by Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The Winter of 2016-2017 was the warmest Winter on record in Tyler since regular observations began in 1896. (Climatological Winter differs from astronomical Winter, with the former referring to the months of December, January, and February.) This past Winter replaces the Winter season of 1910-1911 as the warmest, with 54.7 the average temperature that year. The average in the 2016-2017 Winter was 56.1.
In addition, February also set a record for the warmest month. Last month replaces February 2000, besting it by 2.6 deg with a mean temperature of 61.6. That value is also 2.6 deg. Higher than the mean March temperature. There are three possible explanations for the warmth of the most recent Winter season: an unusually strong and persistent flow of moisture from the Tropical Pacific into Western North America called an atmospheric river, this prevented Arctic air from making it this far south often; the warming of the climate, which became noticeable here in the 1970s, and the fact that the instruments are now located in the city. This is called the "urban heat island effect". The were moved into the city in March 1973.
The thirty-day outlook for February 2017, issued on January 19, called for above normal temperatures and near normal precipitation. It was not changed with the January 31 issuance. Compared with February 2016, the month was 6.3 deg. Warmer and 0.51 inch drier. Year-to-date rainfall was 5.84 inches greater in 2017 than in 2016.
The month began mild, but modified Canadian air entered the region on the morning of the 2nd. This brought below normal temperatures through the 4th. Warmer and more moist air returned between the 5th and 7th, with a weak disturbance crossing on the 5th and 6th resulting in light rain.
A weak cold front on the 8th lowered temperatures until tropical air returned on the 10th. This brought significant warming until another cold front arrived on the 13th. That front combined with an upper air low to bring widespread rainfall to the region of between one-half inch and an inch and a half to the region on the 14th. Temperatures fell to near normal values between the 15th and 17th, with a returning warm front bringing light showers on the 17th.
Warmer temperatures followed on the 18th and 19th, with another upper air low crossing on the 20th with widespread rains of between one-half inch and two inches on the latter date. Drier air entered the region on the 21st, resulting in very warm temperatures until a cold front arrived on the 24th. This brought temperatures back closer to normal through the 26th when another upper air storm arrived. Temperatures warmed through the end of the month, with showers beginning on the afternoon of the 26th. The 69-degree minimum temperature on the 28th was the warmest minimum ever observed in February since records began in 1896.
The reporting period for temperatures and phenomenon on each day is for the twenty-four hours ending at midnight hours GMT--6 p.m. CST and 7 p.m. CDT. The reporting period for precipitation is for the twenty-four hours ending at noon GMT--6 a.m. CST and 7 a.m. CDT. All times are given using the twenty-four hour clock, and are expressed in Greenwich Mean Time.
Observations are from NWS Station 41/9207/4 in Tyler, Texas. The term "normal" refers to averages from the standard climatic period 1971-2000.
MX MN OBS PCPN REMARKS
February 2017, RECORDS AND SUMMARY: