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

Station:

 KOAK

Date/Time:

 11 MAR 2010

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)
7 AM Thu 41 41 SW 3 997 2040 0 Blue 0
8 AM Thu 43 43 SW 3 997 2040 0 Blue 0
9 AM Thu 46 47 SW 3 1982 2040 0 Blue 2
10 AM Thu 50 52 SW 3 3224 2287 247 Blue 7
11 AM Thu 53 55 SW 3 4154 3194 1154 White 10
12 Noon Thu 55 58 SW 3 4796 4156 2116 Blue 13
1 PM Thu 57 60 S 4 5052 4606 2566 Blue 15
2 PM Thu 56 58 S 4 4796 4156 2116 Blue 13
3 PM Thu 56 57 S 4 4581 3930 1890 White 12
4 PM Thu 54 54 SW 8 3940 2763 723 White 9
5 PM Thu 53 53 SW 8 3652 2572 532 Blue 8
6 PM Thu 51 51 SW 8 2788 2095 55 Blue 6
7 PM Thu 49 49 SW 6 2310 2040 0 Blue 4
8 PM Thu 48 48 SW 6 2099 2040 0 Blue 3
9 PM Thu 48 48 SW 6 2099 2040 0 Blue 3
10 PM Thu 47 47 SW 4 1982 2040 0 Blue 2
11 PM Thu 47 47 SW 4 1982 2040 0 Blue 2
12 Midnight Fri 47 47 SW 4 1982 2040 0 Blue 2
1 AM Fri 46 46 S 6 1866 2040 0 Blue 1
2 AM Fri 46 46 S 6 1866 2040 0 Blue 1
3 AM Fri 46 46 S 6 1866 2040 0 Blue 1
4 AM Fri 46 46 S 8 1866 2040 0 Blue 1
5 AM Fri 46 46 S 8 1866 2040 0 Blue 1
6 AM Fri 45 45 S 8 1749 2040 0 Blue 0
7 AM Fri 45 45 S 8 1749 2040 0 Blue 0
8 AM Fri 47 47 S 8 1982 2040 0 Blue 2
9 AM Fri 49 49 S 8 2310 2040 0 Blue 4
10 AM Fri 51 51 S 16 2788 2095 55 Blue 6
11 AM Fri 53 53 S 16 3652 2572 532 Blue 8
12 Noon Fri 54 54 S 16 3940 2763 723 White 9
1 PM Fri 55 55 S 16 4154 3194 1154 White 10
2 PM Fri 55 55 S 16 4154 3194 1154 White 10
3 PM Fri 54 54 S 16 3940 2763 723 White 9
4 PM Fri 52 52 SW 13 3224 2287 247 Blue 7
5 PM Fri 51 51 SW 13 2788 2095 55 Blue 6
6 PM Fri 49 49 SW 13 2310 2040 0 Blue 4
7 PM Fri 48 48 SW 13 2099 2040 0 Blue 3
8 PM Fri 47 47 SW 13 1982 2040 0 Blue 2
9 PM Fri 46 46 SW 13 1866 2040 0 Blue 1
10 PM Fri 46 46 W 10 1866 2040 0 Blue 1
11 PM Fri 45 45 W 10 1749 2040 0 Blue 0
12 Midnight Sat 45 45 W 10 1749 2040 0 Blue 0
1 AM Sat 45 45 W 10 1749 2040 0 Blue 0
2 AM Sat 45 45 W 10 1749 2040 0 Blue 0
3 AM Sat 44 44 W 10 1255 2040 0 Blue 0
4 AM Sat 44 44 N 7 1255 2040 0 Blue 0
5 AM Sat 44 44 N 7 1255 2040 0 Blue 0
6 AM Sat 44 44 N 7 1255 2040 0 Blue 0
7 AM Sat 44 44 N 7 1255 2040 0 Blue 0
8 AM Sat 46 46 N 7 1866 2040 0 Blue 1
9 AM Sat 48 49 N 7 2310 2040 0 Blue 4
10 AM Sat 51 53 N 7 3652 2572 532 Blue 8
11 AM Sat 53 56 N 7 4368 3616 1576 White 11
12 Noon Sat 55 58 N 7 4796 4156 2116 Blue 13
1 PM Sat 56 59 N 7 4941 4381 2341 Blue 14
2 PM Sat 56 58 N 7 4796 4156 2116 Blue 13
3 PM Sat 55 57 N 7 4581 3930 1890 White 12
4 PM Sat 53 54 NW 12 3940 2763 723 White 9
5 PM Sat 52 52 NW 12 3224 2287 247 Blue 7
6 PM Sat 49 49 NW 12 2310 2040 0 Blue 4
7 PM Sat 47 47 NW 12 1982 2040 0 Blue 2
8 PM Sat 46 46 NW 12 1866 2040 0 Blue 1
9 PM Sat 46 46 NW 12 1866 2040 0 Blue 1
10 PM Sat 45 45 NW 14 1749 2040 0 Blue 0
11 PM Sat 45 45 NW 14 1749 2040 0 Blue 0
12 Midnight Sun 44 44 NW 14 1255 2040 0 Blue 0
1 AM Sun 44 44 NW 14 1255 2040 0 Blue 0
2 AM Sun 44 44 NW 14 1255 2040 0 Blue 0
3 AM Sun 43 43 NW 14 997 2040 0 Blue 0
4 AM Sun 43 43 NW 9 997 2040 0 Blue 0
5 AM Sun 43 43 NW 9 997 2040 0 Blue 0
6 AM Sun 42 42 NW 9 997 2040 0 Blue 0
7 AM Sun 42 42 NW 9 997 2040 0 Blue 0
8 AM Sun 45 45 NW 9 1749 2040 0 Blue 0
9 AM Sun 48 49 NW 9 2310 2040 0 Blue 4
10 AM Sun 52 54 N 3 3940 2763 723 White 9
11 AM Sun 56 59 N 3 4941 4381 2341 Blue 14
12 Noon Sun 58 62 N 3 5427 4923 2883 Blue 17
1 PM Sun 60 64 N 3 5942 5147 3107 Blue 19
2 PM Sun 59 62 N 3 5427 4923 2883 Blue 17
3 PM Sun 59 61 N 3 5162 4778 2738 Blue 16
4 PM Sun 56 57 NW 8 4581 3930 1890 White 12
5 PM Sun 55 55 NW 8 4154 3194 1154 White 10
6 PM Sun 53 53 NW 8 3652 2572 532 Blue 8
7 PM Sun 50 50 NW 8 2579 2040 0 Blue 5
8 PM Sun 49 49 NW 8 2310 2040 0 Blue 4
9 PM Sun 49 49 NW 8 2310 2040 0 Blue 4
10 PM Sun 48 48 NW 5 2099 2040 0 Blue 3
11 PM Sun 47 47 NW 5 1982 2040 0 Blue 2
12 Midnight Mon 47 47 NW 5 1982 2040 0 Blue 2
1 AM Mon 47 47 NW 5 1982 2040 0 Blue 2
2 AM Mon 46 46 NW 5 1866 2040 0 Blue 1
3 AM Mon 46 46 NW 5 1866 2040 0 Blue 1
4 AM Mon 46 46 E 2 1866 2040 0 Blue 1
5 AM Mon 45 45 E 2 1749 2040 0 Blue 0
6 AM Mon 45 45 E 2 1749 2040 0 Blue 0
7 AM Mon 45 45 E 2 1749 2040 0 Blue 0
8 AM Mon 48 48 E 2 2099 2040 0 Blue 3
9 AM Mon 50 51 E 2 2788 2095 55 Blue 6
10 AM Mon 54 57 E 5 4581 3930 1890 White 12
11 AM Mon 57 60 E 5 5052 4606 2566 Blue 15
12 Noon Mon 59 63 E 5 5693 5037 2997 Blue 18
1 PM Mon 61 65 E 5 6061 5388 3348 Blue 20
2 PM Mon 60 63 E 5 5693 5037 2997 Blue 18
3 PM Mon 60 62 E 5 5427 4923 2883 Blue 17
4 PM Mon 58 59 S 3 4941 4381 2341 Blue 14
5 PM Mon 56 56 S 3 4368 3616 1576 White 11
6 PM Mon 54 54 S 3 3940 2763 723 White 9
7 PM Mon 53 53 S 3 3652 2572 532 Blue 8
8 PM Mon 52 52 S 3 3224 2287 247 Blue 7
9 PM Mon 51 51 S 3 2788 2095 55 Blue 6
10 PM Mon 50 50 SW 5 2579 2040 0 Blue 5
11 PM Mon 50 50 SW 5 2579 2040 0 Blue 5
12 Midnight Tue 50 50 SW 5 2579 2040 0 Blue 5
1 AM Tue 49 49 SW 5 2310 2040 0 Blue 4
2 AM Tue 49 49 SW 5 2310 2040 0 Blue 4
3 AM Tue 49 49 SW 5 2310 2040 0 Blue 4
4 AM Tue 49 49 SW 4 2310 2040 0 Blue 4
5 AM Tue 48 48 SW 4 2099 2040 0 Blue 3
6 AM Tue 48 48 SW 4 2099 2040 0 Blue 3
7 AM Tue 48 48 SW 4 2099 2040 0 Blue 3
8 AM Tue 50 50 SW 4 2579 2040 0 Blue 5
9 AM Tue 52 53 SW 4 3652 2572 532 Blue 8
10 AM Tue 55 57 W 9 4581 3930 1890 White 12
11 AM Tue 57 60 W 9 5052 4606 2566 Blue 15
12 Noon Tue 59 62 W 9 5427 4923 2883 Blue 17
1 PM Tue 60 63 W 9 5693 5037 2997 Blue 18
2 PM Tue 59 61 W 9 5162 4778 2738 Blue 16
3 PM Tue 59 60 W 9 5052 4606 2566 Blue 15
4 PM Tue 56 56 NW 10 4368 3616 1576 White 11
5 PM Tue 55 55 NW 10 4154 3194 1154 White 10
6 PM Tue 53 53 NW 10 3652 2572 532 Blue 8
7 PM Tue 51 51 NW 10 2788 2095 55 Blue 6
8 PM Tue 50 50 NW 10 2579 2040 0 Blue 5
9 PM Tue 50 50 NW 10 2579 2040 0 Blue 5
10 PM Tue 49 49 NW 12 2310 2040 0 Blue 4
11 PM Tue 49 49 NW 12 2310 2040 0 Blue 4
12 Midnight Wed 48 48 NW 12 2099 2040 0 Blue 3
1 AM Wed 48 48 NW 12 2099 2040 0 Blue 3
2 AM Wed 48 48 NW 12 2099 2040 0 Blue 3
3 AM Wed 48 48 NW 12 2099 2040 0 Blue 3
4 AM Wed 48 48 NW 8 2099 2040 0 Blue 3
5 AM Wed 47 47 NW 8 1982 2040 0 Blue 2
6 AM Wed 47 47 NW 8 1982 2040 0 Blue 2

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