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

Station:

KOAK

Date/Time:

17 NOV 2017

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 Fri 49 49 NW 14 663 2040 0 Blue 0
5 AM Fri 49 49 NW 14 663 2040 0 Blue 0
6 AM Fri 49 49 NW 14 663 2040 0 Blue 0
7 AM Fri 48 48 N 15 663 2040 0 Blue 0
8 AM Fri 49 49 N 15 663 2040 0 Blue 0
9 AM Fri 51 51 N 15 2373 2040 0 White 0
10 AM Fri 52 53 N 12 2813 2040 0 White 2
11 AM Fri 54 56 N 12 3459 3362 1322 White 5
12 Noon Fri 55 57 N 12 3673 3606 1566 White 6
1 PM Fri 56 58 NE 12 3888 3871 1831 White 7
2 PM Fri 56 57 NE 12 3673 3606 1566 White 6
3 PM Fri 55 55 NE 12 3244 3121 1081 White 4
4 PM Fri 54 54 N 15 3028 2879 839 White 3
5 PM Fri 51 51 N 15 2373 2040 0 White 0
6 PM Fri 49 49 N 15 663 2040 0 Blue 0
7 PM Fri 49 49 NE 17 663 2040 0 Blue 0
8 PM Fri 48 48 NE 17 663 2040 0 Blue 0
9 PM Fri 48 48 NE 17 663 2040 0 Blue 0
10 PM Fri 48 48 NE 15 663 2040 0 Blue 0
11 PM Fri 47 47 NE 15 663 2040 0 Blue 0
12 Midnight Sat 47 47 NE 15 663 2040 0 Blue 0
1 AM Sat 47 47 N 12 663 2040 0 Blue 0
2 AM Sat 47 47 N 12 663 2040 0 Blue 0
3 AM Sat 46 46 N 12 663 2040 0 Blue 0
4 AM Sat 46 46 N 6 663 2040 0 Blue 0
5 AM Sat 45 45 N 6 663 2040 0 Blue 0
6 AM Sat 45 45 N 6 663 2040 0 Blue 0
7 AM Sat 44 44 N 6 663 2040 0 Blue 0
8 AM Sat 46 46 N 6 663 2040 0 Blue 0
9 AM Sat 49 49 N 6 663 2040 0 Blue 0
10 AM Sat 51 52 SW 2 2595 2040 0 White 1
11 AM Sat 53 55 SW 2 3244 3121 1081 White 4
12 Noon Sat 55 57 SW 2 3673 3606 1566 White 6
1 PM Sat 56 58 W 6 3888 3871 1831 White 7
2 PM Sat 56 57 W 6 3673 3606 1566 White 6
3 PM Sat 56 56 W 6 3459 3362 1322 White 5
4 PM Sat 54 54 N 7 3028 2879 839 White 3
5 PM Sat 51 51 N 7 2373 2040 0 White 0
6 PM Sat 49 49 N 7 663 2040 0 Blue 0
7 PM Sat 49 49 N 7 663 2040 0 Blue 0
8 PM Sat 48 48 N 7 663 2040 0 Blue 0
9 PM Sat 48 48 N 7 663 2040 0 Blue 0
10 PM Sat 48 48 NW 5 663 2040 0 Blue 0
11 PM Sat 47 47 NW 5 663 2040 0 Blue 0
12 Midnight Sun 47 47 NW 5 663 2040 0 Blue 0
1 AM Sun 47 47 NW 5 663 2040 0 Blue 0
2 AM Sun 47 47 NW 5 663 2040 0 Blue 0
3 AM Sun 46 46 NW 5 663 2040 0 Blue 0
4 AM Sun 46 46 NW 6 663 2040 0 Blue 0
5 AM Sun 45 45 NW 6 663 2040 0 Blue 0
6 AM Sun 44 44 NW 6 663 2040 0 Blue 0
7 AM Sun 44 44 NW 6 663 2040 0 Blue 0
8 AM Sun 45 45 NW 6 663 2040 0 Blue 0
9 AM Sun 48 48 NW 6 663 2040 0 Blue 0
10 AM Sun 50 51 W 12 2373 2040 0 White 0
11 AM Sun 52 53 W 12 2813 2040 0 White 2
12 Noon Sun 54 55 W 12 3244 3121 1081 White 4
1 PM Sun 55 56 W 12 3459 3362 1322 White 5
2 PM Sun 55 56 W 12 3459 3362 1322 White 5
3 PM Sun 55 55 W 12 3244 3121 1081 White 4
4 PM Sun 54 54 W 12 3028 2879 839 White 3
5 PM Sun 53 53 W 12 2813 2040 0 White 2
6 PM Sun 52 52 W 12 2595 2040 0 White 1
7 PM Sun 52 52 W 12 2595 2040 0 White 1
8 PM Sun 52 52 W 12 2595 2040 0 White 1
9 PM Sun 52 52 W 12 2595 2040 0 White 1
10 PM Sun 52 52 E 3 2595 2040 0 White 1
11 PM Sun 52 52 E 3 2595 2040 0 White 1
12 Midnight Mon 52 52 E 3 2595 2040 0 White 1
1 AM Mon 52 52 E 3 2595 2040 0 White 1
2 AM Mon 52 52 E 3 2595 2040 0 White 1
3 AM Mon 52 52 E 3 2595 2040 0 White 1
4 AM Mon 51 51 E 6 2373 2040 0 White 0
5 AM Mon 51 51 E 6 2373 2040 0 White 0
6 AM Mon 51 51 E 6 2373 2040 0 White 0
7 AM Mon 51 51 E 6 2373 2040 0 White 0
8 AM Mon 52 52 E 6 2595 2040 0 White 1
9 AM Mon 54 54 E 6 3028 2879 839 White 3
10 AM Mon 55 55 S 18 3244 3121 1081 White 4
11 AM Mon 56 56 S 18 3459 3362 1322 White 5
12 Noon Mon 58 58 S 18 3888 3871 1831 White 7
1 PM Mon 59 59 S 18 4102 4102 2062 White 8
2 PM Mon 59 59 S 18 4102 4102 2062 White 8
3 PM Mon 58 58 S 18 3888 3871 1831 White 7
4 PM Mon 58 58 S 9 3888 3871 1831 White 7
5 PM Mon 57 57 S 9 3673 3606 1566 White 6
6 PM Mon 56 56 S 9 3459 3362 1322 White 5
7 PM Mon 56 56 S 9 3459 3362 1322 White 5
8 PM Mon 56 56 S 9 3459 3362 1322 White 5
9 PM Mon 56 56 S 9 3459 3362 1322 White 5
10 PM Mon 56 56 S 9 3459 3362 1322 White 5
11 PM Mon 56 56 S 9 3459 3362 1322 White 5
12 Midnight Tue 55 55 S 9 3244 3121 1081 White 4
1 AM Tue 56 56 S 9 3459 3362 1322 White 5
2 AM Tue 56 56 S 9 3459 3362 1322 White 5
3 AM Tue 55 55 S 9 3244 3121 1081 White 4
4 AM Tue 55 55 S 7 3244 3121 1081 White 4
5 AM Tue 55 55 S 7 3244 3121 1081 White 4
6 AM Tue 55 55 S 7 3244 3121 1081 White 4
7 AM Tue 54 54 S 7 3028 2879 839 White 3
8 AM Tue 56 56 S 7 3459 3362 1322 White 5
9 AM Tue 57 57 S 7 3673 3606 1566 White 6
10 AM Tue 59 59 SE 9 4102 4102 2062 White 8
11 AM Tue 60 60 SE 9 4315 4315 2275 White 9
12 Noon Tue 62 62 SE 9 4750 4750 2710 White 11
1 PM Tue 63 63 SE 9 4963 4963 2923 White 12
2 PM Tue 63 63 SE 9 4963 4963 2923 White 12
3 PM Tue 62 62 SE 9 4750 4750 2710 White 11
4 PM Tue 62 62 SE 12 4750 4750 2710 White 11
5 PM Tue 61 61 SE 12 4528 4528 2488 White 10
6 PM Tue 61 61 SE 12 4528 4528 2488 White 10
7 PM Tue 61 61 SE 12 4528 4528 2488 White 10
8 PM Tue 60 60 SE 12 4315 4315 2275 White 9
9 PM Tue 60 60 SE 12 4315 4315 2275 White 9
10 PM Tue 60 60 S 15 4315 4315 2275 White 9
11 PM Tue 60 60 S 15 4315 4315 2275 White 9
12 Midnight Wed 60 60 S 15 4315 4315 2275 White 9
1 AM Wed 60 60 S 15 4315 4315 2275 White 9
2 AM Wed 60 60 S 15 4315 4315 2275 White 9
3 AM Wed 60 60 S 15 4315 4315 2275 White 9
4 AM Wed 60 60 SE 14 4315 4315 2275 White 9
5 AM Wed 60 60 SE 14 4315 4315 2275 White 9
6 AM Wed 60 60 SE 14 4315 4315 2275 White 9
7 AM Wed 59 59 SE 14 4102 4102 2062 White 8
8 AM Wed 60 60 SE 14 4315 4315 2275 White 9
9 AM Wed 61 61 SE 14 4528 4528 2488 White 10
10 AM Wed 62 62 S 14 4750 4750 2710 White 11
11 AM Wed 62 63 S 14 4963 4963 2923 White 12
12 Noon Wed 63 64 S 14 5173 5173 3133 White 13
1 PM Wed 64 65 S 14 5384 5384 3344 White 14
2 PM Wed 64 64 S 14 5173 5173 3133 White 13
3 PM Wed 63 63 S 14 4963 4963 2923 White 12
4 PM Wed 62 62 S 8 4750 4750 2710 White 11
5 PM Wed 61 61 S 8 4528 4528 2488 White 10
6 PM Wed 60 60 S 8 4315 4315 2275 White 9
7 PM Wed 60 60 S 8 4315 4315 2275 White 9
8 PM Wed 60 60 S 8 4315 4315 2275 White 9
9 PM Wed 60 60 S 8 4315 4315 2275 White 9
10 PM Wed 60 60 S 3 4315 4315 2275 White 9
11 PM Wed 59 59 S 3 4102 4102 2062 White 8
12 Midnight Thu 59 59 S 3 4102 4102 2062 White 8
1 AM Thu 59 59 S 3 4102 4102 2062 White 8
2 AM Thu 59 59 S 3 4102 4102 2062 White 8
3 AM Thu 59 59 S 3 4102 4102 2062 White 8

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