Detailed Predictions for: Weaver Bally
Launch Altitude (f): 6900
LZ Altitude (f): 1480
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 45 45 NE 3 4911 6900 0 Blue 0
6 AM Tue 45 45 NE 3 4911 6900 0 Blue 0
7 AM Tue 46 46 NE 3 4911 6900 0 Blue 0
8 AM Tue 48 48 NE 2 4911 6900 0 Blue 0
9 AM Tue 50 51 NE 2 4911 6900 0 Blue 0
10 AM Tue 52 54 NE 2 4911 6900 0 Blue 0
11 AM Tue 55 58 NW 1 5606 6900 0 Blue 0
12 Noon Tue 57 61 NW 1 6758 6900 0 Blue 3
1 PM Tue 60 65 NW 1 7749 7093 193 Blue 7
2 PM Tue 62 67 NW 3 8370 7536 636 Blue 9
3 PM Tue 64 68 NW 3 8775 7734 834 Blue 10
4 PM Tue 65 68 NW 3 8775 7734 834 Blue 10
5 PM Tue 65 66 W 7 7958 7337 437 Blue 8
6 PM Tue 64 64 W 7 7550 6900 0 Blue 6
7 PM Tue 62 62 W 7 7112 6900 0 Blue 4
8 PM Tue 59 59 NW 7 6057 6900 0 Blue 1
9 PM Tue 56 56 NW 7 4911 6900 0 Blue 0
10 PM Tue 52 52 NW 7 4911 6900 0 Blue 0
11 PM Tue 50 50 N 6 4911 6900 0 Blue 0
12 Midnight Wed 47 47 N 6 4911 6900 0 Blue 0
1 AM Wed 46 46 N 6 4911 6900 0 Blue 0
2 AM Wed 45 45 N 6 4911 6900 0 Blue 0
3 AM Wed 44 44 N 6 4911 6900 0 Blue 0
4 AM Wed 44 44 N 6 4911 6900 0 Blue 0
5 AM Wed 45 45 N 7 4911 6900 0 Blue 0
6 AM Wed 46 46 N 7 4911 6900 0 Blue 0
7 AM Wed 47 47 N 7 4911 6900 0 Blue 0
8 AM Wed 49 49 N 7 4911 6900 0 Blue 0
9 AM Wed 51 52 N 7 4911 6900 0 Blue 0
10 AM Wed 54 56 N 7 4911 6900 0 Blue 0
11 AM Wed 56 60 NW 6 6405 6900 0 Blue 2
12 Noon Wed 59 64 NW 6 7550 6900 0 Blue 6
1 PM Wed 62 67 NW 6 8370 7536 636 Blue 9
2 PM Wed 64 69 NW 7 9174 7932 1032 Blue 11
3 PM Wed 66 70 NW 7 9567 8330 1430 Blue 12
4 PM Wed 67 70 NW 7 9567 8330 1430 Blue 12
5 PM Wed 67 68 NW 7 8775 7734 834 Blue 10
6 PM Wed 66 66 NW 7 7958 7337 437 Blue 8
7 PM Wed 63 63 NW 7 7350 6900 0 Blue 5
8 PM Wed 61 61 NW 7 6758 6900 0 Blue 3
9 PM Wed 57 57 NW 7 4911 6900 0 Blue 0
10 PM Wed 54 54 NW 7 4911 6900 0 Blue 0
11 PM Wed 51 51 NW 5 4911 6900 0 Blue 0
12 Midnight Thu 49 49 NW 5 4911 6900 0 Blue 0
1 AM Thu 47 47 NW 5 4911 6900 0 Blue 0
2 AM Thu 46 46 NW 5 4911 6900 0 Blue 0
3 AM Thu 45 45 NW 5 4911 6900 0 Blue 0
4 AM Thu 45 45 NW 5 4911 6900 0 Blue 0
5 AM Thu 46 46 N 7 4911 6900 0 Blue 0
6 AM Thu 47 47 N 7 4911 6900 0 Blue 0
7 AM Thu 49 49 N 7 4911 6900 0 Blue 0
8 AM Thu 51 51 N 7 4911 6900 0 Blue 0
9 AM Thu 53 54 N 7 4911 6900 0 Blue 0
10 AM Thu 56 58 N 7 5606 6900 0 Blue 0
11 AM Thu 59 63 NW 7 7350 6900 0 Blue 5
12 Noon Thu 63 68 NW 7 8775 7734 834 Blue 10
1 PM Thu 66 71 NW 7 9954 8731 1831 Blue 13
2 PM Thu 69 74 NW 7 11921 9898 2998 Blue 16
3 PM Thu 71 75 NW 7 12189 10261 3361 Blue 17
4 PM Thu 72 75 NW 7 12189 10261 3361 Blue 17
5 PM Thu 72 73 NW 7 10626 9514 2614 Blue 15
6 PM Thu 71 71 NW 7 9954 8731 1831 Blue 13
7 PM Thu 68 68 NW 7 8775 7734 834 Blue 10
8 PM Thu 64 64 NW 7 7550 6900 0 Blue 6
9 PM Thu 61 61 NW 7 6758 6900 0 Blue 3
10 PM Thu 57 57 NW 7 4911 6900 0 Blue 0
11 PM Thu 54 54 NW 6 4911 6900 0 Blue 0
12 Midnight Fri 51 51 NW 6 4911 6900 0 Blue 0
1 AM Fri 50 50 NW 6 4911 6900 0 Blue 0
2 AM Fri 49 49 NW 6 4911 6900 0 Blue 0
3 AM Fri 49 49 NW 6 4911 6900 0 Blue 0
4 AM Fri 50 50 NW 6 4911 6900 0 Blue 0
5 AM Fri 51 51 NW 6 4911 6900 0 Blue 0
6 AM Fri 53 53 NW 6 4911 6900 0 Blue 0
7 AM Fri 55 55 NW 6 4911 6900 0 Blue 0
8 AM Fri 57 57 NW 6 4911 6900 0 Blue 0
9 AM Fri 60 61 NW 6 6758 6900 0 Blue 3
10 AM Fri 62 64 NW 6 7550 6900 0 Blue 6
11 AM Fri 65 68 S 1 8775 7734 834 Blue 10
12 Noon Fri 67 71 S 1 9954 8731 1831 Blue 13
1 PM Fri 68 72 S 1 10311 9125 2225 Blue 14
2 PM Fri 69 73 S 1 10626 9514 2614 Blue 15
3 PM Fri 70 73 S 1 10626 9514 2614 Blue 15
4 PM Fri 70 72 S 1 10311 9125 2225 Blue 14
5 PM Fri 69 70 W 8 9567 8330 1430 Blue 12
6 PM Fri 67 67 W 8 8370 7536 636 Blue 9
7 PM Fri 65 65 W 8 7749 7093 193 Blue 7
8 PM Fri 62 62 W 8 7112 6900 0 Blue 4
9 PM Fri 59 59 W 8 6057 6900 0 Blue 1
10 PM Fri 56 56 W 8 4911 6900 0 Blue 0
11 PM Fri 54 54 NW 3 4911 6900 0 Blue 0
12 Midnight Sat 51 51 NW 3 4911 6900 0 Blue 0
1 AM Sat 50 50 NW 3 4911 6900 0 Blue 0
2 AM Sat 49 49 NW 3 4911 6900 0 Blue 0
3 AM Sat 48 48 NW 3 4911 6900 0 Blue 0
4 AM Sat 48 48 NW 3 4911 6900 0 Blue 0
5 AM Sat 49 49 W 2 4911 6900 0 Blue 0
6 AM Sat 50 50 W 2 4911 6900 0 Blue 0
7 AM Sat 51 51 W 2 4911 6900 0 Blue 0
8 AM Sat 53 53 W 2 4911 6900 0 Blue 0
9 AM Sat 55 55 W 2 4911 6900 0 Blue 0
10 AM Sat 57 58 W 2 5606 6900 0 Blue 0
11 AM Sat 60 63 W 3 7350 6900 0 Blue 5
12 Noon Sat 61 64 W 3 7550 6900 0 Blue 6
1 PM Sat 63 67 W 3 8370 7536 636 Blue 9
2 PM Sat 64 68 W 3 8775 7734 834 Blue 10
3 PM Sat 65 68 W 3 8775 7734 834 Blue 10
4 PM Sat 65 67 W 3 8370 7536 636 Blue 9
5 PM Sat 64 65 W 5 7749 7093 193 Blue 7
6 PM Sat 63 63 W 5 7350 6900 0 Blue 5
7 PM Sat 61 61 W 5 6758 6900 0 Blue 3
8 PM Sat 59 59 W 5 6057 6900 0 Blue 1
9 PM Sat 56 56 W 5 4911 6900 0 Blue 0
10 PM Sat 54 54 W 5 4911 6900 0 Blue 0
11 PM Sat 51 51 NW 7 4911 6900 0 Blue 0
12 Midnight Sun 49 49 NW 7 4911 6900 0 Blue 0
1 AM Sun 47 47 NW 7 4911 6900 0 Blue 0
2 AM Sun 46 46 NW 7 4911 6900 0 Blue 0
3 AM Sun 45 45 NW 7 4911 6900 0 Blue 0
4 AM Sun 45 45 NW 7 4911 6900 0 Blue 0
5 AM Sun 45 45 NW 7 4911 6900 0 Blue 0
6 AM Sun 46 46 NW 7 4911 6900 0 Blue 0
7 AM Sun 47 47 NW 7 4911 6900 0 Blue 0
8 AM Sun 48 48 NW 7 4911 6900 0 Blue 0
9 AM Sun 50 50 NW 7 4911 6900 0 Blue 0
10 AM Sun 52 53 NW 7 4911 6900 0 Blue 0
11 AM Sun 54 57 NW 5 4911 6900 0 Blue 0
12 Noon Sun 56 60 NW 5 6405 6900 0 Blue 2
1 PM Sun 59 63 NW 5 7350 6900 0 Blue 5
2 PM Sun 61 65 NW 5 7749 7093 193 Blue 7
3 PM Sun 62 65 NW 5 7749 7093 193 Blue 7
4 PM Sun 63 65 NW 5 7749 7093 193 Blue 7
5 PM Sun 63 64 W 7 7550 6900 0 Blue 6
6 PM Sun 62 62 W 7 7112 6900 0 Blue 4
7 PM Sun 60 60 W 7 6405 6900 0 Blue 2
8 PM Sun 58 58 W 7 5606 6900 0 Blue 0
9 PM Sun 55 55 W 7 4911 6900 0 Blue 0
10 PM Sun 52 52 W 7 4911 6900 0 Blue 0
11 PM Sun 49 49 NW 5 4911 6900 0 Blue 0
12 Midnight Mon 47 47 NW 5 4911 6900 0 Blue 0
1 AM Mon 45 45 NW 5 4911 6900 0 Blue 0
2 AM Mon 44 44 NW 5 4911 6900 0 Blue 0
3 AM Mon 43 43 NW 5 4911 6900 0 Blue 0
4 AM Mon 43 43 NW 5 4911 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 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