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

Station:

KOAK

Date/Time:

17 JAN 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)
4 AM Wed 50 30 NW 2 0 200 0 Blue 0
5 AM Wed 50 30 NW 2 0 200 0 Blue 0
6 AM Wed 50 30 NW 2 0 200 0 Blue 0
7 AM Wed 49 29 W 2 0 200 0 Blue 0
8 AM Wed 50 30 W 2 0 200 0 Blue 0
9 AM Wed 52 32 W 2 0 200 0 Blue 0
10 AM Wed 54 34 SW 5 0 200 0 Blue 0
11 AM Wed 56 37 SW 5 0 200 0 Blue 0
12 Noon Wed 57 38 SW 5 0 200 0 Blue 0
1 PM Wed 58 39 SW 6 0 200 0 Blue 0
2 PM Wed 58 38 SW 6 0 200 0 Blue 0
3 PM Wed 58 38 SW 6 0 200 0 Blue 0
4 PM Wed 58 38 W 9 0 200 0 Blue 0
5 PM Wed 56 36 W 9 0 200 0 Blue 0
6 PM Wed 55 35 W 9 0 200 0 Blue 0
7 PM Wed 54 34 SW 5 0 200 0 Blue 0
8 PM Wed 54 34 SW 5 0 200 0 Blue 0
9 PM Wed 53 33 SW 5 0 200 0 Blue 0
10 PM Wed 53 33 SE 7 0 200 0 Blue 0
11 PM Wed 53 33 SE 7 0 200 0 Blue 0
12 Midnight Thu 52 32 SE 7 0 200 0 Blue 0
1 AM Thu 52 32 SE 7 0 200 0 Blue 0
2 AM Thu 51 31 SE 7 0 200 0 Blue 0
3 AM Thu 51 31 SE 7 0 200 0 Blue 0
4 AM Thu 51 31 SE 6 0 200 0 Blue 0
5 AM Thu 51 31 SE 6 0 200 0 Blue 0
6 AM Thu 51 31 SE 6 0 200 0 Blue 0
7 AM Thu 51 31 S 14 0 200 0 Blue 0
8 AM Thu 51 31 S 14 0 200 0 Blue 0
9 AM Thu 52 32 S 14 0 200 0 Blue 0
10 AM Thu 54 34 S 20 0 200 0 Blue 0
11 AM Thu 55 35 S 20 0 200 0 Blue 0
12 Noon Thu 56 36 S 20 0 200 0 Blue 0
1 PM Thu 57 37 S 23 0 200 0 Blue 0
2 PM Thu 56 36 S 23 0 200 0 Blue 0
3 PM Thu 56 36 S 23 0 200 0 Blue 0
4 PM Thu 56 36 W 17 0 200 0 Blue 0
5 PM Thu 54 34 W 17 0 200 0 Blue 0
6 PM Thu 53 33 W 17 0 200 0 Blue 0
7 PM Thu 52 32 W 17 0 200 0 Blue 0
8 PM Thu 52 32 W 17 0 200 0 Blue 0
9 PM Thu 51 31 W 17 0 200 0 Blue 0
10 PM Thu 50 30 W 15 0 200 0 Blue 0
11 PM Thu 50 30 W 15 0 200 0 Blue 0
12 Midnight Fri 50 30 W 15 0 200 0 Blue 0
1 AM Fri 49 29 W 15 0 200 0 Blue 0
2 AM Fri 48 28 W 15 0 200 0 Blue 0
3 AM Fri 48 28 W 15 0 200 0 Blue 0
4 AM Fri 48 28 W 20 0 200 0 Blue 0
5 AM Fri 48 28 W 20 0 200 0 Blue 0
6 AM Fri 48 28 W 20 0 200 0 Blue 0
7 AM Fri 48 28 W 20 0 200 0 Blue 0
8 AM Fri 48 28 W 20 0 200 0 Blue 0
9 AM Fri 49 29 W 20 0 200 0 Blue 0
10 AM Fri 50 30 NW 17 0 200 0 Blue 0
11 AM Fri 52 32 NW 17 0 200 0 Blue 0
12 Noon Fri 53 34 NW 17 0 200 0 Blue 0
1 PM Fri 54 34 NW 17 0 200 0 Blue 0
2 PM Fri 53 33 NW 17 0 200 0 Blue 0
3 PM Fri 53 33 NW 17 0 200 0 Blue 0
4 PM Fri 53 33 NW 20 0 200 0 Blue 0
5 PM Fri 51 31 NW 20 0 200 0 Blue 0
6 PM Fri 50 30 NW 20 0 200 0 Blue 0
7 PM Fri 49 29 NW 20 0 200 0 Blue 0
8 PM Fri 48 28 NW 20 0 200 0 Blue 0
9 PM Fri 48 28 NW 20 0 200 0 Blue 0
10 PM Fri 47 27 NW 15 0 200 0 Blue 0
11 PM Fri 47 27 NW 15 0 200 0 Blue 0
12 Midnight Sat 46 26 NW 15 0 200 0 Blue 0
1 AM Sat 46 26 NW 15 0 200 0 Blue 0
2 AM Sat 45 25 NW 15 0 200 0 Blue 0
3 AM Sat 44 24 NW 15 0 200 0 Blue 0
4 AM Sat 45 25 NW 14 0 200 0 Blue 0
5 AM Sat 45 25 NW 14 0 200 0 Blue 0
6 AM Sat 45 25 NW 14 0 200 0 Blue 0
7 AM Sat 44 24 NW 14 0 200 0 Blue 0
8 AM Sat 45 25 NW 14 0 200 0 Blue 0
9 AM Sat 47 27 NW 14 0 200 0 Blue 0
10 AM Sat 49 29 NW 13 0 200 0 Blue 0
11 AM Sat 51 32 NW 13 0 200 0 Blue 0
12 Noon Sat 53 34 NW 13 0 200 0 Blue 0
1 PM Sat 54 35 NW 13 0 200 0 Blue 0
2 PM Sat 54 35 NW 13 0 200 0 Blue 0
3 PM Sat 54 34 NW 13 0 200 0 Blue 0
4 PM Sat 53 33 NW 12 0 200 0 Blue 0
5 PM Sat 52 32 NW 12 0 200 0 Blue 0
6 PM Sat 51 31 NW 12 0 200 0 Blue 0
7 PM Sat 50 30 NW 12 0 200 0 Blue 0
8 PM Sat 50 30 NW 12 0 200 0 Blue 0
9 PM Sat 49 29 NW 12 0 200 0 Blue 0
10 PM Sat 49 29 W 7 0 200 0 Blue 0
11 PM Sat 49 29 W 7 0 200 0 Blue 0
12 Midnight Sun 48 28 W 7 0 200 0 Blue 0
1 AM Sun 48 28 W 7 0 200 0 Blue 0
2 AM Sun 47 27 W 7 0 200 0 Blue 0
3 AM Sun 47 27 W 7 0 200 0 Blue 0
4 AM Sun 47 27 S 1 0 200 0 Blue 0
5 AM Sun 47 27 S 1 0 200 0 Blue 0
6 AM Sun 47 27 S 1 0 200 0 Blue 0
7 AM Sun 47 27 S 1 0 200 0 Blue 0
8 AM Sun 47 27 S 1 0 200 0 Blue 0
9 AM Sun 49 29 S 1 0 200 0 Blue 0
10 AM Sun 51 31 S 9 0 200 0 Blue 0
11 AM Sun 52 32 S 9 0 200 0 Blue 0
12 Noon Sun 54 34 S 9 0 200 0 Blue 0
1 PM Sun 55 35 S 9 0 200 0 Blue 0
2 PM Sun 54 34 S 9 0 200 0 Blue 0
3 PM Sun 54 34 S 9 0 200 0 Blue 0
4 PM Sun 54 34 S 17 0 200 0 Blue 0
5 PM Sun 53 33 S 17 0 200 0 Blue 0
6 PM Sun 53 33 S 17 0 200 0 Blue 0
7 PM Sun 52 32 S 17 0 200 0 Blue 0
8 PM Sun 52 32 S 17 0 200 0 Blue 0
9 PM Sun 52 32 S 17 0 200 0 Blue 0
10 PM Sun 51 31 S 20 0 200 0 Blue 0
11 PM Sun 51 31 S 20 0 200 0 Blue 0
12 Midnight Mon 51 31 S 20 0 200 0 Blue 0
1 AM Mon 51 31 S 20 0 200 0 Blue 0
2 AM Mon 50 30 S 20 0 200 0 Blue 0
3 AM Mon 50 30 S 20 0 200 0 Blue 0
4 AM Mon 50 30 W 7 0 200 0 Blue 0
5 AM Mon 50 30 W 7 0 200 0 Blue 0
6 AM Mon 50 30 W 7 0 200 0 Blue 0
7 AM Mon 50 30 W 7 0 200 0 Blue 0
8 AM Mon 50 30 W 7 0 200 0 Blue 0
9 AM Mon 51 31 W 7 0 200 0 Blue 0
10 AM Mon 52 32 W 8 0 200 0 Blue 0
11 AM Mon 54 34 W 8 0 200 0 Blue 0
12 Noon Mon 55 35 W 8 0 200 0 Blue 0
1 PM Mon 55 35 W 8 0 200 0 Blue 0
2 PM Mon 55 35 W 8 0 200 0 Blue 0
3 PM Mon 55 35 W 8 0 200 0 Blue 0
4 PM Mon 55 35 W 8 0 200 0 Blue 0
5 PM Mon 53 33 W 8 0 200 0 Blue 0
6 PM Mon 52 32 W 8 0 200 0 Blue 0
7 PM Mon 51 31 W 8 0 200 0 Blue 0
8 PM Mon 51 31 W 8 0 200 0 Blue 0
9 PM Mon 50 30 W 8 0 200 0 Blue 0
10 PM Mon 50 30 N 5 0 200 0 Blue 0
11 PM Mon 50 30 N 5 0 200 0 Blue 0
12 Midnight Tue 50 30 N 5 0 200 0 Blue 0
1 AM Tue 49 29 N 5 0 200 0 Blue 0
2 AM Tue 48 28 N 5 0 200 0 Blue 0
3 AM Tue 48 28 N 5 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