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

Station:

KMFR

Date/Time:

23 JUN 2021

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 Wed 68 68 SW 1 3 14902 11144 4244 Blue 8
1 AM Wed 59 59 SE 1 2 6947 6900 0 Blue 0
2 AM Wed 51 51 NE 0 0 6312 6900 0 Blue 0
3 AM Wed 51 51 NE 0 2 6312 6900 0 Blue 0
4 AM Wed 50 50 NE 1 3 6312 6900 0 Blue 0
5 AM Wed 50 50 NE 2 4 6312 6900 0 Blue 0
6 AM Wed 56 56 ENE 2 4 6312 6900 0 Blue 0
7 AM Wed 62 62 E 2 3 9717 6944 44 Blue 2
8 AM Wed 68 69 ESE 3 3 15816 11842 4942 White 9
9 AM Wed 72 75 ESE 3 4 17061 17061 10161 White 15
10 AM Wed 76 80 ESE 4 5 18079 18079 11179 White 19
11 AM Wed 80 86 ESE 5 5 19303 19303 12403 White 25
12 Noon Wed 82 90 ESE 6 6 20089 20089 13189 White 29
1 PM Wed 84 92 ESE 7 8 20476 20476 13576 White 31
2 PM Wed 86 94 SE 8 9 20862 20862 13962 White 33
3 PM Wed 86 93 SE 7 8 20669 20669 13769 White 32
4 PM Wed 86 91 SE 7 8 20283 20283 13383 White 30
5 PM Wed 86 89 SE 7 8 19893 19893 12993 White 28
6 PM Wed 85 87 SSE 6 7 19501 19501 12601 White 26
7 PM Wed 84 84 SSW 4 6 18903 18903 12003 White 23
8 PM Wed 82 82 SW 3 4 18480 18480 11580 White 21
9 PM Wed 81 81 WSW 3 5 18280 18280 11380 White 20
10 PM Wed 80 80 W 3 6 18079 18079 11179 White 19
11 PM Wed 79 79 WNW 3 7 17878 17878 10978 White 18
12 Midnight Thu 70 70 NW 3 6 16024 12605 5705 White 10
1 AM Thu 60 60 NW 2 5 8384 6900 0 Blue 0
2 AM Thu 51 51 NNW 2 4 6312 6900 0 Blue 0
3 AM Thu 51 51 NW 2 4 6312 6900 0 Blue 0
4 AM Thu 50 50 NW 2 4 6312 6900 0 Blue 0
5 AM Thu 50 50 NW 2 4 6312 6900 0 Blue 0
6 AM Thu 57 57 NW 1 2 6312 6900 0 Blue 0
7 AM Thu 63 63 WNW 0 1 10292 8326 1426 Blue 3
8 AM Thu 70 71 WNW 0 0 16232 14404 7504 White 11
9 AM Thu 75 77 WSW 1 1 17473 17473 10573 White 17
10 AM Thu 81 85 S 1 2 19106 19106 12206 White 24
11 AM Thu 86 91 SE 2 3 20283 20283 13383 White 30
12 Noon Thu 89 96 SE 3 3 21244 21244 14344 White 35
1 PM Thu 91 98 SE 4 4 21626 21626 14726 White 37
2 PM Thu 93 100 SE 4 5 22003 22003 15103 White 39
3 PM Thu 91 96 SE 5 6 21244 21244 14344 White 35
4 PM Thu 89 92 SSE 6 7 20476 20476 13576 White 31
5 PM Thu 87 89 SSE 6 8 19893 19893 12993 White 28
6 PM Thu 85 85 ESE 5 7 19106 19106 12206 White 24
7 PM Thu 82 82 E 4 6 18480 18480 11580 White 21
8 PM Thu 80 80 NE 2 5 18079 18079 11179 White 19
9 PM Thu 78 78 SE 2 4 17676 17676 10776 White 18
10 PM Thu 75 75 SW 2 4 17061 17061 10161 White 15
11 PM Thu 73 73 NW 2 4 16647 16647 9747 White 13
12 Midnight Fri 68 68 NW 1 4 14902 11144 4244 Blue 8
1 AM Fri 62 62 NW 1 3 9717 6944 44 Blue 2
2 AM Fri 57 57 WNW 1 3 6312 6900 0 Blue 0
3 AM Fri 56 56 WNW 1 3 6312 6900 0 Blue 0
4 AM Fri 56 56 WNW 1 3 6312 6900 0 Blue 0
5 AM Fri 55 55 NW 1 3 6312 6900 0 Blue 0
6 AM Fri 62 62 WNW 1 3 9717 6944 44 Blue 2
7 AM Fri 68 68 WNW 1 2 14902 11144 4244 Blue 8
8 AM Fri 75 76 WNW 1 1 17267 17267 10367 White 16
9 AM Fri 81 84 WSW 1 2 18903 18903 12003 White 23
10 AM Fri 86 91 S 1 2 20283 20283 13383 White 30
11 AM Fri 92 98 SE 2 2 21626 21626 14726 White 37
12 Noon Fri 95 103 SE 2 2 22565 22565 15665 White 42
1 PM Fri 97 105 SE 2 3 22939 22939 16039 White 44
2 PM Fri 100 108 SE 3 3 23494 23494 16594 White 47
3 PM Fri 100 107 SE 3 4 23309 23309 16409 White 46
4 PM Fri 99 104 SSE 3 4 22753 22753 15853 White 43
5 PM Fri 99 102 SSE 3 4 22378 22378 15478 White 41
6 PM Fri 97 99 S 4 6 21815 21815 14915 White 38
7 PM Fri 95 95 SW 4 8 21053 21053 14153 White 34
8 PM Fri 92 92 W 4 10 20476 20476 13576 White 31
9 PM Fri 90 90 W 4 9 20089 20089 13189 White 29
10 PM Fri 89 89 WNW 4 9 19893 19893 12993 White 28
11 PM Fri 87 87 WNW 4 8 19501 19501 12601 White 26

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]