Deadline Driven: The 12-Hour Shifts that Power Weather Forecasting from the Northeast’s Highest Peak

By Wendy Almeida 

As a new member of the Mount Washington Observatory team, I wanted to gain a deeper understanding of the unique operations of the weather station and the meticulous work of observers to help better explain to our members how our summit team works. Having previously volunteered at the summit to cook for our EduTrips, I was familiar with the general rhythm. But this time, I shadowed an observer for a couple of 12-hour shifts. My goal was to delve into the nuances of their work, the pressure of hourly deadlines, and the coding language used for weather observations at the summit. 

Many who follow the MWOBS social media and blog know that weather observers brave harsh conditions to collect weather data. What may not be as clear is that this data collection and reporting operates on a constant timer of deadlines. 

Having worked at a daily newspaper, I understand the pressure of deadlines to get pages off to the presses for printing and distribution. Those were tight daily and weekly deadlines that required quick work and accuracy. 

While shadowing observers at the summit, I witnessed that same pressure of deadlines, but on an hourly basis for 12 hours straight. They must record and submit observations before :15 past the hour. So, while the observation can take 2 to 10 minutes for non-synoptic observations, it can take another 5 to 10 minutes to fill in and code all the data correctly. An observer needs to be a hardy soul who enjoys the challenge of facing all sorts of harsh weather; it’s also a person who thrives under pressure.   

Daily Observations and Data Reporting 

Observations are conducted hourly, but the level of data collection varies. In addition to these hourly observations, there are “mini” reports every 3 hours and more comprehensive synoptic reports four times daily, each requiring a different level of detail and analysis.

Shaded lines indicate what type of report is recorded. Dark gray is the more comprehensive synoptic report. Light gray lines are “minis,” which have more details than the hourly reports.

A typical hourly observation involves venturing outside with a sling psychrometer. This device resembles a double thermometer, with a dry bulb to take the current temperature and the other with a “wet bulb” to get the evaporative temperature. The wet bulb is left in distilled water and, when brought outside to “sling,” measures the temperature as it evaporates. Using both the dry and wet bulb calculates the dew point and relative humidity. However, it is not used when the summit is in the clouds because the conditions are already at 100% saturation. 

The wet bulb in the sling psychrometer is wrapped in a cloth “sock” and stored in distilled water.

After noting the current temperature and humidity, observers assess the visibility from the deck in each direction to determine the most dominant visibility conditions. Then there are the clouds. Various cloud types can be present at different levels, and the type of cloud informs the general height of the clouds, but experience provides the best estimate of cloud cover height. (This blog explains more about identifying clouds) 

METAR reports include multiple cloud layers above and below the summit.

The observation starts as a 2-minute task outside, but sometimes it can take longer, especially if “slinging” takes several minutes or multiple cloud layers need to be assessed. Once inside the station, the observations are recorded through a METAR coded report. 

Synoptic reports are a more comprehensive report of weather condition measurements and are recorded both online for our weather partners as well as in paper records.

In addition to recording the hourly observations, the synoptic report is submitted every 6 hours and shared with the National Weather Service for use in nationwide forecasting models and regional reports. This data helps NWS update models by informing them of current conditions, including precipitation and pressure changes. This data also produces specialized forecasts for the higher summits of the White Mountains and the greater White Mountains region. 

Understanding the Legacy of Continuous Observations 

MWOBS has been diligently recording hourly observations since 1932, making it North America’s longest continuous historical climate record maintained by human observation. This invaluable data allows us to gain deeper insights into weather patterns and their changes. (Learn more about the Observatory’s climatological records here)

Supporting the Observatory’s Mission 

Seek the Peak, our largest annual fundraiser, is underway! Join in on the fun at or consider making a donation to the MWOBS Weather Observers’ team page to support our work in forecasting, education, and research. 

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