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

Station:

KOAK

Date/Time:

18 SEP 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 Tue 54 34 W 12 0 200 0 Blue 0
6 AM Tue 54 34 W 12 0 200 0 Blue 0
7 AM Tue 54 34 W 12 0 200 0 Blue 0
8 AM Tue 55 35 W 9 0 200 0 Blue 0
9 AM Tue 57 37 W 9 0 200 0 Blue 0
10 AM Tue 58 38 W 9 0 200 0 Blue 0
11 AM Tue 59 40 SW 10 0 200 0 Blue 0
12 Noon Tue 59 40 SW 10 0 200 0 Blue 0
1 PM Tue 60 41 SW 10 0 200 0 Blue 0
2 PM Tue 60 43 SW 12 0 200 0 Blue 0
3 PM Tue 60 43 SW 12 0 200 0 Blue 0
4 PM Tue 59 41 SW 12 0 200 0 Blue 0
5 PM Tue 58 39 W 13 0 200 0 Blue 0
6 PM Tue 58 38 W 13 0 200 0 Blue 0
7 PM Tue 57 37 W 13 0 200 0 Blue 0
8 PM Tue 56 36 W 15 0 200 0 Blue 0
9 PM Tue 56 36 W 15 0 200 0 Blue 0
10 PM Tue 55 35 W 15 0 200 0 Blue 0
11 PM Tue 55 35 W 16 0 200 0 Blue 0
12 Midnight Wed 55 35 W 16 0 200 0 Blue 0
1 AM Wed 54 34 W 16 0 200 0 Blue 0
2 AM Wed 54 34 W 16 0 200 0 Blue 0
3 AM Wed 54 34 W 16 0 200 0 Blue 0
4 AM Wed 54 34 W 16 0 200 0 Blue 0
5 AM Wed 54 34 W 15 0 200 0 Blue 0
6 AM Wed 54 34 W 15 0 200 0 Blue 0
7 AM Wed 54 34 W 15 0 200 0 Blue 0
8 AM Wed 55 35 NW 10 0 200 0 Blue 0
9 AM Wed 57 37 NW 10 0 200 0 Blue 0
10 AM Wed 59 39 NW 10 0 200 0 Blue 0
11 AM Wed 60 44 NW 12 0 200 0 Blue 0
12 Noon Wed 61 46 NW 12 0 200 0 Blue 0
1 PM Wed 61 46 NW 12 0 200 0 Blue 0
2 PM Wed 62 47 NW 16 0 200 0 Blue 0
3 PM Wed 62 46 NW 16 0 200 0 Blue 0
4 PM Wed 61 44 NW 16 0 200 0 Blue 0
5 PM Wed 60 41 W 15 0 200 0 Blue 0
6 PM Wed 59 39 W 15 0 200 0 Blue 0
7 PM Wed 58 38 W 15 0 200 0 Blue 0
8 PM Wed 57 37 W 15 0 200 0 Blue 0
9 PM Wed 57 37 W 15 0 200 0 Blue 0
10 PM Wed 56 36 W 15 0 200 0 Blue 0
11 PM Wed 56 36 SW 7 0 200 0 Blue 0
12 Midnight Thu 56 36 SW 7 0 200 0 Blue 0
1 AM Thu 55 35 SW 7 0 200 0 Blue 0
2 AM Thu 54 34 SW 7 0 200 0 Blue 0
3 AM Thu 54 34 SW 7 0 200 0 Blue 0
4 AM Thu 54 34 SW 7 0 200 0 Blue 0
5 AM Thu 54 34 SW 5 0 200 0 Blue 0
6 AM Thu 54 34 SW 5 0 200 0 Blue 0
7 AM Thu 54 34 SW 5 0 200 0 Blue 0
8 AM Thu 56 36 SW 5 0 200 0 Blue 0
9 AM Thu 58 38 SW 5 0 200 0 Blue 0
10 AM Thu 60 41 SW 5 0 200 0 Blue 0
11 AM Thu 62 46 W 7 0 200 0 Blue 0
12 Noon Thu 63 48 W 7 0 200 0 Blue 0
1 PM Thu 63 48 W 7 0 200 0 Blue 0
2 PM Thu 64 49 W 7 0 200 0 Blue 0
3 PM Thu 63 47 W 7 0 200 0 Blue 0
4 PM Thu 62 45 W 7 0 200 0 Blue 0
5 PM Thu 61 42 SW 8 0 200 0 Blue 0
6 PM Thu 60 40 SW 8 0 200 0 Blue 0
7 PM Thu 59 39 SW 8 0 200 0 Blue 0
8 PM Thu 57 37 SW 8 0 200 0 Blue 0
9 PM Thu 57 37 SW 8 0 200 0 Blue 0
10 PM Thu 56 36 SW 8 0 200 0 Blue 0
11 PM Thu 56 36 SW 8 0 200 0 Blue 0
12 Midnight Fri 56 36 SW 8 0 200 0 Blue 0
1 AM Fri 55 35 SW 8 0 200 0 Blue 0
2 AM Fri 54 34 SW 8 0 200 0 Blue 0
3 AM Fri 54 34 SW 8 0 200 0 Blue 0
4 AM Fri 54 34 SW 8 0 200 0 Blue 0
5 AM Fri 54 34 SW 5 0 200 0 Blue 0
6 AM Fri 54 34 SW 5 0 200 0 Blue 0
7 AM Fri 54 34 SW 5 0 200 0 Blue 0
8 AM Fri 55 35 SW 5 0 200 0 Blue 0
9 AM Fri 57 37 SW 5 0 200 0 Blue 0
10 AM Fri 59 40 SW 5 0 200 0 Blue 0
11 AM Fri 60 44 NW 12 0 200 0 Blue 0
12 Noon Fri 61 46 NW 12 0 200 0 Blue 0
1 PM Fri 61 46 NW 12 0 200 0 Blue 0
2 PM Fri 62 47 NW 12 0 200 0 Blue 0
3 PM Fri 62 46 NW 12 0 200 0 Blue 0
4 PM Fri 61 44 NW 12 0 200 0 Blue 0
5 PM Fri 60 41 NW 13 0 200 0 Blue 0
6 PM Fri 59 39 NW 13 0 200 0 Blue 0
7 PM Fri 58 38 NW 13 0 200 0 Blue 0
8 PM Fri 57 37 NW 13 0 200 0 Blue 0
9 PM Fri 57 37 NW 13 0 200 0 Blue 0
10 PM Fri 56 36 NW 13 0 200 0 Blue 0
11 PM Fri 56 36 NW 9 0 200 0 Blue 0
12 Midnight Sat 56 36 NW 9 0 200 0 Blue 0
1 AM Sat 55 35 NW 9 0 200 0 Blue 0
2 AM Sat 54 34 NW 9 0 200 0 Blue 0
3 AM Sat 54 34 NW 9 0 200 0 Blue 0
4 AM Sat 54 34 NW 9 0 200 0 Blue 0
5 AM Sat 54 34 NW 9 0 200 0 Blue 0
6 AM Sat 54 34 NW 9 0 200 0 Blue 0
7 AM Sat 54 34 NW 9 0 200 0 Blue 0
8 AM Sat 55 35 NW 9 0 200 0 Blue 0
9 AM Sat 57 37 NW 9 0 200 0 Blue 0
10 AM Sat 59 40 NW 9 0 200 0 Blue 0
11 AM Sat 60 44 NW 13 0 200 0 Blue 0
12 Noon Sat 60 45 NW 13 0 200 0 Blue 0
1 PM Sat 61 46 NW 13 0 200 0 Blue 0
2 PM Sat 62 47 NW 13 0 200 0 Blue 0
3 PM Sat 61 45 NW 13 0 200 0 Blue 0
4 PM Sat 60 43 NW 13 0 200 0 Blue 0
5 PM Sat 60 41 NW 12 0 200 0 Blue 0
6 PM Sat 59 39 NW 12 0 200 0 Blue 0
7 PM Sat 58 38 NW 12 0 200 0 Blue 0
8 PM Sat 57 37 NW 12 0 200 0 Blue 0
9 PM Sat 57 37 NW 12 0 200 0 Blue 0
10 PM Sat 56 36 NW 12 0 200 0 Blue 0
11 PM Sat 56 36 NW 10 0 200 0 Blue 0
12 Midnight Sun 56 36 NW 10 0 200 0 Blue 0
1 AM Sun 55 35 NW 10 0 200 0 Blue 0
2 AM Sun 55 35 NW 10 0 200 0 Blue 0
3 AM Sun 55 35 NW 10 0 200 0 Blue 0
4 AM Sun 55 35 NW 10 0 200 0 Blue 0
5 AM Sun 54 34 W 10 0 200 0 Blue 0
6 AM Sun 54 34 W 10 0 200 0 Blue 0
7 AM Sun 54 34 W 10 0 200 0 Blue 0
8 AM Sun 55 35 W 10 0 200 0 Blue 0
9 AM Sun 57 37 W 10 0 200 0 Blue 0
10 AM Sun 59 39 W 10 0 200 0 Blue 0
11 AM Sun 60 44 W 13 0 200 0 Blue 0
12 Noon Sun 60 45 W 13 0 200 0 Blue 0
1 PM Sun 61 46 W 13 0 200 0 Blue 0
2 PM Sun 62 47 W 13 0 200 0 Blue 0
3 PM Sun 61 45 W 13 0 200 0 Blue 0
4 PM Sun 60 43 W 13 0 200 0 Blue 0
5 PM Sun 60 41 W 13 0 200 0 Blue 0
6 PM Sun 59 39 W 13 0 200 0 Blue 0
7 PM Sun 58 38 W 13 0 200 0 Blue 0
8 PM Sun 56 36 W 13 0 200 0 Blue 0
9 PM Sun 56 36 W 13 0 200 0 Blue 0
10 PM Sun 56 36 W 13 0 200 0 Blue 0
11 PM Sun 56 36 W 10 0 200 0 Blue 0
12 Midnight Mon 55 35 W 10 0 200 0 Blue 0
1 AM Mon 55 35 W 10 0 200 0 Blue 0
2 AM Mon 54 34 W 10 0 200 0 Blue 0
3 AM Mon 54 34 W 10 0 200 0 Blue 0
4 AM Mon 54 34 W 10 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