by Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of February 2018 was warmer and much wetter than normal. In fact, it becomes the second wettest Ffebruary on record. The thirty-day outlook for February 2018, issued on January 18, had called for above normal temperatures and below normal precipitation. The January 31 revision made no changes to this outlook. Compared with February 2017, the month was 7.6 deg. Cooler and 6.51 inches wetter. February 2017 was the warmest February on record.
Year-to-date rainfall through the end of the month was 1.36 inches more in 2018 than in 2017; last year, January was very wet. The Winter season of 2017-2018 saw near normal precipitation with 11.97 inches. December and January were dry, but February was very wet. Normal Winter precipitation is 12.02 inches. The Winter saw near normal temperatures, with December and January colder than normal and February warmer than normal.
The Winter of 2017-2018 was 7.6 deg. Cooler than the previous Winter, and 1.75 inches drier. 2.2 inches of snow fell in this most recent Winter, with only a trace in 2016-2017. Weak cold fronts crossed early in the month, with fluctuations between above normal and near normal temperatures through the 6th. An upper air disturbance crossed on the 3rd, with light rainfall covering about 70 percent of the area. Most amounts over the central and northern counties were under one-tenth inch, with heavier amounts over the southern counties. Milam received 0.83 inch.
A strong cold front and accompanying upper air low crossed on the 6th. This brought widespread rain and thunderstorms followed by much colder temperatures. Rainfall amounts over the northern two-thirds of the region ranged from one to more than four inches, with amounts over the southern counties under one inch. The heaviest rainfall was 4.19 inches at Karnack. There were a few reports of hail of under one inch in diameter from Tyler to Texarkana on the afternoon of the 6th. There were also a few occurrences of very light freezing rain along Red River on the evening of the 6th.
Cold temperatures persisted into the morning of the 8th, with warming to above normal temperatures until another Arctic cold front arrived on the morning of the 10th. Showers and a few thunderstorms accompanied the front, with most rainfall amounts over the central and northern counties under one-fourth inch. Over the southern counties, thunderstorms associated with the upper air low which pulled the cold front through the region brought amounts of around one inch. The heaviest was 1.94 inches at Sam Rayburn Reservoir.
On the 11th, moist air overrode the shallow Arctic air layer, resulting in light precipitation. In the northern two-thirds of the region, this fell as freezing rain or sleet, with precipitation amounts under one-fourth inch and coverage of about 80 percent. Ice formed on bridges and some road surfaces, but little accumulated on grassy surfaces. A crossing disturbance the last associated with the previous day's upper air trough--triggered the precipitation.
Temperatures ran below normal until a dramatic warm-up occurred on the 14th with the passage of a warm front. This boundary was preceded by dense fog on the morning of the 14th, and was accompanied by widespread showers and a few thunderstorms on the 13th and 14th. Coverage was near 100 percent, and amounts were mostly around one-half inch. The heaviest was 1.23 inches at Avinger.
A weak cold front came through on the morning of the 16th, lowering temperatures slightly until it came back through on the afternoon of the 18th as a warm front. A southwest flow aloft and its attendant disturbances brought showers on the 17th and 18th. Coverage on the 17th neared 100 percent with amounts mostly under one-fourth inch. The heaviest was 0.66 inch at Powderly. Coverage was considerably less on the 18th under 25 percent. Amounts were mostly under one-tenth inch.
The area remained in the warm air mass, with temperatures well above normal, until an Arctic front arrived on the evening of the 20th. It was accompanied by a large and strong upper air low, and a very strong moisture feed from the Western Caribbean Sea and Gulf of Mexico, This resulted in heavy rains from the 20th through the 24th. The heaviest reported on the morning of the 21st was 5.20 inches at Cumby. Amounts north of IH-20 were one inch or greater, with lighter amounts to the south. Coverage was near 100 percent. The heaviest rain reported on the morning of the 22nd was 8.58 inches at Noble, while the heaviest on the 23rd was 4.04 inches at Dreka.
Rainfall reports on the morning of the 24th were mostly under one-tenth of an inch except north of IH-30. Arthur City reported 1.84 inches of rain that morning. The heaviest report on the morning of the 25th was 2.26 inches at Powderly. The arrival of a cold front on the evening of the 24th largely shut down the rainfall, except over the southern and eastern counties where scattered showers continued into the 25th. Rainfall reports were under one-fourth inch over the eastern counties; but were significantly heavier over the extreme southeast, where Rockland measured 3.92 inches.
Temperatures were near normal on the 21st and 22nd, but then went above normal from the 23rd through the end of the month. Shower coverage was about 75 percent on the 27th from a crossing disturbance. Amounts were mostly between one-ahlf inch and one inch, with Avinger the heaviest with 1.55 inches. Coverage was minimal on the 28th.
NOTE: Beginning with the March 2018 summary, the text description of the month's weather will no longer appear; nothing else changes. RKP
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.
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February 2018, RECORDS AND SUMMARY: