Menampilkan postingan dari Juni, 2019

Tools for Crucial Weather Routing: With an ongoing comparison of GFS and FV3-GFS.

We will add new data at the end here until we figure out which model wins out!
It can happen that crucial decisions depend on details of a forecast. Usually this will be for a longer term forecast, since one or two days out are generally pretty good.  We have a specific case at hand now, which is a classic, real-world example.  The vessel has two optional routes, on each a crucial turn must be  made roughly 96 hr from now, meaning we are in interested in what happens on Friday, May 31.

The two main primary sources we have are the GFS and the new FV3 GFS, which will replace the former on June 12.  We see below that these two do not agree at all for Friday.

Again, Friday shown here is 4 days out from these  Monday 18z forecasts.  The displays are the meteograms from LuckGrib.  The standard GFS we have used for years shows roughly 20 kts from the east, or just above east.  The in-principle-better model FV3 GFS shows 30 kts from the SE.  For the vessel at hand here, and almost all vessels…

Compare ASCAT and WindSAT Scatterometer Wind Data

We have two sources of scatterometer data these days, the 3 Metop satellites with ASCAT data and the US Navy Coriolis satellite with WindSAT data. The latter does not get much mention in official NWS forecast discussions, whereas ASCAT is referred to frequently. The reason for this is not clear, so in  a first step toward trying to understand this, we will compare the data whenever we can spot passes at about the same time, over the same region.  It could be we can calculate that conjunction of passes, which if so we will add to our satellite prediction time article, which is underway.

The OSWT site presents the ASCAT data in a 10º x 15º Lat-Lon grid and the WindSAT in a 20 x 30 grid. They both have in principle 25-km resolution, so the reason for this is not completely clear. It could be simply that the single WindSAT data swath is about twice as wide as one of the halves of the two ASCAT swaths, so it would likely take a different file layout to account for it.

If the WindSAT data a…


I’ve read so many articles recently on the sad state of our children’s outdoor lives – what some call Nature Deficit Disorder -- that I've been wanting to put my two cents in as well. So here goes...

Most of the articles rightly make the argument that children need fresh air and sunshine for their good health, and an appreciation of nature for their well-rounded well-being. Parents know this intellectually. Kids know this intuitively. Researchers will back them both up. And I whole-heartedly agree with all of them. But beyond health and well-being, I think there are even more reasons why kids need to get outside and get to know nature personally...


Kids need to move their bodies everyday in lots of ways and with as much freedom of choice as is safe and practical to allow in order to develop both their bodies and their brains. To that end...

MORE movement is possible outdoors than in. Just is.

See if this sounds familiar. Don’t run in the house... don’t make a…


Some months ago, I entered the on-line world of blogging, Twitter, Facebook, and most recently Pinterest, and have since found so many wonderful stories about playtime. It's heartening to see today's time-strapped parents taking such an active role in their children's play, and so many dedicated early childhood educators sharing their innovative ideas for play-based learning.

But one story in particular stood out for me the other day. 
Amy (@babybabylemon) tweeted...
"Spencer has decided he has a "play button."  I push it and he runs around and goes crazy."

I laughed right out loud. Pure kid logic. It's these head-scratching, where-did-he-get-that-idea stories that continually reaffirm my belief in the inherent wisdom of a child's imagination, and of parents who, like Amy, instinctively honor and trust in that wisdom.

But more, this got me thinking about the eloquence of Spencer's invitation to play.