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

Station:

KOAK

Date/Time:

13 JUL 2024

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 87 87 WNW 9 16 2739 2821 0 Blue 1
1 AM Sat 87 87 NW 9 14 2739 2821 0 Blue 1
2 AM Sat 84 84 WNW 9 14 2551 2821 0 Blue 0
3 AM Sat 85 85 WNW 9 14 2610 2821 0 Blue 0
4 AM Sat 84 84 WNW 9 14 2551 2821 0 Blue 0
5 AM Sat 82 82 WNW 9 14 2516 2821 0 Blue 0
6 AM Sat 83 83 WNW 9 14 2516 2821 0 Blue 0
7 AM Sat 82 82 NW 9 14 2516 2821 0 Blue 0
8 AM Sat 82 82 WNW 9 14 2516 2821 0 Blue 0
9 AM Sat 80 81 W 9 14 2516 2821 0 Blue 0
10 AM Sat 80 81 WSW 8 13 2516 2821 0 Blue 0
11 AM Sat 77 79 WSW 6 13 2516 2821 0 Blue 0
12 Noon Sat 80 83 SW 8 14 2516 2821 0 Blue 0
1 PM Sat 80 85 SW 9 16 2610 2821 0 Blue 0
2 PM Sat 80 84 WSW 10 18 2551 2821 0 Blue 0
3 PM Sat 82 85 WSW 12 19 2610 2821 0 Blue 0
4 PM Sat 80 82 WSW 12 20 2516 2821 0 Blue 0
5 PM Sat 79 80 WSW 11 20 2516 2821 0 Blue 0
6 PM Sat 78 79 WSW 11 20 2516 2821 0 Blue 0
7 PM Sat 77 77 WSW 11 20 2516 2821 0 Blue 0
8 PM Sat 77 77 WSW 12 20 2516 2821 0 Blue 0
9 PM Sat 77 77 W 12 21 2516 2821 0 Blue 0
10 PM Sat 77 77 W 12 20 2516 2821 0 Blue 0
11 PM Sat 78 78 WSW 12 20 2516 2821 0 Blue 0
12 Midnight Sun 78 78 W 12 19 2516 2821 0 Blue 0
1 AM Sun 78 78 W 11 18 2516 2821 0 Blue 0
2 AM Sun 78 78 W 10 18 2516 2821 0 Blue 0
3 AM Sun 79 79 W 10 17 2516 2821 0 Blue 0
4 AM Sun 79 79 W 9 17 2516 2821 0 Blue 0
5 AM Sun 77 77 W 9 16 2516 2821 0 Blue 0
6 AM Sun 75 75 W 9 14 2516 2821 0 Blue 0
7 AM Sun 75 75 W 8 14 2516 2821 0 Blue 0
8 AM Sun 75 75 W 8 13 2516 2821 0 Blue 0
9 AM Sun 73 74 WSW 6 12 2516 2821 0 Blue 0
10 AM Sun 74 76 WSW 6 11 2516 2821 0 Blue 0
11 AM Sun 76 80 SW 5 11 2516 2821 0 Blue 0
12 Noon Sun 78 83 SW 6 12 2516 2821 0 Blue 0
1 PM Sun 80 87 SW 8 13 2739 2821 0 Blue 1
2 PM Sun 81 88 SW 9 16 2829 2821 0 Blue 2
3 PM Sun 82 88 SW 9 17 2829 2821 0 Blue 2
4 PM Sun 81 86 WSW 10 18 2668 2821 0 Blue 0
5 PM Sun 80 83 WSW 10 19 2516 2821 0 Blue 0
6 PM Sun 79 80 WSW 11 19 2516 2821 0 Blue 0
7 PM Sun 78 78 WSW 11 20 2516 2821 0 Blue 0
8 PM Sun 76 76 WSW 11 20 2516 2821 0 Blue 0
9 PM Sun 76 76 WSW 11 20 2516 2821 0 Blue 0
10 PM Sun 76 76 WSW 11 20 2516 2821 0 Blue 0
11 PM Sun 76 76 WSW 11 19 2516 2821 0 Blue 0
12 Midnight Mon 75 75 WSW 11 19 2516 2821 0 Blue 0
1 AM Mon 75 75 WSW 11 18 2516 2821 0 Blue 0
2 AM Mon 74 74 WSW 10 18 2516 2821 0 Blue 0
3 AM Mon 74 74 WSW 10 17 2516 2821 0 Blue 0
4 AM Mon 73 73 WSW 10 17 2516 2821 0 Blue 0
5 AM Mon 72 72 WSW 10 17 2516 2821 0 Blue 0
6 AM Mon 72 72 WSW 10 16 2516 2821 0 Blue 0
7 AM Mon 72 72 WSW 9 16 2516 2821 0 Blue 0
8 AM Mon 72 73 WSW 9 14 2516 2821 0 Blue 0
9 AM Mon 72 74 WSW 8 13 2516 2821 0 Blue 0
10 AM Mon 73 77 SW 6 11 2516 2821 0 Blue 0
11 AM Mon 75 81 SW 5 11 2516 2821 0 Blue 0
12 Noon Mon 76 84 SW 6 12 2551 2821 0 Blue 0
1 PM Mon 78 86 SW 8 14 2668 2821 0 Blue 0
2 PM Mon 79 87 SW 9 17 2739 2821 0 Blue 1
3 PM Mon 79 86 SW 10 18 2668 2821 0 Blue 0
4 PM Mon 79 84 SW 10 18 2551 2821 0 Blue 0
5 PM Mon 78 81 SW 10 19 2516 2821 0 Blue 0
6 PM Mon 77 79 SW 11 20 2516 2821 0 Blue 0
7 PM Mon 76 76 WSW 11 20 2516 2821 0 Blue 0
8 PM Mon 75 75 WSW 11 20 2516 2821 0 Blue 0
9 PM Mon 74 74 WSW 11 20 2516 2821 0 Blue 0
10 PM Mon 74 74 WSW 11 20 2516 2821 0 Blue 0
11 PM Mon 73 73 WSW 11 19 2516 2821 0 Blue 0
12 Midnight Tue 73 73 WSW 11 19 2516 2821 0 Blue 0
1 AM Tue 73 73 WSW 11 18 2516 2821 0 Blue 0
2 AM Tue 73 73 WSW 10 18 2516 2821 0 Blue 0
3 AM Tue 71 71 WSW 10 18 2516 2821 0 Blue 0
4 AM Tue 70 70 WSW 10 17 2516 2821 0 Blue 0
5 AM Tue 69 69 WSW 10 17 2516 2821 0 Blue 0
6 AM Tue 69 69 WSW 10 16 2516 2821 0 Blue 0
7 AM Tue 69 69 WSW 9 16 2516 2821 0 Blue 0
8 AM Tue 69 70 WSW 9 14 2516 2821 0 Blue 0
9 AM Tue 70 72 WSW 8 12 2516 2821 0 Blue 0
10 AM Tue 71 75 WSW 6 11 2516 2821 0 Blue 0
11 AM Tue 73 79 SW 5 11 2516 2821 0 Blue 0
12 Noon Tue 74 82 SW 6 12 2516 2821 0 Blue 0
1 PM Tue 75 83 SW 8 13 2516 2821 0 Blue 0
2 PM Tue 76 84 SW 9 16 2551 2821 0 Blue 0
3 PM Tue 76 83 SW 10 17 2516 2821 0 Blue 0
4 PM Tue 76 81 SW 10 18 2516 2821 0 Blue 0
5 PM Tue 76 79 SW 10 19 2516 2821 0 Blue 0
6 PM Tue 74 76 SW 11 20 2516 2821 0 Blue 0
7 PM Tue 73 73 WSW 11 20 2516 2821 0 Blue 0
8 PM Tue 72 72 WSW 11 20 2516 2821 0 Blue 0
9 PM Tue 72 72 WSW 11 19 2516 2821 0 Blue 0
10 PM Tue 71 71 WSW 11 19 2516 2821 0 Blue 0
11 PM Tue 71 71 WSW 10 19 2516 2821 0 Blue 0
12 Midnight Wed 71 71 WSW 10 18 2516 2821 0 Blue 0
1 AM Wed 71 71 WSW 10 17 2516 2821 0 Blue 0
2 AM Wed 70 70 WSW 10 17 2516 2821 0 Blue 0
3 AM Wed 70 70 WSW 10 17 2516 2821 0 Blue 0
4 AM Wed 69 69 W 10 17 2516 2821 0 Blue 0
5 AM Wed 69 69 W 9 17 2516 2821 0 Blue 0
6 AM Wed 68 68 W 9 16 2516 2821 0 Blue 0
7 AM Wed 68 68 W 9 14 2516 2821 0 Blue 0
8 AM Wed 68 69 W 8 13 2516 2821 0 Blue 0
9 AM Wed 68 70 WSW 6 12 2516 2821 0 Blue 0
10 AM Wed 70 74 WSW 5 10 2516 2821 0 Blue 0
11 AM Wed 71 77 SW 5 10 2516 2821 0 Blue 0
12 Noon Wed 72 80 SW 6 11 2516 2821 0 Blue 0
1 PM Wed 74 82 SW 8 13 2516 2821 0 Blue 0
2 PM Wed 75 83 SW 9 16 2516 2821 0 Blue 0
3 PM Wed 76 83 SW 9 17 2516 2821 0 Blue 0
4 PM Wed 76 81 SW 10 17 2516 2821 0 Blue 0
5 PM Wed 75 78 SW 10 18 2516 2821 0 Blue 0
6 PM Wed 74 76 SW 10 18 2516 2821 0 Blue 0
7 PM Wed 72 72 WSW 10 18 2516 2821 0 Blue 0
8 PM Wed 71 71 WSW 9 18 2516 2821 0 Blue 0
9 PM Wed 71 71 WSW 9 18 2516 2821 0 Blue 0
10 PM Wed 71 71 WSW 9 17 2516 2821 0 Blue 0
11 PM Wed 72 72 WSW 9 16 2516 2821 0 Blue 0
12 Midnight Thu 72 72 WSW 9 16 2516 2821 0 Blue 0
1 AM Thu 72 72 WSW 8 14 2516 2821 0 Blue 0
2 AM Thu 71 71 WSW 8 14 2516 2821 0 Blue 0
3 AM Thu 71 71 WSW 8 13 2516 2821 0 Blue 0
4 AM Thu 70 70 W 6 13 2516 2821 0 Blue 0
5 AM Thu 70 70 W 6 13 2516 2821 0 Blue 0
6 AM Thu 70 70 W 6 13 2516 2821 0 Blue 0
7 AM Thu 69 69 WSW 6 12 2516 2821 0 Blue 0
8 AM Thu 70 71 WSW 5 12 2516 2821 0 Blue 0
9 AM Thu 70 72 WSW 5 11 2516 2821 0 Blue 0
10 AM Thu 72 76 SW 4 10 2516 2821 0 Blue 0
11 AM Thu 73 79 SW 4 10 2516 2821 0 Blue 0
12 Noon Thu 75 83 SW 5 10 2516 2821 0 Blue 0
1 PM Thu 77 85 SW 6 11 2610 2821 0 Blue 0
2 PM Thu 79 87 SW 6 13 2739 2821 0 Blue 1
3 PM Thu 79 86 SW 8 14 2668 2821 0 Blue 0
4 PM Thu 79 84 SW 9 16 2551 2821 0 Blue 0
5 PM Thu 79 82 SW 9 17 2516 2821 0 Blue 0
6 PM Thu 78 79 SW 9 17 2516 2821 0 Blue 0
7 PM Thu 77 77 SW 9 17 2516 2821 0 Blue 0
8 PM Thu 76 76 SW 9 16 2516 2821 0 Blue 0
9 PM Thu 76 76 SW 9 16 2516 2821 0 Blue 0
10 PM Thu 76 76 WSW 8 16 2516 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]