Smoke, heat, and air pollution across much of the U.S.

Smoke from Arizona's second largest fire on record, the massive Wallow fire near the New Mexico border, has now blown downwind over 1,500 miles to the Northeast U.S. The fire, which is 0% contained, is expected to rage full-force for at least another day due to unfavorable weather. Hot, dry, and windy weather is predicted again today over Eastern Arizona, where NOAA has issued red flag warnings for critical fire conditions. A large trough of low pressure is anchored over the Southwest, and a disturbance rippling along this trough will bring strong southwesterly surface winds of 20 - 25 mph, with gusts near 35 mph today to eastern Arizona. Extremely low humidities of 5 - 15% and hot summer temperatures are also expected, creating a dangerous fire weather situation. Yesterday, Luna, New Mexico, located about 50 miles northeast of the fire, had wind gusts in excess of 20 mph for 9 hours, temperatures near 80°F, and humidities as low as 7%. The fire grew from 300 square miles on Sunday to 365 square miles on Monday and 487 square miles Tuesday--about 40% of the size of Rhode Island. A separate fire burning in Southeast Arizona, the 166-square-mile Horseshoe Two fire, is the state's 5th largest fire on record. Winds are expected to diminish for Thursday and Friday, which should allow firefighters to make headway controlling the blazes. According to the Interagency Fire Center, 3.5 million acres have burned in the U.S. so far this year, the most on record for this early in the year--and more than double the 10-year average from 2001 - 2010 of 1.4 million acres. Extreme to exceptional drought conditions over most of Texas, New Mexico, and Eastern Arizona are largely responsible for the record fire season.


Figure 1. Active wildfires and smoke as visualized at 9am EDT June 8, 2011 using our wundermap for the U.S. with the Fire layer turned on. Smoke from the Wallow fire and Horseshoe Two fire in Arizona extended more than 1,500 miles, and was pushing into the Northeast U.S.


Figure 2. Smoke billows from the rapidly growing Wallow fire in Eastern Arizona in this image taken by NASA's Aqua satellite on June 7, 2011. Heavy smoke from the fire covers large portions of New Mexico, Texas, Colorado, Kansas, Oklahoma, South Dakota, and Nebraska in this image. Image credit: NASA.

Unusual June heat wave
An intense blast of heat set new daily high temperature marks in 14 states from Texas to Minnesota Tuesday, including a remarkable 103°F in Minneapolis. It was the hottest day in the city in nearly 23 years, since 105°F was recorded on July 31, 1988, and the second earliest date the city had ever hit 100°. Minneapolis' earliest 100° day came on May 31, 1934, when the mercury also hit 103°. Yesterday was the 5th consecutive day that the Austin, Texas Bergstrom Airport tied or set a new daily temperature record. On Monday, June 6, the airport hit 103°F, the earliest in the year that location had ever hit 103°. Record keeping began there in 1942, and the last time Austin was so warm so early in the year was on June 14, 1998, when the mercury hit 109°.


Figure 3. Air pollution forecast for Wednesday, June 8, 2011, calls for a large-spread region of pollution that is Unhealthy for Sensitive Groups (USG), over the eastern third of the nation. Image credit: EPA Airnow.

Significant air pollution episode today
The heat will continue today for much of the eastern half of the country, and heat advisories are posted in fourteen states. The high heat, combined with abundant sunshine and very stagnant air, is expected to bring the most severe large-scale air pollution event of the year to the nation. Adding to the hazard is the presence of fine smoke particles from the fires in Arizona, which have blown downwind to cover most of the eastern 2/3 of the country. Air quality on Wednesday is expected to be Unhealthy for Sensitive Groups (Code Orange, or over 100 on the Air Quality Index), in more than 80 cities, including Baton Rouge, La., Indianapolis, Detroit, Nashville, Tenn., Columbus, Ohio, Philadelphia, Pittsburgh, Newark, N.J., Richmond, Va., and Atlanta. If you live in these areas, cut back on strenuous outdoor exercise today if you have asthma or other respiratory problems.

Caribbean disturbance 94L no threat to develop
The large, disorganized tropical disturbance (Invest 94L) in the Northwestern to North Central Caribbean Sea near Jamaica is very disorganized this morning, but is still capable of bringing heavy rains as it pushes slowly northwards at less than 5 mph. I heard from wunderground user Anthony Zed in the Kingston, Jamaica suburb of Norbrook, and he reported that his rain gauge received 11.27" of rain from 94L from June 1 - 7, which is more rain than had fallen all year. The big rain day was yesterday, with 3.47". Satellite loops show a few disorganized clumps of thunderstorms in the region, and NHC has downgraded 94L's chances of development by Friday to 0%. Wind shear is very high, 30 - 50 knots, making development very unlikely.

First tropical cyclone of the Eastern Pacific hurricane season forms
Tropical Storm Adrian, the first named storm of the Eastern Pacific hurricane season, formed last night off the coast of Mexico. Adrian is in an ideal environment for intensification, with light wind shear and ocean temperatures of 30°C (86°), and will likely become a hurricane on Thursday. Adrian is expected to remain far enough offshore the coast of Mexico to not pose a threat to that country, at least for the next three days. June hurricanes in the Eastern Pacific are much more common than in the Atlantic.

NOAA's pre-season prediction of the Eastern Pacific hurricane season, issued on May 16, calls for below average activity, with 12 named storms, 6.5 hurricanes, and 2 major hurricanes, with an ACE index 75% of the median. The 1981-2010 averages for the Eastern Pacific hurricane season are 15 - 16 named storms, 8 - 9 hurricanes, and 4 major hurricanes.

Amazing solar flare erupts
In recent months, the sun has awakened from its longest and quietest period since the satellite era bgan in the late 1970s. An increasing number of sunspots, solar flares, and Coronal Mass Ejections have occurred, as solar activity builds towards a peak expected in 2013. Yesterday, the sun unleased the most spectacular solar flare ever captured on video, highlighted in the Youtube link below.


Video 1. A spectacular solar flare erupted at 06:41 UTC on June 6, 2011, when magnetic fields above sunspot complex 1226-1227 became unstable. The blast produced a massive Coronal Mass Ejection (CME) that was not aimed directly at Earth, but fringes of the blast may cause aurora activity on June 8 and 9. This is probably the most dramatic and beautiful solar flare captured by the cameras on NASA's Solar Dynamics Observatory (SDO.) Additional movies and information are available at spaceweather.com, and additional information on the latest solar activity is available from NOAA's Space Weather Prediction Center.

Jeff Masters