Friday/ the AWPAG is thirsty

We are all ready for cool weather, and a little rain, to take away the heat and the haze here in the Puget Sound.  And yes! – there is rain in the forecast for Saturday night! (The expected 56 days of dry weather by Saturday will be a new record on the books).

Seattle-Tacoma airport has a state-of-the-art AWPAG* rain gauge (a far cry from the graduated cone we once had in our backyard when I was young!).  The gauge is surrounded by two shields to improve readings under windy conditions, and will melt snow so that it can measure the liquid equivalent accumulation.  Fancy.

*All Weather Precipitation Accumulation Gauge (AWPAG)

Update Sun 10 am: 0.02 inch of rain at SeaTac late Saturday evening ended the record streak of 55 days (June 18-August 11) without measurable rain.

The AWPAG at Seattle-Tacoma airport (installed in 2006). The gauge has a so-called Tretyakov shield around it, as well as an 8-ft diameter Alter windshield.

Here’s a close-up of the guage. If it catches snow, the snow will be melted.  I’m not sure of the inside of this specific gauge, but some gauges will mix precipitation (rain, ice or snow) with glycol to melt any ice or snow; the oil reduces evaporation loss – and then the reading is calculated every few minutes and transmitted to a control center by a radio signal.

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