Blog

Radar Malfunction

The National Weather Service Marquette has experienced a radar transmitter failure.  See updates below.

See: https://forecast.weather.gov/product.php?site=NWS&issuedby=mqt&product=FTM

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UPDATE 2/16/20 10:00 AM: Radar has been returned to service.

UPDATE 2/16/20 7:00 AM: Radar transmitter out of service again. Technician will work on it this morning.

UPDATE 2/13/20 1:20 PM: Radar has been returned to service.

UPDATE 2/12/20 2:40 PM: Parts are on order. Return to service expected by 4 PM tomorrow.

UPDATE 2/12/20 8:00 AM: Radar transmitter out of service again.

UPDATE 2/10/20 6:30 PM: Radar has been returned to service.

UPDATE 2/10/20 4:50 PM: Radar transmitter out of service again.

UPDATE 2/9/20 12:30 PM: Radar has been returned to service.

Radar Down from 9/9 – 9/13

The National Weather Service Marquette will be replacing some radar equipment starting Monday September 9th through Friday September 13th. During that time, you will see a “Down for Maintenance” indicator where the radar image typically resides on our home page.

For more info, see their blog article: https://www.weather.gov/mqt/KMQT_SLEP

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UPDATE 9/11/19: Apparently the NWS radar techs wrapped up their work 2 days early. The radar was returned to service this afternoon.

Radar Down Until Thursday 8/8

According to the local National Weather Service office, the radar will be down for preventative maintenance until Thursday August 8th at 3:00 PM EDT.

If a storm develops, the radar should be temporarily re-enabled.

All radar options on our site will be affected by the outage.

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UPDATE 8/6/19 2:00 PM EDT: Radar is back online. No storms expected today. Not sure what’s going on. No update from NWS.

Humidity Adjustments

It appears our humidity sensor’s maximum value has lowered over time. This is, unfortunately, common with our particular weather station’s sensor. The process is accelerated by 24 hour fan aspiration. We’ve seen this behavior in 3 other units we’ve deployed in the past.

When we first installed this sensor last July, the top possible humidity reading was 98%. The ceiling has since lowered to 96%.

After a round of tests using an independently calibrated device yesterday & today, and in an effort to stay within +/- 3% of true ambient humidity, we’ve programmed adjustments to the following humidity readings:

  1. 94% +2% = 96%
  2. 95% +3% = 98%
  3. 96% + 4% = 100%

Because we use a 5 minute rolling average for humidity at times you will see values between 96%, 98%, and 100%.

The good news is, based on experience with this sensor model, the biases should now be fairly solidified and predictable.

The bad news is that when humidity starts to descend from persistently moist conditions (>95% and >2 hours) the sensor can lag because of moisture uptake within the protective housing. Our programmed offsets exaggerate this process. We believe it’s more important to properly indicate the arrival of fog & dew than the drier air that immediately follows.

As always, though, we will test to verify sensor performance every so often and adjust accordingly.

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NOTE: We send corrected humidities to CWOP & Weather Underground.

UPDATE 5/28/19: After an overnight period of saturated air, discovered the sensor’s ceiling is actually 96%; corrected offsets.

New Rain Gauge

Today I installed a new tipping spoon automatic rain gauge that will report real-time rainfall to the website. This is described by the manufacturer, Davis Instruments, as an “incremental improvement” over the previous tipping bucket gauge.

For the most part, our automatic gauge has run very close to our 4″ reference gauge which is 6 ft away & 2 ft lower. However, sometimes — particularly during large rain events — we encounter under reports of approximately 25% to 50%. Discrepancies can appear at any time regardless of wind speed or direction. Many others have reported similar, inexplicable anomalies with the old gauge.

Astute, long-time readers may notice the new “Aerocone” funnel in the picture. Supposedly, this cuts down on rain-induced measurement errors by reducing turbulence where rain is collected.

We’ll see how the new gauge performs. Early side-by-side comparisons from other station owners with reference equipment are encouraging. I’m definitely in the “trust but verify” camp nonetheless.

[UPDATE 5/20/19: The new gauge is performing marvelously so far. This weekend the tipping spoon reported 2.70″ of rain. Our reference gauge caught 2.67″. That’s about a 1% departure. Given the distance & design differences between the two gauges, small variances are normal.]