April 2008 National Climate Report

• For the contiguous United States, the average temperature for April was 51.0°F (10.6°C), which was 1.0°F (0.6°C) below the 20th century mean and ranked as the 29th coolest April on record, based on preliminary data.

• On the Regional level, much of the U.S. experienced cooler than normal temperatures during April. The Northwest region had much below average temperatures and the Northeast experienced much above average temperatures.

• Fifteen states in the contiguous U.S., all in the Northeast, Great Lakes, and Mid-Atlantic regions, were warmer than average for April, with New York ranking third warmest and Rhode Island fourth warmest. Sixteen states, all west of the Mississippi, were colder than average for April, with Washington ranking second coldest and Oregon fifth coldest.

• While temperatures varied from one extreme to the other regionally during April, the extremes balanced each other out, keeping the nations overall temperature-related residential energy demand for April near average based on NOAA's Residential Energy Demand Temperature Index (REDTI - an index developed at NOAA to relate energy usage to climate).

• April 2008 tied with 1896 and 1955 as the 54th driest in the 1895—2008 record. An average of 2.4 inches (61 mm) fell across the contiguous U.S. this month, which is 0.04 inches (1.1 mm) below average.

• April brought much above normal precipitation to the East North Central region and much below normal precipitation to the West and Southwest regions.

• Four states (Iowa, Missouri, Virginia, and Wisconsin) were much wetter than average for April, with Iowa and Wisconsin ranking fourth wettest on record. Four other states (Arizona, California, Nevada, and Utah) were much drier than average, with Arizona having the third driest April on record and California ranking fifth driest.

• Rainfall across parts of the Southeast led to improving drought conditions, with about 43% of the region classified in moderate to extreme drought at the end of April compared to 59% a month ago.

• Precipitation was below normal across most of the West in April. Many stations in California and Nevada reported their driest March-April total precipitation. Mountain snowpack, however, remained healthy with most of the intermountain and Northwest regions reporting above normal snow packs by the end of the month.

• April was much wetter than normal over parts of Alaska. Bethel received 11.7 inches (29.7 cm) of snow during the month, bringing the seasonal total to 102.4 inches (260.1 cm), nearly twice the average and only the second time in the last thirty years with over 100 inches (254 cm) of accumulated snowfall. By April 19, Nome accumulated 105.4 inches (268 cm) of snowfall, ranking as the second-snowiest winter on record behind 1994-95.

• Several strong storm systems affected the central and eastern U.S. during April. On the 4th, 21 tornadoes were reported across Louisiana, Mississippi, Alabama, North and South Carolina, while 62 tornadoes ravaged Texas and Oklahoma April 9-11. These storms, and others during the latter third of the month, also brought heavy rain, strong winds, and hail. Heavy rains during April 20-22 brought the monthly total to 8.32 inches (211 mm) at Richmond, Virginia.

• Four separate weather systems dropped heavy snow across parts of North Dakota, Minnesota, Wisconsin, and the Michigan Upper Peninsula during April. Babbit, Minnesota recorded 26 inches (66.0 cm) of snow, and 32 inches (81.3 cm) accumulated near the town of Virginia, Minnesota early in the month. This was the largest ever April multi-day snowfall in the Iron Range of northern Minnesota. The combination of snow melt and heavy rain resulted in continued flooding of rivers and streams throughout the northern half of the Midwest, particularly in northern Illinois and southern Wisconsin, and along the St. John River in Maine. At the end of the month, major flooding was occurring on the Mississippi River between Rock Island, Illinois and Burlington, Iowa. Heavy rains in the upper reaches of the Lower Mississippi River spawned historic water levels downstream.

• La Niña conditions were present in the tropical Pacific Ocean by the end of April. Equatorial sea-surface temperatures remained below average from the Date Line eastward to 130°W, but negative departures have been weakening over the past couple of months. According to the CPC, recent trends and model forecasts indicate the possibility of ENSO-neutral conditions developing during the next 2-3 months. A weakening La Niña may result in warmer than average conditions in the west, southwest, and northeast U.S. and drier than average conditions in the intermountain and Pacific Northwest. For additional information on ENSO conditions, please visit the NCDC ENSO Monitoring page and the latest NOAA ENSO Advisory.

• Alaska had its 43rd coolest April since records began in 1918, with a temperature 1.2°F (0.7°C) below the 1971—2000 average.
  
  
• Alaska had its 37th warmest February—April on record, with a temperature 0.3°F (0.2°C) above the 1971—2000 average.
  
  
• Alaska had its 39th warmest January—April on record, with a temperature 0.1°F (0.1°C) below the 1971—2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Monthly and Seasonal Highlights section below and visit the April Climate Summary page. For information on local temperature and precipitation records during the month of April, please visit NCDC's Extremes page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.

• Every one of the states in the Northeast averaged within the top twenty warmest on record in April. New York had its 3rd warmest April since 1895 and Maryland placed 19th in the rankings of warmest Aprils. The Northeast overall averaged 48.3°F (9.1°C), which made this month the 6th warmest April in 114 years. Departures ranged from 2.8°F (1.5°C) above normal in Maryland to 5.5°F (3.0°C) in New York.
  
  
• On average, the Northeast saw 90% of its normal April precipitation. The extreme southern and northern states saw the most precipitation this month while the centrally located states saw the least. Maryland, Maine, West Virginia and New Hampshire were the wettest states, with 129%, 116%, 114% and 104% of normal precipitation, respectively. New York (67% of normal), New Jersey (71% of normal) and Pennsylvania (75% of normal) were the driest spots. Rainfall this month resulted in an improvement in drought conditions in southeastern Maryland and southern Delaware. These areas, which had previously been classified as in severe drought for an extended period, experienced an improvement in conditions to moderate drought levels by the end of April.
  
  
• Strong thunderstorms brought torrential rain and two small tornados to portions of Charles, Prince Georges, Baltimore and Harford Counties in MD on April 20th. Spotter reports included flash flooding, downed trees and structural damage to two schools and a few homes. High water levels along the St. John River during the end of April flooded more than 100 homes and businesses in Fort Kent, ME, and caused the International Bridge between Fort Kent and Clair, New Brunswick, Canada to be closed amid fears of its collapse. Snowmelt from the record winter snowfall and 2-3 inches (5-8 cm) of rain at the end of April sent the river 5 feet (1.5 m) above flood stage and 2.8 feet (0.85 m) above the previous record set in 1979. Parts of Fort Kent through Van Buren in Aroostook County, ME were evacuated while Canadian officials warned residents downstream to prepare for the worst flood since 1973. Elsewhere in northern Maine, flood warnings were issued for sections of the Penobscot River, the Aroostook River, the Fish River and the Mattawamkeag River.
  

• There was a marked difference in both temperature and precipitation across the Midwest during April 2008, but patterns for both were very similar. Along a line from northeastern Wisconsin to northwestern Illinois to central Kentucky, average daily temperatures were near normal, rising eastward to as much as 5°F (2.8°C) above normal in northeastern Ohio. West of the aforementioned line, temperatures were below normal during the month. The largest departures of 3°F (1.7°C) to 5°F (2.8°C) below normal occurred from Minnesota south through the western halves of Iowa and Missouri. Temperatures did not reach the 70s (21-26°C) across much of the region until the second week of April.
  
  
• April precipitation was 150-200% of normal from southern Missouri northward through the eastern half of Iowa, Wisconsin, northern Minnesota, and the Michigan Upper Peninsula (UP). In contrast, precipitation was 60-75% of normal for the month from eastern Illinois through most of Indiana, Ohio, and southern Lower Michigan. Areas of above normal precipitation coincided closely with the colder areas of the Midwest in April, and the drier areas with the warmer eastern Midwest. The wet weather pattern over the southern Midwest in February and March continued into the first half of April. In the period between February 10 and April 10, 16 to 20 inches (40.6 to 50.8 cm) of precipitation accumulated across the southern third of Missouri, far southern Illinois, and far western Kentucky, two to three times normal. The 3-month period from February-April 2008 was the wettest on record for the Midwest region, with an average of 11.64 inches (29.6 cm) of precipitation. This was also the wettest February-April for Missouri with over 18 inches (460 mm) of precipitation, and second-wettest for Illinois. The continuation of wet weather rapidly improved dry conditions across the Midwest, and the April 8 U.S. Drought Monitor marked the first time since the second week of May 2005 that there was no D1 (Moderate) drought depicted anywhere in the Midwest.
  
  
• April snowfall was seven times normal across much of Minnesota, and two to three times normal across the northern half of Wisconsin and the Michigan UP. At the end of the month, there was still more than 4 inches (10.2 cm) of snow over much of northern Minnesota, and more than a foot across the Arrowhead. During April, the northern Midwest made up for the lack of snow early in the season when four weather systems dropped heavy snow on the region. On April 1, 8-10 inches (20-25 cm) of snow piled up in the central UP of Michigan, with 18-24 inches (46-61 cm) in Marquette County. A few days later, a small but strong wave of low pressure produced a narrow band of heavy snow from eastern North Dakota across the Iron Range of northern Minnesota. Snowfall amounts across northern Minnesota were generally in the 6-12 inch (15-30 cm) range, but portions of St. Louis County received more than two feet (61 cm) of snow. Babbitt, MN recorded 26 inches (66.0 cm) of snow, and 32 inches (81.3 cm) accumulated near Virginia, MN. This was the largest ever April multi-day snowfall in the Iron Range. The heavy wet snow caused trees and powers lines to snap, resulting in power outages to thousands of customers. During April, the combination of snow melt and heavy rain resulted in continued flooding of rivers and streams throughout the northern half of the region, particularly in northern Illinois and southern Wisconsin. At the end of the month, major flooding was occurring on the Mississippi River between Rock Island, IL and Burlington, IA. Moderate flooding was occurring on some rivers in Iowa, northern Illinois, and southern Wisconsin.
  

• Richmond, VA and Washington, D.C. both had average April temperatures more than 2.4°F (1.5°C) above normal, while some southern locations had slightly below normal temperatures for the month. Much of this was attributed to short spells of rather low overnight temperatures around the 15th and again on the 30th of the month. These cold snaps were not nearly as devastating as the Easter freeze of April 2007. On April 30, the temperature at Montgomery, AL was 40°F (4°C), 4°F (2°C) below normal.
  
  
• With a few notable exceptions, April was a rather quiet month. There was some rain throughout the region, although relatively few intense storms and little flooding. Many stations in the northern part of the region had above normal rainfall for the month, with Richmond, VA exceeding its long term average by over 150%, with a monthly total of 8.32 inches (211 mm). Much of this fell between April 20-22, when an upper level low brought rain to much of Virginia and eastern North Carolina. Cape Hatteras, on the Carolina coast, had its third wettest April since 1895. No major recording stations anywhere in the region were more than 1 inches (25 mm) below their long-term average values for the month. During the last 3 months, large portions of the coastal plains of all states have had slightly above normal precipitation, but inland areas received less than normal. Areas west of Charlotte, NC, south of Atlanta, GA and east of Birmingham, AL all have had little more than 50% of their usual precipitation since the beginning of February. Despite the recent rain, dry conditions continued throughout most of the region, with the northern parts of Alabama and Georgia, along with west-central North Carolina, still categorized as experiencing Extreme Drought. In some regions, particularly in the north, the reservoirs were full at month's end, giving a superficial impression that the drought was over. However, ground water levels were still very low, with many wells throughout the region having levels several feet below normal.
  
  
• Near the end of April, a strong frontal boundary passed through southeastern Virginia, producing 10 reports of tornadoes, the worst producing EF-3 magnitude damage. The most recent outbreak of such strong tornadoes in that area was back in 1993, when one touched down in Middlesex County, in the same system as an F4 twister in the Petersburg, VA area.
  

• The average temperature patterns warmed over the region during April, which is typical for this time of year, with the coldest temperatures to the north and the warmest temperatures to the south. The exception was in the mountains, where the average temperatures were the lowest owing to the decrease in temperature with elevation. The average April temperature over the region was below the April mean temperature for the normal period 1971-2000, with ranges across the region of 0-8°F (0-4°C) below average for the month. A few stations in Colorado and Kansas experienced temperatures from 0-2°F (0-1°C) above the monthly normal.
  
  
• Dryness was present over the western two thirds of the High Plains region during the month of April 2008. Dry areas in the eastern third of the region improved significantly with respect to March. Snow fell in the western Dakotas and in western Nebraska and in the mountainous states of Wyoming and Colorado, while much of the east and southeast portion of the region received mostly rainfall. Several stations in the western part of the region received 0.1 inches (2.5 mm) of precipitation or less, while stations in southeast Kansas received 5-8 inches (127-203 mm) of precipitation. A few parts of the region were above 100% of normal and some areas approached 200% of the normal precipitation for the 30 year period 1971-2000.
  
  

• The month of April was associated with near-normal temperatures throughout the domain of the Southern Region, with most average values deviating only slightly from normal. In general, temperatures were only slightly above normal in the gulf rim and slightly below normal in northern Oklahoma and northern Arkansas. The most anomalous temperatures were observed in northern Mississippi and eastern Tennessee, where values were ranged from 2-5°F (1-3°C) above the expected values.
  
  
• April monthly precipitation totals varied spatially throughout the Southern Region. The wettest portions of the region included most of Arkansas, western Tennessee, and central and northeastern Texas. In the state of Arkansas, only the southern counties that border Louisiana received near-normal or below-normal precipitation, and the rest received precipitation values that ranged from 150 to over 200 percent of normal. For example, Mammoth Spring recorded a total of 9.08 inches (~230 mm) for the month, which equates to 208% of normal. In central and northeastern Texas, precipitation totals in ranged from almost 3.5 inches (89 mm) in the vicinity of Austin, to approximately 5 inches (127 mm) at Waco. The former equates to roughly 140% of normal, while the latter equates to roughly 180% of normal precipitation. Elsewhere in the state, conditions were quite dry with precipitation totals ranging from as low as 4% of normal at El Paso and Del Rio, to approximately 30% near Amarillo and 40% at Houston. In Oklahoma, April precipitation totals were quite low in the panhandle (approximately 5-25% of normal), near-normal in the central counties, and anomalously high (130-230% of normal) in the eastern quarter of the state. Tulsa, OK recorded a total of 9.33 (237 mm) inches of precipitation, or 236% of normal. In Louisiana and southern Mississippi, precipitation totals for the month at most stations varied from approximately 25 to 50% of normal. In Tennessee, precipitation anomalies in the western quarter of the state ranged from 130 to 150% of normal. Similar values were also observed in northeastern Mississippi. Heavy rains in the upper reaches of the Lower Mississippi river spawned historic water levels along the Mississippi River this past month. At the Mississippi River hydrological station in Vicksburg, TN, water levels reached a stage of 50.77 feet (15.47 m) on April 26, making this the 7th highest crest in that location's history. As the aforementioned crests were approaching, so too were fears of high levee pressure and associated flood risks in New Orleans. As a result, Louisiana Governor Bobby Jindal gave the order to open the Bonnet Carré spillway on April 11, 2008. Last opened in 1997, this event marked the ninth opening of the spillway since 1927.
  
  
• With the onset of spring, a dramatic increase in the number of severe weather reports was observed in the Southern Region. A number of weak tornadoes were reported in Arkansas on April 3rd near the towns of Benton, Bryant, Little Rock and Gravel Ridge. Although no damage was reported from the tornadoes, the same storms brought large hail that damaged several trees and roofs. The following day, softball-sized hail was reported in Decatur, TX and tennis ball-sized hail was reported in Denton, TX. On April 7th, a tornado was reported in Electra, TX, with no reports of damage. Two days later, tornadoes were reported in Arnett, TX and in Gatesville, TX. Several hail reports in the vicinity of these tornadoes were also made; most of which resulted in minor damage to roofs and trees. Two days later, non-damaging tornadoes were reported in the following locations in Texas: Tye, Breckenridge, and Graford, and in Oklahoma: Soper and Kent. The same storm system delivered baseball-sized hail to Hamby, TX. On the 11th of the month, several twisters were reported in the state of Tennessee near the towns of Dickson, Lawrenceburg, Lewisburg, Manchester, and McMinnville, damaging multiple homes and trailers. The same day, a tornado in Opelousas, LA damaged power lines and downed numerous trees. On the 22nd, tennis ball-sized hail was reported in Baton Rouge, LA., while on the 23rd, several tornadoes touched down in central Texas near Rotan, Roby, Anson, Hawley, Lueders and Albany with no damage reports.
  

• Temperatures throughout the West were below normal except for the extreme southwest, with some locations reporting their coolest April in over a decade. Great Falls, MT reported a new April record low temperature of -8°F (-22°C) on the 21st, which was also the new record for the latest spring date below 0°F (-18°C). There has been a widespread perception that this has been a more traditional winter like those of the past. The cool winter and its extension into spring have significantly delayed the snow melt season, especially in the northern half of the region, with concerns rising for late spring flooding from the heavy mountain snow packs.
  
  
• Precipitation was below normal throughout the entire region. Many stations in California and Nevada reported their driest March-April total precipitation. Mountain snowpack, however, remained healthy with most of the intermountain and northwest reporting above normal snow packs on May 1st. Only the central Sierra was below average at a dismal 56% of normal. The Central Sierra Snow Lab, near Donner Summit, CA, measured only 26 inches (66 cm) of snow for March and April combined. The average is 112 inches (285 cm).
  
  
• There were only a handful of noteworthy events for April 2008 western weather. A strong cold front passed through Reno, NV on the 14th, producing winds of over 80 mph (129 km/hr) in certain locations, which produced light to moderate damage to roofs, uprooted trees and downed power lines. Parts of greater Seattle experienced a rare April snow event on the 18th with some locations measuring up to 2 inches (5 cm) of snow. This same event produced blizzard conditions in western Montana on the 19th, closing Interstate 90 near Deer Lodge for nearly 12 hours.
  

• Temperatures in the Juneau, Alaska Weather Forecast Office (WFO) area were cooler than normal during April, primarily a result of cool daytime highs in northern locations. Cold Bay, Alaska, set a new record high maximum temperature for April 13th of 52°F (11°C), breaking the previous record of 48°F (9°C) set in 1990. Valdez reached a new record high on April 23rd of 60°F (15.6°C). Bethel set one and tied two new record high minimums from April 20-22. Conversely, St. Paul tied the record low temperature on March 26th of -2°F (-19°C) set in 1976. The ice pack remained around St. Paul Island through March 19, the latest date in memory. In northern Alaska, Barrow set a new record high temperature of 30°F (-1°C) on April 2nd, far exceeding the previous record of 25°F (-4°C) from 2007. Two days later, Eielson Air Force Base recorded a high temperature of 52°F (11°C) and Bettles recorded a new high temperature of 43°F (6.1°C). The average temperature in Fairbanks during April was 2.2°F (1.2°C) below normal.
  
  
• The distribution of precipitation in the Juneau WFO area in April was mixed, with northern and southern locations reporting 86% of normal, but central locations reporting up to 162% of normal for the month. Central locations in the Hoonah and Juneau areas experienced a significant snow event from April 16-17, bringing 10-12 inches (25-30 cm) of snow, the fourth heaviest April snowfall at the Juneau airport and the greatest 1-day and 2-day totals there since at least 1943. Kodiak, AK was rather dry during April and received only 41% of normal precipitation; 2.26 inches (57 mm) fell, less than half of the long-term mean of 5.48 inches (139 mm) normally received during the month. Conversely, Bethel received 11.7 inches (29.7 cm) of snow during the month, bringing the seasonal total to 102.4 inches (260.1 cm), nearly twice the average and only the second time in the last thirty years with over 100 inches (254 cm) of accumulated snowfall. In northern Alaska, Fairbanks recorded its third wettest April in the 95-year record with 1.27 inches (32.3 mm) of precipitation, more than five times the April average. 14.7 inches (37 cm) of snow fell in Fairbanks during the month, making it the 3rd snowiest on record, although the seasonal total remains well below normal. By April 19, Nome accumulated 105.4 inches (268 cm) of snowfall, ranking as the second-snowiest winter on record behind 1994-95.