Detailed Predictions for: Dumps
Launch Altitude (f): 200
LZ Altitude (f): 0
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 58 38 W 2 0 200 0 Blue 0
6 AM Sun 59 39 W 2 0 200 0 Blue 0
7 AM Sun 58 38 W 2 0 200 0 Blue 0
8 AM Sun 58 38 W 5 0 200 0 Blue 0
9 AM Sun 57 37 W 5 0 200 0 Blue 0
10 AM Sun 58 39 W 5 0 200 0 Blue 0
11 AM Sun 59 41 W 7 0 200 0 Blue 0
12 Noon Sun 60 43 W 7 0 200 0 Blue 0
1 PM Sun 60 44 W 7 0 200 0 Blue 0
2 PM Sun 62 47 SW 8 0 200 0 Blue 0
3 PM Sun 61 45 SW 8 0 200 0 Blue 0
4 PM Sun 62 45 SW 8 0 200 0 Blue 0
5 PM Sun 62 44 SW 9 0 200 0 Blue 0
6 PM Sun 64 44 SW 9 0 200 0 Blue 0
7 PM Sun 62 42 SW 9 0 200 0 Blue 0
8 PM Sun 62 42 SW 9 0 200 0 Blue 0
9 PM Sun 60 40 SW 9 0 200 0 Blue 0
10 PM Sun 60 40 SW 9 0 200 0 Blue 0
11 PM Sun 59 39 SW 7 0 200 0 Blue 0
12 Midnight Mon 59 39 SW 7 0 200 0 Blue 0
1 AM Mon 59 39 SW 7 0 200 0 Blue 0
2 AM Mon 58 38 SW 7 0 200 0 Blue 0
3 AM Mon 58 38 SW 7 0 200 0 Blue 0
4 AM Mon 57 37 SW 7 0 200 0 Blue 0
5 AM Mon 57 37 SW 6 0 200 0 Blue 0
6 AM Mon 57 37 SW 6 0 200 0 Blue 0
7 AM Mon 56 36 SW 6 0 200 0 Blue 0
8 AM Mon 56 36 SW 6 0 200 0 Blue 0
9 AM Mon 56 36 SW 6 0 200 0 Blue 0
10 AM Mon 58 39 SW 6 0 200 0 Blue 0
11 AM Mon 58 41 SW 7 0 200 0 Blue 0
12 Noon Mon 59 42 SW 7 0 200 0 Blue 0
1 PM Mon 61 45 SW 7 0 200 0 Blue 0
2 PM Mon 63 47 SW 8 0 200 0 Blue 0
3 PM Mon 63 47 SW 8 0 200 0 Blue 0
4 PM Mon 63 46 SW 8 0 200 0 Blue 0
5 PM Mon 63 44 SW 9 0 200 0 Blue 0
6 PM Mon 63 43 SW 9 0 200 0 Blue 0
7 PM Mon 63 43 SW 9 0 200 0 Blue 0
8 PM Mon 64 44 SW 8 0 200 0 Blue 0
9 PM Mon 63 43 SW 8 0 200 0 Blue 0
10 PM Mon 63 43 SW 8 0 200 0 Blue 0
11 PM Mon 62 42 SW 7 0 200 0 Blue 0
12 Midnight Tue 61 41 SW 7 0 200 0 Blue 0
1 AM Tue 60 40 SW 7 0 200 0 Blue 0
2 AM Tue 59 39 SW 6 0 200 0 Blue 0
3 AM Tue 58 38 SW 6 0 200 0 Blue 0
4 AM Tue 58 38 SW 6 0 200 0 Blue 0
5 AM Tue 57 37 SW 5 0 200 0 Blue 0
6 AM Tue 57 37 SW 5 0 200 0 Blue 0
7 AM Tue 57 37 SW 5 0 200 0 Blue 0
8 AM Tue 57 37 SW 6 0 200 0 Blue 0
9 AM Tue 58 39 SW 6 0 200 0 Blue 0
10 AM Tue 58 40 SW 6 0 200 0 Blue 0
11 AM Tue 59 43 SW 7 0 200 0 Blue 0
12 Noon Tue 60 45 SW 7 0 200 0 Blue 0
1 PM Tue 62 47 SW 7 0 200 0 Blue 0
2 PM Tue 63 46 SW 8 0 200 0 Blue 0
3 PM Tue 64 47 SW 8 0 200 0 Blue 0
4 PM Tue 64 46 SW 8 0 200 0 Blue 0
5 PM Tue 64 46 SW 9 0 200 0 Blue 0
6 PM Tue 64 44 SW 9 0 200 0 Blue 0
7 PM Tue 64 44 SW 9 0 200 0 Blue 0
8 PM Tue 64 44 SW 8 0 200 0 Blue 0
9 PM Tue 64 44 SW 8 0 200 0 Blue 0
10 PM Tue 64 44 SW 8 0 200 0 Blue 0
11 PM Tue 63 43 SW 7 0 200 0 Blue 0
12 Midnight Wed 62 42 SW 7 0 200 0 Blue 0
1 AM Wed 60 40 SW 7 0 200 0 Blue 0
2 AM Wed 59 39 SW 9 0 200 0 Blue 0
3 AM Wed 58 38 SW 9 0 200 0 Blue 0
4 AM Wed 58 38 SW 9 0 200 0 Blue 0
5 AM Wed 58 38 SW 10 0 200 0 Blue 0
6 AM Wed 58 38 SW 10 0 200 0 Blue 0
7 AM Wed 58 38 SW 10 0 200 0 Blue 0
8 AM Wed 58 38 SW 12 0 200 0 Blue 0
9 AM Wed 58 38 SW 12 0 200 0 Blue 0
10 AM Wed 59 39 SW 12 0 200 0 Blue 0
11 AM Wed 59 44 SW 14 0 200 0 Blue 0
12 Noon Wed 60 46 SW 14 0 200 0 Blue 0
1 PM Wed 60 47 SW 14 0 200 0 Blue 0
2 PM Wed 61 48 SW 13 0 200 0 Blue 0
3 PM Wed 62 48 SW 13 0 200 0 Blue 0
4 PM Wed 62 46 SW 13 0 200 0 Blue 0
5 PM Wed 62 44 SW 12 0 200 0 Blue 0
6 PM Wed 62 43 SW 12 0 200 0 Blue 0
7 PM Wed 63 43 SW 12 0 200 0 Blue 0
8 PM Wed 63 43 SW 9 0 200 0 Blue 0
9 PM Wed 64 44 SW 9 0 200 0 Blue 0
10 PM Wed 64 44 SW 9 0 200 0 Blue 0
11 PM Wed 64 44 SW 9 0 200 0 Blue 0
12 Midnight Thu 63 43 SW 9 0 200 0 Blue 0
1 AM Thu 62 42 SW 9 0 200 0 Blue 0
2 AM Thu 62 42 SW 9 0 200 0 Blue 0
3 AM Thu 62 42 SW 9 0 200 0 Blue 0
4 AM Thu 62 42 SW 9 0 200 0 Blue 0
5 AM Thu 62 42 SW 10 0 200 0 Blue 0
6 AM Thu 61 41 SW 10 0 200 0 Blue 0
7 AM Thu 60 40 SW 10 0 200 0 Blue 0
8 AM Thu 60 40 W 12 0 200 0 Blue 0
9 AM Thu 59 39 W 12 0 200 0 Blue 0
10 AM Thu 59 39 W 12 0 200 0 Blue 0
11 AM Thu 60 45 W 14 0 200 0 Blue 0
12 Noon Thu 61 47 W 14 0 200 0 Blue 0
1 PM Thu 62 49 W 14 0 200 0 Blue 0
2 PM Thu 63 49 W 13 0 200 0 Blue 0
3 PM Thu 63 48 W 13 0 200 0 Blue 0
4 PM Thu 63 47 W 13 0 200 0 Blue 0
5 PM Thu 63 45 W 12 0 200 0 Blue 0
6 PM Thu 63 44 W 12 0 200 0 Blue 0
7 PM Thu 63 43 W 12 0 200 0 Blue 0
8 PM Thu 63 43 W 12 0 200 0 Blue 0
9 PM Thu 62 42 W 12 0 200 0 Blue 0
10 PM Thu 62 42 W 12 0 200 0 Blue 0
11 PM Thu 62 42 W 9 0 200 0 Blue 0
12 Midnight Fri 62 42 W 9 0 200 0 Blue 0
1 AM Fri 61 41 W 9 0 200 0 Blue 0
2 AM Fri 61 41 W 9 0 200 0 Blue 0
3 AM Fri 61 41 W 9 0 200 0 Blue 0
4 AM Fri 61 41 W 9 0 200 0 Blue 0
5 AM Fri 60 40 W 9 0 200 0 Blue 0
6 AM Fri 60 40 W 9 0 200 0 Blue 0
7 AM Fri 60 40 W 9 0 200 0 Blue 0
8 AM Fri 59 39 W 10 0 200 0 Blue 0
9 AM Fri 58 38 W 10 0 200 0 Blue 0
10 AM Fri 58 38 W 10 0 200 0 Blue 0
11 AM Fri 58 43 W 14 0 200 0 Blue 0
12 Noon Fri 59 45 W 14 0 200 0 Blue 0
1 PM Fri 60 47 W 14 0 200 0 Blue 0
2 PM Fri 62 49 W 15 0 200 0 Blue 0
3 PM Fri 62 48 W 15 0 200 0 Blue 0
4 PM Fri 62 46 W 15 0 200 0 Blue 0
5 PM Fri 62 44 W 13 0 200 0 Blue 0
6 PM Fri 62 43 W 13 0 200 0 Blue 0
7 PM Fri 62 42 W 13 0 200 0 Blue 0
8 PM Fri 62 42 W 13 0 200 0 Blue 0
9 PM Fri 62 42 W 13 0 200 0 Blue 0
10 PM Fri 62 42 W 13 0 200 0 Blue 0
11 PM Fri 62 42 W 12 0 200 0 Blue 0
12 Midnight Sat 62 42 W 12 0 200 0 Blue 0
1 AM Sat 61 41 W 12 0 200 0 Blue 0
2 AM Sat 60 40 W 12 0 200 0 Blue 0
3 AM Sat 60 40 W 12 0 200 0 Blue 0
4 AM Sat 59 39 W 12 0 200 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