RUC Soundings

[NM Doug]

A ways back (viewtopic.php?f=3&t=296#p2279), Keith mentioned RUC Soundings and AvWxWorkshops. I'm diving in and enjoying the bite-sized pieces of WX edification available from the 6-month regular membership

I used RUC Soundings r/w yesterday when I decided to cancel a VFR flight in New Mexico - the soundings gave me some info on likely winds and gusts at airports that don't have TAFs, and I cancelled because of borderline conditions with non-runway-aligning winds and gusts (I knew I'd be able to get out OK, but it didn't look great for my return). I followed the METARs during the day, and although the winds didn't get quite as strong as I thought they might, they weren't far off.

A question for you RUC Soundings folks out there: is the Op20 working for you? Scott Dennstaedt (of AvWxWorkshops) talks about using the Op20 if getting a plot for an airport in the vicinity of higher terrain, but I can't get it to load. (Op40 loads fine, as does Bak20).

- Doug

[Orest Skrypuch]

You can always use the Bakxx dataset as well. The 20km grid is a good idea, wherever terrain varies widely.

There surely is no other single tool of greater value for aviation forecasting, than Skew-T's, yet you won't find them mentioned anywhere in the usual Met aviation resources, a real shame. Scott's workshops (AvWxWorkshops.com) are second to none as well. I have started running a series of In-Depth Met seminars at our flying club, and I'm covering Soundings over four sessions.

Also, don't miss Scott's Beyond the Weather Briefing as well as his Ice is Not Nice series. For folks not familiar, here is a link where you can access the Skew-T presented sounding data:

http://rucsoundings.noaa.gov/

There are several links for free tutorials on soundings as well, as the bottom.


However for surface winds at an airport without a TAF, you should have a peek at MOS data. I'll get you a link later, I'm on the slopes ...

* Orest

[Orest Skrypuch]

Here is that link for a graphical MOS (Model Output Statistics) grid. A caution, these numbers are purely computer generated, there is no human overview, so occasionally they can give misleading data, for example if a sensor is failing at some station. However, on the overall these are very useful where a TAF is unavailable, and in particular if any nearby TAFs are unlikely to be representative.

http://www.nws.noaa.gov/mdl/forecast/graphics/MAV/

* Orest

[NM Doug]

Thank you, Orest! I will explore this.

- Doug

[Orest Skrypuch]

You can also get the full MOS "text message" for most every airport, selected by state here:

http://www.nws.noaa.gov/mdl/synop/avnmosmap.php


It is a little more difficult to read this as it is categorical and uses abbreviations, but the key & legend is here:

http://www.nws.noaa.gov/mdl/synop/mavcard.php

* Orest

[NM Doug]

Excellent - thanks!

Doug

[scottcame]

Running RUC skew-t outputs for my origin, destination, and a couple of enroute points is a standard part of my r/w VFR flight planning routine (I usually do a thorough self briefing online before I call up wx-brief). I find it to be an indispensable tool. Given where I fly (Pacific Northwest) I rely on it to forecast temp/dp spreads, which of course aren't in the TAF. I also use it for surface winds, likely shear, inversions, winds aloft, and ceiling height. So much data packed into one little diagram! Many times I've scrubbed a flight because the RUC showed a spread of 1-2 degrees but the TAF did not forecast reduced vis. I'd say about half the time the field wound up being IFR.

It's good to consider the RUC output in concert with other information...and feel good when it is all mutually reinforcing, and as food for thought (and ADM) when the sources don't fully align... Often my pre-briefing briefing tells me what detailed questions to ask the Lockheed briefer when I get them on the phone.

I've been thinking of signing up for Scott's workshops. Appreciate the recommendations from you all.

Orest, really appreciate the link to the graphical model interface. Had no idea that existed.

[Orest Skrypuch]

You're most welcome Scott.

And about Scott Dennstaedt's Site/Workshops (http://www.AvWxWorkshops.com), don't think about it, just DO IT!

Even better, if a road show "Live Workshop" weekend session is coming to a town near you -- go!

* Orest