NWS Huntsville: January 2014 Climate Summary

January 2014 Climate Summary for Huntsville and Muscle Shoals...

Temperatures...

What a January it was!  Temperatures for January were quite cold in the Tennessee Valley, and across a good portion of the central and eastern United States.  At Huntsville, the monthly average of 33.8 degrees was 7.7 degrees below normal and ranked as the 8th coldest January on record.  At Muscle Shoals, the average was a little higher at 35.2 degrees, which was 5.8 degrees below normal, ranking as the 12th coldest on record.  For both locations, it was the coldest January since 1985. 

At Huntsville, below normal temperatures occurred on 25 days of the month, and low temperatures dipped below freezing on all but four days.  Temperatures did not even rise above freezing on six days (January 6th, 7th, 23rd, 24th, 28th, and 29th), which was the most for any January since 1985.  The record for the most days below freezing in January occurred in 1978 (13 days).  Low temperatures fell below 10 degrees on five days (January 6th, 7th, 24th, 29th and 30th), which was the most in any January since 1977, when single digit temperatures occurred on eight days.  Record low temperatures were set on the 6th and 7th, with morning lows of 8 and 4 degrees, respectively.  Record low maximum temperatures of 25 degrees and 20 degrees occurred on the 6th and the 28th, respectively.   

At Muscle Shoals, below normal temperatures occurred on 20 days during the month, and low temperatures dipped below freezing on all but five days.  Temperatures did not reach above freezing on five days (January 6th, 7th, 23rd, 28th and 29th), which was the most for any January at thet Shoals since 1988, when temperatures also did not rise above freezing for a total of five days.  The record for the most days below freezing in January occurred in 1978 (13 days).  Low temperatures fell into the single ditis on four days, which was the most in any January since 1982, which also contained four such days.  Amazingly, no record low minimum temperatures were set at Muscle Shoals for the month, however, a record low maximum temperature of 22 degrees was set on the 28th.  

The primary question being asked is...why was it so cold this January?  As usual, especially in the winter months, the reason lies largely in the mean configuration of the jet stream.  The annotated image to the left shows the mean upper-level wind pattern across North America and adjacent Ocean waters during the month of January (background imagery/data courtesy NOAA/ESRL, Physical Sciences Division¹).  Notice that the jet stream exhibited a high amplitude pattern and was located far northward across portions of the eastern Pacific and western North America, including Alaska, during the month.  This was due to a very large "blocking" high pressure system situated over that region.  Air will tend to flow around and to the left of these large high pressure systems, which forced the jet stream well northward into the high latitudes of Alaska and northwest Canada, even into the Arctic.  So, what goes north must eventually go south, and a compensating southward push of air out of the arctic lead to a pronounced "dip" in the jet downstream over portions of eastern North America.  This overall pattern was relatively stagnant and lead to a series of cold air outbreaks across the Tennessee Valley.  Not only that, but these airmasses typically origniated from the cold arctic region.  The pattern of temperature anomalies (temperature departures from normal) across the North American domain can be seen in the annotated image to the right (image courtesy of NOAA ESRL Physical Scienced Division¹).  Temperatures averaged around 2-5 degrees (C) below normal across a swath from the Great Lakes region through the Tennessee Valley and into the northern Gulf Coast region.  Notice that temperatures were much above normal, however, over the West Coast and especially Alaska and Greenland, where anomalies up to 8-10 degrees (C) occurred.    

Daily Temperature Graphs for each location (click on the images for a larger version).

Huntsville - Jan 2014 Temperature Graph	Muscle Shoals - Jan 2014 Temperature Graph

Temperature Statistics for Huntsville and Muscle Shoals. All temperatures are in degrees Fahrenheit.

Precipitation...

Precipitation was below normal across nearly all of the Tennesse Valley during the month of January.  Precipitation was highest in portions of the Bankhead National Forest and in a swath from Huntsville northeastward through the Cumberland Plateau, and was lowest across much of DeKalb and Marshall Counties (as noted in the images below).  At Huntsville, precipitation measured 3.30 inches, which was 1.59 inches below normal.  At Muscle Shoals, precipitation tallied 1.70 inches, which was 2.91 inches below normal. The heaviest precipitation event occurred on the 11th, as rain and thunderstorms moved across the area.  Huntsville received 2.11 inches, which accounted for about 64% of the precipitation for the entire month.  The precipitation was heavy enough to cause minor flooding on the Paint Rock River just following the rain on the 12th.  After this rain event and particularly the middle of the month, very little precipitation fell across the area.  By the end of the month, due to the very dry airmasses and lack of rain or snow, D0 (abnormally dry) conditions had developed, per the U. S. Drought Monitor. 

Despite the pervasive cold temperatures, only trace amounts of snow occurred at both Huntsville and Muscle Shoals.  However, some locations in the Huntsville Warning and Forecast Area did receive measurable snow.  The most snowfall for the month of January was recorded in the small town of Sewanee, TN atop the Cumberland Plateau, where 5.7 inches were measured.  In Alabama, the snowfall leaders (official Cooperative and Backyard stations for the Huntsville area) were Valley Head and Boaz, which both received one inch of snow.                  

Precipitation Estimates and Departures from Normal for January for the Huntsville Forecast Area (amounts are in units of inches).

Precipitation Estimates	Precipitation Departures from Normal

Precipitation Statistics for Huntsville and Muscle Shoals (amounts are in units of inches). 

The Monthly Outlook for February from the Climate Prediction Center...

The one month temperature outlook indicates equal chances for above, near or below normal temperatures for the Tennessee Valley climatic zones.  The 3-tiered probabilities are as follows...

Above Normal....33%
Near Normal......34%
Below Normal....33%

The one month precipitation outlook indicates higher chances for above normal precipitation for the central Tennessee Valley climatic zones. The 3-tiered probabilities are as follows...

Above Normal....45%
Near Normal......33%
Below Normal....22%

What is normal for February? ...Huntsville daily normals and records / Muscle Shoals daily normals and records

¹ Image provided by the NOAA/ESRL Physical Sciences Division, Boulder Colorado from their Web site at https://www.esrl.noaa.gov/psd/.  NCEP Reanalysis: Kalnay, E. and Coauthors, 1996: The NCEP/NCAR Reanalysis 40-year Project. Bull. Amer. Meteor. Soc., 77, 437-471

* Normal temperatures and precipitation are based on the 1981-2010 climatological period. All temperature data are expressed in degrees Fahrenheit.
** Temperature data for Huntsville date back to 1907, while precipitation data are available since 1894. Any months that contain missing daily temperature or precipitation data are not counted in the rankings.

*** Temperature and precipitation data for Muscle Shoals date back to 1893, however sporadic outages of data occur especially in the 1910s and again from September 1995 through May 1997. Any months that contain missing daily temperature or precipitation data are not counted in the rankings.

Note...all data above are preliminary and have not undergone final quality control by the National Climatic Data Center (NCDC). Therefore, these data are subject to revision. Final and certified data can be accessed at the NCDC at the following location... https://www.ncdc.noaa.gov

One month and seasonal temperature and precipitation outlooks may be obtained from the Climate Prediction Center at the following location...http://www.cpc.ncep.noaa.gov

KDW