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

Station:

KOAK

Date/Time:

25 NOV 2020

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)
4 AM Wed 50 50 NW 15 1245 2040 0 Blue 0
5 AM Wed 51 51 NW 14 1718 2040 0 Blue 1
6 AM Wed 49 49 NW 15 942 2040 0 Blue 0
7 AM Wed 48 48 NW 15 883 2040 0 Blue 0
8 AM Wed 48 48 NW 17 883 2040 0 Blue 0
9 AM Wed 48 48 NW 17 883 2040 0 Blue 0
10 AM Wed 50 51 NW 15 1718 2040 0 Blue 1
11 AM Wed 54 56 N 14 3418 2263 223 Blue 6
12 Noon Wed 56 58 NW 12 3664 3024 984 Blue 8
1 PM Wed 57 59 NW 12 3788 3408 1368 Blue 9
2 PM Wed 56 57 NW 13 3541 2414 374 Blue 7
3 PM Wed 56 56 NW 14 3418 2263 223 Blue 6
4 PM Wed 54 54 NW 14 2420 2040 0 Blue 4
5 PM Wed 52 52 N 15 2118 2040 0 Blue 2
6 PM Wed 49 49 N 18 942 2040 0 Blue 0
7 PM Wed 48 48 N 20 883 2040 0 Blue 0
8 PM Wed 48 48 N 17 883 2040 0 Blue 0
9 PM Wed 48 48 N 15 883 2040 0 Blue 0
10 PM Wed 48 48 N 15 883 2040 0 Blue 0
11 PM Wed 47 47 N 15 883 2040 0 Blue 0
12 Midnight Thu 47 47 N 17 883 2040 0 Blue 0
1 AM Thu 47 47 N 21 883 2040 0 Blue 0
2 AM Thu 47 47 N 22 883 2040 0 Blue 0
3 AM Thu 47 47 N 23 883 2040 0 Blue 0
4 AM Thu 47 47 N 24 883 2040 0 Blue 0
5 AM Thu 48 48 N 23 883 2040 0 Blue 0
6 AM Thu 47 47 N 22 883 2040 0 Blue 0
7 AM Thu 47 47 N 22 883 2040 0 Blue 0
8 AM Thu 48 48 N 23 883 2040 0 Blue 0
9 AM Thu 48 48 N 22 883 2040 0 Blue 0
10 AM Thu 52 53 N 20 2269 2040 0 Blue 3
11 AM Thu 55 57 N 20 3541 2414 374 Blue 7
12 Noon Thu 58 60 N 20 3911 3531 1491 Blue 10
1 PM Thu 60 62 N 21 4158 3777 1737 Blue 12
2 PM Thu 61 62 N 21 4158 3777 1737 Blue 12
3 PM Thu 60 60 N 21 3911 3531 1491 Blue 10
4 PM Thu 59 59 N 17 3788 3408 1368 Blue 9
5 PM Thu 58 58 N 17 3664 3024 984 Blue 8
6 PM Thu 56 56 N 17 3418 2263 223 Blue 6
7 PM Thu 56 56 NE 25 3418 2263 223 Blue 6
8 PM Thu 54 54 NE 25 2420 2040 0 Blue 4
9 PM Thu 54 54 NE 25 2420 2040 0 Blue 4
10 PM Thu 53 53 N 14 2269 2040 0 Blue 3
11 PM Thu 52 52 N 14 2118 2040 0 Blue 2
12 Midnight Fri 52 52 N 14 2118 2040 0 Blue 2
1 AM Fri 52 52 NE 8 2118 2040 0 Blue 2
2 AM Fri 51 51 NE 8 1718 2040 0 Blue 1
3 AM Fri 50 50 NE 8 1245 2040 0 Blue 0
4 AM Fri 49 49 NE 12 942 2040 0 Blue 0
5 AM Fri 48 48 NE 12 883 2040 0 Blue 0
6 AM Fri 47 47 NE 12 883 2040 0 Blue 0
7 AM Fri 46 46 NE 13 883 2040 0 Blue 0
8 AM Fri 47 47 NE 13 883 2040 0 Blue 0
9 AM Fri 48 48 NE 13 883 2040 0 Blue 0
10 AM Fri 50 51 NE 9 1718 2040 0 Blue 1
11 AM Fri 53 55 NE 9 3063 2113 73 Blue 5
12 Noon Fri 56 58 NE 9 3664 3024 984 Blue 8
1 PM Fri 58 60 NE 6 3911 3531 1491 Blue 10
2 PM Fri 59 60 NE 6 3911 3531 1491 Blue 10
3 PM Fri 59 59 NE 6 3788 3408 1368 Blue 9
4 PM Fri 58 58 NE 3 3664 3024 984 Blue 8
5 PM Fri 57 57 NE 3 3541 2414 374 Blue 7
6 PM Fri 55 55 NE 3 3063 2113 73 Blue 5
7 PM Fri 54 54 NE 7 2420 2040 0 Blue 4
8 PM Fri 53 53 NE 7 2269 2040 0 Blue 3
9 PM Fri 52 52 NE 7 2118 2040 0 Blue 2
10 PM Fri 52 52 NE 8 2118 2040 0 Blue 2
11 PM Fri 51 51 NE 8 1718 2040 0 Blue 1
12 Midnight Sat 50 50 NE 8 1245 2040 0 Blue 0
1 AM Sat 49 49 NE 7 942 2040 0 Blue 0
2 AM Sat 48 48 NE 7 883 2040 0 Blue 0
3 AM Sat 47 47 NE 7 883 2040 0 Blue 0
4 AM Sat 46 46 NE 7 883 2040 0 Blue 0
5 AM Sat 45 45 NE 7 883 2040 0 Blue 0
6 AM Sat 45 45 NE 7 883 2040 0 Blue 0
7 AM Sat 45 45 NE 6 883 2040 0 Blue 0
8 AM Sat 46 46 NE 6 883 2040 0 Blue 0
9 AM Sat 47 47 NE 6 883 2040 0 Blue 0
10 AM Sat 49 50 NE 7 1245 2040 0 Blue 0
11 AM Sat 52 54 NE 7 2420 2040 0 Blue 4
12 Noon Sat 55 57 NE 7 3541 2414 374 Blue 7
1 PM Sat 58 60 NE 6 3911 3531 1491 Blue 10
2 PM Sat 59 60 NE 6 3911 3531 1491 Blue 10
3 PM Sat 60 60 NE 6 3911 3531 1491 Blue 10
4 PM Sat 59 59 N 2 3788 3408 1368 Blue 9
5 PM Sat 57 57 N 2 3541 2414 374 Blue 7
6 PM Sat 56 56 N 2 3418 2263 223 Blue 6
7 PM Sat 54 54 N 2 2420 2040 0 Blue 4
8 PM Sat 53 53 N 2 2269 2040 0 Blue 3
9 PM Sat 52 52 N 2 2118 2040 0 Blue 2
10 PM Sat 52 52 N 2 2118 2040 0 Blue 2
11 PM Sat 51 51 N 2 1718 2040 0 Blue 1
12 Midnight Sun 50 50 N 2 1245 2040 0 Blue 0
1 AM Sun 49 49 NE 3 942 2040 0 Blue 0
2 AM Sun 48 48 NE 3 883 2040 0 Blue 0
3 AM Sun 47 47 NE 3 883 2040 0 Blue 0
4 AM Sun 46 46 NE 3 883 2040 0 Blue 0
5 AM Sun 46 46 NE 3 883 2040 0 Blue 0
6 AM Sun 45 45 NE 3 883 2040 0 Blue 0
7 AM Sun 45 45 NE 5 883 2040 0 Blue 0
8 AM Sun 46 46 NE 5 883 2040 0 Blue 0
9 AM Sun 47 47 NE 5 883 2040 0 Blue 0
10 AM Sun 49 49 NE 6 942 2040 0 Blue 0
11 AM Sun 52 53 NE 6 2269 2040 0 Blue 3
12 Noon Sun 56 57 NE 6 3541 2414 374 Blue 7
1 PM Sun 58 59 NE 3 3788 3408 1368 Blue 9
2 PM Sun 59 60 NE 3 3911 3531 1491 Blue 10
3 PM Sun 58 58 NE 3 3664 3024 984 Blue 8
4 PM Sun 57 57 NW 2 3541 2414 374 Blue 7
5 PM Sun 56 56 NW 2 3418 2263 223 Blue 6
6 PM Sun 55 55 NW 2 3063 2113 73 Blue 5
7 PM Sun 53 53 NW 2 2269 2040 0 Blue 3
8 PM Sun 52 52 NW 2 2118 2040 0 Blue 2
9 PM Sun 51 51 NW 2 1718 2040 0 Blue 1
10 PM Sun 50 50 NW 2 1245 2040 0 Blue 0
11 PM Sun 50 50 NW 2 1245 2040 0 Blue 0
12 Midnight Mon 49 49 NW 2 942 2040 0 Blue 0
1 AM Mon 48 48 NW 3 883 2040 0 Blue 0
2 AM Mon 48 48 NW 3 883 2040 0 Blue 0
3 AM Mon 48 48 NW 3 883 2040 0 Blue 0
4 AM Mon 47 47 NW 3 883 2040 0 Blue 0
5 AM Mon 47 47 NW 3 883 2040 0 Blue 0
6 AM Mon 46 46 NW 3 883 2040 0 Blue 0
7 AM Mon 46 46 N 3 883 2040 0 Blue 0
8 AM Mon 46 46 N 3 883 2040 0 Blue 0
9 AM Mon 47 47 N 3 883 2040 0 Blue 0
10 AM Mon 49 49 NE 6 942 2040 0 Blue 0
11 AM Mon 51 52 NE 6 2118 2040 0 Blue 2
12 Noon Mon 54 55 NE 6 3063 2113 73 Blue 5
1 PM Mon 56 57 NW 6 3541 2414 374 Blue 7
2 PM Mon 58 58 NW 6 3664 3024 984 Blue 8
3 PM Mon 58 58 NW 6 3664 3024 984 Blue 8
4 PM Mon 57 57 NW 6 3541 2414 374 Blue 7
5 PM Mon 56 56 NW 6 3418 2263 223 Blue 6
6 PM Mon 55 55 NW 6 3063 2113 73 Blue 5
7 PM Mon 54 54 NW 5 2420 2040 0 Blue 4
8 PM Mon 54 54 NW 5 2420 2040 0 Blue 4
9 PM Mon 54 54 NW 5 2420 2040 0 Blue 4
10 PM Mon 54 54 NW 5 2420 2040 0 Blue 4
11 PM Mon 53 53 NW 5 2269 2040 0 Blue 3
12 Midnight Tue 53 53 NW 5 2269 2040 0 Blue 3
1 AM Tue 52 52 N 6 2118 2040 0 Blue 2
2 AM Tue 51 51 N 6 1718 2040 0 Blue 1
3 AM Tue 50 50 N 6 1245 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