Detailed Predictions for: Mt Tamalpais
Launch Lat, Long, Altitude (f): 37.90719, -122.62, 2040
LZ Altitude (f): 0
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 50 50 NNW 13 19 1511 2040 0 Blue 1
1 AM Sat 49 49 NNW 12 18 1270 2040 0 Blue 0
2 AM Sat 49 49 NW 10 17 1270 2040 0 Blue 0
3 AM Sat 49 49 NNW 10 16 1270 2040 0 Blue 0
4 AM Sat 49 49 NNW 10 16 1270 2040 0 Blue 0
5 AM Sat 48 48 NW 10 14 571 2040 0 Blue 0
6 AM Sat 49 49 NW 9 16 1270 2040 0 Blue 0
7 AM Sat 49 49 NW 9 16 1270 2040 0 Blue 0
8 AM Sat 50 50 NW 9 16 1511 2040 0 Blue 1
9 AM Sat 50 50 NW 9 16 1511 2040 0 Blue 1
10 AM Sat 50 51 NW 10 17 1746 2040 0 Blue 2
11 AM Sat 52 54 WNW 10 18 2152 2040 0 Blue 5
12 Noon Sat 53 54 WNW 10 19 2152 2040 0 Blue 5
1 PM Sat 53 55 WNW 11 19 2287 2040 0 Blue 6
2 PM Sat 53 55 WNW 11 20 2287 2040 0 Blue 6
3 PM Sat 54 56 WNW 12 21 2421 2040 0 Blue 7
4 PM Sat 53 55 WNW 13 21 2287 2040 0 Blue 6
5 PM Sat 53 54 WNW 13 23 2152 2040 0 Blue 5
6 PM Sat 53 53 WNW 13 21 2017 2040 0 Blue 4
7 PM Sat 51 51 NW 12 21 1746 2040 0 Blue 2
8 PM Sat 50 50 NW 12 20 1511 2040 0 Blue 1
9 PM Sat 50 50 NW 12 20 1511 2040 0 Blue 1
10 PM Sat 51 51 NW 11 19 1746 2040 0 Blue 2
11 PM Sat 51 51 NW 11 19 1746 2040 0 Blue 2
12 Midnight Sun 50 50 NNW 10 18 1511 2040 0 Blue 1
1 AM Sun 51 51 NNW 10 17 1746 2040 0 Blue 2
2 AM Sun 50 50 NNW 10 16 1511 2040 0 Blue 1
3 AM Sun 50 50 NNW 9 14 1511 2040 0 Blue 1
4 AM Sun 50 50 NNW 8 13 1511 2040 0 Blue 1
5 AM Sun 50 50 NNW 6 12 1511 2040 0 Blue 1
6 AM Sun 48 48 NNW 6 11 571 2040 0 Blue 0
7 AM Sun 50 50 NNW 6 11 1511 2040 0 Blue 1
8 AM Sun 51 51 NNW 5 11 1746 2040 0 Blue 2
9 AM Sun 53 53 NW 5 10 2017 2040 0 Blue 4
10 AM Sun 56 58 NW 4 9 2985 2281 241 Blue 9
11 AM Sun 58 61 WNW 5 10 3810 2968 928 Blue 12
12 Noon Sun 60 65 WNW 5 10 5734 4280 2240 White 16
1 PM Sun 61 66 WNW 5 10 5947 5191 3151 White 17
2 PM Sun 62 67 W 6 13 6160 5589 3549 White 18
3 PM Sun 62 66 W 6 13 5947 5191 3151 White 17
4 PM Sun 62 64 W 6 13 5521 3786 1746 White 15
5 PM Sun 62 63 WNW 9 14 5246 3515 1475 Blue 14
6 PM Sun 61 61 WNW 9 14 3810 2968 928 Blue 12
7 PM Sun 60 60 WNW 9 14 3536 2692 652 Blue 11
8 PM Sun 58 58 WNW 6 12 2985 2281 241 Blue 9
9 PM Sun 57 57 WNW 6 12 2707 2147 107 Blue 8
10 PM Sun 56 56 WNW 6 12 2421 2040 0 Blue 7
11 PM Sun 55 55 WNW 5 9 2287 2040 0 Blue 6
12 Midnight Mon 54 54 WNW 5 9 2152 2040 0 Blue 5
1 AM Mon 54 54 WNW 5 9 2152 2040 0 Blue 5
2 AM Mon 53 53 NW 3 6 2017 2040 0 Blue 4
3 AM Mon 53 53 NW 3 6 2017 2040 0 Blue 4
4 AM Mon 53 53 NW 3 6 2017 2040 0 Blue 4
5 AM Mon 53 53 N 2 5 2017 2040 0 Blue 4
6 AM Mon 53 53 N 2 5 2017 2040 0 Blue 4
7 AM Mon 53 53 N 2 5 2017 2040 0 Blue 4
8 AM Mon 54 54 NNE 2 6 2152 2040 0 Blue 5
9 AM Mon 55 56 NNE 2 6 2421 2040 0 Blue 7
10 AM Mon 58 60 NNE 2 6 3536 2692 652 Blue 11
11 AM Mon 60 64 NNE 4 9 5521 3786 1746 White 15
12 Noon Mon 64 69 NNE 4 9 6576 6152 4112 Blue 20
1 PM Mon 68 73 NNE 4 9 7422 6685 4645 White 24
2 PM Mon 70 75 N 4 10 7838 7186 5146 White 26
3 PM Mon 70 74 N 4 10 7630 6932 4892 White 25
4 PM Mon 69 72 N 4 10 7212 6552 4512 White 23
5 PM Mon 67 68 NW 5 11 6371 5987 3947 White 19
6 PM Mon 66 66 NW 5 11 5947 5191 3151 White 17
7 PM Mon 64 64 NW 5 11 5521 3786 1746 White 15
8 PM Mon 62 62 NW 5 9 4457 3242 1202 Blue 13
9 PM Mon 60 60 NW 5 9 3536 2692 652 Blue 11
10 PM Mon 60 60 NW 5 9 3536 2692 652 Blue 11
11 PM Mon 59 59 NNW 4 6 3261 2415 375 Blue 10
12 Midnight Tue 58 58 NNW 4 6 2985 2281 241 Blue 9
1 AM Tue 57 57 NNW 4 6 2707 2147 107 Blue 8
2 AM Tue 56 56 N 3 6 2421 2040 0 Blue 7
3 AM Tue 56 56 N 3 6 2421 2040 0 Blue 7
4 AM Tue 55 55 N 3 6 2287 2040 0 Blue 6
5 AM Tue 54 54 NNE 3 6 2152 2040 0 Blue 5
6 AM Tue 55 55 NNE 3 6 2287 2040 0 Blue 6
7 AM Tue 55 55 NNE 3 6 2287 2040 0 Blue 6
8 AM Tue 57 57 NE 3 8 2707 2147 107 Blue 8
9 AM Tue 58 58 NE 3 8 2985 2281 241 Blue 9
10 AM Tue 60 62 NE 3 8 4457 3242 1202 Blue 13
11 AM Tue 62 65 NE 4 9 5734 4280 2240 White 16
12 Noon Tue 64 68 NE 4 9 6371 5987 3947 White 19
1 PM Tue 66 70 NE 4 9 6724 6285 4245 Blue 21
2 PM Tue 67 70 W 5 10 6724 6285 4245 Blue 21
3 PM Tue 67 70 W 5 10 6724 6285 4245 Blue 21
4 PM Tue 66 68 W 5 10 6371 5987 3947 White 19
5 PM Tue 65 65 W 8 12 5734 4280 2240 White 16
6 PM Tue 63 63 W 8 12 5246 3515 1475 Blue 14
7 PM Tue 60 60 W 8 12 3536 2692 652 Blue 11
8 PM Tue 58 58 W 6 12 2985 2281 241 Blue 9
9 PM Tue 57 57 W 6 12 2707 2147 107 Blue 8
10 PM Tue 56 56 W 6 12 2421 2040 0 Blue 7
11 PM Tue 55 55 WSW 6 12 2287 2040 0 Blue 6
12 Midnight Wed 54 54 WSW 6 12 2152 2040 0 Blue 5
1 AM Wed 54 54 WSW 6 12 2152 2040 0 Blue 5
2 AM Wed 54 54 WSW 8 13 2152 2040 0 Blue 5
3 AM Wed 53 53 WSW 8 13 2017 2040 0 Blue 4
4 AM Wed 53 53 WSW 8 13 2017 2040 0 Blue 4
5 AM Wed 53 53 W 9 14 2017 2040 0 Blue 4
6 AM Wed 52 52 W 9 14 1881 2040 0 Blue 3
7 AM Wed 52 52 W 9 14 1881 2040 0 Blue 3
8 AM Wed 53 53 SW 10 17 2017 2040 0 Blue 4
9 AM Wed 53 53 SW 10 17 2017 2040 0 Blue 4
10 AM Wed 54 54 SW 10 17 2152 2040 0 Blue 5
11 AM Wed 55 56 SW 11 20 2421 2040 0 Blue 7
12 Noon Wed 55 57 SW 11 20 2707 2147 107 Blue 8
1 PM Wed 56 58 SW 11 20 2985 2281 241 Blue 9
2 PM Wed 56 58 SW 14 25 2985 2281 241 Blue 9
3 PM Wed 56 57 SW 14 25 2707 2147 107 Blue 8
4 PM Wed 55 56 SW 14 25 2421 2040 0 Blue 7
5 PM Wed 54 54 SW 13 24 2152 2040 0 Blue 5
6 PM Wed 54 54 SW 13 24 2152 2040 0 Blue 5
7 PM Wed 53 53 SW 13 24 2017 2040 0 Blue 4
8 PM Wed 52 52 WSW 13 24 1881 2040 0 Blue 3
9 PM Wed 52 52 WSW 13 24 1881 2040 0 Blue 3
10 PM Wed 52 52 WSW 13 24 1881 2040 0 Blue 3
11 PM Wed 52 52 WSW 13 24 1881 2040 0 Blue 3
12 Midnight Thu 52 52 WSW 13 24 1881 2040 0 Blue 3
1 AM Thu 53 53 WSW 13 24 2017 2040 0 Blue 4
2 AM Thu 53 53 W 14 24 2017 2040 0 Blue 4
3 AM Thu 52 52 W 14 24 1881 2040 0 Blue 3
4 AM Thu 52 52 W 14 24 1881 2040 0 Blue 3
5 AM Thu 51 51 W 13 24 1746 2040 0 Blue 2
6 AM Thu 51 51 W 13 24 1746 2040 0 Blue 2
7 AM Thu 50 50 W 13 24 1511 2040 0 Blue 1
8 AM Thu 50 50 W 14 24 1511 2040 0 Blue 1
9 AM Thu 51 51 W 14 24 1746 2040 0 Blue 2
10 AM Thu 52 53 W 14 24 2017 2040 0 Blue 4
11 AM Thu 52 54 W 16 25 2152 2040 0 Blue 5
12 Noon Thu 53 56 W 16 25 2421 2040 0 Blue 7
1 PM Thu 53 56 W 16 25 2421 2040 0 Blue 7
2 PM Thu 53 56 W 18 27 2421 2040 0 Blue 7
3 PM Thu 53 55 W 18 27 2287 2040 0 Blue 6
4 PM Thu 52 54 W 18 27 2152 2040 0 Blue 5
5 PM Thu 52 53 W 18 28 2017 2040 0 Blue 4
6 PM Thu 51 51 W 18 28 1746 2040 0 Blue 2
7 PM Thu 50 50 W 18 28 1511 2040 0 Blue 1
8 PM Thu 50 50 WNW 17 27 1511 2040 0 Blue 1
9 PM Thu 49 49 WNW 17 27 1270 2040 0 Blue 0
10 PM Thu 49 49 WNW 17 27 1270 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 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]