2012 Year in Review

Climate Stats:
Huntsville or Muscle Shoals 

 

 The climate and weather headlines for 2012 in the Tennessee Valley were:

  • Warmest year on record!
  • Rainy January and mild winter temperatures 
  • Record warm March
  • Spring record warmth and dry conditions
  • March 2nd, significant tornado event (7 Tornadoes - including long-track EF3 and an EF2)
  • Drought conditions develop in April and reach "severe" level briefly in July
  • The late June to early July heat wave and flash drought 
  • Heavy Rainfall and severe weather in July
  • July 5th, macroburst wind event (115 mph winds)
  • Cool fall temperatures
  • Mild December with strong Christmas wind event

 

Narrative Climate and Weather Summary for Huntsville and Muscle Shoals

 


JANUARY AND FEBRUARY

 

Location

January Temperatures

Deviation

January Precipitation

Deviation

Huntsville

46.9 F

 +5.4

7.79 

+2.90 

Muscle Shoals

47.6 F

 +6.6

6.87 

+2.26 

 

February Temperatures

Deviation

February Precipitation

Deviation

Huntsville

48.8 F

+3.1

3.56

-1.28

Muscle Shoals

49.2 F

+4.0

2.79

-1.87

January

Temperature graph for Muscle Shoals for January 2012. A warm start to the year continued throughout the month of January, except on the 2nd and 3rd, ending with temperatures well above normal at both the Huntsville and Muscle Shoals Airports. The coldest day of the month occurred on the 3rd at both locations, with highs only in the 30s. Huntsville recorded lows of 20 degrees on the 3rd and 4th, which represented the lowest temperatures of the month. At Muscle Shoals, the temperature fell to 19 degrees on the 3rd, making it the only occurrence of temperatures in the teens for the month at that location. During this time of colder temperatures, surface winds were northerly to northeasterly, bringing colder air southward from northern latitudes. Temperatures fell near to below normal again on the 12th through 15th and then again on the 18th. However, persistent south to southwesterly flow through much of the month ensured above normal temperatures. This lead to above normal temperatures occurring 20 out of 31 days of the month at both Huntsville and Muscle Shoals. The warmest daytime highs occurred at most locations on the 25th, when temperatures climbed well into the 60s and even into the 70s. The high at Muscle Shoals of 74 degrees that day was some 23 degrees above normal for the date, but wasn't enough to break a record. Huntsville topped out at 70 degrees on the 25th, which was 7 degrees shy of the record. In fact, in spite of the nearly continuous above normal temperatures, no temperature records were set for the month. For the month, the average daily temperature at Huntsville was 46.9 degrees, which was 5.4 degrees above normal, ranking as the 11th warmest January on record. The average temperature at Muscle Shoals was 47.6, which was 6.6 degrees above normal, ranking as the 10th warmest January there. 

In addition, this surface flow lead to much warmer and moister conditions than normal across northern Alabama and Southern Middle Tennessee for the month. Combined with an active storm track through the Tennessee and Ohio valleys, this predominate surface wind flow lead to above normal rainfall as well across northern Alabama and Southern Middle Tennessee. The rainiest day for most locations occurred on the 11th, as a relatively moist airmass moved into the region ahead of a cold front. Rain with embedded areas of thunderstorms dropped 2.42 inches of precipitation at Huntsville, setting a new daily precipitation record for the 11th. The rainfall amount at the Shoals was less, at 1.23 inches, but still a respectable amount. Based on radar estimates, some locations in western Morgan County may have received around 3 to 4 inches. Colder air poured into the area on the 12th and 13th, allowing quick bursts of snow and flurries to fall at some locations. Muscle Shoals received 0.1 inches of snow on the 12th, which was the only measurable snow recorded there for the month. Huntsville only received trace amounts of snow for this event and for the entire month.

February

Temperature graph for Muscle Shoals forFebruary 2012. Well above normal temperatures continued into February, as a mean zonal to slightly southwesterly flow pattern continued. The average temperature of 48.8 degrees at Huntsville was 3.1 degrees above normal and ranked as the 16th warmest February on record. At Muscle Shoals, it was even warmer. The average monthly temperature of 49.2 degrees was 4.0 degrees above normal and ranked as the 14th warmest February there. The month started out relatively warm with high temperatures well into the 50s and 60s during the first week. The first freezing temperature at Huntsville did not occur until the 10th. On successive days however, the temperature continued to drop as a much colder Canadian airmass moved into the region. Highs only topped out in the low 40s at Huntsville and Muscle Shoals on the 11th and 12th with morning low temperatures well below normal. The low of 19 degrees at Huntsville on the 12th was the coldest temperature during the month and for the whole winter season. The highest temperature for the month at both locations occurred on the 23rd as very dry, strong southwesterly winds brought an unusually warm airmass into the region. The high temperature of 83 degrees at Muscle Shoals set not only a record high for the date, but tied the all-time high for the month of February. It was also the 2nd highest all-time high temperature for the meteorological winter season (December-February) at the Shoals. The warmest temperature ever recorded at Muscle Shoals during the winter was 84 degrees on January 17th, 1936. The high temperature of 77 degrees at Huntsville was 19 degrees above normal, but 6 degrees shy of the record for the date.

Precipitation for February was below normal for nearly all of northern Alabama and southern middle Tennessee. At Huntsville, the precipitation total of 3.56 inches was 1.28 inches below normal, but only ranked as the 46th driest February. At Muscle Shoals, the total was lower, at 2.79 inches, and ranked as the 27th driest. The heaviest precipitation for much of the area occurred on the 4th, with totals just over three quarters of an inch at Huntsville and Muscle Shoals. Traces of snow fell at several locations around the area during the month, particularly the 10th through the 13th, but measurable snow was not reported.


MARCH

 

Location

March Temperatures

Deviation

March Precipitation

Deviation

Huntsville

63.4 F

+9.9

4.32

 -0.89

Muscle Shoals

63.3 F

+10.1

2.85

 -1.91

March

Temperature graph for Muscle Shoals for March 2012. March 2012 finished as one of the most anomalously warm months on record for much of the Tennessee Valley...and in fact for much of the United States. Over 15,000 daily record high temperatures were set during the month across the nation...including several in our own area: five at Huntsville and two at Muscle Shoals. Some locations in the Upper Midwest even bested previous record daily high temperatures by 20 degrees or more on some days. Temperatures for the month here in the Tennessee Valley began very warm...helping to fuel severe weather across portions of north central Alabama on March 2nd...including some very destructive tornadoes in Limestone and Madison Counties. One tornado, reaching EF-3 intensity, tracked for approximately 34 miles from near Athens to the north side of the Huntsville metro.  Strong thunderstorms during the afternoon produced hail to the size of softballs and baseballs in northwest Alabama.  After the severe weather of the 2nd, temperatures then cooled a little during the middle and latter half of the first week and then again briefly on the 9th and 10th. However...the pattern that would eventually bring unusually warm conditions to much of the United States and surrounding areas began to take shape by the middle of the month. A very strong blocking high pressure system...similar to those during the summer...developed in the western Atlantic basin and steered very warm and moist air into much of the eastern two-thirds of the country. Perhaps the most remarkable feature of this pattern was its consistency. In a month where changes in the jet stream and the resulting weather pattern are often the rule...the pattern became uncharacteristically stagnant. The result was a continuation of above normal temperatures through the end of the month. Daily average temperatures ranged from 10-20 degrees above normal on many days and had more similarity with normal temperatures in late May to early June than mid to late March. By the end of March...average monthly temperatures were an astounding 9.9 degrees above normal at Huntsville...and an even more impressive 10.1 degrees above normal at Muscle Shoals. March 2012 eclipsed the previous record warm March at Huntsville, set in 1910, by 3.2 degrees! The previous record warm March for the Shoals (1945) was beat by 2.2 degrees. Just as impressive, temperatures reached or exceeded 80 degrees on 14 days at Muscle Shoals and 13 days at Huntsville, which was the highest number of days for both locations for any March on record. The temperature did not even reach the freezing mark at Huntsville on any day during the month, which has never happened in the historical record at Huntsville. In three previous Marches the temperature did only reach freezing on one day: 1918, 1973 and 2011. The temperature only reached freezing on one day at Muscle Shoals, however, the freezing mark was not reached at all during three previous Marches in the historical record there: 1897, 1905 and 1953.

Precipitation only tallied 2.85 inches at Muscle Shoals, which is nearly two inches below normal. At Huntsville, the total was greater, at 4.32 inches, but this was 0.89 inches below normal for the month. Some locations received heavy rainfall, including severe weather on March 2nd, but these storms mostly missed the Huntsville and Muscle Shoals airport locations. The biggest rainfall event for Huntsville (1.50 inches) occurred on the 8th and 9th as rain and thunderstorms developed and moved across the area ahead of a cold front. This was also the heaviest precipitation event for Muscle Shoals (1.43 inches). Huntsville received similar rainfall on the 15th (1.47 inches) as severe thunderstorms crossed portions of the area. A wind gust of 70 mph was recorded at Huntsville International Airport during the early evening of the 15th, which was the strongest wind gust for the month, and in fact, the strongest wind gust recorded since automated observations began at the Huntsville airport (August 1st, 1994).

APRIL - JUNE

 

Location

April Temperatures

Deviation

April Precipitation

Deviation

Huntsville

64.7 F

 +2.9

2.18

-2.14

Muscle Shoals

64.5 F

 +3.1

0.90

-3.45

 

May Temperatures

Deviation

May Precipitation

Deviation

Huntsville

73.9 F

+3.6

2.79

-2.32

Muscle Shoals

73.7 F

+3.9

4.28

-0.84

 

June Temperatures

Deviation

June Precipitation

Deviation

Huntsville

78.3 F

+0.6

1.43

-2.86

Muscle Shoals

77.8 F

+0.9

1.51

-3.25

 
April

Temperature graph for Muscle Shoals for April 2012. Temperatures for the month of April finished around three degrees above normal at Huntsville and Muscle Shoals. The monthly average of 64.7 degrees at Huntsville was 2.9 degrees above normal, and tied Aprils in 1908, 1957 and 2010 as the 11th warmest on record. At Muscle Shoals, the monthly average of 64.5 degrees was 3.1 degrees above normal, and tied Aprils in 1965, 1977 and 2001 as the 16th warmest on record there. For the first several days of the month, temperatures averaged around 10 to 15 degrees above normal as the unusually strong ridge that held sway across much of the eastern continental United States during the month of March continued to dominate the weather in the Tennessee Valley. This feature finally began to break down by the end of the first week, allowing a cooler airmass to move into the region. Temperatures fell initially on the 5th and 6th, but fell further as a cool Canadian airmass slipped into the Southeast towards the end of the second week. Morning lows eventually fell into the 30s at many locations across the area from the 11th through the 13th. While neither Huntsville nor Muscle Shoals reached freezing, some other locations did experience their last freeze of the cold season on the 12th. Temperatures climbed quickly, reaching the 80s at most locations by the middle of the month, but this was followed by another quick cool-down at the start of the 4th week. Morning lows fell into the 30s and 40s across the area from the 21st through the 24th. Temperatures then climbed sharply on the 25th, with morning lows starting out in the 50s and 60s as a very moist airmass moved back into the region. Daytime highs climbed well into the 80s at many locations through the remainder of the month. The high temperature reached 90 degrees for the first time this year on April 30th at Muscle Shoals, but was just one degree shy at Huntsville.

While temperatures were above normal across the area during April, precipitation was below normal. In fact, by the end of the month, precipitation tallied less than one inch in parts of northern Alabama and southern middle Tennessee, including Muscle Shoals, where the 0.90 inch that fell there during the month ranked as the 4th lowest on record for April. Huntsville received a little more precipitation, mainly due to some shower and thunderstorm activity on the 4th and 5th. However, the total of 2.18 inches at Huntsville was low enough to rank as the 16th driest April. After the showers and storms of the 4th and 5th that brought beneficial rains to areas from Russellville to the Huntsville/Decatur metro to Valley Head, rainfall was quite sparse for the rest of the month. Muscle Shoals received nearly all of its rainfall for the month on the 16th and 17th, when 0.76 inches was recorded at the official airport location. Otherwise, conditions were generally dry for the month. By the end of April, conditions were classified as D0 (abnormally dry) across nearly all of northern Alabama and southern middle Tennessee

May

Temperature graph for Huntsville for May 2012. In keeping with the trend for this year, and since November of last year, temperatures continued to average above normal during the month of May. The average monthly temperature of 73.9 degrees at Huntsville was 3.6 degrees above normal and tied the May in 1933 as the 3rd warmest on record. The warmest May at Huntsville occurred in 1962 when the average monthly temperature was 76.1 degrees. The average monthly temperature at Muscle Shoals was just slightly cooler at 73.7 degrees, but this was 3.9 degrees above the monthly normal there. At the Shoals, this May ranked as the 8th warmest on record, also tied with 1933. The warmest May on record there occurred in 1962 and 1902 when the average temperature was 75.4 degrees. Several daily record highs were set during the month, including daily record maximum temperatures of 91 degrees at Huntsville on the 1st and 2nd, while record highs of 97 degrees were set at Muscle Shoals on the 26th and 27th. A record high of 92 degrees was also set at the Shoals on the 2nd and an overnight record warm minimum temperature of 73 degrees was set at Huntsville on the 28th. Temperatures were generally above normal during most of the month, especially during the first week and then again during the last week. On the 28th, the average daily temperature at Huntsville was 84 degrees, which tied an all-time high for the month of May. This tied similar days of May 30, 1914, May 26, 1965 and May 31, 2011 in the historical record.  At the conclusion of May and meteorological spring, the average seasonal temperature of 67.3 degrees was the warmest on record, besting the previous warmest spring by 2.8 degrees!

Precipitation for the month of May was below normal across a large part of the area. Amounts were generally lower in the east, where radar estimates and ground observations showed some locations receiving under two inches. Amounts ranged from around three to five inches in the west at most locations, but were still generally below normal. Although, heavy showers and thunderstorms on a few days brought above normal precipitation mainly to parts of southern Cullman County. On the drier end of the area, Huntsville received 2.79 inches of precipitation, ranking as the 32nd driest May. At Muscle Shoals, the total was higher, at 4.28 inches, but this still was 0.84 inches shy of normal. By the end of the month, moderate drought conditions had crept into much of the area, with streamflows running well below normal and soil moisture values relatively low for this time of year.

June

Temperature graph for Muscle Shoals for June 2012. June was a tale of two months. What started out as a relatively cool first month of summer, ended quite hot, with record setting highs on the last few days. Despite the cool start to the month, including daily temperatures which were about 10 degrees below normal, the hot temperatures at the end of the month were enough to bring the monthly average above normal. At Huntsville, June temperatures finished 0.6 degrees above normal, while temperatures at Muscle Shoals finished at 0.8 degrees above normal.  As stated above, June started quite cool, with highs mostly in the low to mid 70s and lows in the 50s on the first day. Temperatures then warmed but stayed mostly near to below normal during the first two weeks. Temperatures did not reach 90 degrees until the 13th at Huntsville, and the 14th at Muscle Shoals. Then, the gradual warmup began, but one that culminated in daily record highs, and the hottest temperatures observed in the area since the 1950s at Huntsville and the 1930s at Muscle Shoals. The temperature first reached 100 degrees at Muscle Shoals on the 23rd and at Huntsville on the 24th. A cold front brought slightly cooler temperatures on the 26th and 27th with highs in the 90s (although touching 100 degrees at the Shoals on the 27th). But, the last few days finished quite hot with temperatures soaring above 100 degrees. The afternoon high reached 106 degrees at Huntsville on the 29th, which was the hottest temperature of the month. Amazingly, this did not set a new record for the date though, which is 108 degrees set in 1931. However, the 105 degree temperature on the 30th did set a new record for the date. At Muscle Shoals, the highs of 105, 107 and 107 on the 28th, 29th and 30th, respectively, were enough to set new record highs for each day. The 107 degree temperatures, although enough for new daily record highs, were just one degree shy of the June monthly and all-time record highs for Muscle Shoals, 108 degrees, which was set on six occasions in the historical record: June 26th, 1914, July 13th, 28th, and 29th, 1930, August 8th, 1930, and September 8th, 1925. 

Precipitation was below normal for most areas for the month, although some locations in northeastern Alabama actually received above normal precipitation. On the 3rd, a stalled front produced severe weather across portions of northern Alabama, mainly west of interstate 65 along with heavier rainfall.  Another round of showers and strong to severe thunderstorms moved across the area on the 10th and the 11th.  Numerous reports of wind damage were received from northwestern to north central Alabama from the late afternoon thunderstorms on the 11th.  As mentioned in the temperature section above, however, June 2012 seemed to have two distinct parts; the first half relatively cool with occasional showers and storms, and the second half hot and very dry.  Rainfall and cooler temperatures earlier in the month eased the drought briefly over much of northern Alabama and Southern Middle Tennessee.   However, very little precipitation fell across the area during the last half of the month. The last precipitation received at Huntsville and Muscle Shoals during the month occurred on the 11th. Due to the lack of precipitation and above normal temperatures, moderate drought conditions had emerged in many locations west of interstate 65 and in Southern Middle Tennessee by the end of the month.

JULY

 

July

Location

July Temperatures

Deviation

July Precipitation

Deviation

Huntsville

83.0 F

+2.4

7.33

+3.28

Muscle Shoals

84.0 F

+3.6

6.37

+2.07

Temperature graph for Huntsville for July 2012. July picked up where the month of June left off, with temperatures soaring into the 100s for the most part to start the first week. Muscle Shoals set record highs on the 1st, 5th, and 6th and tied a record high on the 7th. The 106F temperature reached at the Shoals on the 1st was the warmest July temperature since July 29, 1952 and was only two degrees shy of the all-time record of 108F. At Huntsville, record high temperatures were set on the 1st, 4th and 5th, including a record warm overnight low temperature on the 2nd. The high temperature of 105F degrees at Huntsville on the 1st was the hottest temperature of the month and was also the hottest July temperature since July 29, 1952. At both Huntsville and Muscle Shoals, this was the hottest start to July (first 7 days) on record. A break in the heat wave began with the start of the second week, as the broad upper high pressure system began a retreat back to the south and west. Temperatures fell a little intitially, back into the mid 90s for the 8th through the 10th. Then, a potent system moved into the Tennessee Valley and brought significant cloud cover and rain from the 10th through the 13th. High temperatures on the 11th and 12th only reached the mid to upper 70s at many locations in the area. At Huntsville, the high of 77 degrees on the 12th set a new record low maximum temperature for the date...what a difference a week makes! After the very hot period, followed by the cool few days with heavy rainfall...temperatures and rainfall amounts moderated. The last couple of weeks featured near to slightly above normal temperatures. Due especially to the very warm start to the month, average temperatures finished around 2-4 degrees above normal for July. It was, in fact, the 8th hottest July on record at Huntsville, and the 4th hottest at Muscle Shoals. 

In contrast to June and the spring season of 2012, precipitation was above normal for July. The great majority of the area received above normal precipitation, with rainfall surpluses on the order of about 3-5 inches in a swath from near the quad cities area in northwestern Alabama through Lawrence, Morgan, and northern Marshall Counties, and along the Sand Mountain area. At Huntsville, the surplus was 3.28 inches, while precipitation was 2.07 inches above normal at Muscle Shoals. Nevertheless, the hot dry weather during the last couple of weeks of June persisted into the early part of the month. On the 3rd, much of northern Alabama and southern middle Tennessee were declared in severe (D2) drought conditions by the U.S. Drought Monitor. However, a pattern change that brought heavy rainfall to the Tennessee Valley helped to stop the drought from reaching further severity and in fact, led to a significant easing of drought conditions across the area later in the month.  The very hot temperatures and abundant low level moisture helped to fuel more severe weather.  On July 1st, 5th, and 6th, these ingredients along with stronger winds aloft in the atmosphere combined to produce separate severe weather events across a good portion of northern Alabama and southern middle Tennessee.  The most notable of these events occurred on July 5th, when a strong macroburst produced extensive damage in the Moulton area.  From the 10th through the 13th, a cold front essentially stalled in the area and led to repeated heavy rain events. Huntsville received an impressive 3.81 inches of rain during this period, while Muscle Shoals recorded a very similar 3.77 inches. The rainfall was stretched over a slightly longer period at the Shoals however, with a total of 5.59 inches from the 8th through the 14th. Periods of rainfall occurred through the remainder of the month, but nothing particularly heavy, especially when considering the precipitation during the 2nd week. By the end of the month, rainfall totals were 7.33 inches at Huntsville and 6.37 inches at Muscle Shoals. It was the 10th wettest July on record at Huntsville and the wettest month since January at both locations. By the end of July, the U.S Drought Monitor declared most of northern Alabama and southern middle Tennessee in D0 status (abnormally dry) as conditions had improved dramatically.

AUGUST - NOVEMBER
 

Location

August Temperatures

Deviation

August Precipitation

Deviation

Huntsville

78.0 F

 -2.1

4.72

+1.11

Muscle Shoals

79.3 F

 -0.5

2.32

-0.83

 

September Temperatures

Deviation

September Precipitation

Deviation

Huntsville

71.5 F

-2.2

5.43

+1.71

Muscle Shoals

72.1 F

-1.1

5.71

+1.99

 

October Temperatures

Deviation

October Precipitation

Deviation

Huntsville

60.5 F

-2.3

3.91

+0.32

Muscle Shoals

60.7 F

-1.4

2.40

-1.03

 

November Temperatures

Deviation

November Precipitation

Deviation

Huntsville

49.5 F

-3.2

2.00

-2.94

Muscle Shoals

49.9 F

-2.2

1.56

-3.10

 
August

Temperature graph for Muscle Shoals for August 2012. Temperatures started out the month of August above normal. The first day of the month turned out to be the warmest day at most locations in the area, with cooler temperatures for the remainder of the month. The daytime high reached 102 degrees at Muscle Shoals on the 1st, and 101 degrees on the 2nd, tying new daily high records for each date. Temperatures at Huntsville were several degrees cooler, in the mid 90s, but the daytime high of 96 degrees on the 1st represented the highest temperature for the entire month. What was somewhat unusual this August was the periodic progression of late summer season cold fronts across the Tennessee Valley. Despite the warm start to the month, temperatures ended up below normal for both locations due to the periodic intrusion of cooler airmasses from the north. The low temperature of 57 degrees at Huntsville on the 12th, tied a record low for the date, but was the only record low set during the month. Although Muscle Shoals also recorded a few lows in the 50s, no record lows were set there. At the end of August, temperatures were 2.1 degrees below normal at Huntsville and 0.5 degrees below normal at Muscle Shoals. It was the first month of the year and since October of 2011 with below normal temperatures.

August 2012 radar estimated precipitation. As is typical in the summertime month of August, precipitation was highly variable across the area. As shown in the images of radar estimates (left), some locations from southern middle Tennessee southward between the Huntsville and Athens areas and southwest into the Bankhead National Forest likely received over 5 inches of rainfall, and more than 8 or 9 inches in a few spots. Other areas of heavy precipitation included central and eastern portions of Lauderdale County and southwestern portions of DeKalb. Meanwhile, other spotty locations particularly in parts of Marshall County only received around 1 to 2 inches of rainfall. Precipitation certainly varied between Huntsville and Muscle Shoals too. Huntsville picked up a relatively healthy 4.72 inches of precipitation, which was 1.11 inches above normal for the month. At Muscle Shoals, only 2.32 inches of precipitation was recorded, which was 0.83 inches below normal.

September

Temperature graph for Huntsville for September 2012. Average temperatures were below normal for the month of September, for the 2nd month in a row. Back to back months with below normal temperatures hadn't occurred at Huntsville or Muscle Shoals since September and October of 2011. The large scale pattern became much more amplified during August and continued into September, leading to more intrusions of cooler airmasses of Canadian origin into the Tennessee Valley and surrounding regions. Although temperatures averaged below normal for the month as a whole, temperatures began a little warm. In fact, the only temperature records set during the month were for overnight record warm minimums, including a low of 77 at Muscle Shoals on the 1st and a low of 74 degrees at Huntsville on the 4th. While temperatures averaged above normal for the first week, conditions changed abruptly at the start of the second week, with a series of cold fronts bringing drier and cooler weather into the region. Daytime highs remained in the 80s for the most part, but some days saw highs in the 70s, while overnight lows were generally in the 50s and 60s. Morning lows even fell into the 40s at many locations on the 19th and 20th, for the first time since early May at Huntsville, and since late April at Muscle Shoals. At the close of September, temperatures averaged around one to two degrees below normal for the month.

Early in September, rounds of showers and thunderstorms developed in the area as a moist and humid airmass enveloped the region. The remnants of once Hurricane Isaac combined with a strong upper-level system to help with the rainfall production. Rainfall totaled just over 0.75 inches at Huntsville and over 1.50 inches at Muscle Shoals for the first five days of the month. More impressive totals around 3 to 5 inches were reported over southern portions of the Huntsville forecast area, from parts of the Bankhead National Forest through Cullman into southern Marshall County. However, more widespread heavier rains moved across the area on the 17th in association with a strong low pressure system from the Gulf. Rainfall totaled around 2 to 5 inches across a broad swath of northern Alabama and middle Tennessee during just a one day period. The rainfall was sufficient to produce some flooding, mainly in northwestern portions of Alabama. The one day totals of 3.69 inches at Huntsville and 3.09 inches at Muscle Shoals broke daily rainfall records for September 17th. At Huntsville, this was the 5th wettest September day on record and the wettest single day since the remnants of Tropical Storm Lee drenched the airport location with 4.42 inches on September 5, 2011. By the end of the month, precipitation totaled 5.43 inches at Huntsville, and 5.71 inches at Muscle Shoals, which was above normal for both locations.
October

Temperature graph for Huntsville for October 2012. Average temperatures were below normal for the month of October, continuing a trend that was begun in August. This was the first time since January-February-March of 2010 that temperatures had been below normal for three consecutive months. Temperatures were particularly cool at the beginning of the second week, with morning lows on the 9th falling into the 30s at many locations for the first time since April. Although close, freezing temperatures did not occur at any of the cooperative observer locations in the Huntsville NWS forecast area with this first cold air outbreak. Temperatures gradually rebounded during the second week, and then wavered from slightly below to above normal into the latter part of the 4th week. Daytime highs reached the low 80s at many locations from the 22nd through the 26th. Then, a quick and significant cool-down ensued as a modified polar airmass moved into the region. High temperatures slipped some 25 to 30 degrees from the 26th to the 27th. Cool, dry air and ideal raditional cooling conditions allowed temperatures to fall to or below freezing at most locations on the 31st (although, Muscle Shoals was an exception). This was near the climatological average for most locations for the first freeze of the cold season (late for some, early for others). At Huntsville, the morning low temperature of 32 degrees was the first freezing temperature since February 26th. This stretch of 247 days without freezing temperatures was the 3rd longest in Huntsville's history, tying a similar period in 2004. Incidentally, the longest stretch of above freezing temperatures at Huntsville was 251 days, which occurred between March 29th and December 4th, 1978.  By the end of the month, temperatures averaged 2.3 degrees below normal at Huntsville, and 1.4 degrees below normal at Muscle Shoals.

In general, precipitation across the Huntsville forecast area for the month of October could be characterized as slightly above normal in the north, to below normal in the south. At Huntsville, the precipitation total of 3.91 inches was slightly above normal, while the 2.40 inch total at Muscle Shoals was just over an inch short of the normal total. Nearly all of the rainfall for October occurred during the first 18 days, with little to no precipitation during the remainder of the month. A rather impressive one-day total of 1.55 inches was recorded at Huntsville as thunderstorms moved across the area on the 14th, just 0.15 inches shy of the record set for the date set in 1909. Otherwise, daily precipitation totals were below one inch for most locations during the month. The largest calendar day total at Muscle Shoals occurred on the 1st, when showers and storms brought 0.75 inches to the airport location.
November

Temperature graph for Huntsville for November 2012. Average temperatures were below normal once again for November, making the fourth month in a row with below normal temperatures. Four back-to-back months with below normal temperatures hadn't occurred since the cold winter of 2009-10 (December to March). While not unusually cold overall, temperatures were fairly persistently below normal, especially morning low temperatures. In fact, high temperatures for the month were actually a little above normal. Nevertheless, the morning low average of 35.2 degrees was the 15th coldest for any November at Huntsville and the 16th coldest at Muscle Shoals. The large diurnal range observed during the month is typical of dry airmasses, which were common during November. Interestingly, despite the overall cold, the only records set were record high temperatures on November 3rd. At Muscle Shoals the high of 85 degrees set a new daily record. However, the high temperature of 84 degrees at Huntsville, set not only a new record for the date, but tied the all-time record high for the month of November, set on three previous dates: Nov 1, 2000, Nov 2, 1961, and Nov 6, 1914.

November 2012 was a particularly dry month. In what is characteristically a lead-in month to the "wet" season, precipitation often begins to ramp up during the month of November. However, precipitation for Novermber 2012 was actually lower than the typically drier months of August, September or October. At Huntsville, the precipitation total of 2.00 inches ranked as the 20th driest on record and was the driest November since 1997. At Muscle Shoals, the total of 1.56 inches ranked as the 14th driest and was the lowest November total since 1998. Most precipitation fell during the first twelve days, with dry northeast flow and cool high pressure dominating for much of the remainder of the month. Through the 12th, precipitation totaled 1.82 inches at Huntsville, representing 91 percent of the total for the month. At Muscle Shoals, 1.45 inches of precipitation fell during the first 12 days, representing nearly 93 percent of the monthly total there.

December

 

Location

December Temperatures

Deviation

December Precipitation

Deviation

Huntsville

49.6 F

+5.7

6.75

 +0.98

Muscle Shoals

49.4 F

+6.1

5.42

 -0.26

December

Temperature graph for Muscle Shoals for December 2012. The trend of below normal temperatures that began in August ended with sharp finality during the month of December. At Huntsville, the average temperature of 49.6 degrees was 5.7 degrees above the normal for the month, ranking as the 8th warmest December on record. In fact, December was 0.1 degrees warmer than the rather cool month of November. This has only happened seven other years at Huntsville: 1911, 1923, 1933, 1951, 1956, 1971, and 1984. This was perhaps a fitting end to a year that was the warmest on record for many locations in northern Alabama and southern middle Tennessee. At Muscle Shoals, the monthly average of 49.4 degrees was 6.1 degrees above normal, ranking as the 5th warmest December on record there. Temperatures started out very warm for the month of December, with daytime highs mainly in the 60s and 70s for the first ten days of the month. A record high temperature of 74 degrees was tied at Muscle Shoals on the 2nd, while record high minimum temperatures were set at Huntsville and Muscle Shoals on the 9th. A colder airmass moved into the region, dropping temperatures to a few degrees below normal mainly from the 11th through the 13th. Then, another significant warmup occurred for the 3rd week, with temperatures once again well above normal. Warm air and strong southwesterly winds ahead of a rather potent weather system brought above normal temperatures to the area for the Christmas holiday, but then temperatures fell below normal once again for most days after the 26th. This system brought strong winds to much of the area on the Christmas holiday.  A rare, but repeating meteorological event for the Tennessee Valley brought strong sustained wind gusts around 45 mph to as much as 70 mph mainly to eastern portions of the area on Christmas night, prompting the issuance of a High Wind Warning for a few hours.

Precipitation was generally near to above normal for most of northern Alabama and southern middle Tennessee. However, a few areas of slightly below normal precipitation did occur, along a narrow swath in northwestern Alabama, including Muscle Shoals, and in parts of northern Jackson County. Rainfall was heaviest in far western portions of Lauderdale County and in southern Cullman County, where amounts near 8 inches were recorded and radar data indicate amounts around 8 to 10 inches may have fallen in some locations. The Huntsville precipitation total of 6.75 inches was nearly one inch above normal for the month, ranking as the 33rd wettest on record. At Muscle Shoals, the precipitation total of 5.42 inches was just over a quarter of an inch below normal, but ranked as the 44th wettest on record.1 A daily precipitation record was set at Huntsville on the 16th, when 2.46 inches of precipitation was recorded at Huntsville International Airport. This eclipsed the previous record of 2.36 inches set in 1961. Traces of snowfall were recorded on the 26th and 29th, but no measurable snowfall was recorded for the month. 

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