Interesting to note that when compared to Dr Jacks BlipMaps, the poor
lift over the Sierras shows in those maps as well (look at March 3).
This is due to surface heat flux values being too low for the
mountains which is represented in the raw model output data. This data
comes from Land Surface Models (LSMs) that try to derive the surface
characteristics. During transitional months (mostly spring time) the
models use a statistical approach for turning on certain key elements
such as snow cover, leaf area index values, and so on. Because of
this, when you compute the lift potential and use surface heat flux
values to determine the top of usable lift, the result shows poor
areas of lift over mountains. With shallow lift profiles, thermal
velocities are calculated as being abnormally low. In the US, the
Sierras and Rockies have this problem in March and April. In Europe,
the Alps are often poorly characterized over spring. In fact, hang
gliding records were broken last April in the Alps (for out and
returns) and all of the models used for forecasting showed that top of
lift was at ridge top heights which was grossly inaccurate.

This problem has plagued boundary layer forecasts for a long time and
there's not a good solution yet. The best approach (being used now) is
to rely on data collected historically and then represent the land
characteristics statistically. Eventually, real-time remote sensing
from satellites will likely replace the source of this data, but it
will take time.

-Chris Galli

On Mar 3, 10:03*pm, "BT" wrote:
I just checked my login
3 day forecast is looking fine.

BT

"Scott Alexander" wrote in message

...

Thanks I sent him an email describing the glitches. *It is the same on
both of my computers.

The main problem is the inability to access forecasted weather on the
NAM or GFS. *Tommorow wont show up, 2 days out only has one forecast
available at 13:00 and 3 days out has no forecast available. *It's
been doing this off and on ever since the format changed a month or so
ago.

Does anyone else have this specific problem?