Tip:
Highlight text to annotate it
X
Welcome to the weekly weather briefing from the National Weather Service in Spokane. My
name is Greg Koch. This briefing covers the expected weather for the week of Monday
March 11th through Monday March 18th, 2013. Forecasts are subject to change so do not use
this presentation after 6 a.m. Tuesday, March 12th.
Here is the overview of the weather through next weekend. A warm front will bring
precipitation to the Inland Northwest tonight into Tuesday morning. Some places will
receive some wet snow tonight and early Tuesday morning. Then, look for warming
temperatures Tuesday afternoon. Much warmer weather is on the way from Tuesday night through
Friday. Temperatures will be unseasonably mild and there will be a good chance of light
to moderate rain and high elevation snow over the Cascades, NE Washington and the
Idaho Panhandle. The weather pattern will undergo a change over the weekend as a cold
front moves into the region. A return to cooler, more typical temperatures is expected over
the weekend.
This map shows the snow forecast for Tuesday morning. Most accumulations will be limited
to elevations above 2500 feet. Some slushy snow up to an inch will be possible in the valleys
around Priest Lake, Cusick and Metaline Falls.
More on Tuesday morning’s snow. Valley accumulations in NE Washington and far N Idaho will
largely be limited to grassy surfaces and will melt quickly on Tuesday as temperatures climb
into the 40s. Early morning travelers may encounter some slick driving conditions at
Sherman Pass in central Washington, or Lookout Pass on I-90 in the Idaho Panhandle. By
afternoon, snow levels in the 5000 to 6500 foot range will bring good travel conditions
even to the highest mountain passes.
From late Tuesday through Friday, the Jet Stream will be directed into southern British
Columbia. A plume of moisture with origins near the Hawaiian Islands will contribute to the
potential for heavy rain over the southern British Columbia coast, Vancouver Island and
northwestern Washington. We will be keeping an eye on the north Washington Cascades for
the threat of heavy rain, but at this time, it appears the best threat will be in Canada.
More on the heavy rain threat. A couple inches of rain will be possible over the northern
Washington Cascades from Tuesday through Friday. Lesser amounts are expected in eastern
Washington and north Idaho. Temperatures will be in the 50s and 60s for most of the region
and snow levels will be very high. We can expect mountain snow to melt from Tuesday
through Friday.
Here is a five day rain total for Tuesday through Saturday. The yellow color is about an
inch of rain. The brown is about 2 inches. Red is around 3 ½ inches. Some of the
precipitation in the high elevations of the Cascades and far north Idaho will fall in the
form of wet snow. This map shows that the Columbia Basin will largely experience a rain
shadow this week. Places like Moses Lake and Wenatchee will receive very little rain. The
most significant rain amounts will occur over the Cascades and the mountains around
Sandpoint and Colville.
The melting mountain snow will be noticed on small streams and creeks in the Pacific
Northwest. Rises can be expected on creeks and streams in the Cascades, Northeast
Washington and North Idaho beginning Wednesday and continuing through the weekend.
Significant flooding is not expected, but some nuisance flooding may occur near small
creeks prone to spring-time flooding. Our main stem rivers (or bigger rivers like the
Kettle River, Stehekin River and Palouse River) will see some rises through early next
week. However, the main stems are running relatively low at this point and none of the NWS
river models forecast any flooding at this time.
This map is an estimation of Snow Water Equivalent (or water trapped in snow cover) over the
Pacific Northwest. There is relatively little SWE in the low elevations of the Idaho
Panhandle in the Palouse, Hangman Creek and Coeur D’Alene basins. This is good news and
should keep rises on these rivers in check. The deep snow pack in the Cascades will likely
soak up the majority of the rain for the Stehekin, Wenatchee and Similkameen
basins.
The 8 to 14 day outlook issued by the Climate Prediction Center shows below normal
precipitation and below normal temperatures for the March 19 through March 25 period. This
cool and dry outlook is good news for the region, and will allow streams and rivers time
to recede next week.
In summary, this week will be warmer than average. A combination of rain and melting
snow will produce rises on creeks and small streams. No significant flooding is
anticipated at this time. A pattern change is expected over the weekend with a return to
cooler, more typical conditions.
If you would like to give us some feedback on our presentations. Send us an
e-mail.
Here is how you can stay informed and get the latest information from the National
Weather Service Spokane Forecast Office. Our forecasts and products are available on
our website weather.gov/spokane. Like us on Facebook, follow us on
Twitter, and subscribe to us on YouTube. And as always, you can listen to us on NOAA
Weather Radio. Thank you for tuning in for this weekly weather briefing. Please do
not use this information after 6 AM on Tuesday March 4.