Maravelias Extreme Performance Anemometry Mesonet (MAREPAM)

October 2021 Nor'easter Special Wind Reconnaissance Mission

N.B.: For detailed info on the 110.0mph and 106.6mph inst. max gusts recorded in this event, scroll down to "Final Anemometrics" section below.

Two portable cellular anemometer tripods were positioned early on 10/26/21 on Cape Cod. The first featured an individually calibrated A.S. Richards high-speed anemometer and was placed at the White Crest Beach parking lot in Wellfleet, MA, 1.2km south of the fixed Wellfleet MAREPAM station for additional verification. The second tripod was placed on an elevated hiking spot along the Dune Shacks Trail in Provincetown, MA. The latter featured an individually calibrated First Class anemometer.

Both positions are highly exposed, elevated coastal locations accustomed to far stronger winds than residential/forested/non-coastal nearby areas. In comparing wind data readings, careful attention should be paid to this fact and also to the wind gust averaging length in use.

To ensure collection of proper and full wind gust averaging information, both anemometer tripods were outfitted with custom engineered MAREPAM sensor controllers, each streaming real-time data packets every 60s over LTE CAT-M uplink. MAREPAM controller firmware uniquely computes and transmits precise calculation of instantaneous, 0.1s avg, 0.5s avg, 1.0s avg, 3.0s avg, 60s avg, 120s avg, and 300s avg wind speeds. This enables proper comparison in context to different wind stations and to historical/climatological data adopting different wind averaging methods. To compare to METAR wind observations, the 3.0s avg should be used.

Anemometer #1: White Crest Beach, Wellfleet, MA
  • Sensor ~11ft AGL
  • Ground 73ft AMSL
  • A.S. Richards C5C-1263-2-SP (Serial No. 25154) compact high-speed anemometer calibrated 9/23/2020 by SOH Wind Engineering, Inc. (Williston, VT, USA / Certificate PDF)



Anemometer #2: Unnamed hill, Dune Shacks Trail, Provincetown, MA
  • Sensor ~12ft AGL
  • Ground 112ft AMSL
  • NRG Systems S1 Anemometer (Serial No. 94120000143) calibrated 9/27/2019 by SOH Wind Engineering, Inc. (Williston, VT, USA / Certificate PDF)

The fixed Wellfleet MAREPAM station at Cahoon Hollow/The Beachcomber was donated in September 2018 and already optimally prepositioned to intercept this event. Data access information follows.

MAREPAM XMRPM1 / Wellfleet, MA
(RAW) (CWOP/MADIS FW3885) (Wunderground KMAWELLF39)

Final Anemometrics

Temporary Anemometer #1: White Crest Beach, Wellfleet, MA
  • Maximum Instantaneous: 110.0mph @ 7:12:56 UTC
  • Maximum 0.1s Average: 109.5mph @ 7:12:56 UTC
  • Maximum 0.5s Average: 108.0mph @ 7:12:56 UTC
  • Maximum 1s Average: 105.4mph @ 7:12:56 UTC
  • Maximum 3s Average: 98.7mph @ 8:10:02 UTC
  • Maximum 60s Average: 80.1mph @ 7:43:45 UTC
  • Maximum 120s Average: 77.5mph @ 7:43:45 UTC
  • Maximum 300s Average: 73.4mph @ 8:03:01 UTC
  • Sensor ~11ft AGL / Ground 73ft AMSL
  • Maximum gust readings represent off-horizontal wind due to aeroelastic flutter induced loosening of Richards cross-arm mount on night of the 26th, causing it to tilt freely to match wind pitch angle. See this GoPro screenshot of loosened mast taken during a visit to the tripod shortly before peak conditions. See also 10/27 sensor retrieval photograph, clearly picturing mast pitch.
  • Sensor calibration (9/23/2020 at SOH Wind Engineering, Inc., Williston, VT, USA) certificate: (PDF Link)
  • Full tabular data (PDF)
  • Full data graph (PNG)
  • Manually validated by remote access of raw pulse buffer data graphically verified as free of artifacts and inertially consistent with the viscosity of air.
  • Raw pulse buffer corroboration of 110.0mph inst. max gust (individual pulse micrograph from 3:12:31am EDT to 3:13:12am EDT, 41-second duration, with 4-pulse Richards C5C instantaneous moving average, 0.1s avg, 0.5s avg, 1.0s avg, and 3.0s avg): (PNG)

Temporary Anemometer #2: Unnamed hill, Dune Shacks Trail, Provincetown, MA
  • Maximum Instantaneous: 106.6mph @ 8:58:52 UTC
  • Maximum 0.1s Average: 104.8mph @ 8:58:52 UTC
  • Maximum 0.5s Average: 99.6mph @ 6:36:45 UTC
  • Maximum 1s Average: 97.1mph @ 8:58:39 UTC
  • Maximum 3s Average: 92.0mph @ 8:58:40 UTC
  • Maximum 60s Average: 79.6mph @ 9:04:26 UTC
  • Maximum 120s Average: 73.8mph @ 7:27:21 UTC
  • Maximum 300s Average: 69.5mph @ 6:55:36 UTC
  • Sensor ~12ft AGL / Ground 112ft AMSL
  • Sensor calibration (9/29/2019 at SOH Wind Engineering, Inc., Williston, VT, USA) certificate: (PDF Link)
  • Full tabular data (PDF)
  • Full data graph (PNG)
  • Manually validated by pulse-momentum real-time gust quality control algorithm.

MAREPAM XMRPM1 / Wellfleet, MA / Selected Adolf Thies, GmbH CLIMA™ First-Class Advanced Anemometer (SN #05156209)
  • Maximum Instantaneous: 96.9mph @ 7:55:56 UTC
  • Maximum 0.1s Average: 95.6mph @ 7:55:56 UTC
  • Maximum 0.5s Average: 93.7mph @ 7:55:56 UTC
  • Maximum 1s Average: 93.3mph @ 7:55:56 UTC
  • Maximum 3s Average: 90.9mph @ 7:55:58 UTC
  • Maximum 60s Average: 75.6mph @ 8:57:54 UTC
  • Maximum 120s Average: 73.4mph @ 8:16:32 UTC
  • Sensor 11ft AGL / Ground 89ft AMSL
  • Sensor calibration (8/12/2015 at SOH Wind Engineering, Inc., Williston, VT, USA) certificate: (PDF Link)
  • Full tabular data (PDF)
  • Raw pulse buffer corroboration of ~97mph inst. max gust (individual pulse micrograph from 3:55:56.7am EDT to 3:55:59.7am EDT, 3.0-second duration, with full-rotor-revolution moving average instantaneous speed): (PNG)

MAREPAM XMRPM2 / Dennis, MA / Selected Vector Instruments, Inc. A100LM (SN 9880/C929) Calibrated Anemometer
  • Maximum Instantaneous: 85.2mph @ 8:15:39 UTC
  • Maximum 1s Average: 78.9mph @ 6:43:54 UTC
  • Maximum 3s Average: 75.7mph @ 8:23:39 UTC
  • Sensor 15ft AGL / Ground 27ft AMSL
  • Full tabular data (PDF)