Detailed Predictions for: Mt Diablo
Launch Altitude (f): 3000
LZ Altitude (f): 1000
Sounding

Station:

KOAK

Date/Time:

25 AUG 2019

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)
5 AM Sun 69 69 S 5 2789 3000 0 Blue 0
6 AM Sun 69 69 S 5 2789 3000 0 Blue 0
7 AM Sun 67 67 S 5 2789 3000 0 Blue 0
8 AM Sun 70 70 S 9 2789 3000 0 Blue 0
9 AM Sun 73 74 S 9 2789 3000 0 Blue 0
10 AM Sun 75 78 S 9 3156 3000 0 Blue 0
11 AM Sun 75 80 SW 10 3976 3000 0 Blue 2
12 Noon Sun 77 84 SW 10 5678 4251 1251 Blue 6
1 PM Sun 79 86 SW 10 6582 5177 2177 Blue 8
2 PM Sun 80 87 SW 14 6890 5637 2637 Blue 9
3 PM Sun 81 87 SW 14 6890 5637 2637 Blue 9
4 PM Sun 80 84 SW 14 5678 4251 1251 Blue 6
5 PM Sun 79 81 W 16 4264 3151 151 Blue 3
6 PM Sun 77 78 W 16 3156 3000 0 Blue 0
7 PM Sun 76 76 W 16 2789 3000 0 Blue 0
8 PM Sun 74 74 W 13 2789 3000 0 Blue 0
9 PM Sun 74 74 W 13 2789 3000 0 Blue 0
10 PM Sun 72 72 W 13 2789 3000 0 Blue 0
11 PM Sun 72 72 W 9 2789 3000 0 Blue 0
12 Midnight Mon 71 71 W 9 2789 3000 0 Blue 0
1 AM Mon 70 70 W 9 2789 3000 0 Blue 0
2 AM Mon 69 69 W 9 2789 3000 0 Blue 0
3 AM Mon 68 68 W 9 2789 3000 0 Blue 0
4 AM Mon 68 68 W 9 2789 3000 0 Blue 0
5 AM Mon 67 67 NW 7 2789 3000 0 Blue 0
6 AM Mon 68 68 NW 7 2789 3000 0 Blue 0
7 AM Mon 68 68 NW 7 2789 3000 0 Blue 0
8 AM Mon 70 70 NW 6 2789 3000 0 Blue 0
9 AM Mon 73 74 NW 6 2789 3000 0 Blue 0
10 AM Mon 75 78 NW 6 3156 3000 0 Blue 0
11 AM Mon 77 81 W 6 4264 3151 151 Blue 3
12 Noon Mon 79 84 W 6 5678 4251 1251 Blue 6
1 PM Mon 81 87 W 6 6890 5637 2637 Blue 9
2 PM Mon 82 89 W 10 7339 6530 3530 Blue 11
3 PM Mon 83 89 W 10 7339 6530 3530 Blue 11
4 PM Mon 83 87 W 10 6890 5637 2637 Blue 9
5 PM Mon 82 84 W 14 5678 4251 1251 Blue 6
6 PM Mon 79 79 W 14 3686 3000 0 Blue 1
7 PM Mon 76 76 W 14 2789 3000 0 Blue 0
8 PM Mon 74 74 W 13 2789 3000 0 Blue 0
9 PM Mon 72 72 W 13 2789 3000 0 Blue 0
10 PM Mon 71 71 W 13 2789 3000 0 Blue 0
11 PM Mon 71 71 W 12 2789 3000 0 Blue 0
12 Midnight Tue 71 71 W 12 2789 3000 0 Blue 0
1 AM Tue 70 70 W 12 2789 3000 0 Blue 0
2 AM Tue 70 70 W 8 2789 3000 0 Blue 0
3 AM Tue 69 69 W 8 2789 3000 0 Blue 0
4 AM Tue 68 68 W 8 2789 3000 0 Blue 0
5 AM Tue 68 68 W 6 2789 3000 0 Blue 0
6 AM Tue 68 68 W 6 2789 3000 0 Blue 0
7 AM Tue 69 69 W 6 2789 3000 0 Blue 0
8 AM Tue 70 70 W 5 2789 3000 0 Blue 0
9 AM Tue 72 73 W 5 2789 3000 0 Blue 0
10 AM Tue 74 77 W 5 2912 3000 0 Blue 0
11 AM Tue 77 82 W 6 4485 3678 678 Blue 4
12 Noon Tue 79 86 W 6 6582 5177 2177 Blue 8
1 PM Tue 81 88 W 6 7155 6088 3088 Blue 10
2 PM Tue 82 88 W 12 7155 6088 3088 Blue 10
3 PM Tue 82 87 W 12 6890 5637 2637 Blue 9
4 PM Tue 81 85 W 12 6134 4442 1442 Blue 7
5 PM Tue 80 82 W 14 4485 3678 678 Blue 4
6 PM Tue 77 77 W 14 2912 3000 0 Blue 0
7 PM Tue 74 74 W 14 2789 3000 0 Blue 0
8 PM Tue 72 72 W 15 2789 3000 0 Blue 0
9 PM Tue 71 71 W 15 2789 3000 0 Blue 0
10 PM Tue 70 70 W 15 2789 3000 0 Blue 0
11 PM Tue 70 70 W 15 2789 3000 0 Blue 0
12 Midnight Wed 70 70 W 15 2789 3000 0 Blue 0
1 AM Wed 70 70 W 15 2789 3000 0 Blue 0
2 AM Wed 70 70 W 14 2789 3000 0 Blue 0
3 AM Wed 70 70 W 14 2789 3000 0 Blue 0
4 AM Wed 69 69 W 14 2789 3000 0 Blue 0
5 AM Wed 69 69 W 13 2789 3000 0 Blue 0
6 AM Wed 69 69 W 13 2789 3000 0 Blue 0
7 AM Wed 70 70 W 13 2789 3000 0 Blue 0
8 AM Wed 70 70 SW 13 2789 3000 0 Blue 0
9 AM Wed 71 73 SW 13 2789 3000 0 Blue 0
10 AM Wed 72 75 SW 13 2789 3000 0 Blue 0
11 AM Wed 74 79 W 17 3686 3000 0 Blue 1
12 Noon Wed 76 82 W 17 4485 3678 678 Blue 4
1 PM Wed 77 84 W 17 5678 4251 1251 Blue 6
2 PM Wed 78 85 W 20 6134 4442 1442 Blue 7
3 PM Wed 78 84 W 20 5678 4251 1251 Blue 6
4 PM Wed 77 81 W 20 4264 3151 151 Blue 3
5 PM Wed 75 77 W 18 2912 3000 0 Blue 0
6 PM Wed 73 74 W 18 2789 3000 0 Blue 0
7 PM Wed 70 70 W 18 2789 3000 0 Blue 0
8 PM Wed 68 68 SW 15 2789 3000 0 Blue 0
9 PM Wed 68 68 SW 15 2789 3000 0 Blue 0
10 PM Wed 68 68 SW 15 2789 3000 0 Blue 0
11 PM Wed 69 69 SW 14 2789 3000 0 Blue 0
12 Midnight Thu 70 70 SW 14 2789 3000 0 Blue 0
1 AM Thu 71 71 SW 14 2789 3000 0 Blue 0
2 AM Thu 71 71 SW 13 2789 3000 0 Blue 0
3 AM Thu 71 71 SW 13 2789 3000 0 Blue 0
4 AM Thu 70 70 SW 13 2789 3000 0 Blue 0
5 AM Thu 70 70 SW 13 2789 3000 0 Blue 0
6 AM Thu 70 70 SW 13 2789 3000 0 Blue 0
7 AM Thu 69 69 SW 13 2789 3000 0 Blue 0
8 AM Thu 69 69 SW 15 2789 3000 0 Blue 0
9 AM Thu 70 72 SW 15 2789 3000 0 Blue 0
10 AM Thu 70 73 SW 15 2789 3000 0 Blue 0
11 AM Thu 71 76 W 18 2789 3000 0 Blue 0
12 Noon Thu 73 80 W 18 3976 3000 0 Blue 2
1 PM Thu 75 82 W 18 4485 3678 678 Blue 4
2 PM Thu 76 83 W 20 5212 3965 965 Blue 5
3 PM Thu 76 82 W 20 4485 3678 678 Blue 4
4 PM Thu 75 79 W 20 3686 3000 0 Blue 1
5 PM Thu 73 75 W 17 2789 3000 0 Blue 0
6 PM Thu 71 72 W 17 2789 3000 0 Blue 0
7 PM Thu 69 69 W 17 2789 3000 0 Blue 0
8 PM Thu 68 68 W 14 2789 3000 0 Blue 0
9 PM Thu 68 68 W 14 2789 3000 0 Blue 0
10 PM Thu 68 68 W 14 2789 3000 0 Blue 0
11 PM Thu 68 68 SW 14 2789 3000 0 Blue 0
12 Midnight Fri 69 69 SW 14 2789 3000 0 Blue 0
1 AM Fri 69 69 SW 14 2789 3000 0 Blue 0
2 AM Fri 69 69 SW 14 2789 3000 0 Blue 0
3 AM Fri 69 69 SW 14 2789 3000 0 Blue 0
4 AM Fri 68 68 SW 14 2789 3000 0 Blue 0
5 AM Fri 67 67 SW 13 2789 3000 0 Blue 0
6 AM Fri 67 67 SW 13 2789 3000 0 Blue 0
7 AM Fri 67 67 SW 13 2789 3000 0 Blue 0
8 AM Fri 67 67 SW 13 2789 3000 0 Blue 0
9 AM Fri 67 69 SW 13 2789 3000 0 Blue 0
10 AM Fri 68 71 SW 13 2789 3000 0 Blue 0
11 AM Fri 69 74 W 17 2789 3000 0 Blue 0
12 Noon Fri 71 78 W 17 3156 3000 0 Blue 0
1 PM Fri 74 81 W 17 4264 3151 151 Blue 3
2 PM Fri 76 83 W 18 5212 3965 965 Blue 5
3 PM Fri 76 82 W 18 4485 3678 678 Blue 4
4 PM Fri 76 80 W 18 3976 3000 0 Blue 2
5 PM Fri 74 76 W 17 2789 3000 0 Blue 0
6 PM Fri 72 73 W 17 2789 3000 0 Blue 0
7 PM Fri 70 70 W 17 2789 3000 0 Blue 0
8 PM Fri 68 68 W 14 2789 3000 0 Blue 0
9 PM Fri 68 68 W 14 2789 3000 0 Blue 0
10 PM Fri 67 67 W 14 2789 3000 0 Blue 0
11 PM Fri 68 68 SW 14 2789 3000 0 Blue 0
12 Midnight Sat 68 68 SW 14 2789 3000 0 Blue 0
1 AM Sat 67 67 SW 14 2789 3000 0 Blue 0
2 AM Sat 67 67 SW 13 2789 3000 0 Blue 0
3 AM Sat 66 66 SW 13 2789 3000 0 Blue 0
4 AM Sat 66 66 SW 13 2789 3000 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