Detailed Predictions for: Mt Tamalpais
Launch Lat, Long, Altitude (f): 37.90719, -122.62, 2040
LZ Altitude (f): 0
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 54 54 NW 4 5 1037 2040 0 Blue 0
1 AM Wed 52 52 NW 3 5 1014 2040 0 Blue 0
2 AM Wed 51 51 NW 3 4 1014 2040 0 Blue 0
3 AM Wed 51 51 WNW 3 4 1014 2040 0 Blue 0
4 AM Wed 50 50 WNW 3 4 1014 2040 0 Blue 0
5 AM Wed 49 49 WNW 2 4 1014 2040 0 Blue 0
6 AM Wed 52 52 W 2 4 1014 2040 0 Blue 0
7 AM Wed 53 53 W 3 5 1014 2040 0 Blue 0
8 AM Wed 55 55 W 3 4 1079 2040 0 Blue 0
9 AM Wed 56 57 WSW 3 4 1163 2040 0 Blue 0
10 AM Wed 56 59 WSW 4 5 1231 2040 0 Blue 1
11 AM Wed 57 61 WSW 4 6 1270 2040 0 Blue 3
12 Noon Wed 59 64 WSW 5 9 1324 2040 0 Blue 6
1 PM Wed 60 66 WSW 5 9 1360 2040 0 Blue 8
2 PM Wed 60 66 W 6 9 1360 2040 0 Blue 8
3 PM Wed 61 66 W 6 10 1360 2040 0 Blue 8
4 PM Wed 61 65 W 6 11 1342 2040 0 Blue 7
5 PM Wed 61 63 W 8 11 1306 2040 0 Blue 5
6 PM Wed 61 62 W 8 11 1288 2040 0 Blue 4
7 PM Wed 58 58 WNW 6 10 1205 2040 0 Blue 0
8 PM Wed 55 55 WNW 5 9 1079 2040 0 Blue 0
9 PM Wed 54 54 WNW 4 8 1037 2040 0 Blue 0
10 PM Wed 52 52 WNW 4 6 1014 2040 0 Blue 0
11 PM Wed 51 51 WNW 4 6 1014 2040 0 Blue 0
12 Midnight Thu 50 50 WNW 4 6 1014 2040 0 Blue 0
1 AM Thu 49 49 W 4 5 1014 2040 0 Blue 0
2 AM Thu 49 49 W 4 6 1014 2040 0 Blue 0
3 AM Thu 48 48 W 4 6 1014 2040 0 Blue 0
4 AM Thu 47 47 W 4 6 1014 2040 0 Blue 0
5 AM Thu 46 46 W 3 5 1014 2040 0 Blue 0
6 AM Thu 46 46 W 3 5 1014 2040 0 Blue 0
7 AM Thu 48 48 W 4 6 1014 2040 0 Blue 0
8 AM Thu 51 51 WSW 4 6 1014 2040 0 Blue 0
9 AM Thu 51 52 WSW 4 8 1014 2040 0 Blue 0
10 AM Thu 52 55 WSW 5 8 1079 2040 0 Blue 0
11 AM Thu 54 58 WSW 6 10 1205 2040 0 Blue 0
12 Noon Thu 55 60 WSW 6 10 1252 2040 0 Blue 2
1 PM Thu 56 61 WSW 6 10 1270 2040 0 Blue 3
2 PM Thu 57 63 W 9 12 1306 2040 0 Blue 5
3 PM Thu 58 63 W 9 12 1306 2040 0 Blue 5
4 PM Thu 58 61 W 9 12 1270 2040 0 Blue 3
5 PM Thu 58 60 W 9 13 1252 2040 0 Blue 2
6 PM Thu 56 57 W 9 13 1163 2040 0 Blue 0
7 PM Thu 55 55 W 9 13 1079 2040 0 Blue 0
8 PM Thu 54 54 WNW 9 13 1037 2040 0 Blue 0
9 PM Thu 53 53 WNW 9 13 1014 2040 0 Blue 0
10 PM Thu 53 53 WNW 9 13 1014 2040 0 Blue 0
11 PM Thu 52 52 WNW 8 11 1014 2040 0 Blue 0
12 Midnight Fri 52 52 WNW 8 11 1014 2040 0 Blue 0
1 AM Fri 51 51 WNW 8 11 1014 2040 0 Blue 0
2 AM Fri 50 50 WNW 4 6 1014 2040 0 Blue 0
3 AM Fri 49 49 WNW 4 6 1014 2040 0 Blue 0
4 AM Fri 49 49 WNW 4 6 1014 2040 0 Blue 0
5 AM Fri 49 49 WNW 3 5 1014 2040 0 Blue 0
6 AM Fri 49 49 WNW 3 5 1014 2040 0 Blue 0
7 AM Fri 50 50 WNW 3 5 1014 2040 0 Blue 0
8 AM Fri 51 51 W 4 6 1014 2040 0 Blue 0
9 AM Fri 53 55 W 4 6 1079 2040 0 Blue 0
10 AM Fri 55 58 W 4 6 1205 2040 0 Blue 0
11 AM Fri 57 61 W 9 13 1270 2040 0 Blue 3
12 Noon Fri 58 63 W 9 13 1306 2040 0 Blue 5
1 PM Fri 59 64 W 9 13 1324 2040 0 Blue 6
2 PM Fri 60 66 W 14 21 1360 2040 0 Blue 8
3 PM Fri 60 65 W 14 21 1342 2040 0 Blue 7
4 PM Fri 60 63 W 14 21 1306 2040 0 Blue 5
5 PM Fri 58 60 WNW 16 24 1252 2040 0 Blue 2
6 PM Fri 56 57 WNW 16 24 1163 2040 0 Blue 0
7 PM Fri 54 54 WNW 16 24 1037 2040 0 Blue 0
8 PM Fri 52 52 WNW 13 20 1014 2040 0 Blue 0
9 PM Fri 51 51 WNW 13 20 1014 2040 0 Blue 0
10 PM Fri 51 51 WNW 13 20 1014 2040 0 Blue 0
11 PM Fri 51 51 W 9 13 1014 2040 0 Blue 0
12 Midnight Sat 50 50 W 9 13 1014 2040 0 Blue 0
1 AM Sat 50 50 W 9 13 1014 2040 0 Blue 0
2 AM Sat 50 50 SW 6 9 1014 2040 0 Blue 0
3 AM Sat 50 50 SW 6 9 1014 2040 0 Blue 0
4 AM Sat 50 50 SW 6 9 1014 2040 0 Blue 0
5 AM Sat 49 49 S 5 9 1014 2040 0 Blue 0
6 AM Sat 50 50 S 5 9 1014 2040 0 Blue 0
7 AM Sat 50 50 S 5 9 1014 2040 0 Blue 0
8 AM Sat 52 52 SW 6 9 1014 2040 0 Blue 0
9 AM Sat 53 54 SW 6 9 1037 2040 0 Blue 0
10 AM Sat 55 58 SW 6 9 1205 2040 0 Blue 0
11 AM Sat 57 62 SW 6 10 1288 2040 0 Blue 4
12 Noon Sat 58 64 SW 6 10 1324 2040 0 Blue 6
1 PM Sat 60 66 SW 6 10 1360 2040 0 Blue 8
2 PM Sat 60 67 WSW 8 11 1378 2040 0 Blue 9
3 PM Sat 61 67 WSW 8 11 1378 2040 0 Blue 9
4 PM Sat 61 65 WSW 8 11 1342 2040 0 Blue 7
5 PM Sat 60 62 WSW 9 13 1288 2040 0 Blue 4
6 PM Sat 58 59 WSW 9 13 1231 2040 0 Blue 1
7 PM Sat 57 57 WSW 9 13 1163 2040 0 Blue 0
8 PM Sat 55 55 WSW 8 11 1079 2040 0 Blue 0
9 PM Sat 54 54 WSW 8 11 1037 2040 0 Blue 0
10 PM Sat 53 53 WSW 8 11 1014 2040 0 Blue 0
11 PM Sat 52 52 SW 8 11 1014 2040 0 Blue 0
12 Midnight Sun 52 52 SW 8 11 1014 2040 0 Blue 0
1 AM Sun 51 51 SW 8 11 1014 2040 0 Blue 0
2 AM Sun 51 51 SW 6 9 1014 2040 0 Blue 0
3 AM Sun 50 50 SW 6 9 1014 2040 0 Blue 0
4 AM Sun 50 50 SW 6 9 1014 2040 0 Blue 0
5 AM Sun 50 50 SSW 8 12 1014 2040 0 Blue 0
6 AM Sun 50 50 SSW 8 12 1014 2040 0 Blue 0
7 AM Sun 50 50 SSW 8 12 1014 2040 0 Blue 0
8 AM Sun 51 51 S 6 9 1014 2040 0 Blue 0
9 AM Sun 52 53 S 6 9 1014 2040 0 Blue 0
10 AM Sun 54 56 S 6 9 1121 2040 0 Blue 0
11 AM Sun 56 60 SSW 8 12 1252 2040 0 Blue 2
12 Noon Sun 57 62 SSW 8 12 1288 2040 0 Blue 4
1 PM Sun 59 65 SSW 8 12 1342 2040 0 Blue 7
2 PM Sun 59 66 SW 10 16 1360 2040 0 Blue 8
3 PM Sun 59 65 SW 10 16 1342 2040 0 Blue 7
4 PM Sun 58 62 SW 10 16 1288 2040 0 Blue 4
5 PM Sun 57 59 SW 11 17 1231 2040 0 Blue 1
6 PM Sun 56 57 SW 11 17 1163 2040 0 Blue 0
7 PM Sun 55 55 SW 11 17 1079 2040 0 Blue 0
8 PM Sun 54 54 SW 9 14 1037 2040 0 Blue 0
9 PM Sun 54 54 SW 9 14 1037 2040 0 Blue 0
10 PM Sun 53 53 SW 9 14 1014 2040 0 Blue 0
11 PM Sun 53 53 SW 8 12 1014 2040 0 Blue 0
12 Midnight Mon 52 52 SW 8 12 1014 2040 0 Blue 0
1 AM Mon 51 51 SW 8 12 1014 2040 0 Blue 0
2 AM Mon 51 51 SW 8 12 1014 2040 0 Blue 0
3 AM Mon 50 50 SW 8 12 1014 2040 0 Blue 0
4 AM Mon 50 50 SW 8 12 1014 2040 0 Blue 0
5 AM Mon 50 50 WSW 9 14 1014 2040 0 Blue 0
6 AM Mon 50 50 WSW 9 14 1014 2040 0 Blue 0
7 AM Mon 50 50 WSW 9 14 1014 2040 0 Blue 0
8 AM Mon 50 50 WSW 8 11 1014 2040 0 Blue 0
9 AM Mon 51 52 WSW 8 11 1014 2040 0 Blue 0
10 AM Mon 52 53 WSW 8 11 1014 2040 0 Blue 0
11 AM Mon 54 57 WSW 8 11 1163 2040 0 Blue 0
12 Noon Mon 56 60 WSW 8 11 1252 2040 0 Blue 2
1 PM Mon 58 62 WSW 8 11 1288 2040 0 Blue 4
2 PM Mon 59 65 W 11 16 1342 2040 0 Blue 7
3 PM Mon 60 65 W 11 16 1342 2040 0 Blue 7
4 PM Mon 60 63 W 11 16 1306 2040 0 Blue 5
5 PM Mon 59 61 W 13 20 1270 2040 0 Blue 3
6 PM Mon 57 58 W 13 20 1205 2040 0 Blue 0
7 PM Mon 56 56 W 13 20 1121 2040 0 Blue 0
8 PM Mon 54 54 W 14 21 1037 2040 0 Blue 0
9 PM Mon 53 53 W 14 21 1014 2040 0 Blue 0
10 PM Mon 52 52 W 14 21 1014 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 ac_soaring@yahoo.com