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

Station:

KOAK

Date/Time:

N/A

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)
4 AM Thu 54 34 SW 20 N/A N/A N/A N/A N/A
5 AM Thu 54 34 SW 20 N/A N/A N/A N/A N/A
6 AM Thu 54 34 SW 20 N/A N/A N/A N/A N/A
7 AM Thu 54 34 SW 20 N/A N/A N/A N/A N/A
8 AM Thu 54 34 SW 20 N/A N/A N/A N/A N/A
9 AM Thu 55 35 SW 20 N/A N/A N/A N/A N/A
10 AM Thu 56 36 SW 21 N/A N/A N/A N/A N/A
11 AM Thu 57 37 SW 21 N/A N/A N/A N/A N/A
12 Noon Thu 58 38 SW 21 N/A N/A N/A N/A N/A
1 PM Thu 58 38 SW 18 N/A N/A N/A N/A N/A
2 PM Thu 58 38 SW 18 N/A N/A N/A N/A N/A
3 PM Thu 58 38 SW 18 N/A N/A N/A N/A N/A
4 PM Thu 57 37 SW 16 N/A N/A N/A N/A N/A
5 PM Thu 57 37 SW 16 N/A N/A N/A N/A N/A
6 PM Thu 56 36 SW 16 N/A N/A N/A N/A N/A
7 PM Thu 55 35 W 15 N/A N/A N/A N/A N/A
8 PM Thu 55 35 W 15 N/A N/A N/A N/A N/A
9 PM Thu 55 35 W 15 N/A N/A N/A N/A N/A
10 PM Thu 54 34 SW 13 N/A N/A N/A N/A N/A
11 PM Thu 54 34 SW 13 N/A N/A N/A N/A N/A
12 Midnight Fri 53 33 SW 13 N/A N/A N/A N/A N/A
1 AM Fri 53 33 SW 7 N/A N/A N/A N/A N/A
2 AM Fri 53 33 SW 7 N/A N/A N/A N/A N/A
3 AM Fri 52 32 SW 7 N/A N/A N/A N/A N/A
4 AM Fri 52 32 SE 7 N/A N/A N/A N/A N/A
5 AM Fri 52 32 SE 7 N/A N/A N/A N/A N/A
6 AM Fri 52 32 SE 7 N/A N/A N/A N/A N/A
7 AM Fri 52 32 S 9 N/A N/A N/A N/A N/A
8 AM Fri 52 32 S 9 N/A N/A N/A N/A N/A
9 AM Fri 54 34 S 9 N/A N/A N/A N/A N/A
10 AM Fri 55 35 S 6 N/A N/A N/A N/A N/A
11 AM Fri 57 37 S 6 N/A N/A N/A N/A N/A
12 Noon Fri 58 39 S 6 N/A N/A N/A N/A N/A
1 PM Fri 58 39 S 14 N/A N/A N/A N/A N/A
2 PM Fri 58 38 S 14 N/A N/A N/A N/A N/A
3 PM Fri 58 38 S 14 N/A N/A N/A N/A N/A
4 PM Fri 58 38 S 12 N/A N/A N/A N/A N/A
5 PM Fri 57 37 S 12 N/A N/A N/A N/A N/A
6 PM Fri 56 36 S 12 N/A N/A N/A N/A N/A
7 PM Fri 56 36 S 12 N/A N/A N/A N/A N/A
8 PM Fri 55 35 S 12 N/A N/A N/A N/A N/A
9 PM Fri 55 35 S 12 N/A N/A N/A N/A N/A
10 PM Fri 55 35 S 9 N/A N/A N/A N/A N/A
11 PM Fri 54 34 S 9 N/A N/A N/A N/A N/A
12 Midnight Sat 54 34 S 9 N/A N/A N/A N/A N/A
1 AM Sat 54 34 S 9 N/A N/A N/A N/A N/A
2 AM Sat 53 33 S 9 N/A N/A N/A N/A N/A
3 AM Sat 53 33 S 9 N/A N/A N/A N/A N/A
4 AM Sat 52 32 SE 7 N/A N/A N/A N/A N/A
5 AM Sat 52 32 SE 7 N/A N/A N/A N/A N/A
6 AM Sat 52 32 SE 7 N/A N/A N/A N/A N/A
7 AM Sat 52 32 SE 7 N/A N/A N/A N/A N/A
8 AM Sat 52 32 SE 7 N/A N/A N/A N/A N/A
9 AM Sat 55 35 SE 7 N/A N/A N/A N/A N/A
10 AM Sat 56 36 W 7 N/A N/A N/A N/A N/A
11 AM Sat 58 38 W 7 N/A N/A N/A N/A N/A
12 Noon Sat 59 40 W 7 N/A N/A N/A N/A N/A
1 PM Sat 60 41 W 7 N/A N/A N/A N/A N/A
2 PM Sat 59 39 W 7 N/A N/A N/A N/A N/A
3 PM Sat 59 39 W 7 N/A N/A N/A N/A N/A
4 PM Sat 59 39 W 2 N/A N/A N/A N/A N/A
5 PM Sat 58 38 W 2 N/A N/A N/A N/A N/A
6 PM Sat 58 38 W 2 N/A N/A N/A N/A N/A
7 PM Sat 57 37 W 2 N/A N/A N/A N/A N/A
8 PM Sat 57 37 W 2 N/A N/A N/A N/A N/A
9 PM Sat 56 36 W 2 N/A N/A N/A N/A N/A
10 PM Sat 56 36 S 12 N/A N/A N/A N/A N/A
11 PM Sat 56 36 S 12 N/A N/A N/A N/A N/A
12 Midnight Sun 55 35 S 12 N/A N/A N/A N/A N/A
1 AM Sun 55 35 S 12 N/A N/A N/A N/A N/A
2 AM Sun 55 35 S 12 N/A N/A N/A N/A N/A
3 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
4 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
5 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
6 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
7 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
8 AM Sun 54 34 S 12 N/A N/A N/A N/A N/A
9 AM Sun 55 35 S 12 N/A N/A N/A N/A N/A
10 AM Sun 56 36 W 12 N/A N/A N/A N/A N/A
11 AM Sun 57 37 W 12 N/A N/A N/A N/A N/A
12 Noon Sun 58 38 W 12 N/A N/A N/A N/A N/A
1 PM Sun 58 38 W 12 N/A N/A N/A N/A N/A
2 PM Sun 58 38 W 12 N/A N/A N/A N/A N/A
3 PM Sun 58 38 W 12 N/A N/A N/A N/A N/A
4 PM Sun 57 37 W 14 N/A N/A N/A N/A N/A
5 PM Sun 56 36 W 14 N/A N/A N/A N/A N/A
6 PM Sun 55 35 W 14 N/A N/A N/A N/A N/A
7 PM Sun 54 34 W 14 N/A N/A N/A N/A N/A
8 PM Sun 54 34 W 14 N/A N/A N/A N/A N/A
9 PM Sun 53 33 W 14 N/A N/A N/A N/A N/A
10 PM Sun 52 32 NW 10 N/A N/A N/A N/A N/A
11 PM Sun 52 32 NW 10 N/A N/A N/A N/A N/A
12 Midnight Mon 51 31 NW 10 N/A N/A N/A N/A N/A
1 AM Mon 51 31 NW 10 N/A N/A N/A N/A N/A
2 AM Mon 50 30 NW 10 N/A N/A N/A N/A N/A
3 AM Mon 49 29 NW 10 N/A N/A N/A N/A N/A
4 AM Mon 49 29 NW 10 N/A N/A N/A N/A N/A
5 AM Mon 49 29 NW 10 N/A N/A N/A N/A N/A
6 AM Mon 48 28 NW 10 N/A N/A N/A N/A N/A
7 AM Mon 48 28 NW 10 N/A N/A N/A N/A N/A
8 AM Mon 49 29 NW 10 N/A N/A N/A N/A N/A
9 AM Mon 52 32 NW 10 N/A N/A N/A N/A N/A
10 AM Mon 54 35 N 10 N/A N/A N/A N/A N/A
11 AM Mon 56 37 N 10 N/A N/A N/A N/A N/A
12 Noon Mon 57 39 N 10 N/A N/A N/A N/A N/A
1 PM Mon 58 39 N 10 N/A N/A N/A N/A N/A
2 PM Mon 57 38 N 10 N/A N/A N/A N/A N/A
3 PM Mon 57 37 N 10 N/A N/A N/A N/A N/A
4 PM Mon 57 37 NW 13 N/A N/A N/A N/A N/A
5 PM Mon 56 36 NW 13 N/A N/A N/A N/A N/A
6 PM Mon 54 34 NW 13 N/A N/A N/A N/A N/A
7 PM Mon 54 34 NW 13 N/A N/A N/A N/A N/A
8 PM Mon 53 33 NW 13 N/A N/A N/A N/A N/A
9 PM Mon 53 33 NW 13 N/A N/A N/A N/A N/A
10 PM Mon 52 32 N 10 N/A N/A N/A N/A N/A
11 PM Mon 52 32 N 10 N/A N/A N/A N/A N/A
12 Midnight Tue 51 31 N 10 N/A N/A N/A N/A N/A
1 AM Tue 51 31 N 10 N/A N/A N/A N/A N/A
2 AM Tue 50 30 N 10 N/A N/A N/A N/A N/A
3 AM Tue 49 29 N 10 N/A N/A N/A N/A N/A
4 AM Tue 49 29 N 9 N/A N/A N/A N/A N/A
5 AM Tue 49 29 N 9 N/A N/A N/A N/A N/A
6 AM Tue 48 28 N 9 N/A N/A N/A N/A N/A
7 AM Tue 48 28 N 9 N/A N/A N/A N/A N/A
8 AM Tue 49 29 N 9 N/A N/A N/A N/A N/A
9 AM Tue 52 32 N 9 N/A N/A N/A N/A N/A
10 AM Tue 54 35 N 8 N/A N/A N/A N/A N/A
11 AM Tue 56 37 N 8 N/A N/A N/A N/A N/A
12 Noon Tue 58 40 N 8 N/A N/A N/A N/A N/A
1 PM Tue 59 41 N 8 N/A N/A N/A N/A N/A
2 PM Tue 58 39 N 8 N/A N/A N/A N/A N/A
3 PM Tue 58 39 N 8 N/A N/A N/A N/A N/A
4 PM Tue 58 38 N 7 N/A N/A N/A N/A N/A
5 PM Tue 57 37 N 7 N/A N/A N/A N/A N/A
6 PM Tue 55 35 N 7 N/A N/A N/A N/A N/A
7 PM Tue 54 34 N 7 N/A N/A N/A N/A N/A
8 PM Tue 54 34 N 7 N/A N/A N/A N/A N/A
9 PM Tue 53 33 N 7 N/A N/A N/A N/A N/A
10 PM Tue 53 33 N 5 N/A N/A N/A N/A N/A
11 PM Tue 52 32 N 5 N/A N/A N/A N/A N/A
12 Midnight Wed 51 31 N 5 N/A N/A N/A N/A N/A
1 AM Wed 51 31 N 5 N/A N/A N/A N/A N/A
2 AM Wed 50 30 N 5 N/A N/A N/A N/A N/A
3 AM Wed 49 29 N 5 N/A N/A N/A N/A N/A

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