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

Station:

KOAK

Date/Time:

26 APR 2018

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 Thu 55 55 SW 13 2592 3000 0 Blue 0
6 AM Thu 55 55 SW 13 2592 3000 0 Blue 0
7 AM Thu 55 55 SW 13 2592 3000 0 Blue 0
8 AM Thu 58 58 W 12 2592 3000 0 Blue 0
9 AM Thu 59 61 W 12 2850 3000 0 Blue 0
10 AM Thu 60 63 W 12 3030 3000 0 Blue 0
11 AM Thu 61 67 W 14 4262 3119 119 Blue 2
12 Noon Thu 62 69 W 14 4983 3813 813 Blue 4
1 PM Thu 63 71 W 14 5393 4664 1664 Blue 6
2 PM Thu 64 71 W 18 5393 4664 1664 Blue 6
3 PM Thu 64 70 W 18 5188 4242 1242 Blue 5
4 PM Thu 64 68 W 18 4689 3376 376 Blue 3
5 PM Thu 63 65 W 21 3385 3000 0 Blue 0
6 PM Thu 60 60 W 21 2760 3000 0 Blue 0
7 PM Thu 56 56 W 21 2592 3000 0 Blue 0
8 PM Thu 50 50 W 22 2592 3000 0 Blue 0
9 PM Thu 48 48 W 22 2592 3000 0 Blue 0
10 PM Thu 48 48 W 22 2592 3000 0 Blue 0
11 PM Thu 47 47 W 22 2592 3000 0 Blue 0
12 Midnight Fri 46 46 W 22 2592 3000 0 Blue 0
1 AM Fri 45 45 W 22 2592 3000 0 Blue 0
2 AM Fri 45 45 W 21 2592 3000 0 Blue 0
3 AM Fri 45 45 W 21 2592 3000 0 Blue 0
4 AM Fri 46 46 W 21 2592 3000 0 Blue 0
5 AM Fri 45 45 W 21 2592 3000 0 Blue 0
6 AM Fri 45 45 W 21 2592 3000 0 Blue 0
7 AM Fri 45 45 W 21 2592 3000 0 Blue 0
8 AM Fri 48 48 W 20 2592 3000 0 Blue 0
9 AM Fri 49 50 W 20 2592 3000 0 Blue 0
10 AM Fri 50 52 W 20 2592 3000 0 Blue 0
11 AM Fri 51 55 W 17 2592 3000 0 Blue 0
12 Noon Fri 52 57 W 17 2592 3000 0 Blue 0
1 PM Fri 53 59 W 17 2670 3000 0 Blue 0
2 PM Fri 54 59 W 18 2670 3000 0 Blue 0
3 PM Fri 54 58 W 18 2592 3000 0 Blue 0
4 PM Fri 55 58 W 18 2592 3000 0 Blue 0
5 PM Fri 54 56 W 22 2592 3000 0 Blue 0
6 PM Fri 52 52 W 22 2592 3000 0 Blue 0
7 PM Fri 50 50 W 22 2592 3000 0 Blue 0
8 PM Fri 46 46 W 22 2592 3000 0 Blue 0
9 PM Fri 44 44 W 22 2592 3000 0 Blue 0
10 PM Fri 44 44 W 22 2592 3000 0 Blue 0
11 PM Fri 44 44 W 21 2592 3000 0 Blue 0
12 Midnight Sat 44 44 W 21 2592 3000 0 Blue 0
1 AM Sat 43 43 W 21 2592 3000 0 Blue 0
2 AM Sat 43 43 W 21 2592 3000 0 Blue 0
3 AM Sat 43 43 W 21 2592 3000 0 Blue 0
4 AM Sat 43 43 W 21 2592 3000 0 Blue 0
5 AM Sat 42 42 W 16 2592 3000 0 Blue 0
6 AM Sat 42 42 W 16 2592 3000 0 Blue 0
7 AM Sat 43 43 W 16 2592 3000 0 Blue 0
8 AM Sat 46 46 W 16 2592 3000 0 Blue 0
9 AM Sat 47 48 W 16 2592 3000 0 Blue 0
10 AM Sat 48 50 W 16 2592 3000 0 Blue 0
11 AM Sat 50 54 W 13 2592 3000 0 Blue 0
12 Noon Sat 50 55 W 13 2592 3000 0 Blue 0
1 PM Sat 52 57 W 13 2592 3000 0 Blue 0
2 PM Sat 53 58 W 13 2592 3000 0 Blue 0
3 PM Sat 53 57 W 13 2592 3000 0 Blue 0
4 PM Sat 54 57 W 13 2592 3000 0 Blue 0
5 PM Sat 53 54 W 18 2592 3000 0 Blue 0
6 PM Sat 52 52 W 18 2592 3000 0 Blue 0
7 PM Sat 50 50 W 18 2592 3000 0 Blue 0
8 PM Sat 47 47 W 18 2592 3000 0 Blue 0
9 PM Sat 46 46 W 18 2592 3000 0 Blue 0
10 PM Sat 46 46 W 18 2592 3000 0 Blue 0
11 PM Sat 46 46 W 15 2592 3000 0 Blue 0
12 Midnight Sun 45 45 W 15 2592 3000 0 Blue 0
1 AM Sun 45 45 W 15 2592 3000 0 Blue 0
2 AM Sun 45 45 W 15 2592 3000 0 Blue 0
3 AM Sun 45 45 W 15 2592 3000 0 Blue 0
4 AM Sun 45 45 W 15 2592 3000 0 Blue 0
5 AM Sun 45 45 W 10 2592 3000 0 Blue 0
6 AM Sun 45 45 W 10 2592 3000 0 Blue 0
7 AM Sun 45 45 W 10 2592 3000 0 Blue 0
8 AM Sun 48 48 W 10 2592 3000 0 Blue 0
9 AM Sun 50 51 W 10 2592 3000 0 Blue 0
10 AM Sun 51 54 W 10 2592 3000 0 Blue 0
11 AM Sun 52 56 W 15 2592 3000 0 Blue 0
12 Noon Sun 53 58 W 15 2592 3000 0 Blue 0
1 PM Sun 54 59 W 15 2670 3000 0 Blue 0
2 PM Sun 55 60 W 15 2760 3000 0 Blue 0
3 PM Sun 55 59 W 15 2670 3000 0 Blue 0
4 PM Sun 56 59 W 15 2670 3000 0 Blue 0
5 PM Sun 56 58 W 17 2592 3000 0 Blue 0
6 PM Sun 54 54 W 17 2592 3000 0 Blue 0
7 PM Sun 52 52 W 17 2592 3000 0 Blue 0
8 PM Sun 49 49 W 17 2592 3000 0 Blue 0
9 PM Sun 48 48 W 17 2592 3000 0 Blue 0
10 PM Sun 48 48 W 17 2592 3000 0 Blue 0
11 PM Sun 47 47 W 12 2592 3000 0 Blue 0
12 Midnight Mon 47 47 W 12 2592 3000 0 Blue 0
1 AM Mon 47 47 W 12 2592 3000 0 Blue 0
2 AM Mon 47 47 W 12 2592 3000 0 Blue 0
3 AM Mon 47 47 W 12 2592 3000 0 Blue 0
4 AM Mon 47 47 W 12 2592 3000 0 Blue 0
5 AM Mon 46 46 N 5 2592 3000 0 Blue 0
6 AM Mon 46 46 N 5 2592 3000 0 Blue 0
7 AM Mon 47 47 N 5 2592 3000 0 Blue 0
8 AM Mon 50 50 N 5 2592 3000 0 Blue 0
9 AM Mon 52 53 N 5 2592 3000 0 Blue 0
10 AM Mon 53 56 N 5 2592 3000 0 Blue 0
11 AM Mon 54 58 NW 5 2592 3000 0 Blue 0
12 Noon Mon 55 60 NW 5 2760 3000 0 Blue 0
1 PM Mon 57 62 NW 5 2940 3000 0 Blue 0
2 PM Mon 58 63 NW 5 3030 3000 0 Blue 0
3 PM Mon 58 62 NW 5 2940 3000 0 Blue 0
4 PM Mon 59 62 NW 5 2940 3000 0 Blue 0
5 PM Mon 58 60 W 13 2760 3000 0 Blue 0
6 PM Mon 57 57 W 13 2592 3000 0 Blue 0
7 PM Mon 55 55 W 13 2592 3000 0 Blue 0
8 PM Mon 53 53 W 13 2592 3000 0 Blue 0
9 PM Mon 52 52 W 13 2592 3000 0 Blue 0
10 PM Mon 52 52 W 13 2592 3000 0 Blue 0
11 PM Mon 51 51 W 8 2592 3000 0 Blue 0
12 Midnight Tue 51 51 W 8 2592 3000 0 Blue 0
1 AM Tue 51 51 W 8 2592 3000 0 Blue 0
2 AM Tue 51 51 W 8 2592 3000 0 Blue 0
3 AM Tue 51 51 W 8 2592 3000 0 Blue 0
4 AM Tue 51 51 W 8 2592 3000 0 Blue 0
5 AM Tue 50 50 N 9 2592 3000 0 Blue 0
6 AM Tue 50 50 N 9 2592 3000 0 Blue 0
7 AM Tue 51 51 N 9 2592 3000 0 Blue 0
8 AM Tue 54 55 N 9 2592 3000 0 Blue 0
9 AM Tue 56 58 N 9 2592 3000 0 Blue 0
10 AM Tue 58 62 N 9 2940 3000 0 Blue 0
11 AM Tue 59 64 N 12 3120 3000 0 Blue 0
12 Noon Tue 60 66 N 12 3827 3029 29 Blue 1
1 PM Tue 62 69 N 12 4983 3813 813 Blue 4
2 PM Tue 63 69 N 12 4983 3813 813 Blue 4
3 PM Tue 63 68 N 12 4689 3376 376 Blue 3
4 PM Tue 64 68 N 12 4689 3376 376 Blue 3
5 PM Tue 64 66 W 21 3827 3029 29 Blue 1
6 PM Tue 62 62 W 21 2940 3000 0 Blue 0
7 PM Tue 60 60 W 21 2760 3000 0 Blue 0
8 PM Tue 57 57 W 21 2592 3000 0 Blue 0
9 PM Tue 56 56 W 21 2592 3000 0 Blue 0
10 PM Tue 56 56 W 21 2592 3000 0 Blue 0
11 PM Tue 56 56 NW 9 2592 3000 0 Blue 0
12 Midnight Wed 56 56 NW 9 2592 3000 0 Blue 0
1 AM Wed 55 55 NW 9 2592 3000 0 Blue 0
2 AM Wed 55 55 NW 9 2592 3000 0 Blue 0
3 AM Wed 55 55 NW 9 2592 3000 0 Blue 0
4 AM Wed 55 55 NW 9 2592 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