ARL Model Graphics
Air Resources Laboratory
Posted 4/2010 / Updated 8/2015
- This site is recommended by John Scott as a source for Skew-T graphs [John's
- The site also offers other graphic model products and John uses it as a
"one stop shop"
- On disadvantage is it is a little cumbersome because you need to enter an
anti-automation access code for each new view
- You can partially back up with your "browser back button" to select
different times without needing to reenter the access code, but you will need
to re-enter a new code to change locations.
- The big advantage is that you can view multiple graphic products from
multiple forecast models for any location you enter, and you can look pretty
far into the future, compared to the VGB balloon which looks at the past.
The see a Skew-T graph
- Reference the [Blank Graph for Unit
from Celsius to Fahrenheit and Millibars to Feet MSL
- From the SCPA Weather Menu, open the model page in a new Browser Tab
- It is time consuming to configure, so once you tunnel in, you don't want
to loose your place. To view multiple models for comparison, open
several browser tabs.
- Enter a location then "Continue" some [local
||Near the Botanic Garden in Mission Canyon
or you can simply enter SBA for the Airport.
The airport has different surface weather than the mountains,
but the soundings look at weather above the surface.
I don't think a few miles will make much difference,
but I haven't studied the inner workings of the models.
||Near Senior Canyon (below Stooges and Twin Peaks)
||Near the main LZs out in front of Oat
||Up the Aqua Caliente Creek Canyon (Forest Rte 5N15)
just north of the Pendola Ranger Station and Middle Santa Ynez Campground
||On the Divide Ridge north of Monte Arido
|Pine South Side
||The rocky ledges above Hwy 33 below the south launch
|Pine North Side
||The large ranch fields north of Pine Mountain and the Lockwood Vly Rd
||Mid Valley Airport
||center valley half way between Quail Lake and the first group of round
||middle group of round fields north of the Fairmont Butte
over the Skyotee Ranch Airport
||SW end of the runway just west of the larger east lake
||Just south of "town" on the flats
||Just south of town
||The east end of the airport
- Select a model under the drop down list for "Soundings"
- Under Sounding (John Scotts says the NAM is more aggressive with the lapse
rate and the GFS is good at predicting high clouds)
- NAM Model (12km, 84 hr, 3hrly, CONUS, Pressure) 2nd item in the drop down
list, ist NAM
- GFS Model (1 degree, 0-192, 3hrly, Global, pressure) 1st GFS, 2nd item
from bottom of drop down list
- Click on GO next to the selected sounding model
- Accept the default Forecast cycle (it is the most current, but you can
look back if you are doing a post mortem) click NEXT
- Configure the Parameters
- select the Profile Graphic Size, Recommend the largest size, 120 DPI
(the default is 96 DPI)
- enter the access code (but don't click on Get Sounding just yet)
- Select a date and time form the Tome to plot drop down list
- 18UTC ~ 10 am PST, 21UTC ~ 1 pm PST
- Click on "Get Profile"
- You can click your browser back button to change the date and time, but
you can't jump to a different model or location without starting over.
- If you want
to toggle between different models, forecast times, or locations, use multiple
- You can also save the GIF image files which will let
you record several forecast times for a particular model without having to
re-enter coordinates and access codes. If you are going to save the
images for comparison, then it's better to use just one window and back up
with your browser back button so when you right click on an image and select
"save image as", it will default to your last hard drive location and you
won't need to tunnel in from your default save to" location.
To read a Skew-T chart, there are tutorials available at:
Information on Blip Maps can be found at:
recommended reading by Don Taber