Using HRECOS to Track the 1/23/17 Nor'easter
A strong nor'easter is predicted to bring near hurricane force winds to the ocean off New York Harbor later today. Forecasters expect mild to moderate coastal flooding in association with the storm. Teachers interested in practicing graph interpretation, exploring earth and environmental science topics, and promoting STEM skills may wish to use remotely sensed data to check out conditions today as the storm approaches, or tomorrow as it winds down.
A good place to start is the National Oceanic and Atmospheric Administration [NOAA] buoy 44065 at the entrance to New York Harbor. Its readings are important because the intensity of the storm out over the ocean will determine its impacts in New York Harbor and the Hudson. Scroll down to the current Conditions table. Click on the graph icon next to Wind Speed or Wind Gusts to see how winds increase. Gusts of more than 40 knots were already being observed at 10:00 this morning. [A little math: 1 knot equals 1.15 miles per hour; 40 knots equals 46 miles per hour.] Watch to see whether winds increase with falling atmospheric pressure as the center of the nor'easter approaches. A graph combining plots for wind speed, wind gusts, and pressure should show the correlation; it's the last item in the table. Click on on the graph icon for Wind Direction to see that the wind went from west to northeast quite rapidly at about 1:00 AM overnight. [Note: As you watch wind direction changes through the storm, keep in mind that 0 and 360 degrees are the same, and indicate a wind out of the north. The plot may bounce from the bottom of the chart – 0 degrees - to the top – 360 degrees – with minor changes in wind direction.]
Is the storm impacting water levels in the estuary? Visit the website for NOAA's tide gauge at the Battery in Manhattan and click on Tides/Water Level in the second line of menu items, then on Water Levels in the dropdown menu. [Note: the default time for the resulting graph is GMT – Greenwich Mean Time; scroll to the Time Zone window below the graph and select LST (Local Standard Time), then hit Plot to reset the time scale to our local time.] The water level graph has two plots: a blue line showing the astronomically predicted tides and a red line showing actual water levels. Moving your cursor along the plots generates a pop-up window showing the difference between predicted and actual levels. As of 10:45 this morning, water levels were already more than three feet higher than predicted. How high might the surge get? Will the time of maximum surge occur at the same time as high tide?
Will the Hudson experience higher water levels due to the storm? Visit the HRECOS homepage and click on the Current Conditions page. Dropdown menu choices there allow you to select the station(s) and parameters of interest. For water level, you will want to choose the (hydro) option for stations that offer separate hydrological and meteorological (met) options; in the parameter menu select Depth or Elevation. If there is significant storm surge from this nor’easter, you should be able to track its higher water levels going up the Hudson to Albany. For better resolution on what’s happening today, change the Start Date to today’s date, so that the plotted graph shows only today’s readings, not the default of four days, though the latter is best for seeing trends. Remember that it takes about 10 hours for a given tide event to move up the river from the Battery to Albany. Use the meteorological parameters to see what wind conditions are like at various places along the estuary. The Piermont meteorological station is particularly exposed; it will be interesting to track wind speeds there. Gusts had reached 31 knots there by ~8:00 this morning.
Check out the HRECOS Lesson Plans page for PowerPoints with more details on using the remotely sensed data in your classroom. These include a very short PowerPoint about how storms impact the estuary.
We hope you have a few minutes to explore these sites. Feel free to contact us with questions or thoughts about the possibilities or – should you use remotely-sensed data to track the storm – your experiences with your students.