Friday, July 26, 2013

Kenai Rainfal

Last night just before midnight AKDT, the Kenai Municipal Airport recorded 1.23" of rain in one hour (and 1.83" in two hours). This is an extraordinary amount. To put it into perspective, according to the newly released NOAA precipitation atlas for Alaska (http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_ak.html), an hourly reading of 1.17" has a 1/1,000 chance of occurring in any given year for the city of Kenai (1,000-year recurrence interval). The 1,000-year recurrence interval for a two hour rainfall is 1.48". Wow! One of the resources that NOAA used to generate their numbers can be found at the following link: ftp://hdsc.nws.noaa.gov/pub/hdsc/data/ak/dur01h_ams_na14v7.txt . According to that rather abbreviated list, here is a list of the top 1-hour rainfall events in Alaska (I accidentally deleted the date column, sorry):

Station Hourly Rain (in.)
80-1940 PREACHER        , AK   1.67
50-6586 NORTHWAY AP     , AK   1.48
80-2440 TELIDA  , AK   1.33
80-0100 ALCAN HWY   1.32
80-2440 TELIDA  , AK   1.32
50-0352 ANNETTE ISLAND AP       , AK   1.22
80-0460 CHATANIKA       , AK   1.22
80-2620 VUNZIK LAKE     , AK   1.21
50-9941 YAKUTAT STATE AP        , AK   1.20
50-9941 YAKUTAT STATE AP        , AK   1.20
80-1280 KAIYUH  , AK   1.20

1 comment:

  1. Thanks for posting this, Brian, it is very interesting. What an extraordinary event! The sea surface temperatures in the north Pacific at large are the warmest on record for the time of year, so that may be favoring much higher levels of evaporation and precipitable water than usual. The 12UTC Anchorage sounding on the 26th showed 29 mm of precipitable water, which I am sure is very high for the region, but I don't know what the record might be. Kodiak and King Salmon showed 32 mm.

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