Luckily Logan doesn't have the major altitude differences that cause many of the low level shear plane accidents. So by the time they reach visibility minimums, pilots have plenty of time to go around. Logan got down to a cat 1 ceiling today. In order to fly a CAT I approach, the cloud based (ceiling) must be no lower than 200 feet and the visibility must be no lower than 550 metres. This is because the pilots must be able to visually identify the runway no later than 200 feet above the ground to be able to land. It goes up to cat 3 ils, there are also several variances to cat 3, making landing requirements more strict.
CAT IIIa has a minimum ceiling of 50 ft and a minimum visibility of 200 metres.
CAT IIIb has no minimum ceiling, but there must be at least 50 metres of visibility.
For a CAT IIIc, which has not actually been implemented anywhere, there are no minimum limits for ceiling and visibility.
Would lead one to believe, 'why isn't cat 3 all the time?'. Cost and pilot experience from most of my research is what limits that.
Always loved planes. It what drew me to weather. Trying to land in low vis while following exact directions is difficult to do alone in a flight Sim, let alone in real life.
I've seen bad conditions ground planes for awhile at Logan. Usually only 30-60 mins. Snow operations some times cannot keep up more than anything. Especially considering blowing and drifting on open airport hellscapes. This was a unique one. Perhaps the type of event we really only accurately pick up immediately now due to things like TDWR. We can see the microbursts in real time now.
Thought it was really obvious pike region to BOS was the target about an hour before due to the cu field and boundary. Did not expect the multiple microbursts though. So a lot of lightning today out of tcu that wasn't even registering on radar yet, exploding into hail packed 70mph monsters just 7 minutes later. There's a really delicate balance of Seabreeze, outflow boundaries etc that seems to contribute to promoting these microbursts right at the coastline.
I truthfully believe Scott may be right regarding uhi and addition of building in Seaport. It's become truly obnoxious. It's beautifully obnoxious if you enjoy coeds.
But a SW wind or W wind probably does bring more heat than even five years ago. But this does not excuse more recent issues with the *temperature* (not wind) readings.