High Water

Nat’l Wx Service, TV, Radio and private forecasters are all speaking out about the large, region-wide high water event that will unfold between now and next Wed.  HEED Alerts, Watches & Warnings!  The amount of rainfall is modeled to cause rapid rise in streams, creeks & rivers over the next 5 days.  Wx models have yet to settle on which areas west of the OR, WA Cascades, and SW BC will be hardest hit, but the charts do indicate nearly everyone west of the mountains will have HIGH WATER problems - be that standing water in low-lying areas or that running down streams & rivers.  If you live or drive in a flood-prone area, be prepared to fight high water issues.  Per the Nat’l Wx Service: “Most coastal rivers will have a 40-60% chance of minor flood stages and 20-30% chance of reaching major flood stage.”  Their words, not ours.  Be Prepared.

Rather than specific details, we will present the broad picture of what will unfold the next several days.  Two to three storms (atmospheric rivers is the current phrase used) will hit the PNW starting now, with each one having the potential to present HIGHER amounts of precip than the one preceding.  They may NOT all hit in the same location (thankfully).  SNOW in the mountains, above 3,000-4,000 ft, will be measured in FEET between now and Saturday night.  Late Saturday, THAT precip will likely be melted when the heavy rains strike overnight Saturday - with freezing level jumping up over 6,000 ft.  Combine snow melt ‘water’ with inches of rain on top and, wham, flood potential down stream.  

Valley level rainfall 3” to 4” range, higher in the coast ranges.  Rain will be moderate-to-heavy starting later on Saturday through much of Sunday.  Another drenching storm or two is modeled to hit the PNW the first half of next week.  Yikes.  Urban flooding concerns are also in play - help, when safe to do so, to keep your local storm drains clear of leaves. 

Overall, things should calm down a bit by late Wed or early Thu, Dec 5,6.  It could turn totally dry for 3 days.  In fact, the latest model scenarios for next Fri through the second weekend of Dec (9,10) call for a dry spell, although chilly, weather, with a return to showers/rain sometime Mon Dec 11.  The week of Dec 11-15 has presented as a mix, with a wet day or two, separated by a dry days.  We’ll see.