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

Station:

KOAK

Date/Time:

25 NOV 2020

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 53 33 NW 12 0 200 0 Blue 0
5 AM Wed 53 33 NW 16 0 200 0 Blue 0
6 AM Wed 51 31 NW 18 0 200 0 Blue 0
7 AM Wed 51 31 NW 22 0 200 0 Blue 0
8 AM Wed 50 30 NW 23 0 200 0 Blue 0
9 AM Wed 50 30 NW 22 0 200 0 Blue 0
10 AM Wed 51 32 NW 21 0 200 0 Blue 0
11 AM Wed 54 36 NW 21 0 200 0 Blue 0
12 Noon Wed 56 38 NW 22 0 200 0 Blue 0
1 PM Wed 56 38 NW 23 0 200 0 Blue 0
2 PM Wed 55 36 NW 25 0 200 0 Blue 0
3 PM Wed 55 35 NW 25 0 200 0 Blue 0
4 PM Wed 55 35 NW 25 0 200 0 Blue 0
5 PM Wed 55 35 NW 23 0 200 0 Blue 0
6 PM Wed 54 34 NW 23 0 200 0 Blue 0
7 PM Wed 54 34 NW 21 0 200 0 Blue 0
8 PM Wed 53 33 NW 18 0 200 0 Blue 0
9 PM Wed 54 34 NW 16 0 200 0 Blue 0
10 PM Wed 52 32 NW 13 0 200 0 Blue 0
11 PM Wed 51 31 N 9 0 200 0 Blue 0
12 Midnight Thu 49 29 N 12 0 200 0 Blue 0
1 AM Thu 49 29 N 14 0 200 0 Blue 0
2 AM Thu 50 30 N 12 0 200 0 Blue 0
3 AM Thu 51 31 N 12 0 200 0 Blue 0
4 AM Thu 49 29 N 17 0 200 0 Blue 0
5 AM Thu 49 29 N 22 0 200 0 Blue 0
6 AM Thu 48 28 N 22 0 200 0 Blue 0
7 AM Thu 48 28 N 22 0 200 0 Blue 0
8 AM Thu 49 29 N 22 0 200 0 Blue 0
9 AM Thu 51 31 N 22 0 200 0 Blue 0
10 AM Thu 52 33 N 16 0 200 0 Blue 0
11 AM Thu 55 37 N 16 0 200 0 Blue 0
12 Noon Thu 57 39 N 16 0 200 0 Blue 0
1 PM Thu 57 39 N 15 0 200 0 Blue 0
2 PM Thu 58 39 N 15 0 200 0 Blue 0
3 PM Thu 59 39 N 15 0 200 0 Blue 0
4 PM Thu 60 40 NE 9 0 200 0 Blue 0
5 PM Thu 58 38 NE 9 0 200 0 Blue 0
6 PM Thu 56 36 NE 9 0 200 0 Blue 0
7 PM Thu 54 34 NE 9 0 200 0 Blue 0
8 PM Thu 53 33 NE 9 0 200 0 Blue 0
9 PM Thu 52 32 NE 9 0 200 0 Blue 0
10 PM Thu 52 32 SE 5 0 200 0 Blue 0
11 PM Thu 52 32 SE 5 0 200 0 Blue 0
12 Midnight Fri 52 32 SE 5 0 200 0 Blue 0
1 AM Fri 51 31 E 15 0 200 0 Blue 0
2 AM Fri 50 30 E 15 0 200 0 Blue 0
3 AM Fri 49 29 E 15 0 200 0 Blue 0
4 AM Fri 48 28 E 15 0 200 0 Blue 0
5 AM Fri 47 27 E 15 0 200 0 Blue 0
6 AM Fri 46 26 E 15 0 200 0 Blue 0
7 AM Fri 46 26 E 15 0 200 0 Blue 0
8 AM Fri 47 27 E 15 0 200 0 Blue 0
9 AM Fri 48 28 E 15 0 200 0 Blue 0
10 AM Fri 50 31 E 12 0 200 0 Blue 0
11 AM Fri 51 33 E 12 0 200 0 Blue 0
12 Noon Fri 52 34 E 12 0 200 0 Blue 0
1 PM Fri 53 35 E 3 0 200 0 Blue 0
2 PM Fri 55 36 E 3 0 200 0 Blue 0
3 PM Fri 56 36 E 3 0 200 0 Blue 0
4 PM Fri 57 37 N 2 0 200 0 Blue 0
5 PM Fri 56 36 N 2 0 200 0 Blue 0
6 PM Fri 55 35 N 2 0 200 0 Blue 0
7 PM Fri 54 34 N 5 0 200 0 Blue 0
8 PM Fri 52 32 N 5 0 200 0 Blue 0
9 PM Fri 52 32 N 5 0 200 0 Blue 0
10 PM Fri 51 31 NE 9 0 200 0 Blue 0
11 PM Fri 50 30 NE 9 0 200 0 Blue 0
12 Midnight Sat 50 30 NE 9 0 200 0 Blue 0
1 AM Sat 50 30 NE 10 0 200 0 Blue 0
2 AM Sat 49 29 NE 10 0 200 0 Blue 0
3 AM Sat 49 29 NE 10 0 200 0 Blue 0
4 AM Sat 48 28 NE 12 0 200 0 Blue 0
5 AM Sat 47 27 NE 12 0 200 0 Blue 0
6 AM Sat 46 26 NE 12 0 200 0 Blue 0
7 AM Sat 46 26 NE 7 0 200 0 Blue 0
8 AM Sat 47 27 NE 7 0 200 0 Blue 0
9 AM Sat 49 29 NE 7 0 200 0 Blue 0
10 AM Sat 51 32 NE 7 0 200 0 Blue 0
11 AM Sat 52 34 NE 7 0 200 0 Blue 0
12 Noon Sat 54 36 NE 7 0 200 0 Blue 0
1 PM Sat 55 37 NE 6 0 200 0 Blue 0
2 PM Sat 56 37 NE 6 0 200 0 Blue 0
3 PM Sat 57 37 NE 6 0 200 0 Blue 0
4 PM Sat 57 37 N 6 0 200 0 Blue 0
5 PM Sat 56 36 N 6 0 200 0 Blue 0
6 PM Sat 54 34 N 6 0 200 0 Blue 0
7 PM Sat 53 33 N 6 0 200 0 Blue 0
8 PM Sat 52 32 N 6 0 200 0 Blue 0
9 PM Sat 51 31 N 6 0 200 0 Blue 0
10 PM Sat 51 31 N 5 0 200 0 Blue 0
11 PM Sat 50 30 N 5 0 200 0 Blue 0
12 Midnight Sun 50 30 N 5 0 200 0 Blue 0
1 AM Sun 49 29 NE 5 0 200 0 Blue 0
2 AM Sun 48 28 NE 5 0 200 0 Blue 0
3 AM Sun 48 28 NE 5 0 200 0 Blue 0
4 AM Sun 47 27 NE 5 0 200 0 Blue 0
5 AM Sun 46 26 NE 5 0 200 0 Blue 0
6 AM Sun 45 25 NE 5 0 200 0 Blue 0
7 AM Sun 45 25 NE 6 0 200 0 Blue 0
8 AM Sun 46 26 NE 6 0 200 0 Blue 0
9 AM Sun 47 27 NE 6 0 200 0 Blue 0
10 AM Sun 49 29 NE 6 0 200 0 Blue 0
11 AM Sun 51 32 NE 6 0 200 0 Blue 0
12 Noon Sun 52 33 NE 6 0 200 0 Blue 0
1 PM Sun 54 35 N 5 0 200 0 Blue 0
2 PM Sun 55 36 N 5 0 200 0 Blue 0
3 PM Sun 56 36 N 5 0 200 0 Blue 0
4 PM Sun 56 36 NW 5 0 200 0 Blue 0
5 PM Sun 54 34 NW 5 0 200 0 Blue 0
6 PM Sun 52 32 NW 5 0 200 0 Blue 0
7 PM Sun 50 30 NW 6 0 200 0 Blue 0
8 PM Sun 50 30 NW 6 0 200 0 Blue 0
9 PM Sun 49 29 NW 6 0 200 0 Blue 0
10 PM Sun 49 29 NW 5 0 200 0 Blue 0
11 PM Sun 49 29 NW 5 0 200 0 Blue 0
12 Midnight Mon 49 29 NW 5 0 200 0 Blue 0
1 AM Mon 49 29 NW 3 0 200 0 Blue 0
2 AM Mon 48 28 NW 3 0 200 0 Blue 0
3 AM Mon 48 28 NW 3 0 200 0 Blue 0
4 AM Mon 47 27 N 5 0 200 0 Blue 0
5 AM Mon 47 27 N 5 0 200 0 Blue 0
6 AM Mon 46 26 N 5 0 200 0 Blue 0
7 AM Mon 46 26 E 6 0 200 0 Blue 0
8 AM Mon 47 27 E 6 0 200 0 Blue 0
9 AM Mon 48 28 E 6 0 200 0 Blue 0
10 AM Mon 50 30 SE 7 0 200 0 Blue 0
11 AM Mon 51 32 SE 7 0 200 0 Blue 0
12 Noon Mon 52 33 SE 7 0 200 0 Blue 0
1 PM Mon 53 34 NW 7 0 200 0 Blue 0
2 PM Mon 54 34 NW 7 0 200 0 Blue 0
3 PM Mon 55 35 NW 7 0 200 0 Blue 0
4 PM Mon 55 35 NW 7 0 200 0 Blue 0
5 PM Mon 55 35 NW 7 0 200 0 Blue 0
6 PM Mon 54 34 NW 7 0 200 0 Blue 0
7 PM Mon 53 33 NW 6 0 200 0 Blue 0
8 PM Mon 52 32 NW 6 0 200 0 Blue 0
9 PM Mon 52 32 NW 6 0 200 0 Blue 0
10 PM Mon 52 32 NW 6 0 200 0 Blue 0
11 PM Mon 52 32 NW 6 0 200 0 Blue 0
12 Midnight Tue 52 32 NW 6 0 200 0 Blue 0
1 AM Tue 52 32 N 6 0 200 0 Blue 0
2 AM Tue 52 32 N 6 0 200 0 Blue 0
3 AM Tue 51 31 N 6 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