What Is This 'Atmospheric River' I Keep Hearing About?
KPIX 5 Morning Weather Anchor Roberta Gonzales answers the questions you never get to ask on-air.
Q: Roberta, with the approaching storm, I keep hearing the phrase, "atmospheric river." I've never heard that before. What is it? Donna McGee; Pleasanton
A: Excellent question. The "atmospheric river" has been a big topic here in our KPIX 5 newsroom! I wanted to make sure my description was correct, so I called on my buddy Jan Null from Golden Gate Weather Services. We are both in complete agreement, It is bascially, a broad band of precipitaton extending to the southwest and tapping into moist subtropical moisture. We here in the Bay Area, commonly refer to it as the "Pineapple Express". But expressions may defer depending on regions. Daily, across the world, in each hemisphere, there can be 2 or 3 atmospheric rivers flowing at once. The reference to these "narrow corridors" depends on LOCATION, LOCATION, LOCATION!
Almost exactly one year ago on February 6 through the 9th, the "Pineapple Express" dumped on the Bay Area leaving in it's wake 11.71 inches of rain in Kentfield. I remember it well, as I was reporting in front of Joe's Tacos in Mill Valley, assisting with sandbagging.
We have a very similar set up again one year later. The rain begins in the far North Bay Thursday and sits there all day long. The bulk of the Bay Area will be cloudy and dry with increasing southerly winds. Friday the rain band is still lingering far North Bay, before finally sliding across the Golden Gate, spilling rain and wind into the San Francisco metropolitian and urban areas around lunch time. The storm tracks into the Santa Clara Valley towards the evening commute.
In anticipation of the impending flooding rains, a Flash Flood Watch is in effect for all the North Bay, Friday morning through Friday night. Be prepared and drive safely!
Do you have a Weather question, observation or picture you would like to share with me? I would love to hear from you! Please email me at: Gonzales@kpix.cbs.com
