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:

 250322/1200

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 44 44 NNW 6 16 2515 2821 0 Blue 0
1 AM Sat 46 46 NW 9 14 2515 2821 0 Blue 0
2 AM Sat 46 46 NW 10 14 2515 2821 0 Blue 0
3 AM Sat 46 46 NW 9 14 2515 2821 0 Blue 0
4 AM Sat 46 46 NW 9 13 2515 2821 0 Blue 0
5 AM Sat 45 45 NW 9 13 2515 2821 0 Blue 0
6 AM Sat 46 46 NW 9 13 2515 2821 0 Blue 0
7 AM Sat 46 46 NW 9 12 2515 2821 0 Blue 0
8 AM Sat 47 47 NW 9 13 2515 2821 0 Blue 0
9 AM Sat 48 48 NW 8 12 2515 2821 0 Blue 0
10 AM Sat 49 49 NW 8 12 2770 2821 0 Blue 0
11 AM Sat 50 51 WNW 8 12 3337 2821 0 Blue 2
12 Noon Sat 50 51 WNW 6 12 3337 2821 0 Blue 2
1 PM Sat 51 52 WNW 6 12 3618 2821 0 Blue 3
2 PM Sat 51 52 WNW 6 13 3618 2821 0 Blue 3
3 PM Sat 52 53 WNW 6 12 3897 3050 229 Blue 4
4 PM Sat 52 53 WNW 8 13 3897 3050 229 Blue 4
5 PM Sat 53 53 WNW 9 13 3897 3050 229 Blue 4
6 PM Sat 54 54 WNW 9 13 4990 3330 509 Blue 5
7 PM Sat 53 53 WNW 9 13 3897 3050 229 Blue 4
8 PM Sat 52 52 NW 8 12 3618 2821 0 Blue 3
9 PM Sat 51 51 NW 9 13 3337 2821 0 Blue 2
10 PM Sat 51 51 NNW 9 13 3337 2821 0 Blue 2
11 PM Sat 50 50 N 9 14 3054 2821 0 Blue 1
12 Midnight Sun 50 50 NNW 10 14 3054 2821 0 Blue 1
1 AM Sun 50 50 NNW 10 14 3054 2821 0 Blue 1
2 AM Sun 50 50 N 10 16 3054 2821 0 Blue 1
3 AM Sun 49 49 NNW 11 16 2770 2821 0 Blue 0
4 AM Sun 49 49 NNW 11 17 2770 2821 0 Blue 0
5 AM Sun 48 48 N 11 17 2515 2821 0 Blue 0
6 AM Sun 48 48 NNW 11 17 2515 2821 0 Blue 0
7 AM Sun 49 49 NW 11 17 2770 2821 0 Blue 0
8 AM Sun 49 49 NW 10 17 2770 2821 0 Blue 0
9 AM Sun 52 53 NW 10 17 3897 3050 229 Blue 4
10 AM Sun 54 56 NNW 11 18 5816 3885 1064 Blue 7
11 AM Sun 56 60 NNW 10 17 6509 6084 3263 Blue 11
12 Noon Sun 59 64 NNW 10 17 7389 6627 3806 Blue 15
1 PM Sun 61 67 NNW 10 17 8172 7348 4527 Blue 18
2 PM Sun 62 67 NNW 8 14 8172 7348 4527 Blue 18
3 PM Sun 64 68 NNW 8 14 8437 7607 4786 Blue 19
4 PM Sun 64 66 NNW 8 14 7911 7087 4266 Blue 17
5 PM Sun 64 65 NNW 8 13 7651 6827 4006 Blue 16
6 PM Sun 63 63 NNW 8 13 7126 6492 3671 Blue 14
7 PM Sun 61 61 NNW 8 13 6646 6220 3399 Blue 12
8 PM Sun 59 59 W 8 11 6373 5772 2951 Blue 10
9 PM Sun 58 58 W 8 11 6236 5366 2545 Blue 9
10 PM Sun 58 58 W 8 11 6236 5366 2545 Blue 9
11 PM Sun 57 57 W 9 12 6099 4906 2085 Blue 8
12 Midnight Mon 56 56 W 9 12 5816 3885 1064 Blue 7
1 AM Mon 55 55 W 9 12 5404 3609 788 Blue 6
2 AM Mon 55 55 NW 9 14 5404 3609 788 Blue 6
3 AM Mon 54 54 NW 9 14 4990 3330 509 Blue 5
4 AM Mon 54 54 NW 9 14 4990 3330 509 Blue 5
5 AM Mon 54 54 NNW 9 14 4990 3330 509 Blue 5
6 AM Mon 53 53 NNW 9 14 3897 3050 229 Blue 4
7 AM Mon 54 54 NNW 9 14 4990 3330 509 Blue 5
8 AM Mon 54 54 N 9 14 4990 3330 509 Blue 5
9 AM Mon 56 57 N 9 14 6099 4906 2085 Blue 8
10 AM Mon 59 61 N 9 14 6646 6220 3399 Blue 12
11 AM Mon 62 66 NNE 9 16 7911 7087 4266 Blue 17
12 Noon Mon 64 69 NNE 9 16 8701 7865 5044 Blue 20
1 PM Mon 67 72 NNE 9 16 9485 8648 5827 Blue 23
2 PM Mon 68 73 NNE 8 13 9743 8908 6087 Blue 24
3 PM Mon 69 73 NNE 8 13 9743 8908 6087 Blue 24
4 PM Mon 68 71 NNE 8 13 9225 8386 5565 Blue 22
5 PM Mon 67 68 NNE 6 11 8437 7607 4786 Blue 19
6 PM Mon 66 66 NNE 6 11 7911 7087 4266 Blue 17
7 PM Mon 64 64 NNE 6 11 7389 6627 3806 Blue 15
8 PM Mon 62 62 N 4 8 6864 6356 3535 Blue 13
9 PM Mon 61 61 N 4 8 6646 6220 3399 Blue 12
10 PM Mon 60 60 N 4 8 6509 6084 3263 Blue 11
11 PM Mon 60 60 NW 5 9 6509 6084 3263 Blue 11
12 Midnight Tue 59 59 NW 5 9 6373 5772 2951 Blue 10
1 AM Tue 58 58 NW 5 9 6236 5366 2545 Blue 9
2 AM Tue 58 58 NNW 6 10 6236 5366 2545 Blue 9
3 AM Tue 56 56 NNW 6 10 5816 3885 1064 Blue 7
4 AM Tue 55 55 NNW 6 10 5404 3609 788 Blue 6
5 AM Tue 55 55 NNW 9 12 5404 3609 788 Blue 6
6 AM Tue 55 55 NNW 9 12 5404 3609 788 Blue 6
7 AM Tue 56 56 NNW 9 12 5816 3885 1064 Blue 7
8 AM Tue 57 57 N 9 12 6099 4906 2085 Blue 8
9 AM Tue 59 60 N 9 12 6509 6084 3263 Blue 11
10 AM Tue 61 63 N 9 12 7126 6492 3671 Blue 14
11 AM Tue 63 66 NNE 8 13 7911 7087 4266 Blue 17
12 Noon Tue 65 69 NNE 8 13 8701 7865 5044 Blue 20
1 PM Tue 67 72 NNE 8 13 9485 8648 5827 Blue 23
2 PM Tue 68 72 ENE 5 11 9485 8648 5827 Blue 23
3 PM Tue 69 72 ENE 5 11 9485 8648 5827 Blue 23
4 PM Tue 69 71 ENE 5 11 9225 8386 5565 Blue 22
5 PM Tue 69 70 SSW 8 13 8964 8122 5301 Blue 21
6 PM Tue 67 67 SSW 8 13 8172 7348 4527 Blue 18
7 PM Tue 65 65 SSW 8 13 7651 6827 4006 Blue 16
8 PM Tue 63 63 WSW 10 16 7126 6492 3671 Blue 14
9 PM Tue 62 62 WSW 10 16 6864 6356 3535 Blue 13
10 PM Tue 60 60 WSW 10 16 6509 6084 3263 Blue 11
11 PM Tue 59 59 W 11 16 6373 5772 2951 Blue 10
12 Midnight Wed 58 58 W 11 16 6236 5366 2545 Blue 9
1 AM Wed 57 57 W 11 16 6099 4906 2085 Blue 8
2 AM Wed 56 56 WSW 13 18 5816 3885 1064 Blue 7
3 AM Wed 55 55 WSW 13 18 5404 3609 788 Blue 6
4 AM Wed 54 54 WSW 13 18 4990 3330 509 Blue 5
5 AM Wed 54 54 WSW 14 20 4990 3330 509 Blue 5
6 AM Wed 54 54 WSW 14 20 4990 3330 509 Blue 5
7 AM Wed 54 54 WSW 14 20 4990 3330 509 Blue 5
8 AM Wed 54 54 WSW 16 23 4990 3330 509 Blue 5
9 AM Wed 55 55 WSW 16 23 5404 3609 788 Blue 6
10 AM Wed 56 57 WSW 16 23 6099 4906 2085 Blue 8
11 AM Wed 57 59 SW 16 24 6373 5772 2951 Blue 10
12 Noon Wed 58 61 SW 16 24 6646 6220 3399 Blue 12
1 PM Wed 58 61 SW 16 24 6646 6220 3399 Blue 12
2 PM Wed 59 62 SW 17 27 6864 6356 3535 Blue 13
3 PM Wed 58 60 SW 17 27 6509 6084 3263 Blue 11
4 PM Wed 56 57 SW 17 27 6099 4906 2085 Blue 8
5 PM Wed 55 55 SW 20 29 5404 3609 788 Blue 6
6 PM Wed 54 54 SW 20 29 4990 3330 509 Blue 5
7 PM Wed 53 53 SW 20 29 3897 3050 229 Blue 4
8 PM Wed 52 52 SW 21 29 3618 2821 0 Blue 3
9 PM Wed 52 52 SW 21 29 3618 2821 0 Blue 3
10 PM Wed 52 52 SW 21 29 3618 2821 0 Blue 3
11 PM Wed 51 51 SW 19 27 3337 2821 0 Blue 2
12 Midnight Thu 51 51 SW 19 27 3337 2821 0 Blue 2
1 AM Thu 51 51 SW 19 27 3337 2821 0 Blue 2
2 AM Thu 51 51 SW 18 25 3337 2821 0 Blue 2
3 AM Thu 51 51 SW 18 25 3337 2821 0 Blue 2
4 AM Thu 50 50 SW 18 25 3054 2821 0 Blue 1
5 AM Thu 50 50 SW 16 24 3054 2821 0 Blue 1
6 AM Thu 49 49 SW 16 24 2770 2821 0 Blue 0
7 AM Thu 49 49 SW 16 24 2770 2821 0 Blue 0
8 AM Thu 49 49 SW 16 25 2770 2821 0 Blue 0
9 AM Thu 49 49 SW 16 25 2770 2821 0 Blue 0
10 AM Thu 49 50 SW 16 25 3054 2821 0 Blue 1
11 AM Thu 50 52 WSW 18 26 3618 2821 0 Blue 3
12 Noon Thu 51 54 WSW 18 26 4990 3330 509 Blue 5
1 PM Thu 51 54 WSW 18 26 4990 3330 509 Blue 5
2 PM Thu 52 55 WSW 16 25 5404 3609 788 Blue 6
3 PM Thu 52 54 WSW 16 25 4990 3330 509 Blue 5
4 PM Thu 51 53 WSW 16 25 3897 3050 229 Blue 4
5 PM Thu 50 51 W 18 27 3337 2821 0 Blue 2
6 PM Thu 49 49 W 18 27 2770 2821 0 Blue 0
7 PM Thu 48 48 W 18 27 2515 2821 0 Blue 0
8 PM Thu 47 47 W 18 27 2515 2821 0 Blue 0
9 PM Thu 47 47 W 18 27 2515 2821 0 Blue 0
10 PM Thu 46 46 W 18 27 2515 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]