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A developing Pacific storm was poised to head into Washington and Northern Idaho early on the night of Jan 15, 2000 (see satellite imagery left). A recent storm left the area in a cool air mass as this developing storm pushed toward the region. In addition, the strength of the storm over the Pacific created a surface pressure gradient that was pulling cooler surface air into eastern Washington and Northern Idaho. This situation was a classic setup for a good overrunning precipitation event for the area. As the storm continued to wind up early on the 16th, precipitation quickly spread into the area. The East Slopes of the Cascades and the Central Basin were the first to see the snow. Eastern Washington and northern Idaho only a few hours behind. By sunrise Sunday, 1/16, the East Slopes of the Cascades and Central Basin picked up between 3 and 6 inches of snow. Meanwhile the remainder of Eastern Washington received between 1 and 3 inches with North Idaho generally seeing an inch or less.
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The northerly surface flow continued through much of the morning and helped keep cooler air at the surface from retreating to the north. Meanwhile, southerly winds a few thousand feet above the surface began to warm the atmosphere. Enough warming took place shortly before sunrise in and around Spokane and Coeur D'Alene that temperatures a few thousand feet above the ground rose to just above freezing. As a result, the snow melted to rain. However, temperatures closer to the ground remained below freezing. Thus, freezing rain and sleet began fall (see 4am radar image right). As the morning wore on, the warm air aloft spread into North Idaho. Similar to Spokane and Coeur D'Alene, snow changed to freezing rain and sleet. Fortunately for travelers, enough warm air filtered into in by mid morning that the sleet and freezing rain turned to just plain rain. The air did not warm up enough aloft across northern sections of Eastern Washington and locations in and around the East Slopes of the Cascades to produce freezing rain and sleet. The precipitation continued in the form of snow. |
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As the snow was changing to freezing rain and sleet over parts of Eastern Washington and North Idaho, an upper level wave or disturbance was swinging around the low pressure system offshore. As this feature pushed inland, it produced an intensifying band of heavy rain and snow showers between 4 and 6 AM. The intensifying showers were not only apparent in radar imagery, but were apparent by the cooling clouds tops in Infrared Satellite Imagery. Very strong winds also accompanied the band of showers. |
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| The band of showers associated with the upper level wave began to spread into Eastern Washington between 8 and 11 am. As it did so, the rain and snow showers intensified into thunderstorms which produced heavy rain, snow, hail, and damaging wind gusts to 50 mph or more. These showers and thunderstorms maintained their strength as they moved through north Idaho. As a result, horrible traveling conditions developed and ski areas in north Idaho had to close. The visible imagery (right) clearly depicts the higher clouds tops associated with the showers and thunderstorms as they blew through the area (green + and - signs depict some of the cloud to ground lightning strikes).
Once the upper level wave pushed into Montana, drier air spread into the region. This brought and end to the precipitation. However, windy conditions persisted across much of the area until around midnight. |
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Storm Reports from around the area
TIME(PST) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0400 AM (GEG)SPOKANE INTL ARPT WA FREEZING RAIN/ICING
01/16/00 SPOKANE 3 HOURS OF FREEZING RAIN
0945 AM 8 N EPHRATA WA HEAVY SNOW
01/16/00 GRANT 6 INCHES OF SNOW AT
LAKE LENORE
1000 AM LA CROSSE WA 50 MPH TSTM GUST
01/16/00 WHITMAN
1025 AM 3 S SPOKANE WA WIND DAMAGE
01/16/00 SPOKANE GREENHOUSE BLOWN DOWN
IN LATAH VALLEY
1030 AM PALOUSE WA WIND DAMAGE
01/16/00 WHITMAN ROOF BLOWN OFF BARN
WITH SEVERAL TREES AND
POWER LINES DOWN
1040 AM ROCKFORD WA WIND DAMAGE
01/16/00 SPOKANE TREE BLOWN DOWN ON TO A
CHURCH OFFICE
1100 AM 3 NE BREWSTER WA HEAVY SNOW
01/16/00 OKANOGAN 5 INCHES OF NEW SNOW
1100 AM 3 E EPHRATA WA HEAVY SNOW
01/16/00 GRANT 4-5 INCHES OF NEW SNOW
1100 AM WATERVILLE WA HEAVY SNOW
01/16/00 DOUGLAS 5 INCHES OF NEW SNOW
1155 AM VIOLA ID WIND DAMAGE
01/16/00 LATAH ROOF BLOWN OFF LOG HOME
AND DAMAGED GARAGE
1200 PM CHELAN WA HEAVY SNOW
01/16/00 CHELAN 4 INCHES OF NEW SNOW
1200 PM WENATCHEE WA HEAVY SNOW
01/16/00 CHELAN 8 INCHES OF NEW SNOW
1200 PM MAZAMA WA SNOW
01/16/00 OKANOGAN 6 INCHES OF NEW SNOW
1200 PM PLAIN WA SNOW
01/16/00 CHELAN 7 INCHES OF NEW SNOW
1200 PM ENTIAT WA HEAVY SNOW
01/16/00 CHELAN 6 INCHES OF NEW SNOW
1200 PM GRAND COULEE WA HEAVY SNOW
01/16/00 GRANT 4 INCHES OF NEW SNOW
1200 PM 19 NW ENTIAT WA SNOW
01/16/00 CHELAN 10 INCHES OF NEW SNOW
AT ENTIAT RIDGE AT 5500
FEET
0200 PM KELLER WA SNOW
01/16/00 FERRY 3 INCHES OF NEW SNOW
0200 PM WALLACE ID .25 INCH HAIL
01/16/00 SHOSHONE IN ADDITION TO LESS
THAN AN INCH OF NEW SNOW
0200 PM REPUBLIC WA SNOW
01/16/00 FERRY 3 INCHES OF NEW SNOW
0400 PM COLVILLE WA HEAVY SNOW
01/16/00 STEVENS 4 INCHES OF NEW SNOW
0500 PM BONNERS FERRY ID HEAVY SNOW
01/16/00 BOUNDARY 7 INCHES OF NEW SNOW
0500 PM 9 W SANDPOINT ID HEAVY SNOW
01/16/00 BONNER 8 INCHES OF NEW SNOW
By Don Moore
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