Detailed Predictions for: Chelan
Launch Lat, Long, Altitude (f): 47.80712500000001, -120.0336861111111, 3820
LZ Altitude (f): 1200
Sounding

Station:

KOTX

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 72 72 WSW 9 12 2546 3820 0 Blue 1
1 AM Wed 69 69 W 9 12 0 3820 0 Blue 0
2 AM Wed 67 67 W 9 12 0 3820 0 Blue 0
3 AM Wed 64 64 W 8 11 0 3820 0 Blue 0
4 AM Wed 63 63 W 8 11 0 3820 0 Blue 0
5 AM Wed 65 65 W 10 13 0 3820 0 Blue 0
6 AM Wed 62 62 W 9 12 0 3820 0 Blue 0
7 AM Wed 65 65 W 8 11 0 3820 0 Blue 0
8 AM Wed 66 66 W 8 10 0 3820 0 Blue 0
9 AM Wed 70 71 W 6 9 2412 3820 0 Blue 0
10 AM Wed 74 76 W 6 9 3300 3820 0 Blue 5
11 AM Wed 78 82 W 8 10 3889 3820 0 Blue 11
12 Noon Wed 81 86 WSW 8 11 4697 4005 185 Blue 15
1 PM Wed 85 91 WSW 9 13 11054 8062 4242 Blue 20
2 PM Wed 89 95 WSW 11 17 12247 11545 7725 White 24
3 PM Wed 90 95 WSW 12 19 12247 11545 7725 White 24
4 PM Wed 90 94 WSW 12 20 12043 10226 6406 White 23
5 PM Wed 90 93 WSW 13 21 11838 8655 4835 White 22
6 PM Wed 89 90 W 13 21 9641 6943 3123 Blue 19
7 PM Wed 87 87 W 14 20 7133 4179 359 Blue 16
8 PM Wed 83 83 W 14 20 4012 3820 0 Blue 12
9 PM Wed 78 78 W 14 20 3432 3820 0 Blue 7
10 PM Wed 75 75 W 13 19 3234 3820 0 Blue 4
11 PM Wed 71 71 W 13 18 2412 3820 0 Blue 0
12 Midnight Thu 70 70 W 11 16 0 3820 0 Blue 0
1 AM Thu 69 69 WNW 11 16 0 3820 0 Blue 0
2 AM Thu 68 68 WNW 11 14 0 3820 0 Blue 0
3 AM Thu 66 66 WNW 11 16 0 3820 0 Blue 0
4 AM Thu 63 63 WNW 11 16 0 3820 0 Blue 0
5 AM Thu 62 62 WNW 11 16 0 3820 0 Blue 0
6 AM Thu 63 63 WNW 10 14 0 3820 0 Blue 0
7 AM Thu 66 66 WNW 9 12 0 3820 0 Blue 0
8 AM Thu 68 69 WNW 8 10 0 3820 0 Blue 0
9 AM Thu 71 73 NW 6 10 3103 3820 0 Blue 2
10 AM Thu 74 78 NNW 5 8 3432 3820 0 Blue 7
11 AM Thu 78 82 NNW 5 8 3889 3820 0 Blue 11
12 Noon Thu 81 86 NNW 8 11 4697 4005 185 Blue 15
1 PM Thu 83 89 NNW 4 6 8440 4620 800 Blue 18
2 PM Thu 85 90 NW 4 6 9641 6943 3123 Blue 19
3 PM Thu 87 91 NW 4 6 11054 8062 4242 Blue 20
4 PM Thu 88 91 NW 5 8 11054 8062 4242 Blue 20
5 PM Thu 89 91 NW 6 9 11054 8062 4242 Blue 20
6 PM Thu 89 90 NW 6 9 9641 6943 3123 Blue 19
7 PM Thu 87 87 NW 6 9 7133 4179 359 Blue 16
8 PM Thu 85 85 N 8 11 4397 3882 62 Blue 14
9 PM Thu 82 82 N 8 11 3889 3820 0 Blue 11
10 PM Thu 79 79 N 8 11 3518 3820 0 Blue 8
11 PM Thu 76 76 NNW 8 10 3300 3820 0 Blue 5
12 Midnight Fri 75 75 NNW 8 10 3234 3820 0 Blue 4
1 AM Fri 74 74 NNW 8 10 3169 3820 0 Blue 3
2 AM Fri 72 72 NNW 6 9 2546 3820 0 Blue 1
3 AM Fri 70 70 NNW 6 9 0 3820 0 Blue 0
4 AM Fri 68 68 NNW 6 9 0 3820 0 Blue 0
5 AM Fri 67 67 NNW 6 9 0 3820 0 Blue 0
6 AM Fri 68 68 NNW 6 9 0 3820 0 Blue 0
7 AM Fri 70 70 NNW 6 9 0 3820 0 Blue 0
8 AM Fri 73 74 N 9 12 3169 3820 0 Blue 3
9 AM Fri 76 79 N 9 12 3518 3820 0 Blue 8
10 AM Fri 79 83 N 9 12 4012 3820 0 Blue 12
11 AM Fri 82 88 NNE 10 14 8167 4383 563 Blue 17
12 Noon Fri 85 92 NNE 10 14 11633 8386 4566 White 21
1 PM Fri 87 94 NNE 10 14 12043 10226 6406 White 23
2 PM Fri 90 97 NE 9 12 12654 12654 8834 White 26
3 PM Fri 92 98 NE 9 12 12856 12856 9036 White 27
4 PM Fri 93 98 NE 9 12 12856 12856 9036 White 27
5 PM Fri 94 97 NE 10 14 12654 12654 8834 White 26
6 PM Fri 94 96 NE 10 14 12451 12451 8631 White 25
7 PM Fri 93 93 NE 10 14 11838 8655 4835 White 22
8 PM Fri 91 91 NE 6 10 11054 8062 4242 Blue 20
9 PM Fri 87 87 NE 6 10 7133 4179 359 Blue 16
10 PM Fri 84 84 NE 6 10 4192 3820 0 Blue 13
11 PM Fri 80 80 N 5 8 3642 3820 0 Blue 9
12 Midnight Sat 78 78 N 5 8 3432 3820 0 Blue 7
1 AM Sat 76 76 N 5 8 3300 3820 0 Blue 5
2 AM Sat 75 75 N 6 9 3234 3820 0 Blue 4
3 AM Sat 72 72 N 6 9 2546 3820 0 Blue 1
4 AM Sat 71 71 N 6 9 2412 3820 0 Blue 0
5 AM Sat 70 70 N 5 8 0 3820 0 Blue 0
6 AM Sat 71 71 N 5 8 2412 3820 0 Blue 0
7 AM Sat 74 74 N 5 8 3169 3820 0 Blue 3
8 AM Sat 77 79 N 5 10 3518 3820 0 Blue 8
9 AM Sat 80 83 N 5 10 4012 3820 0 Blue 12
10 AM Sat 83 88 N 5 10 8167 4383 563 Blue 17
11 AM Sat 86 92 ENE 8 12 11633 8386 4566 White 21
12 Noon Sat 89 96 ENE 8 12 12451 12451 8631 White 25
1 PM Sat 92 100 ENE 8 12 13259 13259 9439 White 29
2 PM Sat 95 102 E 9 13 13656 13656 9836 White 31
3 PM Sat 97 103 E 9 13 13854 13854 10034 White 32
4 PM Sat 98 103 E 9 13 13854 13854 10034 White 32
5 PM Sat 98 101 E 9 13 13457 13457 9637 White 30
6 PM Sat 98 99 E 9 13 13057 13057 9237 White 28
7 PM Sat 96 96 E 9 13 12451 12451 8631 White 25
8 PM Sat 94 94 E 8 12 12043 10226 6406 White 23
9 PM Sat 90 90 E 8 12 9641 6943 3123 Blue 19
10 PM Sat 86 86 E 8 12 4697 4005 185 Blue 15
11 PM Sat 82 82 N 5 8 3889 3820 0 Blue 11
12 Midnight Sun 80 80 N 5 8 3642 3820 0 Blue 9
1 AM Sun 79 79 N 5 8 3518 3820 0 Blue 8
2 AM Sun 78 78 N 5 8 3432 3820 0 Blue 7
3 AM Sun 76 76 N 5 8 3300 3820 0 Blue 5
4 AM Sun 75 75 N 5 8 3234 3820 0 Blue 4
5 AM Sun 74 74 N 5 6 3169 3820 0 Blue 3
6 AM Sun 75 75 N 5 6 3234 3820 0 Blue 4
7 AM Sun 77 77 N 5 6 3366 3820 0 Blue 6
8 AM Sun 80 82 NNE 5 10 3889 3820 0 Blue 11
9 AM Sun 84 87 NNE 5 10 7133 4179 359 Blue 16
10 AM Sun 87 92 NNE 5 10 11633 8386 4566 White 21
11 AM Sun 90 96 E 9 14 12451 12451 8631 White 25
12 Noon Sun 93 100 E 9 14 13259 13259 9439 White 29
1 PM Sun 96 104 E 9 14 14052 14052 10232 White 33
2 PM Sun 99 106 E 10 16 14447 14447 10627 White 35
3 PM Sun 101 107 E 10 16 14645 14645 10825 White 36
4 PM Sun 102 107 E 10 16 14645 14645 10825 White 36
5 PM Sun 102 105 E 10 13 14250 14250 10430 White 34
6 PM Sun 101 102 E 10 13 13656 13656 9836 White 31
7 PM Sun 100 100 E 10 13 13259 13259 9439 White 29
8 PM Sun 97 97 E 8 12 12654 12654 8834 White 26
9 PM Sun 93 93 E 8 12 11838 8655 4835 White 22
10 PM Sun 89 89 E 8 12 8440 4620 800 Blue 18
11 PM Sun 85 85 N 5 9 4397 3882 62 Blue 14
12 Midnight Mon 83 83 N 5 9 4012 3820 0 Blue 12
1 AM Mon 82 82 N 5 9 3889 3820 0 Blue 11
2 AM Mon 80 80 NNW 5 6 3642 3820 0 Blue 9
3 AM Mon 78 78 NNW 5 6 3432 3820 0 Blue 7
4 AM Mon 76 76 NNW 5 6 3300 3820 0 Blue 5
5 AM Mon 75 75 NNW 5 5 3234 3820 0 Blue 4
6 AM Mon 76 76 NNW 5 5 3300 3820 0 Blue 5
7 AM Mon 79 79 NNW 5 5 3518 3820 0 Blue 8
8 AM Mon 82 83 N 5 6 4012 3820 0 Blue 12
9 AM Mon 86 89 N 5 6 8440 4620 800 Blue 18
10 AM Mon 89 94 N 5 6 12043 10226 6406 White 23
11 AM Mon 93 99 ENE 8 10 13057 13057 9237 White 28
12 Noon Mon 96 103 ENE 8 10 13854 13854 10034 White 32
1 PM Mon 99 106 ENE 8 10 14447 14447 10627 White 35
2 PM Mon 101 108 E 8 12 14841 14841 11021 White 37
3 PM Mon 103 109 E 8 12 15038 15038 11218 White 38
4 PM Mon 104 109 E 8 12 15038 15038 11218 White 38
5 PM Mon 104 107 SE 9 12 14645 14645 10825 White 36
6 PM Mon 103 104 SE 9 12 14052 14052 10232 White 33
7 PM Mon 102 102 SE 9 12 13656 13656 9836 White 31
8 PM Mon 99 99 NNE 6 11 13057 13057 9237 White 28
9 PM Mon 95 95 NNE 6 11 12247 11545 7725 White 24
10 PM Mon 91 91 NNE 6 11 11054 8062 4242 Blue 20

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]