WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

The June 2012 U.S. heat wave: one of the greatest in recorded history

By: Dr. Jeff Masters, 7:34 PM GMT on July 03, 2012

Intense heat continues to bake a large portion of the U.S. this Tuesday, with portions of 17 states under heat advisories for dangerously high temperatures. The heat is particularly dangerous for the 1.4 million people still without power and air conditioning due to Friday's incredible derecho event, which is now being blamed for 23 deaths. The ongoing heat wave is one of the most intense and widespread in U.S. history, according to wunderground's weather historian, Christopher C. Burt. In his Sunday post, The Amazing June Heat Wave of 2012 Part 2: The Midwest and Southeast June 28-30, Mr. Burt documents that eighteen of the 298 locations (6%) that he follows closely because of their long period of record and representation of U.S. climate broke or tied their all-time heat records during the past week, and that "this is especially extraordinary since they have occurred in June rather than July or August when 95% of the previous all-time heat records have been set for this part of the country." The only year with more all-time heat records than 2012 is 1936, when 61 cities of the 298 locations (20%) set all-time heat records. The summer of 1936 was the hottest summer in U.S. history, and July 1936 was the hottest month in U.S. history.

According to wunderground analysis of the National Climatic Data Center (NCDC) extremes database, during June 2012, 11% of the country's 777 weather stations with a period of record of a century or more broke or tied all-time heat records for the month of June. Only 1936 (13% of June records broken or tied) and 1988 (12.5%) had a greater number of all-time monthly June records. I expect when NCDC releases their analysis of the June 2012 weather next week, they will rank the month as one of the top five hottest Junes in U.S. history.

Figure 1. Across the entire Continental U.S., 72% of the land area was classified as being in dry or drought conditions as of June 26, 2012. Conditions are not expected to improve much over the summer: the NOAA Climate Prediction Center’s latest drought outlook shows much of the U.S. in persistent drought conditions, with very few areas improving. The rains brought by Tropical Storm Debby did help out Florida and Georgia, however. Image credit: NOAA Environmental Visualization Laboratory.

The forecast: hot and dry
July is traditionally the hottest month of the year, and July 2012 is likely to set more all-time heat records. The latest predictions from the GFS and ECMWF models show that a ridge of high pressure and dry conditions will dominate the weather over about 80 - 90% of the country during the next two weeks, except for the Pacific Northwest and New England. This will bring wicked hot conditions to most of the nation, but no all-time heat records are likely to fall. However, around July 11, a sharp ridge of high pressure is expected to build in over the Western U.S., bringing the potential for crazy-hot conditions capable of toppling all-time heat records in many western states.

The intense heat and lack of rain, combined with soils that dried out early in the year due to lack of snowfall, have led to widespread areas of moderate to extreme drought over much of the nation's grain growing regions, from Kansas to Indiana. The USDA is reporting steadily deteriorating crop conditions for corn and soybeans, and it is likely that a multi-billion dollar drought disaster is underway in the Midwest.

The wunderground Extremes page has an interactive map that allows one to look at the records for the 298 U.S. cities that Mr. Burt tracks. Click on the "Wunderground U.S. Records" button to see them.

Quiet in the Atlantic
There are no threat areas to discuss in the Atlantic, and none of the reliable computer models are developing a tropical cyclone over the next seven days.

Have a great 4th of July holiday, everyone, and I'll be back Thursday with a new post.

Jeff Masters

Sheep Mountain Ablaze!
Sheep Mountain Ablaze!
The Squirrel Creek Fire spread rapidly last night, and topped the crest of Sheep Mountain as we watched last night. This is a telephoto shot from our west patio. The line of light below the fire is Harmony Wyoming. Sheep mountain is 22 air miles away from us...
Derecho Damage
Derecho Damage
A woman makes a photograph of Mike Wolfe's pick-up truck as it lies under a fallen tree in front of his house after a severe storm in Falls Church, Va., Saturday, June 30, 2012. Wolfe's daughter Samanth Wolfe created the for sale sign as a joke. (AP Photo/Cliff Owen)
Derecho in Catlett
Derecho in Catlett
Ground strike reflected off car
Mink Creek Fire
Mink Creek Fire
Fire currently burning on mink creek to johnny creek. the fire has claimed 10 house that i know of. My hearts go out to the families.

Heat Drought

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.