Eastern Arizona’s massive Wallow Fire grew to 700 square miles over the weekend, bringing it very close to being Arizona’s largest fire on record. The 2002 Rodeo-Chediski fire (732 square miles) currently holds that distinction. However, NOAA’s Storm Prediction Center forecasts that critical fire conditions will spread over Eastern Arizona and Western New Mexico this afternoon. Strong southwesterly winds of 15 – 20 mph are expected, with very low relative humidities of 5 – 15%. With the Wallow Fire just 10% contained, this means that the fire will likely expand significantly today and become Arizona’s largest fire on record. Firefighting conditions are expected to improve on Tuesday and Wednesday, with much weaker winds, but stronger winds may return again on Thursday. A separate fire burning in Southeast Arizona, the Horseshoe Two fire, has grown to 200 square miles, and is 40% contained. This is Arizona’s 5th largest fire on record.

Figure 1. Smoke from the Horseshoe Two fire in Southeast Arizona, taken on Friday, June 10, 2011. Image credit: wunderphotographeer rixx.

The Earth is active
We now have two volcanic eruptions that are emitting large ash clouds causing significant disruptions to aircraft flights. Last week, the Puyehue-Cordón Caulle volcano in Chile erupted, sending aloft an ash cloud that circled the Southern Hemisphere, canceling flights thousands of miles away in Australia and New Zealand. At approximately 5pm EDT on Sunday, a new major eruption occurred in Africa at Eritrea’s Nabro volcano. This volcano has no eruptions in historical records, but sent an ash plume over 21,000 feet (13 km) high over Eritrea after an earthquake of magnitude 5.7 rocked the area. The ash has now spread to the northwest over Sudan, and is expected to spread to the north over Egypt later today. On Tuesday, the ash is expected to get caught in a west-to-east jet stream flow, and spread over much of the Middle East. The latest forecasts from Meteo France (Figure 3) show impacts to Israel, Saudi Arabia, Jordan, and Iraq on Tuesday morning. The latest MODIS image from NASA shows the plume nicely.

Figure 2. Eruption of Puyehue-Cordón Caulle volcano, Chile as seen by NASA’s Aqua satellite at 18:05 UTC on June 12, 2011. Image credit: NASA.

Figure 3. Forecast issued at 8am EDT by Meteo France showing the expected spread of the ash plume from Eritrea’s Nabro volcano. Ash between 35,000 and 45,000 feet altitude (light dashed lines) is predicted to move over the Middle East, including southern Israel, by 2am EDT (0600 Z) on Tuesday, June 14. The volcano is mis-identified as the Dubbi volcano on this image.

The Atlantic is quiet
In the Atlantic, none of the reliable computer models is predicting tropical cyclone development over the next seven days.

Jeff Masters