Bolt from the Blue is a news letter from the Sacramento office of the National Weather Service intended for those involved in the local weather spotter service. Skywarn is a national weather spotter service in which many hams participate. There are several Skywarn nets.
A ham license is not required to be a weather spotter but because so many hams are in the program I felt it was a good fit for this blog. It is just one of those articles that when I read it I really enjoyed it and thought there would be a lot of other hams who would enjoy it too so I immediately shot off an email to Eric Kurth asking his permission to reprint it in this blog. There were some photos with the article but I am not experienced enough to know how to down load them from a PDF file and insert them into the blog.
I want to thank Eric his article and now I will shut up and let you read the article.
Dual Polarized Radar Upgrade Complete for Sacramento NWS Forecast Area
By: Eric Kurth, NWS Sacramento The most significant upgrade in the history of the National Weather Service WSR-88D weather radar is now in progress across the nation. The installation of dual-polarization (dual-pol) at the Davis WSR-88D radar is now complete. The other radar which covers the forecast area of NWS Sacramento is the Beale WSR-88D radar, which was completed in mid-March. This means that one of the most effective tools available for detecting severe weather conditions is now available to forecasters at the Sacramento National Weather Service Forecast Office. Dual pol radar adds a vertical polarization to the existing horizontal polarization of radar pulses. This allows the shape of hydrometeors to be determined, allowing for rain drops, hail, snowflakes and other hydrometeors to be distinguished from each other as they fall through the sky. There is also some capability to tell heavy rain from lighter rain, which should allow for better projection of flash flood events. Severe thunderstorms have special dual-pol signatures which can alert forecasters of their strength. Research has shown that very large hail can frequently be discriminated from small hail in thunderstorms, before it hits the ground. Even better winter storm forecasts are possible, due to the detection of the height of the melting layer, which can help determine snow levels in higher terrain. Non-meteorological phenomena, such as birds, insects and chaff, can also be separated out. The result of the upgrade should be more accurate and timely warnings of weather hazards. Forecasters have received detailed training to use the new dual-pol radar data. Experience and future research will further act to enhance forecaster skills to use this powerful new tool.