At 12, 16, 20, 00, and 04, it is predicting P6SM OVC025. But, for 12-16, 16-20, 20-24, 00-04, 04-06, it is predicting snow with much lower ceilings. Whats the deal? I could understand it if the times were spread out, but for example, 12-16 and 16-20 is snow, while 16 on the dot is much better weather.
SlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 65
Reply 1, posted (12 years 5 days 14 hours ago) and read 2268 times:
I'll have to wait until later to chart this one out, but at a glance it appears to me that they have kind of a baseline forecast going all day long but with the consecutive TEMPOs for lower. That sort of looks like they maybe should have used a PROB instead.
Like the weather is going to be P6SM and OVC025 but from time to time during the day snow showers are going to make it lower - they just don't know when.
Just hedging, or so it looks.
Happiness is not seeing another trite Ste. Maarten photo all week long.
CFIcraigAPA From United States of America, joined Jan 2004, 223 posts, RR: 4
Reply 2, posted (12 years 5 days 14 hours ago) and read 2267 times:
I'd agree. Looks like they know it's going to be variable, but there is no certainty as to when it is going to happen. I don't have am AIM in front of me, but there may be an implied probability percentage when the TEMPO term is used. Interesting catch, F15.
Air1727 From , joined Dec 1969, posts, RR:
Reply 3, posted (12 years 5 days 9 hours ago) and read 2220 times:
Folks, a TEMPO is to be looked at as a fluctuation in predominant conditions. TEMPOs are usually expected to last less than an hour at a time and over all less that half the period indicated.
So from the example above from Colorado Springs, you would look at it like this:
FM1600 02006KT P6SM OVC025
TEMPO 1620 3SM -SHSN BKN015
The predominant conditions from 1600-on are vis greater than 6 statute miles with ceiling overcast at 2500feet; but between the hours of 1600 and 2000, vis of 3 statute miles ceiling broken at 1500ft with light snow showers will exist for periods of less than one hour.
So essentially, from a forecast point of view the visibility and ceilings stay constant, however there are bands of snow showers moving through the area in intervals.