Re-Tracing February’s Arctic Air Mass and Record Cold It took 89 years, but as the headlines have reported, on Feb. 4 Mount Washington Observatory managed to tie its all-time record low air temperature of -47 °F, originally set in January 1934. Observer Karl Philipoff documented the harrowing and historic day in a previous observer comment, and while I will probably think about my experiences that day for the rest of my life, my aim with this post is to take a look at the meteorology behind this event. To start, we need to look up, way up, to the

Red Sky at Morning, Hikers Take Warning Having grown up along the coast of Maine, there was a saying instilled in me by my parents every time I was planning to go outside for an extended period of time: “Red sky at morning, sailors take warning. Red sky at night, sailors’ delight.” This got me in the habit of looking out at the sunrise and sunset every day with the phrase repeating in the back of my mind. It was my parents’ way of getting me to pay attention to the weather when I was going out, and to

Traditional Mount Washington Rockpile Crunch Recipe Winter on top of Mount Washington means high winds, snow, and of course, lots of rime ice! Rime ice is a phenomenon that occurs when supercooled water droplets freeze on contact with any surface they come into contact with. When foggy conditions occur concurrently with high winds, rime ice can accumulate pretty quickly. Unlike glaze ice, which is clear and dense, rime ice is opaque, light, and fluffy. These qualities make it the perfect ingredient for ice cream! Rime ice cream (also known as Rockpile Crunch or R’ice cream) is a Mount Washington

Brutal Cold on Mount Washington: A Weather Story Hello! My name is Karl Philippoff and I am a new weather observer at Mount Washington Observatory. Although I am from New Jersey, I have been up on the summit multiple times – once as a tourist, once as a thru-hiker, once as a summit volunteer, and most recently as an intern. I am very excited to experience all that a winter on Mount Washington has to offer. I also feel incredibly lucky to have one of the most beautiful views I can imagine from my desk, looking out at the

Autumn 2022 Weather Was Warm, Wet, and Less Snowy The fall of 2022 on Mount Washington will go down in the record books as a warm, wet, and less snowy season compared to average. September started the season off on a slightly cooler note, with an average temperature of 42.8 degrees. This temperature corresponded with an anomaly of 0.3 degrees below the 1991-2010 baseline. A tendency for ridging over the eastern United States during the month of October created the ideal conditions for anomalous warmth. In fact, at +6.4 degrees, October 2022 was the fifth warmest October in our

Christmas Bomb Cyclone Sweeps through the Northeast Strong winds and heavy snow came to Mount Washington just in time for Christmas thanks to a nasty bomb cyclone sweeping through the Northeast. I wrote this comment Christmas morning at our summit weather station, where sustained winds exceeded 100 mph. What is a bomb cyclone and how does it form? A bomb cyclone forms when two very different air masses interact. Commonly, a cold, arctic mass shifts down from the north and a warm airmass is drawn into the storm. This type of system is defined by how rapidly it intensifies,

New Trail Signs Meant to Improve Weather Safety in the White Mountains New signs at trail heads leading to upper elevations in the White Mountains state the following, WARNING: Weather Conditions At High Elevations May Be Dangerous. For information from the Mount Washington Observatory about weather conditions & high elevation forecasts, text "weather forecast" to 603-356-2137. A project led by Observatory Life Trustee Jack Middleton to design and print over 100 warning signs for display at White Mountain trailheads was recently completed. The bright yellow signs, printed on 1/8” sturdy metal, warn of potentially dangerous weather at higher elevations

It's Cooler at the Top Capturing the moment while doing field research below Mount Washington. There’s a lot that goes on at the summit of Mount Washington. As many know, one of Mount Washington Observatory’s core priorities is to observe the weather. Observers take an observation every single hour of the day, adding to our 90-year (and counting!) climate record and sharing our data to improve weather models for meteorologists, pilots, climbers, researchers, weather enthusiasts, and other communities. As the fall intern, I’ve been able to participate in this work, and have also learned how to write the twice-daily

Forecast Discussion is Key to Interpreting Complex Mountain Weather As a meteorologist, I’ve had opportunities to forecast for a wide variety of environments and audiences. From the roads of Vermont to the valleys of California and climbers ascending Mount Everest, I’ve learned a lot about forecasting. At least that’s what I believed before starting to predict the weather at New England’s highest summit. In my few months here, I’ve been humbled on several occasions when forecasting this mountain’s dynamic weather. Mount Washington has taken me to task. What I am going for here is not the sympathy of the