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

Station:

KOAK

Date/Time:

20 JUN 2021

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 Sun 78 78 WSW 8 12 2431 2821 0 Blue 0
1 AM Sun 70 70 WSW 8 13 2431 2821 0 Blue 0
2 AM Sun 70 70 WSW 8 13 2431 2821 0 Blue 0
3 AM Sun 68 68 WSW 6 13 2431 2821 0 Blue 0
4 AM Sun 68 68 W 5 12 2431 2821 0 Blue 0
5 AM Sun 68 68 W 5 12 2431 2821 0 Blue 0
6 AM Sun 65 65 W 5 11 2431 2821 0 Blue 0
7 AM Sun 66 66 WSW 5 9 2431 2821 0 Blue 0
8 AM Sun 70 71 WSW 4 8 2431 2821 0 Blue 0
9 AM Sun 70 73 SW 4 9 2431 2821 0 Blue 0
10 AM Sun 71 76 SW 4 9 2431 2821 0 Blue 0
11 AM Sun 73 80 SW 5 11 2469 2821 0 Blue 0
12 Noon Sun 77 85 SW 6 13 3149 2821 0 Blue 0
1 PM Sun 80 89 SW 6 16 4103 3383 562 Blue 4
2 PM Sun 81 89 SW 9 17 4103 3383 562 Blue 4
3 PM Sun 80 87 SW 10 19 3628 2992 171 Blue 2
4 PM Sun 80 85 SW 10 19 3149 2821 0 Blue 0
5 PM Sun 78 81 WSW 9 20 2600 2821 0 Blue 0
6 PM Sun 76 78 WSW 9 19 2431 2821 0 Blue 0
7 PM Sun 73 73 WSW 8 17 2431 2821 0 Blue 0
8 PM Sun 70 70 WSW 8 14 2431 2821 0 Blue 0
9 PM Sun 67 67 WSW 9 16 2431 2821 0 Blue 0
10 PM Sun 65 65 WSW 9 16 2431 2821 0 Blue 0
11 PM Sun 64 64 WSW 9 16 2431 2821 0 Blue 0
12 Midnight Mon 64 64 WSW 9 16 2431 2821 0 Blue 0
1 AM Mon 63 63 W 9 16 2431 2821 0 Blue 0
2 AM Mon 62 62 WSW 9 17 2431 2821 0 Blue 0
3 AM Mon 61 61 W 9 17 2431 2821 0 Blue 0
4 AM Mon 59 59 W 9 16 2431 2821 0 Blue 0
5 AM Mon 60 60 WSW 8 13 2431 2821 0 Blue 0
6 AM Mon 60 60 W 8 13 2431 2821 0 Blue 0
7 AM Mon 63 63 W 6 12 2431 2821 0 Blue 0
8 AM Mon 66 67 WSW 6 11 2431 2821 0 Blue 0
9 AM Mon 67 70 WSW 5 11 2431 2821 0 Blue 0
10 AM Mon 67 71 WSW 5 11 2431 2821 0 Blue 0
11 AM Mon 69 76 WSW 6 13 2431 2821 0 Blue 0
12 Noon Mon 71 79 WSW 6 13 2431 2821 0 Blue 0
1 PM Mon 73 82 WSW 6 13 2731 2821 0 Blue 0
2 PM Mon 74 82 SW 9 18 2731 2821 0 Blue 0
3 PM Mon 75 82 SW 9 18 2731 2821 0 Blue 0
4 PM Mon 74 79 SW 9 18 2431 2821 0 Blue 0
5 PM Mon 72 75 WSW 9 20 2431 2821 0 Blue 0
6 PM Mon 70 72 WSW 9 20 2431 2821 0 Blue 0
7 PM Mon 67 67 WSW 9 20 2431 2821 0 Blue 0
8 PM Mon 64 64 WSW 9 17 2431 2821 0 Blue 0
9 PM Mon 62 62 WSW 9 17 2431 2821 0 Blue 0
10 PM Mon 60 60 WSW 9 17 2431 2821 0 Blue 0
11 PM Mon 60 60 WSW 11 19 2431 2821 0 Blue 0
12 Midnight Tue 60 60 WSW 11 19 2431 2821 0 Blue 0
1 AM Tue 60 60 WSW 11 19 2431 2821 0 Blue 0
2 AM Tue 60 60 WSW 10 19 2431 2821 0 Blue 0
3 AM Tue 59 59 WSW 10 19 2431 2821 0 Blue 0
4 AM Tue 59 59 WSW 10 19 2431 2821 0 Blue 0
5 AM Tue 59 59 WSW 9 16 2431 2821 0 Blue 0
6 AM Tue 59 59 WSW 9 16 2431 2821 0 Blue 0
7 AM Tue 60 60 WSW 9 16 2431 2821 0 Blue 0
8 AM Tue 61 62 WSW 9 14 2431 2821 0 Blue 0
9 AM Tue 62 65 WSW 9 14 2431 2821 0 Blue 0
10 AM Tue 63 67 WSW 9 14 2431 2821 0 Blue 0
11 AM Tue 64 71 SW 6 14 2431 2821 0 Blue 0
12 Noon Tue 66 74 SW 6 14 2431 2821 0 Blue 0
1 PM Tue 68 77 SW 6 14 2431 2821 0 Blue 0
2 PM Tue 69 77 SW 9 17 2431 2821 0 Blue 0
3 PM Tue 69 76 SW 9 17 2431 2821 0 Blue 0
4 PM Tue 68 73 SW 9 17 2431 2821 0 Blue 0
5 PM Tue 66 69 SW 9 18 2431 2821 0 Blue 0
6 PM Tue 64 66 SW 9 18 2431 2821 0 Blue 0
7 PM Tue 61 61 SW 9 18 2431 2821 0 Blue 0
8 PM Tue 58 58 WSW 9 17 2431 2821 0 Blue 0
9 PM Tue 57 57 WSW 9 17 2431 2821 0 Blue 0
10 PM Tue 57 57 WSW 9 17 2431 2821 0 Blue 0
11 PM Tue 58 58 SW 10 17 2431 2821 0 Blue 0
12 Midnight Wed 58 58 SW 10 17 2431 2821 0 Blue 0
1 AM Wed 58 58 SW 10 17 2431 2821 0 Blue 0
2 AM Wed 58 58 SW 9 17 2431 2821 0 Blue 0
3 AM Wed 58 58 SW 9 17 2431 2821 0 Blue 0
4 AM Wed 58 58 SW 9 17 2431 2821 0 Blue 0
5 AM Wed 58 58 WSW 8 16 2431 2821 0 Blue 0
6 AM Wed 58 58 WSW 8 16 2431 2821 0 Blue 0
7 AM Wed 58 58 WSW 8 16 2431 2821 0 Blue 0
8 AM Wed 59 60 SW 8 13 2431 2821 0 Blue 0
9 AM Wed 59 62 SW 8 13 2431 2821 0 Blue 0
10 AM Wed 60 64 SW 8 13 2431 2821 0 Blue 0
11 AM Wed 62 69 SSW 5 12 2431 2821 0 Blue 0
12 Noon Wed 64 72 SSW 5 12 2431 2821 0 Blue 0
1 PM Wed 66 75 SSW 5 12 2431 2821 0 Blue 0
2 PM Wed 68 76 SW 6 16 2431 2821 0 Blue 0
3 PM Wed 69 76 SW 6 16 2431 2821 0 Blue 0
4 PM Wed 69 74 SW 6 16 2431 2821 0 Blue 0
5 PM Wed 68 71 SW 8 17 2431 2821 0 Blue 0
6 PM Wed 66 68 SW 8 17 2431 2821 0 Blue 0
7 PM Wed 64 64 SW 8 17 2431 2821 0 Blue 0
8 PM Wed 62 62 WSW 8 16 2431 2821 0 Blue 0
9 PM Wed 61 61 WSW 8 16 2431 2821 0 Blue 0
10 PM Wed 61 61 WSW 8 16 2431 2821 0 Blue 0
11 PM Wed 61 61 WSW 9 16 2431 2821 0 Blue 0
12 Midnight Thu 60 60 WSW 9 16 2431 2821 0 Blue 0
1 AM Thu 60 60 WSW 9 16 2431 2821 0 Blue 0
2 AM Thu 59 59 WSW 8 12 2431 2821 0 Blue 0
3 AM Thu 58 58 WSW 8 12 2431 2821 0 Blue 0
4 AM Thu 58 58 WSW 8 12 2431 2821 0 Blue 0
5 AM Thu 58 58 WSW 8 13 2431 2821 0 Blue 0
6 AM Thu 59 59 WSW 8 13 2431 2821 0 Blue 0
7 AM Thu 60 60 WSW 8 13 2431 2821 0 Blue 0
8 AM Thu 62 63 WSW 6 12 2431 2821 0 Blue 0
9 AM Thu 64 67 WSW 6 12 2431 2821 0 Blue 0
10 AM Thu 66 71 WSW 6 12 2431 2821 0 Blue 0
11 AM Thu 68 75 SW 4 10 2431 2821 0 Blue 0
12 Noon Thu 71 79 SW 4 10 2431 2821 0 Blue 0
1 PM Thu 74 83 SW 4 10 2862 2821 0 Blue 0
2 PM Thu 76 84 SW 6 13 2993 2821 0 Blue 0
3 PM Thu 77 84 SW 6 13 2993 2821 0 Blue 0
4 PM Thu 78 83 SW 6 13 2862 2821 0 Blue 0
5 PM Thu 76 79 SW 6 16 2431 2821 0 Blue 0
6 PM Thu 74 76 SW 6 16 2431 2821 0 Blue 0
7 PM Thu 71 71 SW 6 16 2431 2821 0 Blue 0
8 PM Thu 68 68 SW 6 14 2431 2821 0 Blue 0
9 PM Thu 67 67 SW 6 14 2431 2821 0 Blue 0
10 PM Thu 66 66 SW 6 14 2431 2821 0 Blue 0
11 PM Thu 66 66 WSW 8 13 2431 2821 0 Blue 0
12 Midnight Fri 65 65 WSW 8 13 2431 2821 0 Blue 0
1 AM Fri 64 64 WSW 8 13 2431 2821 0 Blue 0
2 AM Fri 63 63 WSW 8 13 2431 2821 0 Blue 0
3 AM Fri 62 62 WSW 8 13 2431 2821 0 Blue 0
4 AM Fri 62 62 WSW 8 13 2431 2821 0 Blue 0
5 AM Fri 63 63 W 6 13 2431 2821 0 Blue 0
6 AM Fri 64 64 W 6 13 2431 2821 0 Blue 0
7 AM Fri 66 66 W 6 13 2431 2821 0 Blue 0
8 AM Fri 68 69 W 5 11 2431 2821 0 Blue 0
9 AM Fri 70 73 W 5 11 2431 2821 0 Blue 0
10 AM Fri 73 78 W 5 11 2431 2821 0 Blue 0
11 AM Fri 75 82 SW 3 10 2731 2821 0 Blue 0
12 Noon Fri 78 86 SW 3 10 3389 2861 40 Blue 1
1 PM Fri 81 90 SW 3 10 4339 3620 799 Blue 5
2 PM Fri 84 92 SW 5 13 4872 4092 1271 Blue 7
3 PM Fri 85 92 SW 5 13 4872 4092 1271 Blue 7
4 PM Fri 84 89 SW 5 13 4103 3383 562 Blue 4
5 PM Fri 83 86 SW 6 18 3389 2861 40 Blue 1
6 PM Fri 80 82 SW 6 18 2731 2821 0 Blue 0
7 PM Fri 76 76 SW 6 18 2431 2821 0 Blue 0
8 PM Fri 73 73 WSW 6 14 2431 2821 0 Blue 0
9 PM Fri 71 71 WSW 6 14 2431 2821 0 Blue 0
10 PM Fri 70 70 WSW 6 14 2431 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]