Significant Snowfall for Washington Cascades and Northern Rocky Mountains

A cold front will linger for several days from the Pacific Northwest to portions of the northern Plains early this week. Cold temperatures and copious moisture will combine to produce several feet of snow into the mountain passes, with up to 4 feet of snow down to 4000 feet in the northern Rockies. Travel through mountain passes will be very difficult.
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Last Update: 540 AM AST Mon Dec 18 2017

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San Juan, PR Local Forecast Office

41NM N San Juan PR

Marine Zone Forecast

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 2 PM AST THIS Afternoon...

Synopsis: Surface and upper level high pressure ridge will remain over the western Atlantic through Thursday. This in turn will tighten the local pressure gradient to maintain fresh to locally strong northeast winds across the regional waters. Choppy and hazardous wind driven seas can therefore be expected to persist across the regional waters. A northerly swell will also arrive across local waters on Monday and Tuesday.

Today
Northeast winds 15 to 20 knots. Seas 5 to 7 feet with occasional seas up to 9 feet. Dominant period 8 seconds. North swell around 4 feet. Scattered showers through the day.
Tonight
Northeast winds 10 to 15 knots. Seas 4 to 6 feet with occasional seas up to 8 feet. Dominant period 8 seconds. Isolated showers.
Tuesday
Northeast winds 10 to 15 knots. Seas 4 to 6 feet with occasional seas up to 8 feet. Dominant period 8 seconds. Isolated showers.
Tuesday Night
Northeast winds 10 to 15 knots. Seas 4 to 6 feet with occasional seas up to 8 feet. Dominant period 10 seconds. North swell 4 to 5 feet after midnight. Scattered showers.
Wednesday
East winds 15 to 20 knots. Seas 5 to 7 feet with occasional seas up to 9 feet. Dominant period 10 seconds. Scattered showers.
Thursday
Northeast winds 15 to 20 knots. Seas 4 to 6 feet with occasional seas up to 8 feet. Dominant period 8 seconds. Scattered showers.
Friday
Northeast winds 15 to 20 knots. Seas 4 to 6 feet with occasional seas up to 8 feet. Dominant period 8 seconds. Scattered showers. Isolated thunderstorms.
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ABOUT THIS FORECAST

Last Update: 540 AM AST Mon Dec 18 2017
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