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

Station:

KOAK

Date/Time:

15 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 Tue 58 58 WNW 10 17 3542 3074 253 Blue 4
1 AM Tue 57 57 WNW 9 16 3447 2821 0 Blue 3
2 AM Tue 56 56 WNW 9 16 3353 2821 0 Blue 2
3 AM Tue 54 54 WNW 9 14 2774 2821 0 Blue 0
4 AM Tue 54 54 WNW 9 14 2774 2821 0 Blue 0
5 AM Tue 53 53 NW 9 14 2549 2821 0 Blue 0
6 AM Tue 54 54 NW 9 14 2774 2821 0 Blue 0
7 AM Tue 56 56 NW 8 13 3353 2821 0 Blue 2
8 AM Tue 58 59 NNW 6 13 3572 3351 530 Blue 5
9 AM Tue 60 63 NNW 5 11 3718 3593 772 Blue 9
10 AM Tue 62 67 NW 4 11 4408 3768 947 Blue 13
11 AM Tue 65 72 NW 4 11 5527 4887 2066 Blue 18
12 Noon Tue 69 77 WNW 3 10 6354 5676 2855 Blue 23
1 PM Tue 72 81 WNW 3 10 7938 6421 3600 Blue 27
2 PM Tue 74 82 WNW 3 11 8272 6498 3677 Blue 28
3 PM Tue 76 83 WNW 3 11 8603 7545 4724 Blue 29
4 PM Tue 76 81 WNW 3 11 7938 6421 3600 Blue 27
5 PM Tue 76 79 NW 3 11 6672 6168 3347 Blue 25
6 PM Tue 76 77 NW 3 11 6354 5676 2855 Blue 23
7 PM Tue 74 74 NNW 2 12 5684 5386 2565 Blue 20
8 PM Tue 72 72 NNW 3 13 5527 4887 2066 Blue 18
9 PM Tue 70 70 NNW 5 18 5156 4394 1573 Blue 16
10 PM Tue 70 70 NNW 8 26 5156 4394 1573 Blue 16
11 PM Tue 70 70 N 9 29 5156 4394 1573 Blue 16
12 Midnight Wed 71 71 NNW 9 31 5408 4641 1820 Blue 17
1 AM Wed 71 71 NNW 9 31 5408 4641 1820 Blue 17
2 AM Wed 70 70 N 10 32 5156 4394 1573 Blue 16
3 AM Wed 70 70 NNW 10 17 5156 4394 1573 Blue 16
4 AM Wed 69 69 NNW 10 18 4906 4145 1324 Blue 15
5 AM Wed 69 69 NNW 10 17 4906 4145 1324 Blue 15
6 AM Wed 70 70 NNW 11 18 5156 4394 1573 Blue 16
7 AM Wed 71 71 N 10 17 5408 4641 1820 Blue 17
8 AM Wed 73 74 N 10 16 5684 5386 2565 Blue 20
9 AM Wed 74 77 N 9 13 6354 5676 2855 Blue 23
10 AM Wed 76 81 N 9 13 7938 6421 3600 Blue 27
11 AM Wed 79 85 NNW 11 17 9256 8211 5390 Blue 31
12 Noon Wed 82 90 NNW 11 17 12131 10021 7200 Blue 36
1 PM Wed 84 92 NNW 11 17 12407 11661 8840 Blue 38
2 PM Wed 86 92 NNW 9 13 12407 11661 8840 Blue 38
3 PM Wed 87 92 NNW 9 13 12407 11661 8840 Blue 38
4 PM Wed 87 91 NNW 9 13 12294 11247 8426 Blue 37
5 PM Wed 87 89 N 6 10 11771 9504 6683 Blue 35
6 PM Wed 85 86 N 6 10 9577 8539 5718 Blue 32
7 PM Wed 83 83 N 6 10 8603 7545 4724 Blue 29
8 PM Wed 81 81 N 10 14 7938 6421 3600 Blue 27
9 PM Wed 80 80 N 10 14 7600 6345 3524 Blue 26
10 PM Wed 78 78 N 10 14 6431 5838 3017 Blue 24
11 PM Wed 78 78 N 14 23 6431 5838 3017 Blue 24
12 Midnight Thu 78 78 N 14 23 6431 5838 3017 Blue 24
1 AM Thu 78 78 N 14 23 6431 5838 3017 Blue 24
2 AM Thu 78 78 N 17 26 6431 5838 3017 Blue 24
3 AM Thu 77 77 N 17 26 6354 5676 2855 Blue 23
4 AM Thu 77 77 N 17 26 6354 5676 2855 Blue 23
5 AM Thu 77 77 N 17 26 6354 5676 2855 Blue 23
6 AM Thu 78 78 N 17 26 6431 5838 3017 Blue 24
7 AM Thu 79 79 N 17 26 6672 6168 3347 Blue 25
8 AM Thu 80 81 N 16 25 7938 6421 3600 Blue 27
9 AM Thu 82 84 N 16 25 8931 7880 5059 Blue 30
10 AM Thu 84 88 N 16 25 11406 9186 6365 Blue 34
11 AM Thu 87 93 N 8 12 12520 12018 9197 Blue 39
12 Noon Thu 90 97 N 8 12 13316 12595 9774 Blue 43
1 PM Thu 92 99 N 8 12 13616 13113 10292 Blue 45
2 PM Thu 94 101 WSW 17 25 14271 13411 10590 Blue 47
3 PM Thu 95 101 WSW 17 25 14271 13411 10590 Blue 47
4 PM Thu 94 98 WSW 17 25 13466 12860 10039 Blue 44
5 PM Thu 93 96 WSW 16 24 13166 12483 9662 Blue 42
6 PM Thu 91 92 WSW 16 24 12407 11661 8840 Blue 38
7 PM Thu 89 89 WSW 16 24 11771 9504 6683 Blue 35
8 PM Thu 86 86 W 12 19 9577 8539 5718 Blue 32
9 PM Thu 84 84 W 12 19 8931 7880 5059 Blue 30
10 PM Thu 81 81 W 12 19 7938 6421 3600 Blue 27
11 PM Thu 80 80 WNW 6 10 7600 6345 3524 Blue 26
12 Midnight Fri 78 78 WNW 6 10 6431 5838 3017 Blue 24
1 AM Fri 77 77 WNW 6 10 6354 5676 2855 Blue 23
2 AM Fri 76 76 W 3 4 6206 5597 2776 Blue 22
3 AM Fri 74 74 W 3 4 5684 5386 2565 Blue 20
4 AM Fri 74 74 W 3 4 5684 5386 2565 Blue 20
5 AM Fri 74 74 SE 2 3 5684 5386 2565 Blue 20
6 AM Fri 74 74 SE 2 3 5684 5386 2565 Blue 20
7 AM Fri 76 76 SE 2 3 6206 5597 2776 Blue 22
8 AM Fri 78 79 W 4 6 6672 6168 3347 Blue 25
9 AM Fri 80 83 W 4 6 8603 7545 4724 Blue 29
10 AM Fri 82 87 W 4 6 10368 8864 6043 Blue 33
11 AM Fri 84 91 S 4 6 12294 11247 8426 Blue 37
12 Noon Fri 86 94 S 4 6 12664 12258 9437 Blue 40
1 PM Fri 88 97 S 4 6 13316 12595 9774 Blue 43
2 PM Fri 89 97 SSW 6 9 13316 12595 9774 Blue 43
3 PM Fri 89 96 SSW 6 9 13166 12483 9662 Blue 42
4 PM Fri 88 93 SSW 6 9 12520 12018 9197 Blue 39
5 PM Fri 86 89 SW 6 10 11771 9504 6683 Blue 35
6 PM Fri 84 85 SW 6 10 9256 8211 5390 Blue 31
7 PM Fri 81 81 SW 6 10 7938 6421 3600 Blue 27
8 PM Fri 78 78 SW 5 9 6431 5838 3017 Blue 24
9 PM Fri 75 75 SW 5 9 5873 5519 2698 Blue 21
10 PM Fri 73 73 SW 5 9 5605 5136 2315 Blue 19
11 PM Fri 72 72 SW 8 11 5527 4887 2066 Blue 18
12 Midnight Sat 70 70 SW 8 11 5156 4394 1573 Blue 16
1 AM Sat 70 70 SW 8 11 5156 4394 1573 Blue 16
2 AM Sat 69 69 WSW 9 13 4906 4145 1324 Blue 15
3 AM Sat 68 68 WSW 9 13 4657 3896 1075 Blue 14
4 AM Sat 66 66 WSW 9 13 4158 3716 895 Blue 12
5 AM Sat 66 66 WSW 6 10 4158 3716 895 Blue 12
6 AM Sat 67 67 WSW 6 10 4408 3768 947 Blue 13
7 AM Sat 69 69 WSW 6 10 4906 4145 1324 Blue 15
8 AM Sat 72 73 WSW 5 9 5605 5136 2315 Blue 19
9 AM Sat 74 77 WSW 5 9 6354 5676 2855 Blue 23
10 AM Sat 76 81 WSW 5 9 7938 6421 3600 Blue 27
11 AM Sat 78 85 SSW 5 8 9256 8211 5390 Blue 31
12 Noon Sat 80 88 SSW 5 8 11406 9186 6365 Blue 34
1 PM Sat 82 91 SSW 5 8 12294 11247 8426 Blue 37
2 PM Sat 84 92 SW 6 9 12407 11661 8840 Blue 38
3 PM Sat 84 91 SW 6 9 12294 11247 8426 Blue 37
4 PM Sat 84 89 SW 6 9 11771 9504 6683 Blue 35
5 PM Sat 82 85 SW 6 10 9256 8211 5390 Blue 31
6 PM Sat 79 80 SW 6 10 7600 6345 3524 Blue 26
7 PM Sat 75 75 SW 6 10 5873 5519 2698 Blue 21
8 PM Sat 72 72 SW 5 9 5527 4887 2066 Blue 18
9 PM Sat 69 69 SW 5 9 4906 4145 1324 Blue 15
10 PM Sat 67 67 SW 5 9 4408 3768 947 Blue 13
11 PM Sat 66 66 SW 8 11 4158 3716 895 Blue 12
12 Midnight Sun 65 65 SW 8 11 3906 3665 844 Blue 11
1 AM Sun 64 64 SW 8 11 3770 3615 794 Blue 10
2 AM Sun 63 63 SW 9 13 3718 3593 772 Blue 9
3 AM Sun 62 62 SW 9 13 3667 3571 750 Blue 8
4 AM Sun 61 61 SW 9 13 3615 3539 718 Blue 7
5 AM Sun 61 61 WSW 8 11 3615 3539 718 Blue 7
6 AM Sun 62 62 WSW 8 11 3667 3571 750 Blue 8
7 AM Sun 64 64 WSW 8 11 3770 3615 794 Blue 10
8 AM Sun 67 68 SW 6 10 4657 3896 1075 Blue 14
9 AM Sun 69 72 SW 6 10 5527 4887 2066 Blue 18
10 AM Sun 72 77 SW 6 10 6354 5676 2855 Blue 23
11 AM Sun 74 81 SW 5 9 7938 6421 3600 Blue 27
12 Noon Sun 77 85 SW 5 9 9256 8211 5390 Blue 31
1 PM Sun 79 88 SW 5 9 11406 9186 6365 Blue 34
2 PM Sun 80 88 SW 8 11 11406 9186 6365 Blue 34
3 PM Sun 81 88 SW 8 11 11406 9186 6365 Blue 34
4 PM Sun 80 85 SW 8 11 9256 8211 5390 Blue 31
5 PM Sun 78 81 SW 9 13 7938 6421 3600 Blue 27
6 PM Sun 75 76 SW 9 13 6206 5597 2776 Blue 22
7 PM Sun 72 72 SW 9 13 5527 4887 2066 Blue 18
8 PM Sun 68 68 SW 8 11 4657 3896 1075 Blue 14
9 PM Sun 66 66 SW 8 11 4158 3716 895 Blue 12
10 PM Sun 65 65 SW 8 11 3906 3665 844 Blue 11

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