September Temperature||71.7||74.2|
|Deviation From Normal|| 0.1 Above
|| 0.4 Above
|Monthly Ranking||39th Warmest (since 1914)||34th Warmest (since 1928)|
||86.0 (2011)||82.1 (1931)|
||63.9 (1974)||66.0 (1974)|
|Highest Temperature (September 2011)|| 97 on the 3rd, 12th, and 29th
||104 on the 12th|
|Lowest Temperature (September 2011)||49 on the 5th and 30th|| 51 on the 23rd
|All-Time Highest Temperature||
105 (September 19, 1930)
108 (September 1, 1951)
|All-Time Lowest Temperature||
33 (September 21, 1983)
(September 29, 1916)
34 (September 30, 1984)*
|Record Highs (September 2011)||
97 on the 29th
104 on the 12th
101 on the 13th
|Record Lows (September 2011)||None||None|
* Period valid (1928-2011)
As was the case in August, very dry conditions persisted into September across the Southern Plains region. However, there were a few instances where some rainfall did occur. Unbelievably, September 2011 marked the first month since October 2010 where over one inch of rainfall was measured at Lubbock during a month as 1.25" was observed at the airport! A few strong cold fronts pushed into the region and were able to focus some of the moisture that was in place across the area to produce convection, which did result in some appreciable rainfall occurring in localized spots across the region. However, due to the scattered nature of this convection and the random, infrequent occurrence of these storms, September will still be characterized as abnormally dry across all of western Texas as historic drought conditions persisted throughout the month. Overall, September will go down as the 43rd driest on record at Lubbock, with Childress ranking much lower (19th driest) as only received 0.68” was observed there during the month.
The first rainfall "event" across the Southern Plains in September occurred on the evening of the 3rd and overnight into the 4th as a cold front pushed into the region, helping to trigger some scattered showers and storms. The heaviest rainfall fell across the southwestern Panhandle and northern South Plains, with several places around Hereford, Dimmitt, Hart and Friona seeing upwards of an inch or more. The Lubbock Airport officially received 0.48” which was one of the higher "event" rainfall totals observed all year for the city. Meanwhile, Childress missed out on most of the heavy rainfall as only 0.06" was observed there on the 4th.
A slightly bigger and more widespread rainfall event occurred from the late morning of the 14th into the evening hours of the 15th as another cold front dropped into the area, focusing some of the low to mid-level moisture across the region to generate several rounds of showers and thunderstorms. The heaviest rainfall occurred to the southwest of Lubbock as between 1-2" of rain fell across the southern South Plains and the northern Permian Basin. Locations along the southern Panhandle and northern Rolling Plains received slightly lower amounts as between 1/4"-1/2" generally was observed in those areas. Officially, 0.73" was observed at the Lubbock Intl Airport, while Childress fared slightly better than earlier in the month as 0.36" fell there during the two day event. By the end of September, the yearly rainfall total at Lubbock had reached 3.00" and was 4.48", still the driest start to a calendar year at both locations.
Given the extremely dry conditions that continue to plague the region, the entire area still remains in D-4 (Exceptional) drought status, the highest ranking possible. This ranking points to how critically dry the area really is as a drought of this stature is incredibly rare with a probability of occurring once every 50-100 years. As a result of this very significant drought, fuels such as grasses, mesquite, and juniper continue to be extremely stressed and are at record levels of dryness. These extremely dry fuels act as kindling to wildfires and along with very strong winds, allow them to grow and spread rapidly once they are initiated. Given the state of these fuels, an elevated fire danger continues to exist across the entire region even on non-windy days. Unfortunately, these exceptional drought conditions are expected to persist (and could even worsen further) if the region does not begin to consistently experience any meaningful rainfall in the coming weeks.
|Departure From Normal||1.26" Below||1.74" Below|
|Monthly Ranking||43rd Driest (since 1911)||19th Driest (since 1924)|
|Wettest September||13.93" (1936)||11.70" (1936)|
|Driest September||0.00" (2000, 1954)||0.00" (2000, 1939)|
|Wettest Day (2011)||0.50" on the 15th||0.24" on the 15th|
|All-Time Wettest September Day||7.46" (September 11, 2008)||5.16" (September 11, 2008)|
|Average Wind Speed (mph)||9.0||8.3|
|Normal Wind Speed (mph)||10.5||11.0|
|Highed Sustained Wind Speed (mph)||37 on the 3rd||31 on the 3rd|
|Highest Wind Gust (mph)||46 on the 3rd||43 on the 1st|
The Outlook for October, November, and December from the Climate Prediction Center
|The three-month temperature outlook for the fall indicates a higher probability of above normal temperatures for the southern Texas Panhandle, South Plains, and Rolling Plains. Click on the image for a larger version!||The three-month precipitation outlook for the fall indicates a higher probablity of below normal precipitation for the southern Texas Panhandle, South Plains, and Rolling Plains. Click on the image for a larger version!|
The latest drought outlook for the state of Texas:
|As of early September, drought conditions were continuing to worsen across all of Texas. D-4 (Exceptional) drought conditions continued to prevail across all of the South Plains region. 100% of the state was experiencing D1 (Moderate) drought or higher. Also, 99% of the state was in a D-2 (Severe) drought or higher, and about 97% of the state had entered a D-3 (Extreme) drought. In addition, 88% of the state was experiencing D-4 (Exceptional) drought, the highest category possible. These drought conditions are extremely rare, with the probability of extreme drought occurring on the order of every 20-50 years and exceptional drought every 50-100 years! Click on the image for a larger version!|
The latest seasonal drought outlook for the United States:
|While the storm system that moved through the region did provide some some improvement in the drought across the Red River Valley, given the higher probabilities for below normal precipitation this fall significant drought conditions are expected to persist across most of the Lone Star State. Click on the image for a larger version!|