Detailed Predictions for: Mt Diablo
Launch Lat, Long, Altitude (f): 37.87787, -121.93, 3000
LZ Altitude (f): 1000
Sounding

Station:

KOAK

Date/Time:

21 SEP 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Tue 72 72 E 10 16 2645 3000 0 Blue 0
1 AM Tue 74 74 E 10 14 3859 3000 0 Blue 1
2 AM Tue 74 74 ESE 9 13 3859 3000 0 Blue 1
3 AM Tue 74 74 SE 6 11 3859 3000 0 Blue 1
4 AM Tue 73 73 SE 5 9 3783 3000 0 Blue 0
5 AM Tue 73 73 SSE 5 8 3783 3000 0 Blue 0
6 AM Tue 73 73 SSE 5 8 3783 3000 0 Blue 0
7 AM Tue 72 72 SE 5 8 2645 3000 0 Blue 0
8 AM Tue 73 73 SE 5 9 3783 3000 0 Blue 0
9 AM Tue 76 77 SE 8 11 4521 3856 856 Blue 4
10 AM Tue 79 81 SSE 8 11 4961 4625 1625 Blue 8
11 AM Tue 80 84 SSE 6 9 5310 4953 1953 Blue 11
12 Noon Tue 80 85 S 4 8 5866 5042 2042 Blue 12
1 PM Tue 82 88 S 4 6 7135 5815 2815 Blue 15
2 PM Tue 83 88 SW 3 4 7135 5815 2815 Blue 15
3 PM Tue 83 87 WSW 3 5 6930 5267 2267 Blue 14
4 PM Tue 83 86 WNW 6 11 6406 5103 2103 Blue 13
5 PM Tue 82 83 WNW 8 12 5107 4844 1844 Blue 10
6 PM Tue 81 81 W 5 9 4961 4625 1625 Blue 8
7 PM Tue 79 79 W 4 6 4741 4169 1169 Blue 6
8 PM Tue 76 76 WSW 4 6 4184 3780 780 Blue 3
9 PM Tue 76 76 SW 5 8 4184 3780 780 Blue 3
10 PM Tue 76 76 SW 4 8 4184 3780 780 Blue 3
11 PM Tue 77 77 SW 4 6 4521 3856 856 Blue 4
12 Midnight Wed 76 76 SSW 4 6 4184 3780 780 Blue 3
1 AM Wed 75 75 SSW 6 9 3935 3000 0 Blue 2
2 AM Wed 75 75 SSW 8 11 3935 3000 0 Blue 2
3 AM Wed 74 74 S 8 12 3859 3000 0 Blue 1
4 AM Wed 74 74 S 8 12 3859 3000 0 Blue 1
5 AM Wed 73 73 S 8 11 3783 3000 0 Blue 0
6 AM Wed 72 72 S 8 12 2645 3000 0 Blue 0
7 AM Wed 70 70 S 9 14 2621 3000 0 Blue 0
8 AM Wed 72 72 S 10 16 2645 3000 0 Blue 0
9 AM Wed 71 72 S 12 18 2645 3000 0 Blue 0
10 AM Wed 73 75 S 12 19 3935 3000 0 Blue 2
11 AM Wed 74 78 SSW 11 18 4631 3932 932 Blue 5
12 Noon Wed 73 78 SSW 11 18 4631 3932 932 Blue 5
1 PM Wed 73 78 SSW 11 18 4631 3932 932 Blue 5
2 PM Wed 74 79 SW 12 18 4741 4169 1169 Blue 6
3 PM Wed 74 78 SW 12 18 4631 3932 932 Blue 5
4 PM Wed 73 76 SW 12 18 4184 3780 780 Blue 3
5 PM Wed 73 74 WSW 12 19 3859 3000 0 Blue 1
6 PM Wed 72 72 WSW 12 19 2645 3000 0 Blue 0
7 PM Wed 72 72 WSW 12 19 2645 3000 0 Blue 0
8 PM Wed 71 71 WSW 9 13 2621 3000 0 Blue 0
9 PM Wed 71 71 WSW 9 13 2621 3000 0 Blue 0
10 PM Wed 70 70 WSW 9 13 2621 3000 0 Blue 0
11 PM Wed 70 70 W 5 8 2621 3000 0 Blue 0
12 Midnight Thu 70 70 W 5 8 2621 3000 0 Blue 0
1 AM Thu 70 70 W 5 8 2621 3000 0 Blue 0
2 AM Thu 70 70 N 4 8 2621 3000 0 Blue 0
3 AM Thu 70 70 N 4 8 2621 3000 0 Blue 0
4 AM Thu 70 70 N 4 8 2621 3000 0 Blue 0
5 AM Thu 70 70 NE 9 13 2621 3000 0 Blue 0
6 AM Thu 70 70 NE 9 13 2621 3000 0 Blue 0
7 AM Thu 70 70 NE 9 13 2621 3000 0 Blue 0
8 AM Thu 71 71 NNE 11 16 2621 3000 0 Blue 0
9 AM Thu 72 73 NNE 11 16 3783 3000 0 Blue 0
10 AM Thu 74 76 NNE 11 16 4184 3780 780 Blue 3
11 AM Thu 76 79 N 6 10 4741 4169 1169 Blue 6
12 Noon Thu 77 82 N 6 10 5046 4734 1734 Blue 9
1 PM Thu 79 84 N 6 10 5310 4953 1953 Blue 11
2 PM Thu 80 84 NNW 6 10 5310 4953 1953 Blue 11
3 PM Thu 81 85 NNW 6 10 5866 5042 2042 Blue 12
4 PM Thu 81 83 NNW 6 10 5107 4844 1844 Blue 10
5 PM Thu 82 83 N 6 10 5107 4844 1844 Blue 10
6 PM Thu 81 81 N 6 10 4961 4625 1625 Blue 8
7 PM Thu 80 80 N 6 10 4851 4515 1515 Blue 7
8 PM Thu 78 78 NNE 6 9 4631 3932 932 Blue 5
9 PM Thu 77 77 NNE 6 9 4521 3856 856 Blue 4
10 PM Thu 77 77 NNE 6 9 4521 3856 856 Blue 4
11 PM Thu 76 76 NNE 5 9 4184 3780 780 Blue 3
12 Midnight Fri 76 76 NNE 5 9 4184 3780 780 Blue 3
1 AM Fri 76 76 NNE 5 9 4184 3780 780 Blue 3
2 AM Fri 75 75 NW 2 2 3935 3000 0 Blue 2
3 AM Fri 74 74 NW 2 2 3859 3000 0 Blue 1
4 AM Fri 73 73 NW 2 2 3783 3000 0 Blue 0
5 AM Fri 72 72 SW 3 5 2645 3000 0 Blue 0
6 AM Fri 72 72 SW 3 5 2645 3000 0 Blue 0
7 AM Fri 73 73 SW 3 5 3783 3000 0 Blue 0
8 AM Fri 74 74 WSW 5 8 3859 3000 0 Blue 1
9 AM Fri 75 76 WSW 5 8 4184 3780 780 Blue 3
10 AM Fri 76 78 WSW 5 8 4631 3932 932 Blue 5
11 AM Fri 77 81 WNW 4 6 4961 4625 1625 Blue 8
12 Noon Fri 78 83 WNW 4 6 5107 4844 1844 Blue 10
1 PM Fri 79 85 WNW 4 6 5866 5042 2042 Blue 12
2 PM Fri 79 84 W 8 11 5310 4953 1953 Blue 11
3 PM Fri 79 83 W 8 11 5107 4844 1844 Blue 10
4 PM Fri 79 82 W 8 11 5046 4734 1734 Blue 9
5 PM Fri 78 79 W 9 14 4741 4169 1169 Blue 6
6 PM Fri 78 78 W 9 14 4631 3932 932 Blue 5
7 PM Fri 77 77 W 9 14 4521 3856 856 Blue 4
8 PM Fri 76 76 WSW 6 10 4184 3780 780 Blue 3
9 PM Fri 74 74 WSW 6 10 3859 3000 0 Blue 1
10 PM Fri 74 74 WSW 6 10 3859 3000 0 Blue 1
11 PM Fri 73 73 WSW 9 14 3783 3000 0 Blue 0
12 Midnight Sat 73 73 WSW 9 14 3783 3000 0 Blue 0
1 AM Sat 73 73 WSW 9 14 3783 3000 0 Blue 0
2 AM Sat 73 73 WSW 8 12 3783 3000 0 Blue 0
3 AM Sat 72 72 WSW 8 12 2645 3000 0 Blue 0
4 AM Sat 72 72 WSW 8 12 2645 3000 0 Blue 0
5 AM Sat 71 71 WSW 8 12 2621 3000 0 Blue 0
6 AM Sat 71 71 WSW 8 12 2621 3000 0 Blue 0
7 AM Sat 70 70 WSW 8 12 2621 3000 0 Blue 0
8 AM Sat 70 70 WSW 8 12 2621 3000 0 Blue 0
9 AM Sat 71 72 WSW 8 12 2645 3000 0 Blue 0
10 AM Sat 71 73 WSW 8 12 3783 3000 0 Blue 0
11 AM Sat 72 76 WSW 8 11 4184 3780 780 Blue 3
12 Noon Sat 72 77 WSW 8 11 4521 3856 856 Blue 4
1 PM Sat 73 78 WSW 8 11 4631 3932 932 Blue 5
2 PM Sat 74 79 W 12 18 4741 4169 1169 Blue 6
3 PM Sat 73 77 W 12 18 4521 3856 856 Blue 4
4 PM Sat 73 76 W 12 18 4184 3780 780 Blue 3
5 PM Sat 72 73 WSW 13 20 3783 3000 0 Blue 0
6 PM Sat 70 70 WSW 13 20 2621 3000 0 Blue 0
7 PM Sat 69 69 WSW 13 20 2621 3000 0 Blue 0
8 PM Sat 68 68 WSW 10 16 2621 3000 0 Blue 0
9 PM Sat 68 68 WSW 10 16 2621 3000 0 Blue 0
10 PM Sat 69 69 WSW 10 16 2621 3000 0 Blue 0
11 PM Sat 70 70 WSW 10 16 2621 3000 0 Blue 0
12 Midnight Sun 70 70 WSW 10 16 2621 3000 0 Blue 0
1 AM Sun 70 70 WSW 10 16 2621 3000 0 Blue 0
2 AM Sun 70 70 WSW 10 16 2621 3000 0 Blue 0
3 AM Sun 70 70 WSW 10 16 2621 3000 0 Blue 0
4 AM Sun 70 70 WSW 10 16 2621 3000 0 Blue 0
5 AM Sun 69 69 WSW 10 16 2621 3000 0 Blue 0
6 AM Sun 68 68 WSW 10 16 2621 3000 0 Blue 0
7 AM Sun 67 67 WSW 10 16 2621 3000 0 Blue 0
8 AM Sun 67 67 WSW 9 14 2621 3000 0 Blue 0
9 AM Sun 67 68 WSW 9 14 2621 3000 0 Blue 0
10 AM Sun 68 70 WSW 9 14 2621 3000 0 Blue 0
11 AM Sun 68 71 WSW 8 12 2621 3000 0 Blue 0
12 Noon Sun 68 72 WSW 8 12 2645 3000 0 Blue 0
1 PM Sun 69 74 WSW 8 12 3859 3000 0 Blue 1
2 PM Sun 69 74 WSW 12 18 3859 3000 0 Blue 1
3 PM Sun 69 73 WSW 12 18 3783 3000 0 Blue 0
4 PM Sun 68 70 WSW 12 18 2621 3000 0 Blue 0
5 PM Sun 68 69 WSW 12 19 2621 3000 0 Blue 0
6 PM Sun 67 67 WSW 12 19 2621 3000 0 Blue 0
7 PM Sun 66 66 WSW 12 19 2621 3000 0 Blue 0
8 PM Sun 66 66 WSW 10 16 2621 3000 0 Blue 0
9 PM Sun 66 66 WSW 10 16 2621 3000 0 Blue 0
10 PM Sun 67 67 WSW 10 16 2621 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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]