Snowpack status and outlook

Looks like our team is rolling 7’s with the conditions this year. The last 3 years have been pretty similar with above average accumulations and none existent spring high pressure’s. Let this be the year to traverse the coast. The information below was taken from http://bcrfc.env.gov.bc.ca/bulletins/watersupply/current.htm

Current Snow Survey and Water Supply Bulletin

The February 1st snow survey is now complete. Data from 107 snow courses and 53 snow pillows around the province and out-of-province sampling locations, and climate data from Environment Canada, have been used to form the basis for the following reports.

Weather
Stable weather conditions prevailed across British Columbia through January. High pressure ridging in the middle of the month created prolonged dry weather and inverted temperatures, with above freezing temperatures above snowline elevations. Conditions were much drier than normal across the province throughout the month. Temperatures were +1 – 3 ̊C above normal through most areas of the province, with some low elevation regions in south-west BC having below normal temperatures.

Snowpack
Due to drier conditions, most regions saw below normal snow accumulation and a decline in snow basin indices through the month of January. Snow basin indices ranged from a low of 78% of normal, to a high of 116%. Drier conditions are prevalent through west-central and north-west British Columbia, including the Nechako, Middle Fraser (Chilcotin), Central Coast and Skeena-Nass basins. Snow packs are above normal (>110%) in the Okanagan-Kettle and South Coast regions, and near normal or slightly below normal (85-110%) through the rest of the province.

BC Snow Basin Indices – February 1, 2013

Basin
% of Normal

Basin

% of Normal

Upper Fraser

86%

Kootenay

97%

Nechako

78%

Okanagan-Kettle

116%

Middle Fraser

83%

Similkameen

89%

Lower Fraser

103%

South Coast

113%

North Thompson

94%

Vancouver Island

107%

South Thompson

109%

Peace

90%

Columbia

93%

Skeena-Nass

84%

Outlook
This season has favored neutral El Niño Southern Oscillation (ENSO) conditions, with near normal sea surface temperatures in the equatorial Pacific Ocean. Current forecasts from the Climate Prediction Centre with the U.S. National Weather Service (NOAA) favour neutral conditions into the spring of 2013. This suggests that current ocean conditions favour normal seasonal weather conditions. Current 3-month seasonal forecasts (February through April) from Environment Canada are fairly neutral, with similar likelihoods of above-normal, below-normal or normal precipitation and temperature. A slight increased likelihood of below normal temperatures is forecast for south-west BC. Current short-term weather forecasts indicate a period of high pressure across most of the province to the middle of February, and limited snowfall is expected.

By this date, generally about two-thirds of the annual BC snowpack has accumulated. While there is still two and a half months left in the snow accumulation season, given current short-term and seasonal outlooks, the current snowpack is not expected to change significantly over the remainder of the season. At this point there are no strong indications of a high likelihood of extreme wet or dry seasonal weather through the rest of the accumulation season. Unless the region experiences some late-season Pacific storm cycles, dry conditions are likely to persist in the Nechako, Central Coast, Skeena-Nass, and Middle Fraser. Normal conditions are expected to persist in other regions. While possible, heavy snow pack accumulation over the remainder of the season is unlikely.

In general snow packs across the province are below levels that were observed last year (see snow basin graphs below). Below normal seasonal flows during freshet and into summer are likely in the west-central region of the province (Nechako, Middle Fraser, Central Coast, Skeena-Nass). Above normal seasonal flow, and the potential for elevated seasonal flood risk, is possible in the Okanagan basin. Above normal seasonal flow is also expected in the Lower Fraser, South Coast and Vancouver Island, however these regions tend to have limited flood potential in the spring, and current snow packs are not expected to have a significant impact on seasonal flood risk. Normal seasonal flow and seasonal flood risk is likely through the rest of the province.

Snow data reporting has been adjusted for this snow bulletin (attached) and this format will be used through the remainder of this snow season. The River Forecast Centre is currently estimating values for 6 snow pillows, and the February 1st, 2013 estimates can be found in Table 1.

The next snow bulletin will be released on March 7th, 2013.

Produced by: BC River Forecast Centre
February 8, 2013

Advertisements
Categories: Posts from the field | Tags: , , , , | 3 Comments

Post navigation

3 thoughts on “Snowpack status and outlook

  1. very nice

  2. nice article !

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Create a free website or blog at WordPress.com.

%d bloggers like this: