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

Station:

KOAK

Date/Time:

26 MAY 2019

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 48 48 W 21 1277 2040 0 Blue 0
6 AM Sun 47 47 W 21 945 2040 0 Blue 0
7 AM Sun 47 47 W 21 945 2040 0 Blue 0
8 AM Sun 48 48 W 23 1277 2040 0 Blue 0
9 AM Sun 50 51 W 23 3092 2040 0 White 2
10 AM Sun 51 52 W 23 3309 2161 121 White 3
11 AM Sun 52 53 W 21 3525 3288 1248 White 4
12 Noon Sun 52 52 W 21 3309 2161 121 White 3
1 PM Sun 54 55 W 21 3958 3958 1918 White 6
2 PM Sun 54 55 W 18 3958 3958 1918 White 6
3 PM Sun 54 55 W 18 3958 3958 1918 White 6
4 PM Sun 54 55 W 18 3958 3958 1918 White 6
5 PM Sun 54 54 W 15 3742 3641 1601 White 5
6 PM Sun 52 52 W 15 3309 2161 121 White 3
7 PM Sun 52 52 W 15 3309 2161 121 White 3
8 PM Sun 51 51 NW 12 3092 2040 0 White 2
9 PM Sun 50 50 NW 12 2875 2040 0 White 1
10 PM Sun 50 50 NW 12 2875 2040 0 White 1
11 PM Sun 49 49 NW 10 2191 2040 0 Blue 0
12 Midnight Mon 49 49 NW 10 2191 2040 0 Blue 0
1 AM Mon 48 48 NW 10 1277 2040 0 Blue 0
2 AM Mon 48 48 NW 9 1277 2040 0 Blue 0
3 AM Mon 48 48 NW 9 1277 2040 0 Blue 0
4 AM Mon 48 48 NW 9 1277 2040 0 Blue 0
5 AM Mon 47 47 NW 12 945 2040 0 Blue 0
6 AM Mon 47 47 NW 12 945 2040 0 Blue 0
7 AM Mon 47 47 NW 12 945 2040 0 Blue 0
8 AM Mon 49 49 NW 12 2191 2040 0 Blue 0
9 AM Mon 52 52 NW 12 3309 2161 121 White 3
10 AM Mon 54 56 NW 12 4174 4174 2134 White 7
11 AM Mon 55 55 W 13 3958 3958 1918 White 6
12 Noon Mon 56 57 W 13 4389 4389 2349 White 8
1 PM Mon 58 59 W 13 4815 4815 2775 White 10
2 PM Mon 58 61 W 14 5238 5238 3198 White 12
3 PM Mon 58 60 W 14 5026 5026 2986 White 11
4 PM Mon 58 60 W 14 5026 5026 2986 White 11
5 PM Mon 58 60 W 14 5026 5026 2986 White 11
6 PM Mon 56 57 W 14 4389 4389 2349 White 8
7 PM Mon 55 55 W 14 3958 3958 1918 White 6
8 PM Mon 54 54 NW 12 3742 3641 1601 White 5
9 PM Mon 53 53 NW 12 3525 3288 1248 White 4
10 PM Mon 53 53 NW 12 3525 3288 1248 White 4
11 PM Mon 51 51 NW 8 3092 2040 0 White 2
12 Midnight Tue 52 52 NW 8 3309 2161 121 White 3
1 AM Tue 51 51 NW 8 3092 2040 0 White 2
2 AM Tue 50 50 N 5 2875 2040 0 White 1
3 AM Tue 50 50 N 5 2875 2040 0 White 1
4 AM Tue 50 50 N 5 2875 2040 0 White 1
5 AM Tue 49 49 N 2 2191 2040 0 Blue 0
6 AM Tue 49 49 N 2 2191 2040 0 Blue 0
7 AM Tue 49 49 N 2 2191 2040 0 Blue 0
8 AM Tue 52 52 W 7 3309 2161 121 White 3
9 AM Tue 54 54 W 7 3742 3641 1601 White 5
10 AM Tue 57 57 W 7 4389 4389 2349 White 8
11 AM Tue 58 62 W 12 5449 5449 3409 White 13
12 Noon Tue 59 64 W 12 5870 5870 3830 White 15
1 PM Tue 61 66 W 12 6286 6286 4246 White 17
2 PM Tue 62 68 NW 14 6702 6702 4662 White 19
3 PM Tue 62 67 NW 14 6494 6494 4454 White 18
4 PM Tue 62 66 NW 14 6286 6286 4246 White 17
5 PM Tue 62 64 NW 14 5870 5870 3830 White 15
6 PM Tue 59 60 NW 14 5026 5026 2986 White 11
7 PM Tue 58 58 NW 14 4604 4604 2564 White 9
8 PM Tue 56 56 NW 13 4174 4174 2134 White 7
9 PM Tue 55 55 NW 13 3958 3958 1918 White 6
10 PM Tue 55 55 NW 13 3958 3958 1918 White 6
11 PM Tue 53 53 N 5 3525 3288 1248 White 4
12 Midnight Wed 53 53 N 5 3525 3288 1248 White 4
1 AM Wed 53 53 N 5 3525 3288 1248 White 4
2 AM Wed 52 52 W 3 3309 2161 121 White 3
3 AM Wed 52 52 W 3 3309 2161 121 White 3
4 AM Wed 51 51 W 3 3092 2040 0 White 2
5 AM Wed 50 50 W 3 2875 2040 0 White 1
6 AM Wed 50 50 W 3 2875 2040 0 White 1
7 AM Wed 50 50 W 3 2875 2040 0 White 1
8 AM Wed 52 52 NW 7 3309 2161 121 White 3
9 AM Wed 55 56 NW 7 4174 4174 2134 White 7
10 AM Wed 58 60 NW 7 5026 5026 2986 White 11
11 AM Wed 60 65 W 9 6078 6078 4038 White 16
12 Noon Wed 60 66 W 9 6286 6286 4246 White 17
1 PM Wed 62 69 W 9 6909 6909 4869 White 20
2 PM Wed 63 71 W 13 7322 7322 5282 White 22
3 PM Wed 63 70 W 13 7116 7116 5076 White 21
4 PM Wed 63 68 W 13 6702 6702 4662 White 19
5 PM Wed 63 66 W 14 6286 6286 4246 White 17
6 PM Wed 60 61 W 14 5238 5238 3198 White 12
7 PM Wed 59 59 W 14 4815 4815 2775 White 10
8 PM Wed 57 57 W 14 4389 4389 2349 White 8
9 PM Wed 56 56 W 14 4174 4174 2134 White 7
10 PM Wed 55 55 W 14 3958 3958 1918 White 6
11 PM Wed 53 53 W 12 3525 3288 1248 White 4
12 Midnight Thu 54 54 W 12 3742 3641 1601 White 5
1 AM Thu 53 53 W 12 3525 3288 1248 White 4
2 AM Thu 52 52 W 12 3309 2161 121 White 3
3 AM Thu 52 52 W 12 3309 2161 121 White 3
4 AM Thu 51 51 W 12 3092 2040 0 White 2
5 AM Thu 50 50 W 12 2875 2040 0 White 1
6 AM Thu 49 49 W 12 2191 2040 0 Blue 0
7 AM Thu 49 49 W 12 2191 2040 0 Blue 0
8 AM Thu 52 53 W 10 3525 3288 1248 White 4
9 AM Thu 54 56 W 10 4174 4174 2134 White 7
10 AM Thu 57 61 W 10 5238 5238 3198 White 12
11 AM Thu 58 63 W 12 5660 5660 3620 White 14
12 Noon Thu 59 65 W 12 6078 6078 4038 White 16
1 PM Thu 61 67 W 12 6494 6494 4454 White 18
2 PM Thu 61 67 W 14 6494 6494 4454 White 18
3 PM Thu 61 66 W 14 6286 6286 4246 White 17
4 PM Thu 61 64 W 14 5870 5870 3830 White 15
5 PM Thu 61 63 W 14 5660 5660 3620 White 14
6 PM Thu 59 60 W 14 5026 5026 2986 White 11
7 PM Thu 57 57 W 14 4389 4389 2349 White 8
8 PM Thu 56 56 W 14 4174 4174 2134 White 7
9 PM Thu 55 55 W 14 3958 3958 1918 White 6
10 PM Thu 54 54 W 14 3742 3641 1601 White 5
11 PM Thu 52 52 W 12 3309 2161 121 White 3
12 Midnight Fri 53 53 W 12 3525 3288 1248 White 4
1 AM Fri 52 52 W 12 3309 2161 121 White 3
2 AM Fri 52 52 W 10 3309 2161 121 White 3
3 AM Fri 51 51 W 10 3092 2040 0 White 2
4 AM Fri 51 51 W 10 3092 2040 0 White 2
5 AM Fri 50 50 NW 9 2875 2040 0 White 1
6 AM Fri 49 49 NW 9 2191 2040 0 Blue 0
7 AM Fri 49 49 NW 9 2191 2040 0 Blue 0
8 AM Fri 52 52 W 8 3309 2161 121 White 3
9 AM Fri 55 56 W 8 4174 4174 2134 White 7
10 AM Fri 58 61 W 8 5238 5238 3198 White 12
11 AM Fri 60 65 W 9 6078 6078 4038 White 16
12 Noon Fri 60 66 W 9 6286 6286 4246 White 17
1 PM Fri 63 69 W 9 6909 6909 4869 White 20
2 PM Fri 63 69 W 12 6909 6909 4869 White 20
3 PM Fri 63 68 W 12 6702 6702 4662 White 19
4 PM Fri 63 67 W 12 6494 6494 4454 White 18
5 PM Fri 63 66 W 14 6286 6286 4246 White 17
6 PM Fri 60 61 W 14 5238 5238 3198 White 12
7 PM Fri 59 59 W 14 4815 4815 2775 White 10
8 PM Fri 57 57 W 14 4389 4389 2349 White 8
9 PM Fri 56 56 W 14 4174 4174 2134 White 7
10 PM Fri 55 55 W 14 3958 3958 1918 White 6
11 PM Fri 53 53 W 10 3525 3288 1248 White 4
12 Midnight Sat 54 54 W 10 3742 3641 1601 White 5
1 AM Sat 53 53 W 10 3525 3288 1248 White 4
2 AM Sat 52 52 W 9 3309 2161 121 White 3
3 AM Sat 52 52 W 9 3309 2161 121 White 3
4 AM Sat 52 52 W 9 3309 2161 121 White 3

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