Thursday, March 26, 2009

Mount Redoubt Erupts To 65,000 Feet, Ashfall Advisory For Kenai Peninsula, And Even Anchorage Isn't Completely Off The Hook

Click HERE to view all previous posts on the 2009 Mt. Redoubt episode in inverse chronological order, with the most recent post appearing first.


Webicorder output captured from this morning. Though a bit difficult to read, you can see down toward the bottom the smaller eruption captured at 8:34, then on the line below, the bigger eruption beginning at 9:24. Note that the output from the bigger eruption so saturates the chart that it bleeds over into adjacent time lines.


The Alaska Volcano Observatory (AVO) is reporting that Mount Redoubt has erupted twice so far on March 26th, 2009. A preliminary eruption to 30,000 feet took place beginning at 8:34 A.M. Alaska time, with the second more violent eruption to 65,000 feet beginning at 9:24 A.M. Accompanying Anchorage Daily News story HERE and Peninsula Clarion story HERE and a Homer News story HERE; excerpts from applicable AVO alerts posted below:

Redoubt Volcano Activity Notifications

2009-03-26 08:56:56 - VAN/VONA
AVO is raising the aviation color code to Red and the alert level to Warning at Redoubt volcano. An explosive event beginning at roughly 08:34 AKDT has produced an eruption cloud to at least 30,000 ft. above sea level. The event continues. Complete report text
HERE.


2009-03-26 09:42:14 - VAN/VONA
A large eruption of Redoubt volcano began at roughly 09:24 AKDT (17:24 UTC). The National Weather Service reports the cloud height to be at least 65,000 ft above sea level. Refer to the
NWS Redoubt Coordination Page for latest cloud information. Complete report text HERE.


Ash at or above 40,000 feet, which would be transported over Anchorage, continues to pose little threat of ashfall below, but primarily impacts flight operations. Ash at the 20,000 foot level continues to pose the primary threat of ashfall below, and the Ash Trajectory Forecasts indicate wind flow from the WNW at this level, becoming more westerly by midnight. Consequently, the National Weather Service has issued an Ashfall Advisory for the Kenai Peninsula from Kenai to Homer, now extended until 4:00 P.M., although the greatest threat of ash will be from Ninilchik southward. Here's the pertinent part of the text:


WWAK71 PAFC 262359
NPWAER

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE ANCHORAGE AK
359 PM AKDT THU MAR 26 2009

AKZ121-270200-
/X.EXT.PAFC.AF.Y.0005.000000T0000Z-090327T0200Z/
WESTERN KENAI PENINSULA-
INCLUDING THE CITIES OF...KENAI...SOLDOTNA...HOMER...
COOPER LANDING
359 PM AKDT THU MAR 26 2009

THE ASHFALL ADVISORY IS NOW IN EFFECT UNTIL 6 PM AKDT THIS EVENING.

ASH FROM THIS MORNINGS ERUPTIONS OF MOUNT REDOUBT HAS TRACKED TO THE SOUTHWEST KENAI PENINSULA. ASH IS CURRENTLY FALLING IN SELDOVIA AND HOMER...BUT IS EXPECTED TO COME TO AN END BETWEEN 4 PM AND 5 PM. THE ASH WILL TRACK NORTHEASTWARD TOWARD INTERIOR
KENAI PENINSULA AND THE KENAI MOUNTAINS. MINOR ASHFALL OF A TRACE TO ONE EIGHT INCH IS LIKELY FROM KACHEMAK BAY TO INTERIOR AREAS ALONG THE KENAI MOUNTAINS. MOST OF THE ACCUMULATION IS EXPECTED TO REMAIN SOUTH OF THE STERLING HIGHWAY. TRACE AMOUNTS OF ASH ARE ALSO POSSIBLE ELSEWHERE ON THE WESTERN KENAI PENINSULA.


The wind is taking the plume in different directions at different elevations, with winds between about 40,000 and 50,000 feet moving the plume toward Anchorage. "It's possible that we could get some trace amounts (of ash in Anchorage), but it may not be anything noticeable right off the bat. People might notice a film on their windshields," Alaska Volcano Observatory geologist Chris Waythomas said.

Flight operations in South Central Alaska and at Stevens International Airport will be affected. The National Weather Service has issued a warning to the Federal Aviation Administration to prohibit flights through a large area east of Redoubt that includes all of the Kenai Peninsula, Prince William Sound and a portion of the Gulf of Alaska. Travelers are advised to check the status of flights with their airline before going to the airport. Alaska Air has now cancelled all flights into Anchorage for the rest of the day.

Update: Starting at 2:00 P.M., Kenai Peninsula residents started phoning in reports to the Dan Fagan show on KFQD. One person reported no ash in Clam Gulch yet. Another person reported about 1/8 inch of ash between Ninilchik and Anchor Point. Ash began falling in Homer shortly after 2:00 P.M., reducing visibility to as low as 2 1/2 miles and ceilings to 1,400 feet. Several individuals state that Redoubt ash is particularly abrasive, that if you wipe it off your vehicle, you WILL scratch it. Some say this particular ash is difficult to breath, and recommend anyone with pulmonary conditions stay indoors if at all possible.

Continue to monitor the following sources for more frequent information:
-- National Weather Service Redoubt Page
-- Alaska Volcano Observatory Redoubt Page
-- Latest NOAA Ash Trajectory Forecasts
-- Mt Redoubt Webcam #1 (Hut)
-- Mt Redoubt Webcam #2 (CI)
-- Webicorder Graph Output

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