- For December, the average contiguous U.S. temperature was 36.5°F, 3.8°F above the 20th century average. This ranked as the sixth warmest December in the 125-year period of record and was the warmest such month since the record warm December of 2015.
- December was a relatively warm month across most of the Lower 48. Much-above-average temperatures were observed from the South to the central Plains and into the Great Lakes as well as across much of the Tennessee Valley and Florida. Nine states throughout the South and Southeast ranked in the top ten percent of the 125-year record. No state had a December average temperature which ranked below-average.
- Alaska ranked in the middle third of the December record with a statewide average temperature of 6.7°F, 3.0°F above the long-term average. A 9-day cold snap near the end of December brought bitter cold temperatures to the interior of Alaska with values bottoming out in the -40°F to -65°F range.
- The nationally averaged maximum temperature (daytime highs) was warmer than average during December at 46.2°F, 3.4°F above average, ranking as the tenth warmest December in the 125-year record. Parts of the Southwest and central Rockies had maximum temperatures which were much-below-average for the month. Much of the South, central Plains, Midwest and Ohio and Tennessee valleys had daytime high temperatures that were much-above average during December.
- The nationally averaged minimum temperature (overnight lows) during December was 26.7°F, 4.1°F above average and ranked as the fourth highest December average in the 125-year record and the warmest overnight low temperatures since the record warm December of 2015. Nine states ranked much-above-average with all but one state's minimum temperatures ranking above-average for the month. No state ranked below-average for minimum temperatures during December.
- Warm records in December outpaced cold records by a six-to-one margin. As of January 13, there were 4,098 warm daily high (1,890) and low (2,208) temperature records tied or broken during December. There were approximately 643 daily cold high (399) and low (244) temperature records set during the month.
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during December was 56 percent below average and ranked as the 14th lowest value on record.
- The December precipitation total for the contiguous U.S. was 2.53 inches, 0.18 inch above average, and ranked in the middle third of the 125-year period of record.
- Above-average precipitation occurred across parts of the West, central and northern Plains, Great Lakes and from the Southeast into parts of New England. Minnesota ranked fourth wettest for December.
- Below-average precipitation fell across portions of the Northwest, South and Mississippi Valley. Louisiana ranked eighth driest for the month.
- According to the December 31 U.S. Drought Monitor report, approximately 11 percent of the contiguous U.S. was in drought, which is similar to the extent of drought noted at the beginning of December. By the end of 2019, drought was entrenched across the Southwest, Texas, the Pacific Northwest and across portions of the Alaskan Panhandle, Hawaii and Puerto Rico.
These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Centers for Environmental Information.
Northeast Region (Information provided by the Northeast Regional Climate Center)
- The Northeast's average temperature for December was 30.2 degrees F (-1.0 degrees C), 1.7 degrees F (0.9 degrees C) warmer than normal. All twelve states wrapped up the month on the warm side of normal, with departures ranging from 0.2 degrees F (0.1 degrees C) above normal in Massachusetts to 4.6 degrees F (2.6 degrees C) in West Virginia, the state's 16th warmest December.
- In December, the Northeast received 4.17 inches (105.92 mm) of precipitation, which was 119 percent of normal. Maine was the lone drier-than-normal state seeing 94 percent of normal precipitation. For the remaining states, precipitation ranged from 102 percent of normal in Vermont to 170 percent of normal in Massachusetts. This December ranked among the 20 wettest on record for four states: Massachusetts, seventh wettest; Rhode Island, ninth wettest; Connecticut, 10th wettest; and New Jersey, 19th wettest. In addition, Kennedy Airport, New York, had its wettest December on record.
- The U.S. Drought Monitor released on December 5 showed 2 percent of the region as abnormally dry. These areas included southern New Jersey, southeastern Pennsylvania, parts of Delaware, and southern and eastern Maryland. Conditions improved during the month for most areas, with abnormal dryness easing in southern New Jersey and southeastern Pennsylvania by December 10 and in southern Maryland by December 17. However, abnormal dryness lingered in eastern Maryland and southern Delaware through month's end. The U.S. Drought Monitor released on January 2, 2020, showed less than 1 percent of the region as abnormally dry.
- A significant storm moved through the region from December 1 to 3. The greatest storm snow totals of 24 inches (61 cm) or more occurred in eastern New York and New England, with a maximum of 36 inches (91 cm) in southern New Hampshire. Snowfall rates of 2 inches (5 cm) per hour were observed in several locations. Albany, New York, reported snow for 39 consecutive hours. When it was over, the site had amassed 22.6 inches (57.4 cm) of snow, ranking among the five largest snowstorms for December and as one of the ten all-time largest snowstorms on record. The storm also produced freezing rain, with ice accumulations of up to 0.40 inches (1 cm) in western Maryland, central Pennsylvania, and the western half of New York. Post-Thanksgiving travel was severely impacted. There were hundreds of vehicle accidents, including several large crashes. For instance, in western Maryland, a pileup involving more than 25 vehicles shut down Interstate 68 for four hours. In central New York, icy road conditions contributed to a crash involving at least 10 vehicles on Interstate 81 and caused a section of Interstate 86 to be closed. Air travel was also hampered. Hundreds of flights were cancelled and thousands were delayed, in some cases for more than three hours. In Buffalo, New York, a plane slid off a taxiway after landing. The storm also resulted in power outages and school closures in the region. Another storm from December 13 to 14 produced mixed precipitation across the region. The greatest rain totals of 3 to 5 inches (76 to 127 mm) were generally in southern Maine, where a few locations experienced flash flooding. Portland, Maine, picked up 3.40 inches (86.36 mm) of rain on December 14, making it the site's third wettest December day. This was only 0.10 inches (2.54 mm) short of the record, which stands at 3.50 inches (88.90 mm) set on December 18, 2012, and December 4, 1990. In portions of the Northeast, icy roads contributed to crashes, including an 11-vehicle crash on Interstate 95 in central Maine. In addition, all lanes along a stretch of Interstate 68 in western Maryland were shut down for a period of time due to hazardous driving conditions. A storm system from December 16 to 17 brought rain, ice, and snow to the region. Up to 3.25 inches (82.55 mm) of rain caused flooding in parts of West Virginia, with some road and school closures. Other areas, including the Eastern Panhandle of West Virginia, eastern Pennsylvania, and northern New Jersey, saw up to 0.50 inches (1.27 cm) of ice accumulation, which downed tree limbs and wires and led to power outages. Snow accumulations were generally less than 8 inches (20 cm). Behind the storm, an Arctic front brought intense snow squalls and strong winds and ushered bitterly cold air into the region. The squalls likely contributed to a pileup involving nearly 60 vehicles on Interstate 80 in central Pennsylvania that resulted in two deaths, sent dozens of people to the hospital, and caused the westbound lanes closed for more than a day. Snow squalls were also blamed for a series of crashes involving more than a dozen vehicles on the New York State Thruway in central New York. At the end of the month, from December 29 to 31, a storm system brought a variety of weather conditions to the Northeast. Portions of northern New Jersey, Long Island, and coastal Connecticut saw up to 2 inches (51 mm) of rain, while freezing rain caused 0.25 to 0.50 inches (6 to 13 mm) of ice accumulation in eastern/northern New York and western/central Massachusetts and snow totals topped a foot (30 cm) in southern Maine. Lightning and hail were also reported in northern Connecticut and central Massachusetts. The main impact was scattered power outages due to downed tree branches and wires.
- For more information, please visit the Northeast Regional Climate Center Home Page.
Midwest Region (Information provided by the Midwest Regional Climate Center)
- December precipitation was above normal in the upper Midwest and in the Ohio River Valley. Values were below normal in all of Illinois, along with most of Missouri and Iowa, and parts of other states. The driest areas were in southern Missouri where totals were less than half of the normal December totals. Totals exceeded twice the normal amount in a small part of eastern Kentucky and in the upper Midwest, including northern and central Minnesota, northern Wisconsin, and Upper Michigan. Averaged over the region, precipitation was 2.51 inches (64 mm) which was 0.30 inches (8 mm) above normal. Minnesota ranked as the 4th wettest December on record (125 years starting in 1895) with Wisconsin and Michigan also ranking among the top-10 in their histories. Stations that set new December precipitation records included Brainerd, Minnesota (72 years of data), Iron Mountain, Michigan (113 years), Superior, Wisconsin (107 years). The Dubuque, Iowa Lock and Dam reported their driest December on record (82 years).
- December temperatures were above normal for nearly the entire Midwest. The region averaged 30.5 degrees F (-0.8 C) which was 4.6 degrees F (2.5 C) above normal. This ranked as the 17th warmest December on record (125 years). Missouri (9th) and Iowa (11th) ranked among the warmest 10 percent of their respective histories (125 years). Moderate warmth to start the month gave way to a colder second week of December. However, the second half of the month was unseasonably warm, with temperatures exceptionally warm between Christmas Day and New Year's Eve. Warmth during the month led to more than 950 record high maximum and minimum daily readings across the Midwest.
- Snowfall totals for December ranged from nothing to more than 50 inches (127 cm) across the region. Compared to normal, the snowiest locations were in northwestern Minnesota where the totals over 30 inches (76 cm) exceeded three times normal. The largest snowfall totals ranging from 30 inches (76 cm) to 50 inches (127 cm) for most of Upper Michigan were typically above normal, although snowfall was below normal for the Keweenaw Peninsula that extends into Lake Superior. The upper Midwest got much of their snow in storm systems that came in the first few days and the last few days of the month. A swath of the Midwest that extended across Missouri, Illinois, Indiana, and into southwestern Ohio picked up above-normal snow in the second week of December. Much of the remainder of the region had below-normal snowfall for the month. Areas with less than 25 percent of normal extended across the southern edge of the region and also extended from parts of Iowa to around the southern tip of Lake Michigan.
- For further details on the weather and climate events in the Midwest, see the weekly and monthly reports at the Midwest Climate Watch page.
Southeast Region (Information provided by the Southeast Regional Climate Center)
- Temperatures were much above average across the Southeast and Puerto Rico for the month of December. Monthly mean temperatures were over 4 degrees F (2.2 degrees C) above normal in more than half of the 178 long-term (i.e., period of record equaling or exceeding 50 years) stations across the region. None of the stations reported below average mean temperatures for the month. San Juan, PR (1898-2019) observed its warmest December mean temperature on record at 81.5 degrees F (27.5 degrees C). While maximum temperatures were generally 3 to 4 degrees F (1.6 to 2.2 degrees C) warmer than average, minimum temperatures throughout the region ranged from around 5 to 7 degrees F (2.8 to 3.9 degrees C) above average, consistent with general trends seen in the region over time. Orlando, FL (1892-2019) tied its 3rd warmest December for average monthly minimum temperature at 58.5 degrees F (14.7 degrees C). The warmest weather of the month occurred on the 30th, as unusually warm and humid air surged northward ahead of an approaching cold front. Daytime maximum temperatures reached or exceeded 70 degrees F (21.1 degrees C) across portions of every state. Raleigh, NC (1887-2019) reported a daytime maximum temperature of 76 degrees F (24 degrees C), which tied the daily record. In contrast, the coldest weather of the month occurred on December 18th - 20th, as a continental high pressure system ushered in unseasonably cold air from the northwest. Daily minimum temperatures fell below 32 degrees F (0 degrees C) across portions of every state, including Florida. Tallahassee, FL (1896-2019) reported a daily minimum temperature of 28 degrees F (-2.2 degrees C), Washington Dulles, VA (1962-2019) reported a daily minimum temperature of 18 degrees F (-7.8 degrees C), and Mt. Mitchell, NC (1925-2019) reported a daily minimum of 6 degrees F (-14.4 degrees C).
- The Southeast was exceptionally wet in December, except for Virginia, eastern North Carolina and Mobile, AL. Most of the rest of the region was about 130 percent wetter than normal, with pockets of more than 300 percent of normal in Florida and southeastern Georgia. There were 4 long-term stations that observed more than 9 inches (229 mm) of precipitation for December, including Darien, GA (1957-2019; 2nd wettest December) at 9.52 inches (242 mm), West Palm Beach, FL (1888-2019; 4th wettest December) at 9.36 inches (238 mm), and Columbia, SC (1887-2019; T-1st wettest December) at 9.31 inches (236 mm). On December 22nd and 23rd, a slow-moving low pressure system produced over 3 inches (76 mm) of rainfall across portions of southern Florida and southeastern Georgia. As a result, Brunswick, GA (1948-2019) observed its wettest maximum daily precipitation for December at 4 inches (102 mm), and Key West, FL (1871-2019) observed its 2nd wettest maximum daily precipitation for December at 5.48 inches (139 mm). In contrast, unusual dryness was found in Virginia, and eastern North Carolina, where the precipitation values ranged from 90 to less than 70 percent of normal. Bluefield, VA (1927-2019) only reported 1.67 inches (42 mm) of precipitation for the month, which was about 2 inches (51 mm) below normal. Parts of Puerto Rico also reported below normal precipitation, with St. Croix (1951-2019) only observing 1.8 inches (46 mm) of rain. Some light snowfall was reported across portions of the northern tier, with Washington Dulles, VA (1962-2019) observing 0.6 inches, Blacksburg, VA (1952-2019) observing 0.5 inches, and Washington Reagan, VA (1871-2019) observing 0.4 inches. Huntsville, AL (1894-2019) reported some ice pellets on the 10th. Mt. Mitchell, NC (1925-2019) recorded the highest snowfall total in the region for the month, at 4.2 inches.
- There were 78 severe weather reports across the Southeast during December, which is about 140 percent of the median monthly frequency of 56 reports during 2000-2018. There were 19 confirmed tornadoes reported for the month, more than triple the monthly average of 6. About 12 of these tornadoes were associated with a low pressure system that moved north of Alabama on December 16th. The most damaging tornado was rated an EF-2 with winds of 134 mph (60 m/s) and occurred in Lawrence County, AL. During the afternoon hours of December 16th, a long-track supercell thunderstorm developed in Mississippi and moved into southwest Alabama. The tornado intensified significantly approximately one mile south of Highway 20. Major damage to three structures was reported, and a doublewide manufactured home rolled off its plot, causing two fatalities and an injury, with additional injuries at the other damaged structures. Another EF-2 tornado with winds of 120 mph (54 m/s) was reported in Marengo County, AL the same day. This tornado also damaged a doublewide and a singlewide mobile home, which resulted in three injuries. There were 2 reports of hail with the severe weather in Alabama, the largest being half-dollar sized. There were 57 wind reports for the month, with Grandfather Mountain, NC reporting a peak wind gust of 107 mph (48 m/s), and Boone, NC reporting a peak wind gust of 67 mph (30 m/s) on December 5th.
- Overall drought conditions have improved for the month of December, with no areas of severe drought (D2). By the end of the month, drought conditions were gone from Virginia, North Carolina, South Carolina, Georgia, and Alabama. There were pockets of moderate drought (D1), ringed by an area of dry conditions (D0), in the Panhandle and southern parts of Florida. Puerto Rico also developed an area of moderate drought (D1), ringed by an area of dry conditions (D0) in the eastern half of the country. The majority of wheat and winter forages were in good condition due to the rainfall and warm temperatures throughout Alabama and Georgia. However, some cattle producers still needed to supplement with hay and feed. Hay was in short supply due to the drought conditions that hurt pastures in autumn. In Florida, several pastures in the Panhandle received some frost damage at the beginning of the month. However, the warm weather toward the end of the month allowed vegetable growers to prepare land for spring plantings and allowed for citrus grove operations to be normal for this time of the year. The late season rainfall and high humidity in North Carolina delayed the harvest of the remaining soybean fields and limited field work. However, in South Carolina winter greens were being harvested and in good condition due to the adequate rainfall and mild temperatures. The persistent dry conditions early this winter, have resulted in damage to some pastures and feeding areas in Virginia.
- For more information, please visit the Southeast Regional Climate Center Home Page.
High Plains Region (Information provided by the High Plains Regional Climate Center)
- In contrast to the past couple of months, the start of winter was generally mild for the High Plains region. Temperature departures of 3.0-6.0 degrees F (1.7-3.3 degrees C) were widespread, especially across Kansas and Nebraska. Although there were some isolated areas where departures exceeded 6.0 degrees F (3.3 degrees C), very few locations ranked in the top 10 warmest Decembers on record. Exceptions to the overall warm conditions included portions of the Rocky Mountains and eastern North Dakota, where temperatures were below normal.
- The month of December brought wet and snowy conditions to portions of the region, especially late in the month. A large storm system tracked across the High Plains region during the last week of December. This system brought widespread precipitation, including strong winds and heavy rain and snow. This created significant travel issues for many that were traveling between Christmas and New Year's Day. The excessive amount of precipitation that this system brought was largely responsible for the well-above-normal precipitation anomalies recorded for the month across parts of the region.
- Crop harvest remained well behind schedule across the northern areas of the High Plains. Farmers across North Dakota continued to struggle getting their crops out of the ground. As of December 8th, less than half (43 percent) of North Dakota's corn crop had been harvested. Sunflower harvest was doing a little better, with 60 percent of North Dakota's crop having been harvested. In South Dakota the sunflower harvest was still not complete but was getting closer at 79 percent complete. Elsewhere across the region, crop harvest was largely complete for the season. The 2019 corn harvest will go down as the slowest harvest in the last 25 years, second only to 2009. It is likely that some crops will not get harvested until spring, or perhaps not harvested at all, due to poor field conditions in northern sections of the region.
- The winter season started off on a relatively mild note across the High Plains. Temperatures throughout the region were generally above normal for the month of December, with departures reaching over 6.0 degrees F (3.3 degrees C) above normal in some locations. This marked the first time since September that above-normal temperatures dominated the High Plains region as a whole. The largest departures occurred across Kansas, Nebraska, eastern Colorado, and eastern Wyoming. Further west, across portions of central Colorado and southwestern Wyoming, there was a small area of below-normal temperatures. Near-normal temperatures were observed over much of North Dakota and South Dakota. While most areas experienced relatively mild month as a whole, the warmest areas only ranked in the top 20 warmest Decembers on record.
- The month of December brought generally above normal temperatures for much of the High Plains, but did not climb high enough to break records. However, an unseasonably warm air mass brought temperatures of over 60.0 degrees F (15.6 degrees C) to central and southern portions of the High Plains toward the end of the month, just in time for the Christmas holiday. One of these locations that experienced anomalous warmth was Concordia, Kansas, which recorded a high temperature of 62.0 degrees F (16.7 degrees C). This was the fourth warmest Christmas Day on record in Concordia. The warmest Christmas Day for Concordia, KS was 64.0 degrees F (17.8 degrees C), which occurred in 2016 (period of record 1885-present).
- Precipitation varied quite significantly across the High Plains region during the month of December. Across central and northern sections of the High Plains there were areas that observed widespread precipitation amounts of 200 to 400 percent of normal, with embedded pockets where amounts were up to 800 percent of normal. Meanwhile, on the other end of the spectrum, precipitation was much below normal across some portions of eastern Colorado, northern Wyoming, the panhandle of Nebraska, and northern North Dakota. Although precipitation in these areas was less than half of normal, these deficits are not large this time of the year. Ultimately, several locations across the region ranked in the top 10 wettest Decembers on record, including Grand Forks, ND (6th wettest); Lincoln, NE (7th wettest); Fargo, ND (8th wettest); and Concordia, KS (10th wettest). Some of the same locations that had their top 10 wettest December also recorded their top 10 snowiest December. This includes Fargo, ND (6th snowiest); and Grand Forks, ND (7th snowiest).
- Similar to the month of November, December started off relatively quiet and dry for much of the region but ended wet and snowy. During the last week of the month, a large storm system tracked across the High Plains. This system arrived on the 27th and brought a swath of heavy snow and strong winds to central Nebraska, much of South Dakota, and eastern North Dakota. Snow totals from this system ranged from 4.0-18.0 inches (10-48 cm) in this area. The combination of heavy snow and strong winds disrupted travelers on I-80 in central Nebraska, forcing the interstate to close for a time. This storm system also produced significant rainfall for this time of year across portions of Kansas and eastern Nebraska. Over 2.00 inches (51 mm) of rain was observed in some areas. For instance, 2.12 inches (54 mm) of rain fell in Lincoln, Nebraska on the 27th. This was just 0.01 inch (0.3 mm) shy of breaking the one-day total precipitation record for the entire month of December (period of record 1887-present). Fortunately, the ground across this area was still not frozen, which allowed at least some of the rain to filter into the soil. If the soil had been frozen there would have been more runoff from this event, which could have been resulted in more abrupt rises of creeks, streams, and rivers.
- Mountain snowpack was generally in good shape this month across much of Colorado and Wyoming. By the end of December, snowpack was near to above normal in all basins in Colorado and most basins in Wyoming. However, a few basins in western Wyoming had below-normal snowpack. Across the Upper Missouri Basin, mountain Snow Water Equivalent (SWE) was near to slightly above normal. As of December 15th, mountain SWE was 96 percent of normal above Fort Peck and 108 percent of normal in the reach from Fort Peck to Garrison, according to the U.S. Army Corps of Engineers. The month of December also brought abundant snowfall to much of the Plains at the end of the month, with the highest snowpack found across central Nebraska and the Dakotas.
- Drought conditions improved or were removed across southern and western portions of the High Plains region during the month of December. According to the U.S. Drought Monitor, the area experiencing drought (D1-D4) in the High Plains region decreased from approximately 15 percent at the end of November to just over 12 percent by the end of December. This improvement was the result of storm systems bringing wetter conditions to the western portion of the High Plains region in December.
- This month, abnormally dry conditions (D0) shrank across portions of western Kansas and central and eastern Colorado. There was some expansion of D0 conditions across western Wyoming, with a small area of D0 remaining in far southwestern Nebraska. Some improvement was observed over northern Colorado during the month, with a slight reduction of abnormally dry conditions in this area. Meanwhile, across southern Colorado and western Kansas, moderate drought (D1) and severe drought (D2) decreased in area through the month of December. A small pocket of extreme drought (D3) that had developed across southwestern Kansas during October and November was removed by the end of December.
- The remainder of the region remained free of drought and abnormally dry conditions. As of the December 31st release of the U.S. Drought Monitor, both Nebraska and South Dakota were drought-free all of 2019.
- For more information, please visit the High Plains Regional Climate Center Home Page.
Southern Region (Information provided by the Southern Regional Climate Center)
- Temperatures for the month of December were above normal across the Southern Region. Parts of eastern, southern, and western Texas; southern Louisiana; and southern Mississippi experienced temperatures 0 to 2 degrees F (0.00 to 1.11 degrees C) above normal. Parts of eastern, central, southern, western, and northern Texas; southern, eastern, and western Oklahoma; southern, central, and eastern Arkansas; southern, central, and northwestern Louisiana; and southern, central, and northwestern Mississippi experienced temperatures 2 to 4 degrees F (1.11 to 2.22 degrees C) above normal. Parts of western, southwestern, central, eastern, and northern Texas; central, eastern, northern, and western Oklahoma; northern Louisiana; southeastern, central, and northern Arkansas; eastern and western Mississippi; and western, central, and eastern Tennessee experienced temperatures 4 to 6 degrees F (2.22 to 3.33 degrees C) above normal. Parts of northern Texas, western Oklahoma, and central and eastern Tennessee experienced temperatures 6 to 8 degrees F (3.33 to 4.44 degrees C) above normal. The statewide monthly average temperatures were as follows: Arkansas – 45.60 degrees F (7.56 degrees C), Louisiana – 54.30 degrees F (12.39 degrees C), Mississippi – 50.60 degrees F (10.33 degrees C), Oklahoma – 43.20 degrees F (6.22 degrees C), Tennessee – 45.20 degrees F (7.33 degrees C), and Texas – 50.60 degrees F (10.33 degrees C). The statewide temperature rankings for December were as follows: Arkansas (sixteenth warmest), Louisiana (twenty-third warmest), Mississippi (twentieth warmest), Oklahoma (tenth warmest), Tennessee (tenth warmest), and Texas (thirteenth warmest). All state rankings are based on the period spanning 1895-2019.
- Precipitation values for the month of December varied spatially across the Southern Region. Parts of central, western, and southern Oklahoma; northern, eastern, western, central, and southern Arkansas; northwestern, southern, and southwestern Louisiana; southern Mississippi; and eastern, northern, western, central, and southern Texas received 50 percent or less of normal precipitation. Parts of southwestern Louisiana, western Arkansas, northeastern and southwestern Oklahoma, and northern, eastern, western, and southern Texas received 25 percent or less of normal precipitation, while parts of northeastern Oklahoma as well as western and southwestern Texas received 5 percent or less of normal precipitation. In contrast, parts of southern, western, and northern Texas; western Oklahoma; and eastern Tennessee received 150 percent or more of normal precipitation, while parts of southern and western Texas received precipitation 200 percent or more of normal. The statewide precipitation totals for the month were as follows: Arkansas – 2.19 inches (55.63 mm), Louisiana – 3.13 inches (79.50 mm), Mississippi – 5.39 inches (136.91 mm), Oklahoma – 1.06 inches (26.92 mm), Tennessee – 5.99 inches (152.15 mm), and Texas – 0.85 inches (21.59 mm). The state precipitation rankings for December were as follows: Arkansas (seventeenth driest), Louisiana (eighth driest), Mississippi (fifty-sixth wettest), Oklahoma (forty-second driest), Tennessee (thirty-eighth wettest), and Texas (twenty-fifth driest). All state rankings are based on the period spanning 1895-2019.
- Drought and Severe Weather:
- At the end of December, drought conditions both improved and deteriorated across the Southern Region. Extreme drought conditions persisted across southwestern Texas, while areas in central Texas experienced development of extreme drought conditions. Severe drought classifications were still present in central and southern Texas as well as southwestern and extreme western Oklahoma, while new areas developed in southwestern Arkansas and eastern Texas. Moderate drought classifications decreased across southwestern and extreme western Oklahoma, northern Texas, northeastern Louisiana, and west-central Texas, while new areas developed in eastern and southeastern Texas, southwestern Arkansas, and northwestern Louisiana. There was an increase in the overall area experiencing abnormally dry conditions despite improvement across southwestern and extreme western Oklahoma, central Tennessee, and extreme western Tennessee. This was due to an increase in abnormally dry conditions across southeastern and eastern Texas, southern, north-central, and northwestern Louisiana, southwestern Mississippi, and southwestern Arkansas.
- In December, there were a total of 131 storm reports across Oklahoma, Texas, Arkansas, Tennessee, Louisiana, and Mississippi. There were 51 tornado reports, 17 hail reports, and 63 wind reports. Mississippi tallied the most tornado (40) hail (14), and wind (27) reports. Unsurprisingly, Mississippi tallied the most reports (81) while Texas tallied the fewest (1). Three states (Oklahoma, Louisiana and Mississippi) reported tornadoes, three states (Arkansas, Louisiana, and Mississippi) had at least 1 hail report, and every state had at least 1 wind report. All 131 reports were reported over a span of 4 days (December 16, 28, 29, and 30).
- On December 16, 2019, there were 38 tornado reports, 16 hail reports, and 40 wind reports across Texas, Louisiana, Arkansas, Mississippi, and Tennessee. One person was killed due to a tornado reported near De Ridder, Louisiana, while three people were injured due to an EF-3 tornado reported near Liberty, Mississippi. One person was injured due to high winds reported near Blair, Mississippi. A multi-vortex tornado was reported near Foxworth, Mississippi, while the tornado reported near Liberty, Mississippi was determined via storm survey to have winds approaching 140 mph (225.31 kph) and a maximum width approaching half a mile wide. Multiple buildings and power lines were damaged or destroyed and several trees were downed.
- On December 28, 2019, a EF-0 tornado was reported near Broken Arrow, Oklahoma, damaging two homes. One person was injured near Iron Springs, Arkansas after a tree was blown down on top of a mobile home.
- On December 29, 2019, there were 11 tornado reports across Mississippi, all of which were reported as either EF-0 or EF-1. A wind gust of 72 mph (115.87 kph) was reported near Walland, Tennessee, while high winds rolled a mobile home near Decatur, Tennessee, injuring two people.
- On December 30, 2019, a tornado was reported near Stratton, Mississippi.
- For more information, please visit the Southern Regional Climate Center Home Page.
Western Region (Information provided by the Western Region Climate Center)
- An equatorward displacement of the Pacific storm track and persistent trough in the eastern North Pacific Ocean favored active weather and anomalous moisture transport into the southwestern United States during December of 2019. Above average precipitation and drought amelioration occurred as a result in California, Nevada, and parts of Arizona. However, below average precipitation worsened drought conditions in Washington and Oregon and triggered drought onset in Idaho. Snowpack in the Pacific Northwest and northern Rockies was well below average at the end of December with most stations reporting less than 80% of 1981-2010 median conditions with many Cascade and Blue Mountain locations reporting 0-25% of median. Snow sports enthusiasts in the Southwest enjoyed excellent snow conditions during this first month of meteorological winter. The Sierra Nevada and Great Basin finished December with snowpack at 90-150% of median. Well-above normal snowpacks (100-250% of median) graced the Wasatch and Uinta ranges as well as the Colorado Rockies. Mountains in the Four Corners region, such as the San Francisco Peaks of Arizona, Sangre de Christo Mountains in New Mexico and Colorado, and the Pine and Escalante Mountains of Utah finished 2019 at 125-300% of median.
- Temperatures throughout the western U.S. were above normal with many regions 3-6°F (1.6-3.3°C) above normal. Below average temperatures were observed in southwestern Wyoming, southern California, and Arizona, while eastern Oregon, all of Montana, northern Wyoming, eastern Colorado, and southern New Mexico had the warmest anomalies. With an average temperature of 30°F (-1.1°C; 8.2°F (4.5°C) above normal), Helena, Montana had its fourth warmest December since 1938. Hope, New Mexico, where records started in 1919, was the sixth warmest at 48°F (8.8°C; 5.9°F (3.3°C) above average). Green River, Wyoming experienced its 12th coldest December with average temperatures of 14.3°F (-9.8°C), which is 7°F (3.8°C) below normal. Green River records began in 1897.
- Synoptic conditions lead to multiple heavy precipitation events in central and southern California, much of Arizona, southern Utah, and Colorado. Williams, Arizona measured 6.6 in (168 mm) of rainfall, its second wettest December since 1897 (335% of normal). Los Banos, California, which began observations in 1906, had its second wettest December with 5 in (127 mm; 320% of average). Dry conditions plagued the Pacific Northwest and northern Intermountain West. Forks, Washington normally observes 16.8 in (427 mm), but only measured 10.43 in (265 mm), or 62% of normal. Bozeman, Montana, had its 2nd driest December since 1941 with 0.09 in (2.3 mm; 18% of normal).
- The Hawaiian Islands continued to experience record warm average temperatures as sea surface temperature anomalies remained 1.8-3°F (1-1.5°C) above average. Lihue Airport averaged 76.5°F (24.7°C) which is 3.2°F (1.8°C) above normal. Molokai Airport averaged 76°F (24.4°C; 3.9°F (2.2°C) above normal), which were the warmest Decembers since 1949 and 1950, respectively. Hilo International Airport, where records began in 1949 recorded its second warmest December at 74.8°F (23.7°C; 2.5°F (1.4°C) above normal). Precipitation was below average on all islands except Oahu. For example, Molokai Airport observed 1.44 in (37 mm) of precipitation, 34% of average.
Precipitation anomalies varied throughout Alaska during December. Tanana measured zero precipitation (average 0.53 in (13 mm)) for the first time since records began in 1902 but further east, Delta Junction recorded 0.67 in (17 mm), 335% of average. Craig reported 14.42 in (366 mm) of precipitation (146% of average), making December the 10th wettest since 1936. At King Salmon, the 2.4 in (61 mm) of precipitation (195% of normal) made for the seventh wettest December since 1917. Anomalously warm sea surface temperatures in the Gulf of Alaska lead to warmer than average temperatures in coastal regions of southern Alaska, with average temperatures at Cordova Airport measuring 36.1°F (2.3°C; 7.7°F (4.3°C) above average and the fourth warmest since 1909) and Juneau having its second warmest December since 1936 with an average temperature of 36.9°F (2.7°C; 7°F (4°C) above average). These above normal temperatures promoted a below average snowpack in the Kenai Peninsula. Near record low Arctic sea ice extent likely favored the seventh warmest December in Barrow since 1901 (-0.8°F (-18°C), 7°F (4°C) above normal). Temperatures in interior Alaska were below average, with Circle Hot Springs averaging -18°F (-7.7°C; 6.7°F (3.2°C) below normal), its eight coldest December since 1935.
- Significant Events for December 2019
- Ice Jam in Alaska's Mat-Su Valley: Residents of the Matanuska-Susitna Borough in south-central Alaska required the help of rescue crews to access their homes after blocks of ice dammed Willow Creek and caused flooding of roads and several homes. Ice formed during a cold snap during December 20-21 when temperatures fell below 0°F (-18°C). The Pt. Mac Alaska Remote Automated Weather Station measured -12°F (-24°C) on December 21. From December 27 to 31, temperatures climbed from -5°F (-21°C) to 45°F (7.2°C), causing additional flooding in the area and hampering clean-up efforts.
- Heavy rainfall in the Mojave Desert of California: A deep, negatively tilted trough brought 1.76 in (45 mm) of precipitation to the Barstow-Daggett Airport in southeastern California on December 26. This was the wettest non-monsoon precipitation day ever, crushing the previous record of 0.43 in (11 mm) set in 1977. This was also the third most precipitation recorded in a day since records began in 1943.
- For more information, please go to the Western Regional Climate Center Home Page.