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

Station:

 KOAK

Date/Time:

 4 FEB 2012

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
4 AM Sat 46 46 NE 13 486 2040 0 Blue 0
5 AM Sat 46 46 NE 13 486 2040 0 Blue 0
6 AM Sat 45 45 NE 13 486 2040 0 Blue 0
7 AM Sat 45 45 NE 13 486 2040 0 Blue 0
8 AM Sat 46 46 NE 13 486 2040 0 Blue 0
9 AM Sat 49 49 NE 13 653 2040 0 Blue 0
10 AM Sat 53 54 E 10 1756 2040 0 Blue 1
11 AM Sat 56 58 E 10 3309 2238 198 Blue 5
12 Noon Sat 59 61 E 10 4564 3278 1238 Blue 8
1 PM Sat 60 62 E 3 4779 3698 1658 Blue 9
2 PM Sat 60 62 E 3 4779 3698 1658 Blue 9
3 PM Sat 60 61 E 3 4564 3278 1238 Blue 8
4 PM Sat 58 58 S 2 3309 2238 198 Blue 5
5 PM Sat 55 55 S 2 2256 2040 0 Blue 2
6 PM Sat 51 51 S 2 991 2040 0 Blue 0
7 PM Sat 49 49 NE 5 653 2040 0 Blue 0
8 PM Sat 48 48 NE 5 486 2040 0 Blue 0
9 PM Sat 48 48 NE 5 486 2040 0 Blue 0
10 PM Sat 48 48 NE 8 486 2040 0 Blue 0
11 PM Sat 47 47 NE 8 486 2040 0 Blue 0
12 Midnight Sun 47 47 NE 8 486 2040 0 Blue 0
1 AM Sun 48 48 NE 10 486 2040 0 Blue 0
2 AM Sun 47 47 NE 10 486 2040 0 Blue 0
3 AM Sun 47 47 NE 10 486 2040 0 Blue 0
4 AM Sun 47 47 NE 13 486 2040 0 Blue 0
5 AM Sun 46 46 NE 13 486 2040 0 Blue 0
6 AM Sun 46 46 NE 13 486 2040 0 Blue 0
7 AM Sun 45 45 NE 14 486 2040 0 Blue 0
8 AM Sun 46 46 NE 14 486 2040 0 Blue 0
9 AM Sun 50 50 NE 14 822 2040 0 Blue 0
10 AM Sun 54 55 NE 15 2256 2040 0 Blue 2
11 AM Sun 57 59 NE 15 3735 2679 639 Blue 6
12 Noon Sun 60 62 NE 15 4779 3698 1658 Blue 9
1 PM Sun 61 63 E 10 4954 4111 2071 Blue 10
2 PM Sun 62 63 E 10 4954 4111 2071 Blue 10
3 PM Sun 61 62 E 10 4779 3698 1658 Blue 9
4 PM Sun 60 60 E 8 4153 2977 937 Blue 7
5 PM Sun 56 56 E 8 2694 2040 0 Blue 3
6 PM Sun 52 52 E 8 1161 2040 0 Blue 0
7 PM Sun 50 50 E 8 822 2040 0 Blue 0
8 PM Sun 49 49 E 8 653 2040 0 Blue 0
9 PM Sun 49 49 E 8 653 2040 0 Blue 0
10 PM Sun 48 48 E 10 486 2040 0 Blue 0
11 PM Sun 48 48 E 10 486 2040 0 Blue 0
12 Midnight Mon 48 48 E 10 486 2040 0 Blue 0
1 AM Mon 48 48 E 10 486 2040 0 Blue 0
2 AM Mon 48 48 E 10 486 2040 0 Blue 0
3 AM Mon 47 47 E 10 486 2040 0 Blue 0
4 AM Mon 47 47 E 12 486 2040 0 Blue 0
5 AM Mon 47 47 E 12 486 2040 0 Blue 0
6 AM Mon 46 46 E 12 486 2040 0 Blue 0
7 AM Mon 46 46 E 12 486 2040 0 Blue 0
8 AM Mon 47 47 E 12 486 2040 0 Blue 0
9 AM Mon 50 50 E 12 822 2040 0 Blue 0
10 AM Mon 53 53 E 9 1330 2040 0 Blue 0
11 AM Mon 55 56 E 9 2694 2040 0 Blue 3
12 Noon Mon 57 58 E 9 3309 2238 198 Blue 5
1 PM Mon 58 59 E 9 3735 2679 639 Blue 6
2 PM Mon 59 60 E 9 4153 2977 937 Blue 7
3 PM Mon 58 58 E 9 3309 2238 198 Blue 5
4 PM Mon 57 57 S 8 2996 2040 0 Blue 4
5 PM Mon 54 54 S 8 1756 2040 0 Blue 1
6 PM Mon 50 50 S 8 822 2040 0 Blue 0
7 PM Mon 48 48 S 8 486 2040 0 Blue 0
8 PM Mon 47 47 S 8 486 2040 0 Blue 0
9 PM Mon 47 47 S 8 486 2040 0 Blue 0
10 PM Mon 46 46 S 12 486 2040 0 Blue 0
11 PM Mon 46 46 S 12 486 2040 0 Blue 0
12 Midnight Tue 46 46 S 12 486 2040 0 Blue 0
1 AM Tue 46 46 S 12 486 2040 0 Blue 0
2 AM Tue 46 46 S 12 486 2040 0 Blue 0
3 AM Tue 45 45 S 12 486 2040 0 Blue 0
4 AM Tue 45 45 SE 8 486 2040 0 Blue 0
5 AM Tue 45 45 SE 8 486 2040 0 Blue 0
6 AM Tue 44 44 SE 8 486 2040 0 Blue 0
7 AM Tue 44 44 SE 8 486 2040 0 Blue 0
8 AM Tue 45 45 SE 8 486 2040 0 Blue 0
9 AM Tue 47 47 SE 8 486 2040 0 Blue 0
10 AM Tue 49 49 S 17 653 2040 0 Blue 0
11 AM Tue 51 51 S 17 991 2040 0 Blue 0
12 Noon Tue 53 53 S 17 1330 2040 0 Blue 0
1 PM Tue 54 54 S 17 1756 2040 0 Blue 1
2 PM Tue 54 54 S 17 1756 2040 0 Blue 1
3 PM Tue 54 54 S 17 1756 2040 0 Blue 1
4 PM Tue 53 53 S 6 1330 2040 0 Blue 0
5 PM Tue 50 50 S 6 822 2040 0 Blue 0
6 PM Tue 47 47 S 6 486 2040 0 Blue 0
7 PM Tue 46 46 S 6 486 2040 0 Blue 0
8 PM Tue 45 45 S 6 486 2040 0 Blue 0
9 PM Tue 44 44 S 6 486 2040 0 Blue 0
10 PM Tue 44 44 N 2 486 2040 0 Blue 0
11 PM Tue 44 44 N 2 486 2040 0 Blue 0
12 Midnight Wed 44 44 N 2 486 2040 0 Blue 0
1 AM Wed 44 44 N 2 486 2040 0 Blue 0
2 AM Wed 44 44 N 2 486 2040 0 Blue 0
3 AM Wed 43 43 N 2 486 2040 0 Blue 0
4 AM Wed 43 43 NE 8 486 2040 0 Blue 0
5 AM Wed 43 43 NE 8 486 2040 0 Blue 0
6 AM Wed 43 43 NE 8 486 2040 0 Blue 0
7 AM Wed 43 43 NE 8 486 2040 0 Blue 0
8 AM Wed 43 43 NE 8 486 2040 0 Blue 0
9 AM Wed 46 46 NE 8 486 2040 0 Blue 0
10 AM Wed 50 51 N 7 991 2040 0 Blue 0
11 AM Wed 53 54 N 7 1756 2040 0 Blue 1
12 Noon Wed 55 57 N 7 2996 2040 0 Blue 4
1 PM Wed 56 57 N 7 2996 2040 0 Blue 4
2 PM Wed 57 58 N 7 3309 2238 198 Blue 5
3 PM Wed 56 56 N 7 2694 2040 0 Blue 3
4 PM Wed 55 55 NW 13 2256 2040 0 Blue 2
5 PM Wed 52 52 NW 13 1161 2040 0 Blue 0
6 PM Wed 49 49 NW 13 653 2040 0 Blue 0
7 PM Wed 48 48 NW 13 486 2040 0 Blue 0
8 PM Wed 47 47 NW 13 486 2040 0 Blue 0
9 PM Wed 47 47 NW 13 486 2040 0 Blue 0
10 PM Wed 46 46 NW 8 486 2040 0 Blue 0
11 PM Wed 46 46 NW 8 486 2040 0 Blue 0
12 Midnight Thu 46 46 NW 8 486 2040 0 Blue 0
1 AM Thu 46 46 NW 8 486 2040 0 Blue 0
2 AM Thu 46 46 NW 8 486 2040 0 Blue 0
3 AM Thu 46 46 NW 8 486 2040 0 Blue 0
4 AM Thu 46 46 N 7 486 2040 0 Blue 0
5 AM Thu 45 45 N 7 486 2040 0 Blue 0
6 AM Thu 45 45 N 7 486 2040 0 Blue 0
7 AM Thu 45 45 N 7 486 2040 0 Blue 0
8 AM Thu 45 45 N 7 486 2040 0 Blue 0
9 AM Thu 49 49 N 7 653 2040 0 Blue 0
10 AM Thu 53 54 NE 8 1756 2040 0 Blue 1
11 AM Thu 56 58 NE 8 3309 2238 198 Blue 5
12 Noon Thu 58 61 NE 8 4564 3278 1238 Blue 8
1 PM Thu 60 62 NE 8 4779 3698 1658 Blue 9
2 PM Thu 60 62 NE 8 4779 3698 1658 Blue 9
3 PM Thu 59 60 NE 8 4153 2977 937 Blue 7
4 PM Thu 58 58 NW 6 3309 2238 198 Blue 5
5 PM Thu 55 55 NW 6 2256 2040 0 Blue 2
6 PM Thu 51 51 NW 6 991 2040 0 Blue 0
7 PM Thu 49 49 NW 6 653 2040 0 Blue 0
8 PM Thu 48 48 NW 6 486 2040 0 Blue 0
9 PM Thu 48 48 NW 6 486 2040 0 Blue 0
10 PM Thu 48 48 N 3 486 2040 0 Blue 0
11 PM Thu 48 48 N 3 486 2040 0 Blue 0
12 Midnight Fri 48 48 N 3 486 2040 0 Blue 0
1 AM Fri 48 48 N 3 486 2040 0 Blue 0
2 AM Fri 47 47 N 3 486 2040 0 Blue 0
3 AM Fri 47 47 N 3 486 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