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

Station:

KOAK

Date/Time:

23 SEP 2017

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 Sat 55 35 NW 2 0 200 0 Blue 0
6 AM Sat 54 34 NW 2 0 200 0 Blue 0
7 AM Sat 53 33 NW 2 0 200 0 Blue 0
8 AM Sat 54 34 N 3 0 200 0 Blue 0
9 AM Sat 57 38 N 3 0 200 0 Blue 0
10 AM Sat 60 42 N 3 0 200 0 Blue 0
11 AM Sat 63 46 W 7 0 200 0 Blue 0
12 Noon Sat 64 48 W 7 0 200 0 Blue 0
1 PM Sat 64 49 W 7 0 200 0 Blue 0
2 PM Sat 63 48 W 9 0 200 0 Blue 0
3 PM Sat 63 47 W 9 0 200 0 Blue 0
4 PM Sat 63 45 W 9 0 200 0 Blue 0
5 PM Sat 63 44 NW 13 0 200 0 Blue 0
6 PM Sat 62 42 NW 13 0 200 0 Blue 0
7 PM Sat 61 41 NW 13 0 200 0 Blue 0
8 PM Sat 59 39 W 8 0 200 0 Blue 0
9 PM Sat 58 38 W 8 0 200 0 Blue 0
10 PM Sat 57 37 W 8 0 200 0 Blue 0
11 PM Sat 56 36 W 6 0 200 0 Blue 0
12 Midnight Sun 56 36 W 6 0 200 0 Blue 0
1 AM Sun 55 35 W 6 0 200 0 Blue 0
2 AM Sun 55 35 SW 6 0 200 0 Blue 0
3 AM Sun 55 35 SW 6 0 200 0 Blue 0
4 AM Sun 54 34 SW 6 0 200 0 Blue 0
5 AM Sun 54 34 SW 6 0 200 0 Blue 0
6 AM Sun 54 34 SW 6 0 200 0 Blue 0
7 AM Sun 53 33 SW 6 0 200 0 Blue 0
8 AM Sun 55 35 E 3 0 200 0 Blue 0
9 AM Sun 58 39 E 3 0 200 0 Blue 0
10 AM Sun 62 44 E 3 0 200 0 Blue 0
11 AM Sun 65 48 W 6 0 200 0 Blue 0
12 Noon Sun 66 50 W 6 0 200 0 Blue 0
1 PM Sun 65 50 W 6 0 200 0 Blue 0
2 PM Sun 65 50 NW 10 0 200 0 Blue 0
3 PM Sun 66 50 NW 10 0 200 0 Blue 0
4 PM Sun 67 49 NW 10 0 200 0 Blue 0
5 PM Sun 67 48 SW 8 0 200 0 Blue 0
6 PM Sun 66 46 SW 8 0 200 0 Blue 0
7 PM Sun 64 44 SW 8 0 200 0 Blue 0
8 PM Sun 62 42 SW 8 0 200 0 Blue 0
9 PM Sun 61 41 SW 8 0 200 0 Blue 0
10 PM Sun 61 41 SW 8 0 200 0 Blue 0
11 PM Sun 60 40 NW 5 0 200 0 Blue 0
12 Midnight Mon 60 40 NW 5 0 200 0 Blue 0
1 AM Mon 59 39 NW 5 0 200 0 Blue 0
2 AM Mon 58 38 NW 5 0 200 0 Blue 0
3 AM Mon 57 37 NW 5 0 200 0 Blue 0
4 AM Mon 57 37 NW 5 0 200 0 Blue 0
5 AM Mon 57 37 SW 2 0 200 0 Blue 0
6 AM Mon 56 36 SW 2 0 200 0 Blue 0
7 AM Mon 56 36 SW 2 0 200 0 Blue 0
8 AM Mon 57 37 SW 2 0 200 0 Blue 0
9 AM Mon 60 41 SW 2 0 200 0 Blue 0
10 AM Mon 64 46 SW 2 0 200 0 Blue 0
11 AM Mon 67 51 SW 10 0 200 0 Blue 0
12 Noon Mon 68 53 SW 10 0 200 0 Blue 0
1 PM Mon 69 54 SW 10 0 200 0 Blue 0
2 PM Mon 69 54 SW 10 0 200 0 Blue 0
3 PM Mon 70 54 SW 10 0 200 0 Blue 0
4 PM Mon 70 53 SW 10 0 200 0 Blue 0
5 PM Mon 70 51 SW 10 0 200 0 Blue 0
6 PM Mon 68 48 SW 10 0 200 0 Blue 0
7 PM Mon 66 46 SW 10 0 200 0 Blue 0
8 PM Mon 64 44 SW 10 0 200 0 Blue 0
9 PM Mon 64 44 SW 10 0 200 0 Blue 0
10 PM Mon 64 44 SW 10 0 200 0 Blue 0
11 PM Mon 64 44 SW 8 0 200 0 Blue 0
12 Midnight Tue 64 44 SW 8 0 200 0 Blue 0
1 AM Tue 64 44 SW 8 0 200 0 Blue 0
2 AM Tue 63 43 SW 8 0 200 0 Blue 0
3 AM Tue 63 43 SW 8 0 200 0 Blue 0
4 AM Tue 62 42 SW 8 0 200 0 Blue 0
5 AM Tue 62 42 S 0 0 200 0 Blue 0
6 AM Tue 60 40 S 0 0 200 0 Blue 0
7 AM Tue 59 39 S 0 0 200 0 Blue 0
8 AM Tue 59 39 S 0 0 200 0 Blue 0
9 AM Tue 61 42 S 0 0 200 0 Blue 0
10 AM Tue 63 45 S 0 0 200 0 Blue 0
11 AM Tue 67 51 NE 5 0 200 0 Blue 0
12 Noon Tue 70 55 NE 5 0 200 0 Blue 0
1 PM Tue 73 58 NE 5 0 200 0 Blue 0
2 PM Tue 74 59 NE 5 0 200 0 Blue 0
3 PM Tue 72 56 NE 5 0 200 0 Blue 0
4 PM Tue 69 52 NE 5 0 200 0 Blue 0
5 PM Tue 67 48 W 10 0 200 0 Blue 0
6 PM Tue 66 46 W 10 0 200 0 Blue 0
7 PM Tue 66 46 W 10 0 200 0 Blue 0
8 PM Tue 66 46 W 10 0 200 0 Blue 0
9 PM Tue 65 45 W 10 0 200 0 Blue 0
10 PM Tue 64 44 W 10 0 200 0 Blue 0
11 PM Tue 63 43 W 3 0 200 0 Blue 0
12 Midnight Wed 62 42 W 3 0 200 0 Blue 0
1 AM Wed 60 40 W 3 0 200 0 Blue 0
2 AM Wed 60 40 W 3 0 200 0 Blue 0
3 AM Wed 59 39 W 3 0 200 0 Blue 0
4 AM Wed 60 40 W 3 0 200 0 Blue 0
5 AM Wed 60 40 NE 2 0 200 0 Blue 0
6 AM Wed 59 39 NE 2 0 200 0 Blue 0
7 AM Wed 59 39 NE 2 0 200 0 Blue 0
8 AM Wed 60 40 NE 2 0 200 0 Blue 0
9 AM Wed 61 42 NE 2 0 200 0 Blue 0
10 AM Wed 64 46 NE 2 0 200 0 Blue 0
11 AM Wed 67 50 NE 5 0 200 0 Blue 0
12 Noon Wed 71 55 NE 5 0 200 0 Blue 0
1 PM Wed 74 58 NE 5 0 200 0 Blue 0
2 PM Wed 75 59 NE 5 0 200 0 Blue 0
3 PM Wed 73 56 NE 5 0 200 0 Blue 0
4 PM Wed 70 52 NE 5 0 200 0 Blue 0
5 PM Wed 68 49 W 7 0 200 0 Blue 0
6 PM Wed 67 47 W 7 0 200 0 Blue 0
7 PM Wed 68 48 W 7 0 200 0 Blue 0
8 PM Wed 68 48 W 7 0 200 0 Blue 0
9 PM Wed 66 46 W 7 0 200 0 Blue 0
10 PM Wed 64 44 W 7 0 200 0 Blue 0
11 PM Wed 62 42 NW 3 0 200 0 Blue 0
12 Midnight Thu 61 41 NW 3 0 200 0 Blue 0
1 AM Thu 61 41 NW 3 0 200 0 Blue 0
2 AM Thu 61 41 NW 3 0 200 0 Blue 0
3 AM Thu 61 41 NW 3 0 200 0 Blue 0
4 AM Thu 60 40 NW 3 0 200 0 Blue 0
5 AM Thu 60 40 N 1 0 200 0 Blue 0
6 AM Thu 59 39 N 1 0 200 0 Blue 0
7 AM Thu 59 39 N 1 0 200 0 Blue 0
8 AM Thu 60 40 N 1 0 200 0 Blue 0
9 AM Thu 62 42 N 1 0 200 0 Blue 0
10 AM Thu 64 45 N 1 0 200 0 Blue 0
11 AM Thu 68 51 N 2 0 200 0 Blue 0
12 Noon Thu 72 56 N 2 0 200 0 Blue 0
1 PM Thu 74 58 N 2 0 200 0 Blue 0
2 PM Thu 75 59 N 2 0 200 0 Blue 0
3 PM Thu 73 56 N 2 0 200 0 Blue 0
4 PM Thu 70 52 N 2 0 200 0 Blue 0
5 PM Thu 67 48 W 9 0 200 0 Blue 0
6 PM Thu 66 46 W 9 0 200 0 Blue 0
7 PM Thu 66 46 W 9 0 200 0 Blue 0
8 PM Thu 66 46 W 9 0 200 0 Blue 0
9 PM Thu 65 45 W 9 0 200 0 Blue 0
10 PM Thu 64 44 W 9 0 200 0 Blue 0
11 PM Thu 62 42 W 5 0 200 0 Blue 0
12 Midnight Fri 61 41 W 5 0 200 0 Blue 0
1 AM Fri 60 40 W 5 0 200 0 Blue 0
2 AM Fri 60 40 W 5 0 200 0 Blue 0
3 AM Fri 59 39 W 5 0 200 0 Blue 0
4 AM Fri 59 39 W 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