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

Station:

 KOAK

Date/Time:

 19 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)
5 AM Fri 53 53 NE 10 433 2040 0 Blue 0
6 AM Fri 52 52 NE 10 433 2040 0 Blue 0
7 AM Fri 52 52 NE 10 433 2040 0 Blue 0
8 AM Fri 53 53 NE 8 433 2040 0 Blue 0
9 AM Fri 58 59 NE 8 433 2040 0 Blue 0
10 AM Fri 62 64 NE 8 893 2040 0 Blue 0
11 AM Fri 66 70 NE 10 1799 2040 0 Blue 5
12 Noon Fri 69 74 NE 10 2548 2040 0 Blue 9
1 PM Fri 71 76 NE 10 3609 2136 96 Blue 11
2 PM Fri 73 78 E 6 4039 3063 1023 Blue 13
3 PM Fri 73 77 E 6 3824 2530 490 Blue 12
4 PM Fri 72 75 E 6 3099 2040 0 Blue 10
5 PM Fri 69 70 W 4 1799 2040 0 Blue 5
6 PM Fri 66 66 W 4 1346 2040 0 Blue 1
7 PM Fri 61 61 W 4 433 2040 0 Blue 0
8 PM Fri 57 57 NW 3 433 2040 0 Blue 0
9 PM Fri 56 56 NW 3 433 2040 0 Blue 0
10 PM Fri 55 55 NW 3 433 2040 0 Blue 0
11 PM Fri 55 55 W 3 433 2040 0 Blue 0
12 Midnight Sat 54 54 W 3 433 2040 0 Blue 0
1 AM Sat 54 54 W 3 433 2040 0 Blue 0
2 AM Sat 53 53 SW 3 433 2040 0 Blue 0
3 AM Sat 52 52 SW 3 433 2040 0 Blue 0
4 AM Sat 52 52 SW 3 433 2040 0 Blue 0
5 AM Sat 51 51 SW 4 433 2040 0 Blue 0
6 AM Sat 51 51 SW 4 433 2040 0 Blue 0
7 AM Sat 50 50 SW 4 433 2040 0 Blue 0
8 AM Sat 51 51 W 3 433 2040 0 Blue 0
9 AM Sat 55 56 W 3 433 2040 0 Blue 0
10 AM Sat 57 59 W 3 433 2040 0 Blue 0
11 AM Sat 60 64 N 7 893 2040 0 Blue 0
12 Noon Sat 62 67 N 7 1459 2040 0 Blue 2
1 PM Sat 64 69 N 7 1686 2040 0 Blue 4
2 PM Sat 65 70 SW 7 1799 2040 0 Blue 5
3 PM Sat 65 69 SW 7 1686 2040 0 Blue 4
4 PM Sat 64 67 SW 7 1459 2040 0 Blue 2
5 PM Sat 62 63 W 7 590 2040 0 Blue 0
6 PM Sat 60 60 W 7 433 2040 0 Blue 0
7 PM Sat 56 56 W 7 433 2040 0 Blue 0
8 PM Sat 53 53 W 7 433 2040 0 Blue 0
9 PM Sat 52 52 W 7 433 2040 0 Blue 0
10 PM Sat 51 51 W 7 433 2040 0 Blue 0
11 PM Sat 51 51 W 4 433 2040 0 Blue 0
12 Midnight Sun 51 51 W 4 433 2040 0 Blue 0
1 AM Sun 51 51 W 4 433 2040 0 Blue 0
2 AM Sun 50 50 W 4 433 2040 0 Blue 0
3 AM Sun 50 50 W 4 433 2040 0 Blue 0
4 AM Sun 49 49 W 4 433 2040 0 Blue 0
5 AM Sun 49 49 NW 5 433 2040 0 Blue 0
6 AM Sun 48 48 NW 5 433 2040 0 Blue 0
7 AM Sun 48 48 NW 5 433 2040 0 Blue 0
8 AM Sun 49 49 NW 5 433 2040 0 Blue 0
9 AM Sun 52 52 NW 5 433 2040 0 Blue 0
10 AM Sun 55 56 NW 5 433 2040 0 Blue 0
11 AM Sun 57 59 NW 5 433 2040 0 Blue 0
12 Noon Sun 60 62 NW 5 433 2040 0 Blue 0
1 PM Sun 61 64 NW 5 893 2040 0 Blue 0
2 PM Sun 62 65 NW 5 1193 2040 0 Blue 0
3 PM Sun 63 65 NW 5 1193 2040 0 Blue 0
4 PM Sun 62 63 NW 5 590 2040 0 Blue 0
5 PM Sun 60 61 NW 9 433 2040 0 Blue 0
6 PM Sun 58 58 NW 9 433 2040 0 Blue 0
7 PM Sun 54 54 NW 9 433 2040 0 Blue 0
8 PM Sun 52 52 NW 9 433 2040 0 Blue 0
9 PM Sun 51 51 NW 9 433 2040 0 Blue 0
10 PM Sun 50 50 NW 9 433 2040 0 Blue 0
11 PM Sun 50 50 NW 8 433 2040 0 Blue 0
12 Midnight Mon 50 50 NW 8 433 2040 0 Blue 0
1 AM Mon 49 49 NW 8 433 2040 0 Blue 0
2 AM Mon 49 49 NW 8 433 2040 0 Blue 0
3 AM Mon 49 49 NW 8 433 2040 0 Blue 0
4 AM Mon 48 48 NW 8 433 2040 0 Blue 0
5 AM Mon 48 48 NW 7 433 2040 0 Blue 0
6 AM Mon 47 47 NW 7 433 2040 0 Blue 0
7 AM Mon 47 47 NW 7 433 2040 0 Blue 0
8 AM Mon 48 48 NW 7 433 2040 0 Blue 0
9 AM Mon 52 52 NW 7 433 2040 0 Blue 0
10 AM Mon 55 56 NW 7 433 2040 0 Blue 0
11 AM Mon 58 60 N 10 433 2040 0 Blue 0
12 Noon Mon 60 63 N 10 590 2040 0 Blue 0
1 PM Mon 62 65 N 10 1193 2040 0 Blue 0
2 PM Mon 63 66 N 10 1346 2040 0 Blue 1
3 PM Mon 64 66 N 10 1346 2040 0 Blue 1
4 PM Mon 63 64 N 10 893 2040 0 Blue 0
5 PM Mon 61 62 NW 17 433 2040 0 Blue 0
6 PM Mon 58 58 NW 17 433 2040 0 Blue 0
7 PM Mon 54 54 NW 17 433 2040 0 Blue 0
8 PM Mon 52 52 NW 17 433 2040 0 Blue 0
9 PM Mon 51 51 NW 17 433 2040 0 Blue 0
10 PM Mon 50 50 NW 17 433 2040 0 Blue 0
11 PM Mon 50 50 N 14 433 2040 0 Blue 0
12 Midnight Tue 49 49 N 14 433 2040 0 Blue 0
1 AM Tue 49 49 N 14 433 2040 0 Blue 0
2 AM Tue 49 49 N 14 433 2040 0 Blue 0
3 AM Tue 48 48 N 14 433 2040 0 Blue 0
4 AM Tue 48 48 N 14 433 2040 0 Blue 0
5 AM Tue 47 47 N 16 433 2040 0 Blue 0
6 AM Tue 47 47 N 16 433 2040 0 Blue 0
7 AM Tue 47 47 N 16 433 2040 0 Blue 0
8 AM Tue 48 48 N 16 433 2040 0 Blue 0
9 AM Tue 52 52 N 16 433 2040 0 Blue 0
10 AM Tue 55 57 N 16 433 2040 0 Blue 0
11 AM Tue 58 61 N 16 433 2040 0 Blue 0
12 Noon Tue 61 65 N 16 1193 2040 0 Blue 0
1 PM Tue 63 67 N 16 1459 2040 0 Blue 2
2 PM Tue 64 68 N 16 1573 2040 0 Blue 3
3 PM Tue 64 67 N 16 1459 2040 0 Blue 2
4 PM Tue 63 65 N 16 1193 2040 0 Blue 0
5 PM Tue 61 62 NW 17 433 2040 0 Blue 0
6 PM Tue 58 58 NW 17 433 2040 0 Blue 0
7 PM Tue 55 55 NW 17 433 2040 0 Blue 0
8 PM Tue 52 52 NW 17 433 2040 0 Blue 0
9 PM Tue 51 51 NW 17 433 2040 0 Blue 0
10 PM Tue 50 50 NW 17 433 2040 0 Blue 0
11 PM Tue 50 50 N 14 433 2040 0 Blue 0
12 Midnight Wed 49 49 N 14 433 2040 0 Blue 0
1 AM Wed 49 49 N 14 433 2040 0 Blue 0
2 AM Wed 48 48 N 14 433 2040 0 Blue 0
3 AM Wed 48 48 N 14 433 2040 0 Blue 0
4 AM Wed 47 47 N 14 433 2040 0 Blue 0
5 AM Wed 47 47 N 9 433 2040 0 Blue 0
6 AM Wed 47 47 N 9 433 2040 0 Blue 0
7 AM Wed 46 46 N 9 433 2040 0 Blue 0
8 AM Wed 47 47 N 9 433 2040 0 Blue 0
9 AM Wed 51 51 N 9 433 2040 0 Blue 0
10 AM Wed 54 55 N 9 433 2040 0 Blue 0
11 AM Wed 56 58 NE 2 433 2040 0 Blue 0
12 Noon Wed 59 62 NE 2 433 2040 0 Blue 0
1 PM Wed 60 63 NE 2 590 2040 0 Blue 0
2 PM Wed 62 65 NE 2 1193 2040 0 Blue 0
3 PM Wed 62 65 NE 2 1193 2040 0 Blue 0
4 PM Wed 61 63 NE 2 590 2040 0 Blue 0
5 PM Wed 59 60 W 5 433 2040 0 Blue 0
6 PM Wed 57 57 W 5 433 2040 0 Blue 0
7 PM Wed 54 54 W 5 433 2040 0 Blue 0
8 PM Wed 52 52 W 5 433 2040 0 Blue 0
9 PM Wed 51 51 W 5 433 2040 0 Blue 0
10 PM Wed 50 50 W 5 433 2040 0 Blue 0
11 PM Wed 50 50 W 5 433 2040 0 Blue 0
12 Midnight Thu 50 50 W 5 433 2040 0 Blue 0
1 AM Thu 49 49 W 5 433 2040 0 Blue 0
2 AM Thu 49 49 W 5 433 2040 0 Blue 0
3 AM Thu 49 49 W 5 433 2040 0 Blue 0
4 AM Thu 48 48 W 5 433 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