Detailed Predictions for: Dumps
Launch Altitude (f): 200
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

18 SEP 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 Wed 59 39 S 7 0 200 0 Blue 0
6 AM Wed 60 40 S 7 0 200 0 Blue 0
7 AM Wed 59 39 S 7 0 200 0 Blue 0
8 AM Wed 61 41 S 13 0 200 0 Blue 0
9 AM Wed 58 38 S 13 0 200 0 Blue 0
10 AM Wed 60 40 S 13 0 200 0 Blue 0
11 AM Wed 59 39 S 14 0 200 0 Blue 0
12 Noon Wed 60 41 S 14 0 200 0 Blue 0
1 PM Wed 59 41 S 14 0 200 0 Blue 0
2 PM Wed 60 44 W 9 0 200 0 Blue 0
3 PM Wed 60 43 W 9 0 200 0 Blue 0
4 PM Wed 60 42 W 9 0 200 0 Blue 0
5 PM Wed 60 41 W 13 0 200 0 Blue 0
6 PM Wed 61 41 W 13 0 200 0 Blue 0
7 PM Wed 60 40 W 13 0 200 0 Blue 0
8 PM Wed 60 40 W 10 0 200 0 Blue 0
9 PM Wed 60 40 W 10 0 200 0 Blue 0
10 PM Wed 60 40 W 10 0 200 0 Blue 0
11 PM Wed 60 40 NW 14 0 200 0 Blue 0
12 Midnight Thu 59 39 NW 14 0 200 0 Blue 0
1 AM Thu 59 39 NW 14 0 200 0 Blue 0
2 AM Thu 59 39 NW 15 0 200 0 Blue 0
3 AM Thu 58 38 NW 15 0 200 0 Blue 0
4 AM Thu 58 38 NW 15 0 200 0 Blue 0
5 AM Thu 58 38 NW 12 0 200 0 Blue 0
6 AM Thu 57 37 NW 12 0 200 0 Blue 0
7 AM Thu 57 37 NW 12 0 200 0 Blue 0
8 AM Thu 56 36 NW 9 0 200 0 Blue 0
9 AM Thu 55 35 NW 9 0 200 0 Blue 0
10 AM Thu 56 36 NW 9 0 200 0 Blue 0
11 AM Thu 55 36 NW 9 0 200 0 Blue 0
12 Noon Thu 56 38 NW 9 0 200 0 Blue 0
1 PM Thu 58 40 NW 9 0 200 0 Blue 0
2 PM Thu 61 45 NW 12 0 200 0 Blue 0
3 PM Thu 62 46 NW 12 0 200 0 Blue 0
4 PM Thu 62 44 NW 12 0 200 0 Blue 0
5 PM Thu 62 43 NW 16 0 200 0 Blue 0
6 PM Thu 62 42 NW 16 0 200 0 Blue 0
7 PM Thu 62 42 NW 16 0 200 0 Blue 0
8 PM Thu 62 42 NW 8 0 200 0 Blue 0
9 PM Thu 61 41 NW 8 0 200 0 Blue 0
10 PM Thu 60 40 NW 8 0 200 0 Blue 0
11 PM Thu 59 39 W 2 0 200 0 Blue 0
12 Midnight Fri 59 39 W 2 0 200 0 Blue 0
1 AM Fri 59 39 W 2 0 200 0 Blue 0
2 AM Fri 59 39 W 1 0 200 0 Blue 0
3 AM Fri 59 39 W 1 0 200 0 Blue 0
4 AM Fri 58 38 W 1 0 200 0 Blue 0
5 AM Fri 58 38 SE 0 0 200 0 Blue 0
6 AM Fri 57 37 SE 0 0 200 0 Blue 0
7 AM Fri 56 36 SE 0 0 200 0 Blue 0
8 AM Fri 56 36 SW 1 0 200 0 Blue 0
9 AM Fri 56 36 SW 1 0 200 0 Blue 0
10 AM Fri 58 39 SW 1 0 200 0 Blue 0
11 AM Fri 59 42 W 5 0 200 0 Blue 0
12 Noon Fri 61 45 W 5 0 200 0 Blue 0
1 PM Fri 63 48 W 5 0 200 0 Blue 0
2 PM Fri 64 48 W 7 0 200 0 Blue 0
3 PM Fri 64 47 W 7 0 200 0 Blue 0
4 PM Fri 64 46 W 7 0 200 0 Blue 0
5 PM Fri 63 44 W 7 0 200 0 Blue 0
6 PM Fri 62 42 W 7 0 200 0 Blue 0
7 PM Fri 62 42 W 7 0 200 0 Blue 0
8 PM Fri 61 41 SW 5 0 200 0 Blue 0
9 PM Fri 60 40 SW 5 0 200 0 Blue 0
10 PM Fri 59 39 SW 5 0 200 0 Blue 0
11 PM Fri 58 38 SW 5 0 200 0 Blue 0
12 Midnight Sat 58 38 SW 5 0 200 0 Blue 0
1 AM Sat 58 38 SW 5 0 200 0 Blue 0
2 AM Sat 57 37 SW 2 0 200 0 Blue 0
3 AM Sat 57 37 SW 2 0 200 0 Blue 0
4 AM Sat 56 36 SW 2 0 200 0 Blue 0
5 AM Sat 56 36 S 1 0 200 0 Blue 0
6 AM Sat 56 36 S 1 0 200 0 Blue 0
7 AM Sat 56 36 S 1 0 200 0 Blue 0
8 AM Sat 56 36 E 3 0 200 0 Blue 0
9 AM Sat 57 38 E 3 0 200 0 Blue 0
10 AM Sat 58 40 E 3 0 200 0 Blue 0
11 AM Sat 60 44 N 5 0 200 0 Blue 0
12 Noon Sat 62 47 N 5 0 200 0 Blue 0
1 PM Sat 64 50 N 5 0 200 0 Blue 0
2 PM Sat 66 52 W 7 0 200 0 Blue 0
3 PM Sat 66 51 W 7 0 200 0 Blue 0
4 PM Sat 66 49 W 7 0 200 0 Blue 0
5 PM Sat 65 46 W 7 0 200 0 Blue 0
6 PM Sat 65 45 W 7 0 200 0 Blue 0
7 PM Sat 64 44 W 7 0 200 0 Blue 0
8 PM Sat 63 43 W 6 0 200 0 Blue 0
9 PM Sat 62 42 W 6 0 200 0 Blue 0
10 PM Sat 61 41 W 6 0 200 0 Blue 0
11 PM Sat 60 40 W 6 0 200 0 Blue 0
12 Midnight Sun 59 39 W 6 0 200 0 Blue 0
1 AM Sun 59 39 W 6 0 200 0 Blue 0
2 AM Sun 58 38 SW 5 0 200 0 Blue 0
3 AM Sun 58 38 SW 5 0 200 0 Blue 0
4 AM Sun 57 37 SW 5 0 200 0 Blue 0
5 AM Sun 57 37 W 6 0 200 0 Blue 0
6 AM Sun 57 37 W 6 0 200 0 Blue 0
7 AM Sun 56 36 W 6 0 200 0 Blue 0
8 AM Sun 56 36 W 7 0 200 0 Blue 0
9 AM Sun 56 37 W 7 0 200 0 Blue 0
10 AM Sun 56 38 W 7 0 200 0 Blue 0
11 AM Sun 57 39 W 10 0 200 0 Blue 0
12 Noon Sun 58 40 W 10 0 200 0 Blue 0
1 PM Sun 60 43 W 10 0 200 0 Blue 0
2 PM Sun 62 44 W 12 0 200 0 Blue 0
3 PM Sun 63 45 W 12 0 200 0 Blue 0
4 PM Sun 64 45 W 12 0 200 0 Blue 0
5 PM Sun 64 45 W 12 0 200 0 Blue 0
6 PM Sun 64 44 W 12 0 200 0 Blue 0
7 PM Sun 64 44 W 12 0 200 0 Blue 0
8 PM Sun 63 43 W 13 0 200 0 Blue 0
9 PM Sun 62 42 W 13 0 200 0 Blue 0
10 PM Sun 61 41 W 13 0 200 0 Blue 0
11 PM Sun 60 40 NW 14 0 200 0 Blue 0
12 Midnight Mon 60 40 NW 14 0 200 0 Blue 0
1 AM Mon 60 40 NW 14 0 200 0 Blue 0
2 AM Mon 60 40 NW 12 0 200 0 Blue 0
3 AM Mon 59 39 NW 12 0 200 0 Blue 0
4 AM Mon 58 38 NW 12 0 200 0 Blue 0
5 AM Mon 57 37 N 7 0 200 0 Blue 0
6 AM Mon 57 37 N 7 0 200 0 Blue 0
7 AM Mon 57 37 N 7 0 200 0 Blue 0
8 AM Mon 57 37 N 7 0 200 0 Blue 0
9 AM Mon 57 38 N 7 0 200 0 Blue 0
10 AM Mon 57 39 N 7 0 200 0 Blue 0
11 AM Mon 58 41 N 9 0 200 0 Blue 0
12 Noon Mon 60 44 N 9 0 200 0 Blue 0
1 PM Mon 62 46 N 9 0 200 0 Blue 0
2 PM Mon 63 47 W 9 0 200 0 Blue 0
3 PM Mon 64 47 W 9 0 200 0 Blue 0
4 PM Mon 64 46 W 9 0 200 0 Blue 0
5 PM Mon 64 45 NW 9 0 200 0 Blue 0
6 PM Mon 64 44 NW 9 0 200 0 Blue 0
7 PM Mon 65 45 NW 9 0 200 0 Blue 0
8 PM Mon 66 46 NW 7 0 200 0 Blue 0
9 PM Mon 66 46 NW 7 0 200 0 Blue 0
10 PM Mon 64 44 NW 7 0 200 0 Blue 0
11 PM Mon 62 42 NW 7 0 200 0 Blue 0
12 Midnight Tue 62 42 NW 7 0 200 0 Blue 0
1 AM Tue 63 43 NW 7 0 200 0 Blue 0
2 AM Tue 63 43 N 7 0 200 0 Blue 0
3 AM Tue 63 43 N 7 0 200 0 Blue 0
4 AM Tue 61 41 N 7 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