XC Skies - NAM

09-21-2008: Some XC maybe...

September 19th, 2008Mark Dowsett
in
Sep 21 2008 - 10:40

Forecast

Forecast Period: 
16:00
Surface Wind Direction: 
NE
Surface Wind Speed: 
16km/h
Wind Direction at Top of Usable Lift: 
NE
Wind Speed at Top of Usable Lift: 
16km/h
Climb rate (fpm): 
450fpm
Top of Useable Lift (ASL): 
4500'
Thermal Tops: 
6000' ASL
Buoyancy / Sheer Ratio: 
6
Rating of Local Soaring: 
7
Rating For going XC: 
6
Title Summary: 
Some XC maybe...

09-20-2008: Maybe some soaring

September 19th, 2008Mark Dowsett
in
Sep 20 2008 - 10:38

Forecast

Forecast Period: 
16:00
Surface Wind Direction: 
W
Surface Wind Speed: 
23km/h
Wind Direction at Top of Usable Lift: 
W
Wind Speed at Top of Usable Lift: 
26km/h
Climb rate (fpm): 
300fpm
Top of Useable Lift (ASL): 
3000'
Thermal Tops: 
7000' ASL
Buoyancy / Sheer Ratio: 
2
Rating of Local Soaring: 
4
Rating For going XC: 
0
Title Summary: 
Maybe some soaring

09-18-2008: XC Potential

September 18th, 2008Mark Dowsett
in
Sep 18 2008 - 09:32

Forecast

Forecast Period: 
16:00
Surface Wind Direction: 
NE
Surface Wind Speed: 
10km/h
Wind Direction at Top of Usable Lift: 
NE
Wind Speed at Top of Usable Lift: 
10km/h
Climb rate (fpm): 
400fpm
Top of Useable Lift (ASL): 
4000'
Thermal Tops: 
6200' ASL
Buoyancy / Sheer Ratio: 
8
Rating of Local Soaring: 
7
Rating For going XC: 
7

Could be a REAL nice fall day..for local and XC soaring.

Title Summary: 
XC Potential

Tue: Not so perfect

August 18th, 2008Mark Dowsett
in
Aug 19 2008 - 09:40

Forecast

Forecast Period: 
16:00
Surface Wind Direction: 
NE
Surface Wind Speed: 
16km/h
Wind Direction at Top of Usable Lift: 
NE
Wind Speed at Top of Usable Lift: 
23km/h
Buoyancy / Sheer Ratio: 
3
Rating of Local Soaring: 
0
Rating For going XC: 
0

Another promising forecast gone down the toilet! I have no idea on what makes these forecasts different...all I know (or think I know) is that the RUC forecast is the most accurate...I suppose that is why they only publish it the morning-of.

I used the NAM forecast model last night...and compare the b/s ratio here of the NAM (left) vs the RUC (right) from this morning: