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

Station:

KOAK

Date/Time:

12 MAY 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 Wed 68 68 NW 5 11 2566 2821 0 Blue 0
1 AM Wed 66 66 NW 5 9 2566 2821 0 Blue 0
2 AM Wed 66 66 NW 5 9 2566 2821 0 Blue 0
3 AM Wed 65 65 NNW 4 8 2566 2821 0 Blue 0
4 AM Wed 65 65 N 4 8 2566 2821 0 Blue 0
5 AM Wed 64 64 ENE 5 8 2566 2821 0 Blue 0
6 AM Wed 66 66 ENE 4 8 2566 2821 0 Blue 0
7 AM Wed 66 66 E 5 5 2566 2821 0 Blue 0
8 AM Wed 70 71 SSE 5 6 2566 2821 0 Blue 0
9 AM Wed 71 74 SSW 4 6 3191 2821 0 Blue 0
10 AM Wed 71 76 SSW 3 6 3858 2850 29 Blue 0
11 AM Wed 72 78 SSW 3 9 5595 3516 695 Blue 2
12 Noon Wed 73 81 SW 4 11 7322 5569 2748 Blue 4
1 PM Wed 75 83 SW 5 12 8659 6124 3303 Blue 6
2 PM Wed 75 83 SW 6 14 8659 6124 3303 Blue 6
3 PM Wed 74 80 SW 6 17 6156 5288 2467 Blue 4
4 PM Wed 74 78 WSW 6 17 5595 3516 695 Blue 2
5 PM Wed 72 74 WSW 8 18 3191 2821 0 Blue 0
6 PM Wed 70 71 WSW 6 16 2566 2821 0 Blue 0
7 PM Wed 69 69 WSW 5 13 2566 2821 0 Blue 0
8 PM Wed 64 64 WSW 6 12 2566 2821 0 Blue 0
9 PM Wed 63 63 W 8 12 2566 2821 0 Blue 0
10 PM Wed 63 63 W 8 12 2566 2821 0 Blue 0
11 PM Wed 62 62 W 8 12 2566 2821 0 Blue 0
12 Midnight Thu 61 61 W 6 12 2566 2821 0 Blue 0
1 AM Thu 60 60 W 6 12 2566 2821 0 Blue 0
2 AM Thu 59 59 W 6 11 2566 2821 0 Blue 0
3 AM Thu 59 59 W 5 10 2566 2821 0 Blue 0
4 AM Thu 59 59 W 5 9 2566 2821 0 Blue 0
5 AM Thu 57 57 W 6 9 2566 2821 0 Blue 0
6 AM Thu 56 56 W 5 9 2566 2821 0 Blue 0
7 AM Thu 58 58 W 5 9 2566 2821 0 Blue 0
8 AM Thu 64 65 W 5 9 2566 2821 0 Blue 0
9 AM Thu 66 68 W 5 9 2566 2821 0 Blue 0
10 AM Thu 66 70 WSW 4 9 2566 2821 0 Blue 0
11 AM Thu 67 73 WSW 4 9 2853 2821 0 Blue 0
12 Noon Thu 69 77 WSW 4 9 5313 3185 364 Blue 1
1 PM Thu 71 79 WSW 4 9 5876 3845 1024 Blue 3
2 PM Thu 72 79 WSW 6 14 5876 3845 1024 Blue 3
3 PM Thu 73 79 WSW 6 14 5876 3845 1024 Blue 3
4 PM Thu 72 76 WSW 6 14 3858 2850 29 Blue 0
5 PM Thu 69 71 WSW 9 17 2566 2821 0 Blue 0
6 PM Thu 66 67 WSW 9 17 2566 2821 0 Blue 0
7 PM Thu 63 63 WSW 9 17 2566 2821 0 Blue 0
8 PM Thu 60 60 WSW 8 12 2566 2821 0 Blue 0
9 PM Thu 58 58 WSW 8 12 2566 2821 0 Blue 0
10 PM Thu 57 57 WSW 8 12 2566 2821 0 Blue 0
11 PM Thu 56 56 SW 9 14 2566 2821 0 Blue 0
12 Midnight Fri 55 55 SW 9 14 2566 2821 0 Blue 0
1 AM Fri 53 53 SW 9 14 2566 2821 0 Blue 0
2 AM Fri 52 52 SW 9 13 2566 2821 0 Blue 0
3 AM Fri 52 52 SW 9 13 2566 2821 0 Blue 0
4 AM Fri 52 52 SW 9 13 2566 2821 0 Blue 0
5 AM Fri 52 52 WSW 9 12 2566 2821 0 Blue 0
6 AM Fri 52 52 WSW 9 12 2566 2821 0 Blue 0
7 AM Fri 52 52 WSW 9 12 2566 2821 0 Blue 0
8 AM Fri 53 54 WSW 9 14 2566 2821 0 Blue 0
9 AM Fri 55 57 WSW 9 14 2566 2821 0 Blue 0
10 AM Fri 58 62 WSW 9 14 2566 2821 0 Blue 0
11 AM Fri 61 67 SW 5 11 2566 2821 0 Blue 0
12 Noon Fri 65 72 SW 5 11 2566 2821 0 Blue 0
1 PM Fri 68 75 SW 5 11 3526 2821 0 Blue 0
2 PM Fri 70 76 SW 6 16 3858 2850 29 Blue 0
3 PM Fri 70 75 SW 6 16 3526 2821 0 Blue 0
4 PM Fri 69 72 SW 6 16 2566 2821 0 Blue 0
5 PM Fri 67 69 SW 9 19 2566 2821 0 Blue 0
6 PM Fri 65 66 SW 9 19 2566 2821 0 Blue 0
7 PM Fri 62 62 SW 9 19 2566 2821 0 Blue 0
8 PM Fri 59 59 SW 9 16 2566 2821 0 Blue 0
9 PM Fri 57 57 SW 9 16 2566 2821 0 Blue 0
10 PM Fri 56 56 SW 9 16 2566 2821 0 Blue 0
11 PM Fri 56 56 SW 9 16 2566 2821 0 Blue 0
12 Midnight Sat 55 55 SW 9 16 2566 2821 0 Blue 0
1 AM Sat 54 54 SW 9 16 2566 2821 0 Blue 0
2 AM Sat 53 53 SW 9 13 2566 2821 0 Blue 0
3 AM Sat 53 53 SW 9 13 2566 2821 0 Blue 0
4 AM Sat 52 52 SW 9 13 2566 2821 0 Blue 0
5 AM Sat 52 52 WSW 9 13 2566 2821 0 Blue 0
6 AM Sat 53 53 WSW 9 13 2566 2821 0 Blue 0
7 AM Sat 55 55 WSW 9 13 2566 2821 0 Blue 0
8 AM Sat 56 57 SW 9 16 2566 2821 0 Blue 0
9 AM Sat 58 60 SW 9 16 2566 2821 0 Blue 0
10 AM Sat 61 64 SW 9 16 2566 2821 0 Blue 0
11 AM Sat 63 69 WSW 4 11 2566 2821 0 Blue 0
12 Noon Sat 65 72 WSW 4 11 2566 2821 0 Blue 0
1 PM Sat 67 75 WSW 4 11 3526 2821 0 Blue 0
2 PM Sat 69 76 SW 5 13 3858 2850 29 Blue 0
3 PM Sat 70 76 SW 5 13 3858 2850 29 Blue 0
4 PM Sat 70 74 SW 5 13 3191 2821 0 Blue 0
5 PM Sat 68 70 SW 5 16 2566 2821 0 Blue 0
6 PM Sat 67 68 SW 5 16 2566 2821 0 Blue 0
7 PM Sat 64 64 SW 5 16 2566 2821 0 Blue 0
8 PM Sat 62 62 SW 6 12 2566 2821 0 Blue 0
9 PM Sat 61 61 SW 6 12 2566 2821 0 Blue 0
10 PM Sat 60 60 SW 6 12 2566 2821 0 Blue 0
11 PM Sat 58 58 WSW 9 14 2566 2821 0 Blue 0
12 Midnight Sun 57 57 WSW 9 14 2566 2821 0 Blue 0
1 AM Sun 56 56 WSW 9 14 2566 2821 0 Blue 0
2 AM Sun 55 55 WSW 10 17 2566 2821 0 Blue 0
3 AM Sun 54 54 WSW 10 17 2566 2821 0 Blue 0
4 AM Sun 54 54 WSW 10 17 2566 2821 0 Blue 0
5 AM Sun 54 54 WSW 9 14 2566 2821 0 Blue 0
6 AM Sun 55 55 WSW 9 14 2566 2821 0 Blue 0
7 AM Sun 56 56 WSW 9 14 2566 2821 0 Blue 0
8 AM Sun 58 59 SW 9 14 2566 2821 0 Blue 0
9 AM Sun 59 61 SW 9 14 2566 2821 0 Blue 0
10 AM Sun 61 65 SW 9 14 2566 2821 0 Blue 0
11 AM Sun 63 69 SW 5 13 2566 2821 0 Blue 0
12 Noon Sun 66 73 SW 5 13 2853 2821 0 Blue 0
1 PM Sun 68 76 SW 5 13 3858 2850 29 Blue 0
2 PM Sun 70 78 SW 6 16 5595 3516 695 Blue 2
3 PM Sun 69 75 SW 6 16 3526 2821 0 Blue 0
4 PM Sun 68 73 SW 6 16 2853 2821 0 Blue 0
5 PM Sun 65 68 SW 9 20 2566 2821 0 Blue 0
6 PM Sun 63 64 SW 9 20 2566 2821 0 Blue 0
7 PM Sun 61 61 SW 9 20 2566 2821 0 Blue 0
8 PM Sun 60 60 SW 9 17 2566 2821 0 Blue 0
9 PM Sun 58 58 SW 9 17 2566 2821 0 Blue 0
10 PM Sun 58 58 SW 9 17 2566 2821 0 Blue 0
11 PM Sun 57 57 SW 11 17 2566 2821 0 Blue 0
12 Midnight Mon 55 55 SW 11 17 2566 2821 0 Blue 0
1 AM Mon 54 54 SW 11 17 2566 2821 0 Blue 0
2 AM Mon 53 53 SW 11 17 2566 2821 0 Blue 0
3 AM Mon 52 52 SW 11 17 2566 2821 0 Blue 0
4 AM Mon 52 52 SW 11 17 2566 2821 0 Blue 0
5 AM Mon 52 52 SW 12 17 2566 2821 0 Blue 0
6 AM Mon 52 52 SW 12 17 2566 2821 0 Blue 0
7 AM Mon 52 52 SW 12 17 2566 2821 0 Blue 0
8 AM Mon 53 54 SW 11 17 2566 2821 0 Blue 0
9 AM Mon 54 56 SW 11 17 2566 2821 0 Blue 0
10 AM Mon 55 59 SW 11 17 2566 2821 0 Blue 0
11 AM Mon 57 63 SW 8 13 2566 2821 0 Blue 0
12 Noon Mon 60 67 SW 8 13 2566 2821 0 Blue 0
1 PM Mon 64 72 SW 8 13 2566 2821 0 Blue 0
2 PM Mon 66 73 SW 6 14 2853 2821 0 Blue 0
3 PM Mon 68 74 SW 6 14 3191 2821 0 Blue 0
4 PM Mon 68 72 SW 6 14 2566 2821 0 Blue 0
5 PM Mon 66 68 SW 9 18 2566 2821 0 Blue 0
6 PM Mon 64 65 SW 9 18 2566 2821 0 Blue 0
7 PM Mon 62 62 SW 9 18 2566 2821 0 Blue 0
8 PM Mon 60 60 SW 10 16 2566 2821 0 Blue 0
9 PM Mon 59 59 SW 10 16 2566 2821 0 Blue 0
10 PM Mon 58 58 SW 10 16 2566 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 ac_soaring@yahoo.com