Detailed Predictions for: Mt Tamalpais
Launch Altitude (f): 2040
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

22 JUL 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 58 58 W 7 1549 2040 0 Blue 0
6 AM Sun 58 58 W 7 1549 2040 0 Blue 0
7 AM Sun 58 58 W 7 1549 2040 0 Blue 0
8 AM Sun 59 59 W 8 1825 2040 0 White 0
9 AM Sun 61 61 W 8 2264 2040 0 White 3
10 AM Sun 63 64 W 8 2466 2330 290 Blue 6
11 AM Sun 65 70 W 12 2608 2536 496 Blue 12
12 Noon Sun 67 73 W 12 2674 2607 567 Blue 15
1 PM Sun 69 76 W 12 2728 2673 633 Blue 18
2 PM Sun 71 78 W 15 2765 2709 669 Blue 20
3 PM Sun 73 79 W 15 2784 2727 687 Blue 21
4 PM Sun 73 77 W 15 2747 2691 651 Blue 19
5 PM Sun 73 76 W 16 2728 2673 633 Blue 18
6 PM Sun 72 73 W 16 2674 2607 567 Blue 15
7 PM Sun 70 70 W 16 2608 2536 496 Blue 12
8 PM Sun 67 67 NW 14 2537 2465 425 Blue 9
9 PM Sun 66 66 NW 14 2514 2426 386 Blue 8
10 PM Sun 64 64 NW 14 2466 2330 290 Blue 6
11 PM Sun 63 63 NW 13 2428 2282 242 Blue 5
12 Midnight Mon 62 62 NW 13 2380 2234 194 Blue 4
1 AM Mon 61 61 NW 13 2264 2040 0 White 3
2 AM Mon 61 61 NW 12 2264 2040 0 White 3
3 AM Mon 60 60 NW 12 2045 2040 0 White 1
4 AM Mon 59 59 NW 12 1825 2040 0 White 0
5 AM Mon 58 58 NW 12 1549 2040 0 Blue 0
6 AM Mon 58 58 NW 12 1549 2040 0 Blue 0
7 AM Mon 58 58 NW 12 1549 2040 0 Blue 0
8 AM Mon 59 59 W 12 1825 2040 0 White 0
9 AM Mon 61 61 W 12 2264 2040 0 White 3
10 AM Mon 63 64 W 12 2466 2330 290 Blue 6
11 AM Mon 65 71 W 15 2632 2560 520 Blue 13
12 Noon Mon 67 74 W 15 2692 2631 591 Blue 16
1 PM Mon 70 78 W 15 2765 2709 669 Blue 20
2 PM Mon 72 80 W 17 2802 2746 706 Blue 22
3 PM Mon 74 81 W 17 2821 2764 724 Blue 23
4 PM Mon 74 79 W 17 2784 2727 687 Blue 21
5 PM Mon 74 77 NW 17 2747 2691 651 Blue 19
6 PM Mon 73 74 NW 17 2692 2631 591 Blue 16
7 PM Mon 71 71 NW 17 2632 2560 520 Blue 13
8 PM Mon 68 68 NW 17 2561 2489 449 Blue 10
9 PM Mon 66 66 NW 17 2514 2426 386 Blue 8
10 PM Mon 65 65 NW 17 2490 2378 338 Blue 7
11 PM Mon 64 64 NW 17 2466 2330 290 Blue 6
12 Midnight Tue 62 62 NW 17 2380 2234 194 Blue 4
1 AM Tue 61 61 NW 17 2264 2040 0 White 3
2 AM Tue 61 61 NW 17 2264 2040 0 White 3
3 AM Tue 60 60 NW 17 2045 2040 0 White 1
4 AM Tue 59 59 NW 17 1825 2040 0 White 0
5 AM Tue 58 58 NW 14 1549 2040 0 Blue 0
6 AM Tue 58 58 NW 14 1549 2040 0 Blue 0
7 AM Tue 58 58 NW 14 1549 2040 0 Blue 0
8 AM Tue 59 59 NW 14 1825 2040 0 White 0
9 AM Tue 62 64 NW 14 2466 2330 290 Blue 6
10 AM Tue 65 68 NW 14 2561 2489 449 Blue 10
11 AM Tue 68 73 W 18 2674 2607 567 Blue 15
12 Noon Tue 70 77 W 18 2747 2691 651 Blue 19
1 PM Tue 74 81 W 18 2821 2764 724 Blue 23
2 PM Tue 77 84 W 18 2883 2820 780 Blue 26
3 PM Tue 79 85 W 18 2974 2839 799 Blue 27
4 PM Tue 80 85 W 18 2974 2839 799 Blue 27
5 PM Tue 80 83 NW 21 2862 2801 761 Blue 25
6 PM Tue 77 78 NW 21 2765 2709 669 Blue 20
7 PM Tue 75 75 NW 21 2710 2655 615 Blue 17
8 PM Tue 71 71 NW 21 2632 2560 520 Blue 13
9 PM Tue 69 69 NW 21 2585 2513 473 Blue 11
10 PM Tue 67 67 NW 21 2537 2465 425 Blue 9
11 PM Tue 65 65 NW 18 2490 2378 338 Blue 7
12 Midnight Wed 63 63 NW 18 2428 2282 242 Blue 5
1 AM Wed 62 62 NW 18 2380 2234 194 Blue 4
2 AM Wed 62 62 NW 18 2380 2234 194 Blue 4
3 AM Wed 60 60 NW 18 2045 2040 0 White 1
4 AM Wed 59 59 NW 18 1825 2040 0 White 0
5 AM Wed 58 58 NW 16 1549 2040 0 Blue 0
6 AM Wed 57 57 NW 16 1235 2040 0 Blue 0
7 AM Wed 58 58 NW 16 1549 2040 0 Blue 0
8 AM Wed 59 59 NW 16 1825 2040 0 White 0
9 AM Wed 62 63 NW 16 2428 2282 242 Blue 5
10 AM Wed 65 68 NW 16 2561 2489 449 Blue 10
11 AM Wed 68 74 W 15 2692 2631 591 Blue 16
12 Noon Wed 71 78 W 15 2765 2709 669 Blue 20
1 PM Wed 76 84 W 15 2883 2820 780 Blue 26
2 PM Wed 79 87 W 15 3435 2882 842 Blue 29
3 PM Wed 81 88 W 15 3678 2961 921 Blue 30
4 PM Wed 82 87 W 15 3435 2882 842 Blue 29
5 PM Wed 82 85 W 17 2974 2839 799 Blue 27
6 PM Wed 79 80 W 17 2802 2746 706 Blue 22
7 PM Wed 76 76 W 17 2728 2673 633 Blue 18
8 PM Wed 72 72 W 17 2655 2584 544 Blue 14
9 PM Wed 70 70 W 17 2608 2536 496 Blue 12
10 PM Wed 68 68 W 17 2561 2489 449 Blue 10
11 PM Wed 66 66 W 14 2514 2426 386 Blue 8
12 Midnight Thu 64 64 W 14 2466 2330 290 Blue 6
1 AM Thu 63 63 W 14 2428 2282 242 Blue 5
2 AM Thu 62 62 W 14 2380 2234 194 Blue 4
3 AM Thu 61 61 W 14 2264 2040 0 White 3
4 AM Thu 60 60 W 14 2045 2040 0 White 1
5 AM Thu 58 58 W 10 1549 2040 0 Blue 0
6 AM Thu 58 58 W 10 1549 2040 0 Blue 0
7 AM Thu 58 58 W 10 1549 2040 0 Blue 0
8 AM Thu 59 59 W 10 1825 2040 0 White 0
9 AM Thu 62 63 W 10 2428 2282 242 Blue 5
10 AM Thu 65 67 W 10 2537 2465 425 Blue 9
11 AM Thu 67 73 W 14 2674 2607 567 Blue 15
12 Noon Thu 69 76 W 14 2728 2673 633 Blue 18
1 PM Thu 73 81 W 14 2821 2764 724 Blue 23
2 PM Thu 76 84 W 14 2883 2820 780 Blue 26
3 PM Thu 77 84 W 14 2883 2820 780 Blue 26
4 PM Thu 78 83 W 14 2862 2801 761 Blue 25
5 PM Thu 78 81 W 15 2821 2764 724 Blue 23
6 PM Thu 76 77 W 15 2747 2691 651 Blue 19
7 PM Thu 73 73 W 15 2674 2607 567 Blue 15
8 PM Thu 69 69 W 15 2585 2513 473 Blue 11
9 PM Thu 68 68 W 15 2561 2489 449 Blue 10
10 PM Thu 66 66 W 15 2514 2426 386 Blue 8
11 PM Thu 64 64 W 12 2466 2330 290 Blue 6
12 Midnight Fri 63 63 W 12 2428 2282 242 Blue 5
1 AM Fri 62 62 W 12 2380 2234 194 Blue 4
2 AM Fri 61 61 W 12 2264 2040 0 White 3
3 AM Fri 60 60 W 12 2045 2040 0 White 1
4 AM Fri 59 59 W 12 1825 2040 0 White 0
5 AM Fri 57 57 W 10 1235 2040 0 Blue 0
6 AM Fri 57 57 W 10 1235 2040 0 Blue 0
7 AM Fri 57 57 W 10 1235 2040 0 Blue 0
8 AM Fri 58 58 W 10 1549 2040 0 Blue 0
9 AM Fri 60 61 W 10 2264 2040 0 White 3
10 AM Fri 62 63 W 10 2428 2282 242 Blue 5
11 AM Fri 64 70 W 13 2608 2536 496 Blue 12
12 Noon Fri 66 73 W 13 2674 2607 567 Blue 15
1 PM Fri 69 77 W 13 2747 2691 651 Blue 19
2 PM Fri 71 79 W 13 2784 2727 687 Blue 21
3 PM Fri 73 80 W 13 2802 2746 706 Blue 22
4 PM Fri 73 78 W 13 2765 2709 669 Blue 20
5 PM Fri 73 76 W 15 2728 2673 633 Blue 18
6 PM Fri 71 73 W 15 2674 2607 567 Blue 15
7 PM Fri 69 69 W 15 2585 2513 473 Blue 11
8 PM Fri 66 66 W 15 2514 2426 386 Blue 8
9 PM Fri 65 65 W 15 2490 2378 338 Blue 7
10 PM Fri 64 64 W 15 2466 2330 290 Blue 6
11 PM Fri 62 62 W 12 2380 2234 194 Blue 4
12 Midnight Sat 61 61 W 12 2264 2040 0 White 3
1 AM Sat 60 60 W 12 2045 2040 0 White 1
2 AM Sat 60 60 W 12 2045 2040 0 White 1
3 AM Sat 59 59 W 12 1825 2040 0 White 0
4 AM Sat 58 58 W 12 1549 2040 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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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