Temps here today have been below freezing for over 8 hours now, 500+ lightning strikes, and my Tempest has recorded 0.89” of rain, which seems right. Icing on trees, and lots of ice building on the Tempest, yet impressively, it’s still recording rainfall. I’d expect the haptic sensor to have frozen over by now. Still getting wind readings, too, despite the ice accretion all around the opening for the ultrasonic wind sensor. The readings are probably modulated a bit, but they’re still coming in - and no wild high readings either.
This means we can use Tempest stations to verify radar indicated rain snow
lines. I am doing so today here in southeast Virginia. Radar indicating snow,
station showing 32.5F with heavy rain, it’s not snow,could be sleet. Below freezing
showing rain, and it’s freezing rain or sleet. Areas showing rain or snow on radar and
station reporting no rain than its most likely snow.
that’s cool. How do rain/snow lines currently get determined by meteorologists?
I believe the radar apps just use surface temp observations of around 32f to 34f
to transition from rain to sleet to snow. Works ok for most rain snow events, but
I have seen it snow at 43f and rain at 28f.
so they just decide based on temperature, not on some radar signature? hmm, not very accurate than.
The radar sites due have settings to determine precipitation types, but do
not think it’s used on most radar apps.
still cool to use tempest to do it yourself
“The radar sites due have settings to determine precipitation types, but do
not think it’s used on most radar apps.”
Well … not really settings at the sites themselves, but, algorithms run on the radar returns (and, these algorithms got better once dual polarity radars became common for weather radars). But, those algorithms are indicating the best guess for precip type at the altitude of the radar beam, which often differs from what is reaching the ground (and, the radar beam can be a mile up or more for “remote” locations … locations further away from the radar). There are other algorithms that include temperatures, etc., that are not directly received from the radar that are used to give a best guess of what is reaching the ground.