August 5, 1998
RECORD HIGH GLOBAL TEMPERATURES CONTINUE IN JUNE OF 1998
The Spring of 1998 has produced an exceptional pattern of weather extremes in the United States. Partially a result of the dissipating El Niño event, a strong and persistent ridge of high pressure has set up over the southeast and south-central United States resulting in severe drought conditions for the southern and southeastern U.S. Exceptionally wet conditions have prevailed for the northern and northeastern U.S. in part due to an enhancement and northward shifting of the sub-tropical jet stream with wind speeds in the jet core as much as 2 times normal for this time of year. The drought in some parts of the southeastern U.S., such as Florida, developed very quickly when precipitation virtually came to a halt during late March.
The Intergovernmental Panel on Climate Change report (1995) suggests that if we have a noticeable change in the climate due to anthropogenic causes, extreme weather events, particularly heavy precipitation events and drought, would be expected to increase. A recent study* performed at the National Climatic Data Center indicates that heavier precipitation events are increasing in the United States. The figure (below left) shows the percent area of the United States that has experienced extremes of climate (warm and dry or cool and wet) based on the Palmer Drought Index for each decade of the 20th century. It is clear that in the decade of the 1990's a greater area of the United States has experienced a climate extreme than in any other decade of this century.
The NDVI image (center) shows comparisons from last year to this year. Specifically, this image, showing a % change from the '95-'97 median, shows a good deal of vegetation stress in western Texas and parts of Florida. For more on NDVI anomalies, see the NOAA/NESDIS/Office of Research and Applications (ORA) Vegetation and Temperature Condition Index page for monitoring vegetation conditions from NOAA Operational Polar-Orbiting Satellites.
Climate Prediction Center Summary
By the end of June, widespread drought covered the southern part of the United States from eastern New Mexico to Florida. The drought was most severe in Texas and Florida, where it adversely impacted crops, ranges and pastures, and contributed to the burning of nearly one-half million acres of Florida land. This drought resulted from well below-normal rainfall in the southern Plains and Gulf Coast states during April - June 1998, and from much above-normal temperatures across the region during May-June 1998. The April - June 1998 period also featured abnormally wet and stormy conditions across much of the central and northern United States. The surplus rainfall was particularly evident in June, when near-record totals were reported in the Midwest and Northeast.
April - June 1998 was the driest such period in 104 years of record in Florida, Texas, Louisiana, and New Mexico, the seventh driest such period in Arkansas, and the eighth driest in Oklahoma. Similarly, May-June 1998 was the warmest such period in 104 years of record in Florida, Texas, Louisiana, and Arkansas.
"In Florida, the drought intensified during June in response to record heat and near-record dryness. These conditions, combined with excess ground cover resulting from abundant January - March rainfall, contributed to numerous uncontrolled wildfires during June and early July." - Climate Prediction Center (CPC), National Centers for Environmental Prediction (NCEP), NOAA
"Atmospheric Circulation: The abnormal temperature and rainfall patterns observed across North America during April - June were essentially manifestations of a persistent atmospheric circulation pattern. Primary features of this pattern included: 1) a pronounced amplification of the subtropical ridge and high-pressure zone across the eastern North Pacific, Mexico and the south-central United States; 2) increased jet stream winds [1.5 - 2 times normal] and increased storminess across the central and northern United States; 3) a strong low-pressure area over the western United States, which acted as a continued source region for the storms; and 4) above-normal pressure and weaker-than-normal jet stream winds across Canada which helped to concentrate the jet stream and storminess over the central United States.
"The interaction of two primary factors contributed to the persistence and amplitude of the above circulation pattern, and to the details of the atmospheric flow which ultimately helped to determine the precise regions of hot, cold, wet and dry. These are 1) the 1997/98 El Niño, and 2) internal atmospheric dynamics which contributed to large-scale changes in the atmospheric circulation across the North Pacific and North America.
"Despite the decay of the El Niño in late May in the east-central tropical Pacific, abnormally warm ocean waters and enhanced tropical rainfall over the eastern tropical Pacific during June contributed to a continuation of the strong subtropical high-pressure zone across the southern United States. Thus, El Niño's impact on the atmospheric circulation had not yet dissipated by late June.
Climate Diagnostics Center Summary
During June 1998, warm anomalies during the first ten days of June 1998 along the Gulf coast spread northward across portions of the Central Plains and Ohio Valley as upper level high pressure built north and west from the Gulf coast. During the last anomaly period (June 21-30) warmest departures had shifted northward across the Southern Plains into the interior Southeast.
These analyses by NOAA 's Climate Diagnostics Center (CDC), are provided by the Western Regional Climate Center, and indicate how the surface temperature and relative humidity values for June 1st-25th depart from a 12 year mean.
The early summer season of 1998 drought and heat in the southern US and rainfall in the northeastern US set records at many locations or established records that were the second in ranking. Some notable (preliminary) examples for June 1998 are:
Mean Temperatures and Other Temperature Extremes Daytona Beach, FL 84.5 new record for any month Melbourne, FL 85.1 new record for any month Tampa, FL 85.6 new record for any month - (record begins 1825) St Petersburg,FL 85.4 new record for any month Miami, FL 85.4 new June record; ties all-time record Orlando, FL 85.0 new June record Tallahassee, FL 85.3 new June record Brownsville, TX 87.3 new June record, 17 days with min temp, >=80 breaks 1880 record Midland, TX 85.6 2nd warmest June Corpus Christi,TX 85.8 ties record June, 106 max temp is all-time record New Orleans, LA 83.7 2nd warmest June Charleston, SC 83.1 2nd warmest June (warmest was 1828) Columbia, SC 82.3 2nd warmest June Amarillo,TX ----- 13 days>=100 is new June record; 108 max temp ties all time record San Antonio, TX ----- 106 max temp is new June record Dodge City, KS ----- 110 max temp is new all-time record Total Precipitation and Other Precipitation Extremes Total Precipitation % of normal Daytona Beach, FL .83 14 2nd driest June Melbourne, FL .16 3 driest June Orlando, FL 1.58 22 driest June Blue Hill, MA 17.32 505 wettest June (2nd wettest month) Burlington, VT 8.66 250 2nd wettest June Indianapolis, IN 10.26 294 2nd wettest June Corpus Christi, TX ---- April-June total precip of .31 broke old record of 1.23"
June 1998 was the 2nd wettest June on record for this midwest region. The wettest June occurred in 1928.
"Although wetness was especially notable during June, parts of the Midwest have experienced above-normal rainfall since April, and surplus moisture dates back to late 1997 in portions of the Northeast. During April - June 1998, total rainfall reached 18 to 27 inches in most of the primary cities in the Ohio Valley, Tennessee Valley, central Appalachians and lower Northeast. The rains frequently fell from strong to severe thunderstorms, especially during May and June, thus leading to abnormally frequent episodes of tornadoes, hail, damaging winds and flash floods. According to preliminary data from the National Storm Prediction Center (SPC site), 372 tornadoes were recorded during June over the nation as a whole, which is nearly 200 more than average.
June 1998 was the 3rd wettest June on record for this northeast region. The wettest on record was 1922. The 2nd wettest June was 1972.How bad is it?
"Numerous new rainfall records were established during June across the northern half of the country, with record amounts reported in Paducah, Kentucky (10.98 inches), Nashville, Tennessee (11.95 inches), and Elkins, West Virginia (10.05 inches). Statewide, June 1998 was the second wettest June in 104 years in Massachusetts, New Hampshire, Rhode Island, and Vermont, and the third wettest June in Iowa and Maine. For the April-June period as a whole, rainfall totals were the highest in the historical record dating back to 1895 in Rhode Island and Massachusetts, the third highest in Tennessee, and the fourth highest in Iowa. As a result of several months of generally above-normal rainfall, combined with localized extremely heavy downpours, rivers in 17 states were near or above flood stage as of 6 July.
Unseasonably wet conditions also set records in the West during April-June 1998, with California, Idaho, and Nevada recording one of the wettest April-June periods in the past 104 years. Since this is typically a dry time of the year, surplus precipitation west of the Rockies does not normally pose a problem. However, this year's unseasonably wet and cool conditions have retarded the typical seasonal snowmelt at some higher elevations across the West, most notably in the Sierra Nevada range where an exceptional late-season snowpack has increased the potential for flooding.
The latest temperature and precipitation forecast is avalible at the NWS site.
"The official Climate Prediction Center monthly outlook for July indicates above-normal rainfall and cooler than normal temperatures in the northern Plains and upper Midwest, and near-normal rainfall and temperatures across the eastern and northeastern states.
"The outlook for July-September indicates an increased likelihood of above-normal rainfall from the Ohio Valley to the mid-Atlantic region, and cooler than normal temperatures in the central Plains. The extended seasonal outlook for the 1998/99 winter season indicates the increased likelihood of drier-than-normal conditions in the mid-Atlantic states and near-normal precipitation in the Midwest."-Climate Prediction Center (CPC), National Centers for Environmental Prediction (NCEP), NOAA
Some Links of Interest...
Real-Time Water Data, Interactive Map of Stream Flow Data
Including special section on Florida Fires and Drought
"Below-normal rainfall covered the southern part of the United States from eastern New Mexico to Florida during April - June. April-June 1998 was the driest such period in 104 years of record-keeping in New Mexico, Texas, Louisiana, and Florida, and among the 10 driest in Oklahoma and Arkansas. During the period, many locations across Florida and Louisiana received less than half of normal rainfall (generally under 6 inches) and broad sections of Texas and New Mexico received less than 25% of normal rainfall (1 - 4 inches). This dryness was a dramatic change from the surplus rainfall observed in much of these areas from late 1997 through March 1998.
"The April - June 1998 dryness was accompanied by above-normal surface temperatures since early May, which exacerbated drought conditions considerably. Much of Texas and parts of Florida, Georgia, and Alabama reached or exceeded 95°F on more than 50% of the days during May - June, with temperatures averaging 4°- 6°F above normal across most of the region. In Florida, the heat became particularly intense by early June, when temperatures routinely exceeded 95°F and new daily record high temperatures became commonplace. Overall during 1998, Florida recorded its warmest May and June periods on record dating back to 1895. Other states which also recorded their warmest May-June period on record with temperatures averaging 3.5°- 4.5°F above normal included Texas, Louisiana and Arkansas. Each of these states also recorded significantly below-normal rainfall during the period.
How bad is it?
"Numerous temperature records were tied or broken across Texas and Florida during May - June 1998. For example, daily high temperatures in Amarillo, Texas reached 100°F on thirteen days during June, and averaged at least 100°F for eight consecutive days between 22 - 29 June, thus tying a record set in 1924. Amarillo also tied its all-time high temperature record of 108°F on 27 June. In Brownsville, June 1998 was the warmest June in their historical record dating back to 1880. During this month the city recorded a record 17 days in which minimum temperatures failed to drop below 80°F. Midland, Texas reported a record 14 consecutive days from 16 - 29 June with high temperatures reaching 100°F, thus breaking the previous record of 13 consecutive days observed in both 1964 and 1981.
"In Florida, numerous temperature records were also broken during June 1998. For example, daily high temperatures at Melbourne either tied or broke records 22 times during the month, and record daily highs at Daytona Beach and Orlando were tied or broken 14 times and 13 times, respectively. Daytona Beach, Melbourne, Orlando, and Miami each recorded their hottest June on record, while Tampa recorded its hottest June in over 100 years. Elsewhere, the extreme heat also affected Kansas during 23-29 June, when Wichita recorded seven consecutive days of 100°F temperatures.
"With respect to the region's dry spell, rainfall in Midland, Texas during January-June totalled only 1.48 inches, their second driest such period on record. Farther east, April - June rainfall at Corpus Christi (0.31 inches) was the lowest in the historical record. This rainfall deficiency has led to widespread moderate to severe drought from eastern New Mexico eastward to Florida, as indicated by both the short-term drought Crop Moisture index and the long-term Palmer Drought Index.
Agricultural and livestock impacts
"The heat and dryness impacted crops and pastures in Texas and Florida, and some negative impacts were also felt in parts of New Mexico, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, and Georgia.
"The Texas Agricultural Statistics Service (TASS) indicated that non-irrigated crops in Texas such as cotton and soybeans were severely short of moisture. Livestock were generally in fair condition with the help of supplemental feeding, but 66% of range and pasture were in poor to very poor conditions. Irrigation kept corn fields in good condition in the Plains of Texas, but much of the crop in other areas was in very poor condition. Statewide, 41% of the Texas corn crop was in poor to very poor condition. Also, 43% of the state's sorghum crop and 40% of the cotton crop was rated in poor to very poor condition.
"In Georgia, approximately 58% of the corn crop was in poor to very poor condition at the end of June. Corn in many non-irrigated fields has already been damaged beyond repair.
"The June - early July 1998 wildfires in Florida have become almost infamous. According to Florida's Emergency Operations Center (EOC site) all 67 Florida counties have been affected by fires. As of 5 July, 483,000 acres and 356 structures had been consumed by fires, resulting in an estimated $276 million in damages. Over 100,000 people had been ordered to leave their dwellings by early July, including the entire population of Flagler County. Also, long stretches of Interstate-95 and other roads were closed because of dense smoke and sharply reduced visibility. Fortunately, increased rainfall and humidity over the 4 July weekend allowed firefighters to make progress toward controlling several large wildfires. Additional control over the fires, particularly those in Flagler county, came on 6-7 July as widespread rainfall covered central Florida.
"In Texas, the Texas Emergency Response Division reported that wildfires during May-June 1998 had burned 143,000 acres. Elsewhere, by early July, large fires in Colorado, New Mexico and Arizona had been contained, but new fires were reported in Utah.
Short-term and intermediate-term outlook:
The latest temperature and precipitation forecast is avalible at the NWS site.
"Long-range outlooks issued at the Climate Prediction Center suggest a continuation during July of warmer and drier than normal conditions across Texas, and a continuation of warmer than normal conditions in Florida and portions of the southeast. The seasonal outlook for July-September also indicates warmer than normal conditions across the Southwest, Texas and southern Florida.
"The latest long-range seasonal outlook issued by the Climate Prediction Center suggests drier-than-normal conditions for the Southwest from September 1998 through May 1999. The outlook also suggests the likelihood that these drier-than-normal conditions will expand eastward during the 1998/99 winter season to encompass Texas, the Gulf Coast, Florida and the Southeast. This outlook indicates the potential for serious long-term drought in these states if summertime rainfall remains deficient." -Special Climate Summary - Climate Prediction Center (CPC), National Centers for Environmental Prediction (NCEP), NOAA
See also...Southeast regional Climate Center
The Texas Drought 1998
Texas Water Development Board
USGS - Oklahoma District
USDA National Agricultural Statistics Service State Offices
Crop Weather and Information
Weekly Weather and Crop Bulletin
National Drought Mitigation Center
CPC Weekly/Monthly Analyses
Over Florida, the unusually wet mild winter promoted abundant growth in the under brush. This weather was immediately followed by a severe drought these last two months (May and June), which rapidly dried out the dense under brush. This combination, wet and mild in the winter, dry and hot in the summer, provided abundant fuel to the wild fires pervasive over Florida.
Fires began burning out of control in Florida on Memorial Day weekend, and have now scorched over 485,000 acres, with more than half being commercial timberland. Most of the fires have been in an area bounded by Jacksonville, Daytona Beach, and Orlando. The timber losses amount to approximately $300 million, and at least 324 homes have been damaged or destroyed. Firefighting costs now total over $100 million and climbing. Over 120,000 residents were forced to evacuate for a day or more, including all of Flagler County. Fortunately, no fire-related deaths have been reported.
National Wildland Fire Issues
The global mean temperature for June 1998 continued this year's record breaking trend with the highest temperature anomaly since reliable records began in 1880. This conclusion was based on separately examining land data using the Global Historical Climatology Network; ocean data using the National Centers for Environmental Prediction (NCEP) - Reynolds Sea Surface Temperatures (SST) blended with the NOAA Comprehensive Ocean-Atmosphere Data Set (COADS) and the United Kingdom Meteorological Office Historical SST analysis; and a global surface temperature index that combines the ocean and land data. The final anomaly may change due to inclusion of new areas of the world not currently represented. Each of the anomaly time series is based on its respective 1880-1998 mean.
Though the recent El Niño has ended, El Niño's higher than average Sea Surface Temperatures over a large area of the tropical eastern Pacific Ocean during the past year put extra warmth into the global climate system, which likely contributed to the recent global record high temperatures.
For more information, refer to ...
The period January-June 1998 was the warmest since reliable records began in 1880, according to the National Climatic Data Center. This conclusion was based on separately examining land data using the Global Historical Climatology Network; ocean data using the National Centers for Environmental Prediction (NCEP) - Reynolds Sea Surface Temperatures (SST) blended with the NOAA Comprehensive Ocean-Atmosphere Data Set (COADS) and the United Kingdom Meteorological Office Historical SST analysis; and a global surface temperature index that combines the ocean and land data. The final anomaly may change due to inclusion of new areas of the world not currently represented. Each of the anomaly time series is based on its respective 1880-1998 mean.
For more information, refer to ...
During the past few decades, global temperatures have persistently broken previous record highs every few years, but never to the extent observed in 1998. Each month this year has set a new all-time record high global temperature. This is unprecedented and is not likely to occur in a stationary climate. New analyses of tree-rings, historical records, and other proxy measurements indicate that these temperatures are warmer than the planet has experienced for at least the last 600 years (Michael Mann, University of Massachusetts, Amherst; the work was presented in the journal "Nature" in April 1998).
As data are being received, scientists at The National Oceanic and Atmospheric Administration's National Climatic Data Center are automatically updating the Global Historical Climatology Network data base to maintain a global climate perspective in near real-time.
for further information on GHCN, contact: