Now that we’ve dried out, we can look back at rainfall totals over the past seven days. Recall that prior to the event, seven-day forecasts had been a little confusing. While most guidance suggested less than three inches, a couple of forecasts flirted with almost eight inches over the city. Nevertheless, SPU and partners prepared […]

With one frontal passage down and a few more to go, rainfall forecasts are in better agreement. Up to three more inches of lowland rain, occasionally heavy, is likely over the next seven days. Decent amounts of high elevation snow, too. Since late Monday, SPU’s south-end rain gages have recorded up to a half an […]

As the advertised series of systems approach, forecast rainfall amounts have edged slightly upward. The map above is not concerning, but the latest point forecast tells a different story—nearly seven inches between tonight and Monday! For what it’s worth, current worst-case model runs don’t look that bad, and the latest NWS Area Forecast Discussion mentions […]

This week is pretty much exactly when fall rains are supposed to begin, and thanks in part to the pattern-busting remnants of Typhoon Hagibis, the atmosphere is obliging. Forecast rainfall amounts are not concerning but it’ll likely be the wettest period we’ve experienced since early April. Up to two inches should fall across the City […]

As predicted, a decent convergence zone has formed in the wake of yesterday’s frontal passage. Heavy showers, some precipitating graupel, or soft hail, will continue to drift through the region today. (SPU’s in-city rain gages have yet to record any significant rainfall intensities, for what it’s worth.) Also: snow in the passes! Dry weather is […]

The local radar is down for maintenance, so it’s a bit difficult to tell what’s really going on, but it certainly didn’t rain as much as forecast in and around Seattle yesterday. The wind ended up being the bigger story, which also probably had to with the size of the west-to-east-oriented rain shadow (above).

Pretty quiet. Around 0.50″ total rainfall is forecast on Monday and Tuesday across Seattle. Three times that amount is expected over SPU’s watersheds, with a few inches of snow near the passes. Convergence zone formation looks likely, especially on Tuesday, which could quickly double totals across some neighborhoods and enhance mountain snowfall.   Dry and […]

Of course, as soon as I note the warmer-than-normal October outlook, The Climate Prediction Center changes it to colder-than-normal. The October-through-December outlook remains warmer-than-normal.   The good news, perhaps, is that this flow pattern appears to be making cold dent in The Blob.     —JRH

  Morning low temperatures dropped below 40ºF throughout the region this morning. It hasn’t been that cold around here since April 28. SeaTac didn’t break its record, though, which remains 36ºF in 1950.   Probable urban heat island effects aside, SeaTac hasn’t measured a low in the 30s this early since September 29, 1983 (NOAA […]

“It will never happen here.”   During Hurricane Harvey, much of metropolitan Houston received as much if not more rainfall than Seattle receives in an entire year. People ask, could we get 50 inches of rain here?  The short answer is no, we could not. But the answer to the follow up—how much rain could […]