Detailed Predictions for: Weaver Bally
Launch Lat, Long, Altitude (f): 40.796231, -123.00509, 6900
LZ Altitude (f): 1480
Sounding

Station:

 KOAK

Date/Time UTC:

 260418/1200

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Wind
 Gust		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
12 Midnight Sat 45 45 NE 3 6 4921 6900 0 Blue 0
1 AM Sat 44 44 NE 3 6 4921 6900 0 Blue 0
2 AM Sat 43 43 E 4 8 4921 6900 0 Blue 0
3 AM Sat 43 43 E 4 8 4921 6900 0 Blue 0
4 AM Sat 42 42 E 4 8 4921 6900 0 Blue 0
5 AM Sat 42 42 E 5 8 4921 6900 0 Blue 0
6 AM Sat 42 42 E 5 8 4921 6900 0 Blue 0
7 AM Sat 43 43 E 5 8 4921 6900 0 Blue 0
8 AM Sat 44 44 ESE 5 8 4921 6900 0 Blue 0
9 AM Sat 47 48 ESE 5 8 5286 6900 0 Blue 0
10 AM Sat 50 52 ESE 5 8 6204 6900 0 Blue 3
11 AM Sat 51 56 SE 8 12 7370 6900 0 Blue 7
12 Noon Sat 53 59 SE 8 12 8388 7352 452 Blue 10
1 PM Sat 54 60 SE 8 12 8828 7636 736 Blue 11
2 PM Sat 55 60 SE 9 14 8828 7636 736 Blue 11
3 PM Sat 56 60 SE 9 14 8828 7636 736 Blue 11
4 PM Sat 56 59 SE 9 14 8388 7352 452 Blue 10
5 PM Sat 57 57 ESE 10 16 7657 6900 0 Blue 8
6 PM Sat 56 56 ESE 10 16 7370 6900 0 Blue 7
7 PM Sat 54 54 ESE 10 16 6791 6900 0 Blue 5
8 PM Sat 52 52 E 11 16 6204 6900 0 Blue 3
9 PM Sat 50 50 E 11 16 5707 6900 0 Blue 1
10 PM Sat 49 49 E 11 16 5597 6900 0 Blue 0
11 PM Sat 47 47 E 13 19 4921 6900 0 Blue 0
12 Midnight Sun 47 47 E 13 19 4921 6900 0 Blue 0
1 AM Sun 46 46 E 13 19 4921 6900 0 Blue 0
2 AM Sun 46 46 E 16 21 4921 6900 0 Blue 0
3 AM Sun 45 45 E 16 21 4921 6900 0 Blue 0
4 AM Sun 45 45 E 16 21 4921 6900 0 Blue 0
5 AM Sun 45 45 E 16 24 4921 6900 0 Blue 0
6 AM Sun 45 45 E 16 24 4921 6900 0 Blue 0
7 AM Sun 45 45 E 16 24 4921 6900 0 Blue 0
8 AM Sun 47 47 E 18 26 4921 6900 0 Blue 0
9 AM Sun 47 47 E 18 26 4921 6900 0 Blue 0
10 AM Sun 49 49 E 18 26 5597 6900 0 Blue 0
11 AM Sun 51 52 ESE 20 31 6204 6900 0 Blue 3
12 Noon Sun 52 54 ESE 20 31 6791 6900 0 Blue 5
1 PM Sun 52 54 ESE 20 31 6791 6900 0 Blue 5
2 PM Sun 52 54 SE 19 28 6791 6900 0 Blue 5
3 PM Sun 52 53 SE 19 28 6499 6900 0 Blue 4
4 PM Sun 52 53 SE 19 28 6499 6900 0 Blue 4
5 PM Sun 52 52 SE 20 31 6204 6900 0 Blue 3
6 PM Sun 51 51 SE 20 31 5908 6900 0 Blue 2
7 PM Sun 51 51 SE 20 31 5908 6900 0 Blue 2
8 PM Sun 50 50 ESE 19 29 5707 6900 0 Blue 1
9 PM Sun 49 49 ESE 19 29 5597 6900 0 Blue 0
10 PM Sun 49 49 ESE 19 29 5597 6900 0 Blue 0
11 PM Sun 48 48 E 18 27 5286 6900 0 Blue 0
12 Midnight Mon 48 48 E 18 27 5286 6900 0 Blue 0
1 AM Mon 48 48 E 18 27 5286 6900 0 Blue 0
2 AM Mon 47 47 E 18 27 4921 6900 0 Blue 0
3 AM Mon 46 46 E 18 27 4921 6900 0 Blue 0
4 AM Mon 44 44 E 18 27 4921 6900 0 Blue 0
5 AM Mon 43 43 E 19 28 4921 6900 0 Blue 0
6 AM Mon 42 42 E 19 28 4921 6900 0 Blue 0
7 AM Mon 42 42 E 19 28 4921 6900 0 Blue 0
8 AM Mon 42 42 E 19 28 4921 6900 0 Blue 0
9 AM Mon 42 42 E 19 28 4921 6900 0 Blue 0
10 AM Mon 41 41 E 19 28 4921 6900 0 Blue 0
11 AM Mon 41 42 ESE 19 29 4921 6900 0 Blue 0
12 Noon Mon 41 42 ESE 19 29 4921 6900 0 Blue 0
1 PM Mon 41 42 ESE 19 29 4921 6900 0 Blue 0
2 PM Mon 41 42 ESE 17 26 4921 6900 0 Blue 0
3 PM Mon 41 41 ESE 17 26 4921 6900 0 Blue 0
4 PM Mon 41 41 ESE 17 26 4921 6900 0 Blue 0
5 PM Mon 41 41 ESE 12 17 4921 6900 0 Blue 0
6 PM Mon 41 41 ESE 12 17 4921 6900 0 Blue 0
7 PM Mon 41 41 ESE 12 17 4921 6900 0 Blue 0
8 PM Mon 41 41 ESE 10 13 4921 6900 0 Blue 0
9 PM Mon 41 41 ESE 10 13 4921 6900 0 Blue 0
10 PM Mon 42 42 ESE 10 13 4921 6900 0 Blue 0
11 PM Mon 42 42 E 9 12 4921 6900 0 Blue 0
12 Midnight Tue 43 43 E 9 12 4921 6900 0 Blue 0
1 AM Tue 43 43 E 9 12 4921 6900 0 Blue 0
2 AM Tue 43 43 ESE 9 11 4921 6900 0 Blue 0
3 AM Tue 42 42 ESE 9 11 4921 6900 0 Blue 0
4 AM Tue 41 41 ESE 9 11 4921 6900 0 Blue 0
5 AM Tue 40 40 ESE 9 11 4921 6900 0 Blue 0
6 AM Tue 40 40 ESE 9 11 4921 6900 0 Blue 0
7 AM Tue 39 39 ESE 9 11 4921 6900 0 Blue 0
8 AM Tue 39 39 E 9 12 4921 6900 0 Blue 0
9 AM Tue 38 38 E 9 12 4921 6900 0 Blue 0
10 AM Tue 38 38 E 9 12 4921 6900 0 Blue 0
11 AM Tue 37 37 ESE 12 16 4921 6900 0 Blue 0
12 Noon Tue 37 37 ESE 12 16 4921 6900 0 Blue 0
1 PM Tue 37 37 ESE 12 16 4921 6900 0 Blue 0
2 PM Tue 37 37 ESE 10 14 4921 6900 0 Blue 0
3 PM Tue 37 37 ESE 10 14 4921 6900 0 Blue 0
4 PM Tue 37 37 ESE 10 14 4921 6900 0 Blue 0
5 PM Tue 37 37 S 9 12 4921 6900 0 Blue 0
6 PM Tue 37 37 S 9 12 4921 6900 0 Blue 0
7 PM Tue 37 37 S 9 12 4921 6900 0 Blue 0
8 PM Tue 37 37 W 9 12 4921 6900 0 Blue 0
9 PM Tue 38 38 W 9 12 4921 6900 0 Blue 0
10 PM Tue 38 38 W 9 12 4921 6900 0 Blue 0
11 PM Tue 39 39 W 8 11 4921 6900 0 Blue 0
12 Midnight Wed 39 39 W 8 11 4921 6900 0 Blue 0
1 AM Wed 39 39 W 8 11 4921 6900 0 Blue 0
2 AM Wed 39 39 W 8 10 4921 6900 0 Blue 0
3 AM Wed 39 39 W 8 10 4921 6900 0 Blue 0
4 AM Wed 38 38 W 8 10 4921 6900 0 Blue 0
5 AM Wed 38 38 WSW 9 11 4921 6900 0 Blue 0
6 AM Wed 37 37 WSW 9 11 4921 6900 0 Blue 0
7 AM Wed 37 37 WSW 9 11 4921 6900 0 Blue 0
8 AM Wed 37 37 WSW 9 12 4921 6900 0 Blue 0
9 AM Wed 37 37 WSW 9 12 4921 6900 0 Blue 0
10 AM Wed 37 38 WSW 9 12 4921 6900 0 Blue 0
11 AM Wed 37 38 W 12 16 4921 6900 0 Blue 0
12 Noon Wed 38 39 W 12 16 4921 6900 0 Blue 0
1 PM Wed 39 40 W 12 16 4921 6900 0 Blue 0
2 PM Wed 39 40 W 12 17 4921 6900 0 Blue 0
3 PM Wed 39 40 W 12 17 4921 6900 0 Blue 0
4 PM Wed 39 40 W 12 17 4921 6900 0 Blue 0
5 PM Wed 39 39 W 13 18 4921 6900 0 Blue 0
6 PM Wed 39 39 W 13 18 4921 6900 0 Blue 0
7 PM Wed 39 39 W 13 18 4921 6900 0 Blue 0
8 PM Wed 39 39 W 12 16 4921 6900 0 Blue 0
9 PM Wed 39 39 W 12 16 4921 6900 0 Blue 0
10 PM Wed 39 39 W 12 16 4921 6900 0 Blue 0
11 PM Wed 39 39 W 9 11 4921 6900 0 Blue 0
12 Midnight Thu 38 38 W 9 11 4921 6900 0 Blue 0
1 AM Thu 38 38 W 9 11 4921 6900 0 Blue 0
2 AM Thu 38 38 WNW 9 10 4921 6900 0 Blue 0
3 AM Thu 37 37 WNW 9 10 4921 6900 0 Blue 0
4 AM Thu 36 36 WNW 9 10 4921 6900 0 Blue 0
5 AM Thu 35 35 W 8 10 4921 6900 0 Blue 0
6 AM Thu 35 35 W 8 10 4921 6900 0 Blue 0
7 AM Thu 36 36 W 8 10 4921 6900 0 Blue 0
8 AM Thu 37 37 W 6 10 4921 6900 0 Blue 0
9 AM Thu 39 40 W 6 10 4921 6900 0 Blue 0
10 AM Thu 41 43 W 6 10 4921 6900 0 Blue 0
11 AM Thu 44 48 W 8 11 5286 6900 0 Blue 0
12 Noon Thu 45 50 W 8 11 5707 6900 0 Blue 1
1 PM Thu 46 51 W 8 11 5908 6900 0 Blue 2
2 PM Thu 47 52 W 9 13 6204 6900 0 Blue 3
3 PM Thu 47 51 W 9 13 5908 6900 0 Blue 2
4 PM Thu 48 51 W 9 13 5908 6900 0 Blue 2
5 PM Thu 48 49 W 11 14 5597 6900 0 Blue 0
6 PM Thu 47 47 W 11 14 4921 6900 0 Blue 0
7 PM Thu 46 46 W 11 14 4921 6900 0 Blue 0
8 PM Thu 44 44 WNW 9 12 4921 6900 0 Blue 0
9 PM Thu 42 42 WNW 9 12 4921 6900 0 Blue 0
10 PM Thu 40 40 WNW 9 12 4921 6900 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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]