Detailed Predictions for: Mt Vaca
Launch Lat, Long, Altitude (f): 38.400316, -122.106135, 2821
LZ Altitude (f): 2000
Sounding

Station:

 KOAK

Date/Time UTC:

 260912/1200

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Wind
 Gust		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
12 Midnight Sat 70 70 W 4 11 2747 2821 0 Blue 0
1 AM Sat 70 70 WNW 3 11 2747 2821 0 Blue 0
2 AM Sat 70 70 WNW 4 11 2747 2821 0 Blue 0
3 AM Sat 67 67 WNW 4 10 2526 2821 0 Blue 0
4 AM Sat 66 66 WNW 4 10 2526 2821 0 Blue 0
5 AM Sat 65 65 WNW 4 10 2526 2821 0 Blue 0
6 AM Sat 64 64 W 4 10 2526 2821 0 Blue 0
7 AM Sat 63 63 W 4 10 2526 2821 0 Blue 0
8 AM Sat 64 64 W 11 16 2526 2821 0 Blue 0
9 AM Sat 65 65 W 11 17 2526 2821 0 Blue 0
10 AM Sat 66 68 W 11 17 2526 2821 0 Blue 0
11 AM Sat 68 72 W 11 18 3013 2821 0 Blue 0
12 Noon Sat 69 75 WSW 11 19 3549 3012 191 Blue 3
1 PM Sat 70 76 WSW 12 21 3688 3179 358 Blue 4
2 PM Sat 70 76 WSW 13 23 3688 3179 358 Blue 4
3 PM Sat 71 75 WSW 14 24 3549 3012 191 Blue 3
4 PM Sat 68 71 WSW 14 24 2880 2821 0 Blue 0
5 PM Sat 66 67 W 14 24 2526 2821 0 Blue 0
6 PM Sat 66 66 W 14 24 2526 2821 0 Blue 0
7 PM Sat 62 62 W 14 24 2526 2821 0 Blue 0
8 PM Sat 61 61 W 14 26 2526 2821 0 Blue 0
9 PM Sat 62 62 W 14 27 2526 2821 0 Blue 0
10 PM Sat 62 62 W 14 27 2526 2821 0 Blue 0
11 PM Sat 63 63 WNW 12 25 2526 2821 0 Blue 0
12 Midnight Sun 62 62 WNW 11 24 2526 2821 0 Blue 0
1 AM Sun 62 62 WNW 11 24 2526 2821 0 Blue 0
2 AM Sun 61 61 NW 10 20 2526 2821 0 Blue 0
3 AM Sun 60 60 NW 9 18 2526 2821 0 Blue 0
4 AM Sun 59 59 NW 9 18 2526 2821 0 Blue 0
5 AM Sun 58 58 NW 9 18 2526 2821 0 Blue 0
6 AM Sun 58 58 NW 9 18 2526 2821 0 Blue 0
7 AM Sun 58 58 NW 9 18 2526 2821 0 Blue 0
8 AM Sun 58 58 NNW 8 17 2526 2821 0 Blue 0
9 AM Sun 60 61 NNW 8 17 2526 2821 0 Blue 0
10 AM Sun 61 64 NNW 8 17 2526 2821 0 Blue 0
11 AM Sun 63 67 NNW 4 12 2526 2821 0 Blue 0
12 Noon Sun 65 71 NNW 4 12 2880 2821 0 Blue 0
1 PM Sun 66 72 NNW 4 12 3013 2821 0 Blue 0
2 PM Sun 67 73 W 3 9 3183 2821 0 Blue 1
3 PM Sun 69 74 W 3 9 3366 2879 58 Blue 2
4 PM Sun 68 71 W 3 9 2880 2821 0 Blue 0
5 PM Sun 68 70 W 0 9 2747 2821 0 Blue 0
6 PM Sun 67 67 W 0 9 2526 2821 0 Blue 0
7 PM Sun 65 65 W 0 9 2526 2821 0 Blue 0
8 PM Sun 63 63 SW 1 6 2526 2821 0 Blue 0
9 PM Sun 63 63 SW 1 6 2526 2821 0 Blue 0
10 PM Sun 64 64 SW 1 6 2526 2821 0 Blue 0
11 PM Sun 65 65 W 2 10 2526 2821 0 Blue 0
12 Midnight Mon 66 66 W 2 10 2526 2821 0 Blue 0
1 AM Mon 67 67 W 2 10 2526 2821 0 Blue 0
2 AM Mon 67 67 W 4 11 2526 2821 0 Blue 0
3 AM Mon 66 66 W 4 11 2526 2821 0 Blue 0
4 AM Mon 65 65 W 4 11 2526 2821 0 Blue 0
5 AM Mon 64 64 WNW 4 14 2526 2821 0 Blue 0
6 AM Mon 64 64 WNW 4 14 2526 2821 0 Blue 0
7 AM Mon 65 65 WNW 4 14 2526 2821 0 Blue 0
8 AM Mon 66 66 WNW 6 16 2526 2821 0 Blue 0
9 AM Mon 68 69 WNW 6 16 2613 2821 0 Blue 0
10 AM Mon 69 71 WNW 6 16 2880 2821 0 Blue 0
11 AM Mon 71 75 NW 5 13 3549 3012 191 Blue 3
12 Noon Mon 73 78 NW 5 13 3855 3543 722 Blue 6
1 PM Mon 74 80 NW 5 13 4133 3769 948 Blue 8
2 PM Mon 75 81 WSW 4 11 4192 3852 1031 Blue 9
3 PM Mon 75 80 WSW 4 11 4133 3769 948 Blue 8
4 PM Mon 75 78 WSW 4 11 3855 3543 722 Blue 6
5 PM Mon 74 76 SW 5 13 3688 3179 358 Blue 4
6 PM Mon 71 71 SW 5 13 2880 2821 0 Blue 0
7 PM Mon 68 68 SW 5 13 2526 2821 0 Blue 0
8 PM Mon 66 66 SW 3 10 2526 2821 0 Blue 0
9 PM Mon 65 65 SW 3 10 2526 2821 0 Blue 0
10 PM Mon 65 65 SW 3 10 2526 2821 0 Blue 0
11 PM Mon 65 65 WSW 1 8 2526 2821 0 Blue 0
12 Midnight Tue 65 65 WSW 1 8 2526 2821 0 Blue 0
1 AM Tue 64 64 WSW 1 8 2526 2821 0 Blue 0
2 AM Tue 64 64 WSW 1 8 2526 2821 0 Blue 0
3 AM Tue 63 63 WSW 1 8 2526 2821 0 Blue 0
4 AM Tue 62 62 WSW 1 8 2526 2821 0 Blue 0
5 AM Tue 61 61 N 0 5 2526 2821 0 Blue 0
6 AM Tue 60 60 N 0 5 2526 2821 0 Blue 0
7 AM Tue 60 60 N 0 5 2526 2821 0 Blue 0
8 AM Tue 60 60 WSW 2 6 2526 2821 0 Blue 0
9 AM Tue 61 62 WSW 2 6 2526 2821 0 Blue 0
10 AM Tue 64 66 WSW 2 6 2526 2821 0 Blue 0
11 AM Tue 66 70 S 2 8 2747 2821 0 Blue 0
12 Noon Tue 68 73 S 2 8 3183 2821 0 Blue 1
1 PM Tue 70 76 S 2 8 3688 3179 358 Blue 4
2 PM Tue 71 76 SSW 4 11 3688 3179 358 Blue 4
3 PM Tue 71 75 SSW 4 11 3549 3012 191 Blue 3
4 PM Tue 71 74 SSW 4 11 3366 2879 58 Blue 2
5 PM Tue 70 71 SW 4 12 2880 2821 0 Blue 0
6 PM Tue 67 67 SW 4 12 2526 2821 0 Blue 0
7 PM Tue 64 64 SW 4 12 2526 2821 0 Blue 0
8 PM Tue 62 62 SW 3 11 2526 2821 0 Blue 0
9 PM Tue 62 62 SW 3 11 2526 2821 0 Blue 0
10 PM Tue 62 62 SW 3 11 2526 2821 0 Blue 0
11 PM Tue 62 62 WSW 3 10 2526 2821 0 Blue 0
12 Midnight Wed 62 62 WSW 3 10 2526 2821 0 Blue 0
1 AM Wed 62 62 WSW 3 10 2526 2821 0 Blue 0
2 AM Wed 62 62 WSW 2 9 2526 2821 0 Blue 0
3 AM Wed 62 62 WSW 2 9 2526 2821 0 Blue 0
4 AM Wed 62 62 WSW 2 9 2526 2821 0 Blue 0
5 AM Wed 62 62 WSW 2 9 2526 2821 0 Blue 0
6 AM Wed 61 61 WSW 2 9 2526 2821 0 Blue 0
7 AM Wed 61 61 WSW 2 9 2526 2821 0 Blue 0
8 AM Wed 61 61 WSW 2 8 2526 2821 0 Blue 0
9 AM Wed 62 63 WSW 2 8 2526 2821 0 Blue 0
10 AM Wed 65 67 WSW 2 8 2526 2821 0 Blue 0
11 AM Wed 67 71 SW 2 8 2880 2821 0 Blue 0
12 Noon Wed 69 74 SW 2 8 3366 2879 58 Blue 2
1 PM Wed 70 75 SW 2 8 3549 3012 191 Blue 3
2 PM Wed 71 76 SSW 4 11 3688 3179 358 Blue 4
3 PM Wed 71 75 SSW 4 11 3549 3012 191 Blue 3
4 PM Wed 71 74 SSW 4 11 3366 2879 58 Blue 2
5 PM Wed 69 71 SW 4 12 2880 2821 0 Blue 0
6 PM Wed 67 67 SW 4 12 2526 2821 0 Blue 0
7 PM Wed 64 64 SW 4 12 2526 2821 0 Blue 0
8 PM Wed 61 61 SW 3 11 2526 2821 0 Blue 0
9 PM Wed 61 61 SW 3 11 2526 2821 0 Blue 0
10 PM Wed 62 62 SW 3 11 2526 2821 0 Blue 0
11 PM Wed 63 63 WSW 3 10 2526 2821 0 Blue 0
12 Midnight Thu 63 63 WSW 3 10 2526 2821 0 Blue 0
1 AM Thu 63 63 WSW 3 10 2526 2821 0 Blue 0
2 AM Thu 63 63 WSW 2 9 2526 2821 0 Blue 0
3 AM Thu 63 63 WSW 2 9 2526 2821 0 Blue 0
4 AM Thu 62 62 WSW 2 9 2526 2821 0 Blue 0
5 AM Thu 62 62 W 2 8 2526 2821 0 Blue 0
6 AM Thu 62 62 W 2 8 2526 2821 0 Blue 0
7 AM Thu 61 61 W 2 8 2526 2821 0 Blue 0
8 AM Thu 62 62 W 2 6 2526 2821 0 Blue 0
9 AM Thu 64 65 W 2 6 2526 2821 0 Blue 0
10 AM Thu 66 68 W 2 6 2526 2821 0 Blue 0
11 AM Thu 69 73 WSW 2 6 3183 2821 0 Blue 1
12 Noon Thu 70 75 WSW 2 6 3549 3012 191 Blue 3
1 PM Thu 72 78 WSW 2 6 3855 3543 722 Blue 6
2 PM Thu 72 77 SW 4 10 3772 3361 540 Blue 5
3 PM Thu 72 76 SW 4 10 3688 3179 358 Blue 4
4 PM Thu 72 75 SW 4 10 3549 3012 191 Blue 3
5 PM Thu 70 71 SW 5 14 2880 2821 0 Blue 0
6 PM Thu 68 68 SW 5 14 2526 2821 0 Blue 0
7 PM Thu 66 66 SW 5 14 2526 2821 0 Blue 0
8 PM Thu 64 64 WSW 3 11 2526 2821 0 Blue 0
9 PM Thu 63 63 WSW 3 11 2526 2821 0 Blue 0
10 PM Thu 63 63 WSW 3 11 2526 2821 0 Blue 0

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse [email protected]