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SPSAJK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JUNEAU AK
1020 AM AKDT MON AUG 11 2025

AKZ325-120600-
CITY AND BOROUGH OF JUNEAU-
1020 AM AKDT MON AUG 11 2025

...SUICIDE BASIN IS OVERTOPPING...

AS OF 10:00 AM MONDAY, THE USGS WEB CAMERA AND LASER GAGE IN
SUICIDE BASIN CONTINUE TO SHOW INDICATIONS OF OVER-TOPPING THE
ICE DAM WITH ICEBERGS BEING PULLED TOWARDS THE OVERFLOW CHANNEL
AND SLOW LOWERING OF WATER LEVELS. THIS MEANS THE BASIN IS AT FULL
CAPACITY AND IN THE PAST IT HAS TAKEN UP TO 6 DAYS FROM THE START OF
OVER-TOPPING, SUNDAY AUGUST 10TH, FOR THE OUTBURST FLOODING EVENT TO
BEGIN.

THE WATER LEVEL IN THE BASIN WILL SLOWLY FALL AS THE OVERFLOW
CHANNEL ERODES. A FASTER DROP IN WATER LEVELS IN THE BASIN ALONG
WITH A RISE ON MENDENHALL LAKE WILL INDICATE A SUB-GLACIER RELEASE
AND OUR OFFICE WILL ISSUE A FLOOD WARNING. FROM THAT POINT, THE
OUTBURST FLOODING EVENT WOULD TAKE ABOUT 48 HOURS TO PEAK.

NOW IS THE TIME TO FINISH UP THE FLOOD PREPARATION/PLANNING AND GET
THOSE PLANS "SET" SO THEY CAN BE PUT INTO ACTION, AND "GO" WHEN A
FLOOD WARNING IS ISSUED. CHECK BACK REGULARLY FOR UPDATES ON THIS
EVOLVING SITUATION.

THIS PRODUCT WILL BE UPDATED BY 10 PM MONDAY OR SOONER AS NEEDED.
VISIT WEATHER.GOV/JUNEAU/SUICIDEBASIN FOR MORE INFORMATION.


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AARON.JACOBS