Tag Archives: National Weather Service

Red Alert: Pavlof Volcano intensifies again in Alaska, flights advised to avoid the ash cloud

Pavlof Volcano

The Pavlof Volcano in the Alaska Peninsula has been a long-running safety concern in Alaska for aviators. The volcano has caused red alerts in the past. The ash cloud from the Pavlof Volcano has again reached 30,000 feet triggering a new round of aviation alerts.  The National Weather Service warned aviation interests that the ash cloud from the erupting volcano was spreading to the west and northwest of the volcano. The volcano intensified yesterday prompting the new aviation warnings. The volcano is the most active volcano in Alaska.

The volcano lies along major Asia-North America air traffic great circle routes.

Pavlof Volcano Information

The Alaska Volcano Observatory issued this statement yesterday (November 15):

PAVLOF VOLCANO (VNUM #312030)
55°25’2″ N 161°53’37” W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: RED

The eruption of Pavlof Volcano that began on November 12 has intensified and the Aviation Color Code was raised to RED and the Volcano Alert Level to WARNING earlier today.

The intensity of seismic tremor remains at high levels and pilot reports though 12:30 AKST (21:30 UTC) indicate that the ash cloud height has increased to 30,000 ft above sea level. Satellite, pilot reports, and wind data show the ash cloud moving towards the northwest over the Bering Sea. Ash cloud height and direction will vary significantly through an eruption and aviation users should refer to the National Weather Service for updated SIGMETs on the ash cloud hazard (http://aawu.arh.noaa.gov/sigmets.php).

No reports of ash fallout on nearby communities have been reported, and the ash cloud is currently moving away from populated areas. We encourage observers to contact AVO should it occur (https://www.avo.alaska.edu/ashfall/ashreport.php). The National Weather Service has issued a Special Weather Statement for the possibility of ash fall in the vicinity of Pavlof and towards the northwest.

Description of the volcano:

From Miller and others (1998): “Pavlof Volcano is a largely snow-covered, cone-shaped mountain with a high ridge extending to the southwest towards the rim of Emmons Lake Caldera. The volcano is approximately 7 km in diameter and has active vents on the north and east sides close to the summit (McNutt and others, 1991). It is situated high on the northeastern flank of Emmons Lake Caldera along a northeast-trending alignment of vents that includes Pavlof Sister, and several intracaldera cones (Kennedy and Waldron, 1955). The stratovolcano is relatively undissected and is mostly Holocene in age. Pavlof lies within the Shumagin seismic gap (Davies and others, 1981).” The name Pavlof comes from Russian, translating to “Paul” or “Saint Paul”. This volcano name was first published as “Pavlovskoi Volcan” by Captain Lutke in 1836.

Ash Cloud Forecast: CLICK HERE

Top photo and map: Alaska Volcano Observatory/Carol Damberg.

 

Southwest completes the installation of Water Vapor Sensing Systems on 87 Boeing 737 aircraft, will fly international routes next year

Southwest Airlines (Dallas) has completed the installation of Water Vapor Sensing Systems (WVSS-II) on 87 Boeing 737 aircraft. The water vapor initiative, a result of a partnership between Aeronautical Radio Incorporated (ARINC), National Oceanic and Atmospheric Administration (NOAA) and SpectraSensors, has the potential to improve weather forecasting by providing real-time and frequent humidity data when aircraft takeoff and land at airports around the country.

“Southwest’s meteorology team has always worked closely with ARINC and NOAA, and the WVSS-II project is symbolic of our strong reliance on each other. We are proud to be the only passenger airline currently participating in the project and look forward to the many ways WVSS-II will impact and improve both weather forecasting and the impact on airline operations,” said Rick Curtis, Chief Meteorologist, Southwest Airlines.

National Weather Service (NWS) forecasters routinely use WVSS-II observations in their day-to-day operations. Monitoring the distribution of moisture in the atmosphere and how the moisture levels change with time play an integral role in forecast preparation. Aviation forecasters rely on WVSS-II data to help determine location and timing of fog, cloud formation, and dissipation, and altitudes of cloud ceilings, all critical to determining safe conditions for aircraft travel.

“Water vapor is the most rapid-changing and under-sampled element in the atmosphere,” said Carl Weiss, an aviation meteorologist for NOAA.  “On the heels of a tumultuous weather year, WVSS-II is part of a larger initiative contributing to Weather Ready Nation, our initiative focused on building community resilience in the face of extreme weather events. WVSS-II data upon takeoffs and landings allow forecasters to monitor and stay on top of how moisture is changing in the atmosphere, specifically in severe weather situations when preparedness is especially important.”

WVSS-II, manufactured by SpectraSensors, Inc., measures water vapor in the atmosphere hundreds of times during an aircraft’s flight. These measurements are automatically transmitted to ARINC’s headquarters in Annapolis, MD, via the ARINC GLOBALink/VHFTM data link service. The moisture data along with other aircraft weather data are then forwarded in near real-time to the U.S. National Weather Service, which uses them to improve the accuracy of its computer-generated weather forecasts and severe weather warnings.

“The WVSS-II observations add a critical new piece of weather data to the forecasting puzzle,” says Jeannine Hendricks, ARINC’s Manager for the WVSS program. “For the first time in aircraft operations, we are collecting water vapor data that measures the humidity in the air. This has the potential to revolutionize weather forecasting—especially when predicting thunderstorms—a significant weather occurrence for aviation.”

While weather balloons, previously the only method for capturing weather data, measure wind, temperature, and humidity data just twice per day at certain locations, the water vapor sensors gather humidity data throughout the day at multiple points across the nation. The improved water vapor data will have a direct benefit in the accuracy of forecasts of precipitation and clouds, which will benefit the aviation community, its customers, and the general public.

Southwest Airlines plans to continue working with ARINC and NOAA in conjunction with the National Weather Service to expand WVSS-II installations on its aircraft fleet.

In other news, Southwest will announce a schedule for international service next year according to CEO Gary Kelly and Reuters. This will be the first international routes for the carrier. Subsidiary AirTran Airways currently flies to Mexico and the Caribbean.

Copyright Photo: Eddie Maloney/AirlinersGallery.com. Boeing 737-8H4 WL N8310C (msn 38807) arrives in Las Vegas.

Southwest Airlines: AG Slide Show

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