Detailed Predictions for: Weaver Bally
Launch Altitude (f): 6900
LZ Altitude (f): 1480
Sounding

Station:

KOAK

Date/Time:

18 SEP 2019

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 Wed 45 45 NW 8 5243 6900 0 Blue 0
6 AM Wed 45 45 NW 8 5243 6900 0 Blue 0
7 AM Wed 45 45 NW 8 5243 6900 0 Blue 0
8 AM Wed 48 48 W 9 5243 6900 0 Blue 0
9 AM Wed 44 44 W 9 5243 6900 0 Blue 0
10 AM Wed 48 48 W 9 5243 6900 0 Blue 0
11 AM Wed 48 48 W 9 5243 6900 0 Blue 0
12 Noon Wed 47 47 W 9 5243 6900 0 Blue 0
1 PM Wed 47 47 W 9 5243 6900 0 Blue 0
2 PM Wed 47 47 W 13 5243 6900 0 Blue 0
3 PM Wed 47 47 W 13 5243 6900 0 Blue 0
4 PM Wed 47 47 W 13 5243 6900 0 Blue 0
5 PM Wed 46 46 NW 12 5243 6900 0 Blue 0
6 PM Wed 46 46 NW 12 5243 6900 0 Blue 0
7 PM Wed 46 46 NW 12 5243 6900 0 Blue 0
8 PM Wed 45 45 NW 10 5243 6900 0 Blue 0
9 PM Wed 45 45 NW 10 5243 6900 0 Blue 0
10 PM Wed 44 44 NW 10 5243 6900 0 Blue 0
11 PM Wed 44 44 N 8 5243 6900 0 Blue 0
12 Midnight Thu 43 43 N 8 5243 6900 0 Blue 0
1 AM Thu 43 43 N 8 5243 6900 0 Blue 0
2 AM Thu 42 42 N 6 5243 6900 0 Blue 0
3 AM Thu 42 42 N 6 5243 6900 0 Blue 0
4 AM Thu 42 42 N 6 5243 6900 0 Blue 0
5 AM Thu 43 43 N 6 5243 6900 0 Blue 0
6 AM Thu 44 44 N 6 5243 6900 0 Blue 0
7 AM Thu 45 45 N 6 5243 6900 0 Blue 0
8 AM Thu 47 47 N 6 5243 6900 0 Blue 0
9 AM Thu 49 50 N 6 5243 6900 0 Blue 0
10 AM Thu 51 53 N 6 5383 6900 0 Blue 0
11 AM Thu 53 56 N 6 6649 6900 0 Blue 2
12 Noon Thu 55 59 N 6 7449 6900 0 Blue 5
1 PM Thu 56 61 N 6 7959 7168 268 Blue 7
2 PM Thu 57 62 N 8 8145 7431 531 Blue 8
3 PM Thu 58 62 N 8 8145 7431 531 Blue 8
4 PM Thu 59 61 N 8 7959 7168 268 Blue 7
5 PM Thu 59 60 NW 7 7712 6904 4 Blue 6
6 PM Thu 58 58 NW 7 7184 6900 0 Blue 4
7 PM Thu 57 57 NW 7 6917 6900 0 Blue 3
8 PM Thu 56 56 NW 7 6649 6900 0 Blue 2
9 PM Thu 54 54 NW 7 5563 6900 0 Blue 0
10 PM Thu 52 52 NW 7 5243 6900 0 Blue 0
11 PM Thu 51 51 N 6 5243 6900 0 Blue 0
12 Midnight Fri 49 49 N 6 5243 6900 0 Blue 0
1 AM Fri 48 48 N 6 5243 6900 0 Blue 0
2 AM Fri 47 47 N 6 5243 6900 0 Blue 0
3 AM Fri 46 46 N 6 5243 6900 0 Blue 0
4 AM Fri 46 46 N 6 5243 6900 0 Blue 0
5 AM Fri 46 46 N 6 5243 6900 0 Blue 0
6 AM Fri 47 47 N 6 5243 6900 0 Blue 0
7 AM Fri 48 48 N 6 5243 6900 0 Blue 0
8 AM Fri 50 50 N 6 5243 6900 0 Blue 0
9 AM Fri 52 53 N 6 5383 6900 0 Blue 0
10 AM Fri 54 56 N 6 6649 6900 0 Blue 2
11 AM Fri 56 59 N 7 7449 6900 0 Blue 5
12 Noon Fri 58 62 N 7 8145 7431 531 Blue 8
1 PM Fri 60 65 N 7 9671 8123 1223 Blue 11
2 PM Fri 62 67 N 7 10603 9159 2259 White 13
3 PM Fri 63 67 N 7 10603 9159 2259 White 13
4 PM Fri 64 67 N 7 10603 9159 2259 White 13
5 PM Fri 64 65 N 7 9671 8123 1223 Blue 11
6 PM Fri 63 63 N 7 8676 7692 792 Blue 9
7 PM Fri 62 62 N 7 8145 7431 531 Blue 8
8 PM Fri 61 61 N 7 7959 7168 268 Blue 7
9 PM Fri 59 59 N 7 7449 6900 0 Blue 5
10 PM Fri 57 57 N 7 6917 6900 0 Blue 3
11 PM Fri 55 55 N 5 5881 6900 0 Blue 1
12 Midnight Sat 53 53 N 5 5383 6900 0 Blue 0
1 AM Sat 52 52 N 5 5243 6900 0 Blue 0
2 AM Sat 51 51 N 5 5243 6900 0 Blue 0
3 AM Sat 50 50 N 5 5243 6900 0 Blue 0
4 AM Sat 50 50 N 5 5243 6900 0 Blue 0
5 AM Sat 50 50 N 3 5243 6900 0 Blue 0
6 AM Sat 51 51 N 3 5243 6900 0 Blue 0
7 AM Sat 53 53 N 3 5383 6900 0 Blue 0
8 AM Sat 55 55 N 3 5881 6900 0 Blue 1
9 AM Sat 57 58 N 3 7184 6900 0 Blue 4
10 AM Sat 59 61 N 3 7959 7168 268 Blue 7
11 AM Sat 61 64 N 5 9226 7944 1044 Blue 10
12 Noon Sat 64 68 N 5 10819 9618 2718 White 14
1 PM Sat 65 70 N 5 11249 10662 3762 White 16
2 PM Sat 67 72 N 5 11675 11675 4775 White 18
3 PM Sat 68 72 N 5 11675 11675 4775 White 18
4 PM Sat 69 72 N 5 11675 11675 4775 White 18
5 PM Sat 69 70 W 7 11249 10662 3762 White 16
6 PM Sat 68 68 W 7 10819 9618 2718 White 14
7 PM Sat 67 67 W 7 10603 9159 2259 White 13
8 PM Sat 65 65 W 7 9671 8123 1223 Blue 11
9 PM Sat 63 63 W 7 8676 7692 792 Blue 9
10 PM Sat 60 60 W 7 7712 6904 4 Blue 6
11 PM Sat 58 58 NW 6 7184 6900 0 Blue 4
12 Midnight Sun 56 56 NW 6 6649 6900 0 Blue 2
1 AM Sun 55 55 NW 6 5881 6900 0 Blue 1
2 AM Sun 53 53 NW 6 5383 6900 0 Blue 0
3 AM Sun 52 52 NW 6 5243 6900 0 Blue 0
4 AM Sun 52 52 NW 6 5243 6900 0 Blue 0
5 AM Sun 52 52 NW 5 5243 6900 0 Blue 0
6 AM Sun 53 53 NW 5 5383 6900 0 Blue 0
7 AM Sun 55 55 NW 5 5881 6900 0 Blue 1
8 AM Sun 57 57 NW 5 6917 6900 0 Blue 3
9 AM Sun 60 60 NW 5 7712 6904 4 Blue 6
10 AM Sun 62 62 NW 5 8145 7431 531 Blue 8
11 AM Sun 64 65 W 10 9671 8123 1223 Blue 11
12 Noon Sun 65 67 W 10 10603 9159 2259 White 13
1 PM Sun 65 67 W 10 10603 9159 2259 White 13
2 PM Sun 65 67 W 10 10603 9159 2259 White 13
3 PM Sun 64 65 W 10 9671 8123 1223 Blue 11
4 PM Sun 64 65 W 10 9671 8123 1223 Blue 11
5 PM Sun 63 64 W 13 9226 7944 1044 Blue 10
6 PM Sun 62 62 W 13 8145 7431 531 Blue 8
7 PM Sun 61 61 W 13 7959 7168 268 Blue 7
8 PM Sun 60 60 W 13 7712 6904 4 Blue 6
9 PM Sun 59 59 W 13 7449 6900 0 Blue 5
10 PM Sun 57 57 W 13 6917 6900 0 Blue 3
11 PM Sun 56 56 NW 9 6649 6900 0 Blue 2
12 Midnight Mon 54 54 NW 9 5563 6900 0 Blue 0
1 AM Mon 53 53 NW 9 5383 6900 0 Blue 0
2 AM Mon 51 51 NW 9 5243 6900 0 Blue 0
3 AM Mon 50 50 NW 9 5243 6900 0 Blue 0
4 AM Mon 50 50 NW 9 5243 6900 0 Blue 0
5 AM Mon 50 50 N 8 5243 6900 0 Blue 0
6 AM Mon 51 51 N 8 5243 6900 0 Blue 0
7 AM Mon 52 52 N 8 5243 6900 0 Blue 0
8 AM Mon 54 54 N 8 5563 6900 0 Blue 0
9 AM Mon 55 56 N 8 6649 6900 0 Blue 2
10 AM Mon 57 59 N 8 7449 6900 0 Blue 5
11 AM Mon 59 62 N 8 8145 7431 531 Blue 8
12 Noon Mon 61 65 N 8 9671 8123 1223 Blue 11
1 PM Mon 62 67 N 8 10603 9159 2259 White 13
2 PM Mon 64 68 N 8 10819 9618 2718 White 14
3 PM Mon 65 69 N 8 11034 9988 3088 White 15
4 PM Mon 65 67 N 8 10603 9159 2259 White 13
5 PM Mon 65 66 N 8 10044 8616 1716 Blue 12
6 PM Mon 64 64 N 8 9226 7944 1044 Blue 10
7 PM Mon 63 63 N 8 8676 7692 792 Blue 9
8 PM Mon 62 62 N 8 8145 7431 531 Blue 8
9 PM Mon 60 60 N 8 7712 6904 4 Blue 6
10 PM Mon 58 58 N 8 7184 6900 0 Blue 4
11 PM Mon 56 56 NE 7 6649 6900 0 Blue 2
12 Midnight Tue 55 55 NE 7 5881 6900 0 Blue 1
1 AM Tue 53 53 NE 7 5383 6900 0 Blue 0
2 AM Tue 52 52 NE 7 5243 6900 0 Blue 0
3 AM Tue 52 52 NE 7 5243 6900 0 Blue 0
4 AM Tue 52 52 NE 7 5243 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