November 19, 2024
Bomb Cyclone Deepening Off the Coast
Last updated 12:35PM, Tuesday, November 19th, 2024
By: Connor Boske, Addison Curp, Kyra Schlezinger, and Annabelle Tjio
Happy (windy) Tuesday Huskies!
Today is a big day in Seattle’s weather history. November 19th is the most likely day of the year to get rain. In the first 120 years of weather recording in Seattle, 89 out of 120 years recorded rainfall, and today will be no different! It’s important to note that while chances of rainfall will start to decrease in the coming weeks, it won’t be by much, and the rainy season is still alive and well. Speaking of rain, we will get about 0.2 inches of rain today in Seattle, so nothing too crazy, but the wind is the real threat today. We have alerts all over the state of inclement weather, so charge up those phones as power outages are a possibility throughout the region. Our highs will be in the mid-40s and our low this morning was 38, so we are running slightly cooler than normal. Our normal high is 51 and our normal low for this time of the year is 40.
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Those of you who have been paying attention to the weather news the past couple of days know that a bomb cyclone is rapidly deepening off the coast. A bomb cyclone is a cyclone that undergoes rapid intensification over a short period of time. The general standard for a bomb cyclone is to have a pressure decrease of 24 millibars or more in 24 hours. NOAA’s Weather Prediction Center has the current pressure at about 956 millibars, having dropped more than 24 millibars in the past 6 hours alone. For context, the lowest pressure recorded during the Hanukkah Eve windstorm of 2006 was 970 millibars and the lowest pressure recorded during the famous Columbus Day Storm of 1962 was 948.The wind strength and location will be different than these two famous storms, because the low center isn’t expected to “make landfall” and move onshore, while it did in 1962 and 2007. The low will sit over the ocean, causing the strongest winds to be on the coast and on the western side of the Cascade passes, where the low will force air through the passes at a greater speed.
There are numerous weather alerts in preparation for the approaching bomb cyclone. The Puget Sound area has been issued a wind advisory, with sustained winds that reach 30 mph and gusts exceeding 50 mph expected from 2pm Tuesday to 4am Wednesday. On the western coast, towns such as Forks and Hoquiam face a high wind warning with gusts reaching up to 65 mph. Meanwhile, winter weather warning blankets the high altitudes (purple zone), where significant snowfall is expected. The orange zone, which includes the North Cascades and its passes, is under a blizzard warning. Expect snow and high winds as the low pressure from the cyclone is funneled through the narrow passes. Along the coast, the salmon zone is expecting Hurricane Force Winds. Prepare for a wild ride as the storm comes in!
Among the plethora of warnings and advisories, the wind warning in particular set for this afternoon will introduce 25-40 mph winds with gusts getting up to 65 mph for those vulnerable coastal regions. Along with the coastal regions, winds suctioned through the passes will reach areas like Bellevue and Issaquah, making these local vicinities subject to those strong gusts as well. This advisory will last until Wednesday morning. Although a relatively short time period, as seen from the image above, areas highlighted in yellow can experience blown down tree limbs and power lines, so be prepared for those potential power outages. Practice caution when driving and perhaps it is best to stay inside for this evening.
Make sure you prepare for the upcoming weather as we simultaneously prepare to end the quarter, Huskies!
Reach forecasters Connor Boske, Addison Curp, Kyra Schlezinger, and Annabelle Tjio at uwdawgcast@uw.edu, on X/Twitter @TheUWDawgcast, or on Instagram @uwdawgcast.
