Detailed Predictions for: Chelan
Launch Altitude (f): 3820
LZ Altitude (f): 1200
Sounding

Station:

KOTX

Date/Time:

15 JUN 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 Sat 59 59 W 2 2469 3820 0 Blue 7
6 AM Sat 61 61 W 2 2538 3820 0 Blue 9
7 AM Sat 64 64 W 2 2720 3820 0 Blue 12
8 AM Sat 67 68 W 2 2939 3820 0 Blue 16
9 AM Sat 70 73 W 2 3208 3820 0 Blue 21
10 AM Sat 73 77 W 2 4758 3820 0 Blue 25
11 AM Sat 76 81 NE 2 8625 5251 1431 Blue 29
12 Noon Sat 78 84 NE 2 10811 8227 4407 White 32
1 PM Sat 80 86 NE 2 11221 11221 7401 White 34
2 PM Sat 82 88 SE 2 11628 11628 7808 White 36
3 PM Sat 84 89 SE 2 11832 11832 8012 White 37
4 PM Sat 85 89 SE 2 11832 11832 8012 White 37
5 PM Sat 85 87 W 2 11425 11425 7605 White 35
6 PM Sat 84 85 W 2 11016 9863 6043 White 33
7 PM Sat 82 82 W 2 10398 5917 2097 White 30
8 PM Sat 78 78 W 2 5311 3881 61 Blue 26
9 PM Sat 75 75 W 2 3905 3820 0 Blue 23
10 PM Sat 71 71 W 2 3068 3820 0 Blue 19
11 PM Sat 69 69 SW 5 2982 3820 0 Blue 17
12 Midnight Sun 67 67 SW 5 2896 3820 0 Blue 15
1 AM Sun 66 66 SW 5 2841 3820 0 Blue 14
2 AM Sun 64 64 W 2 2720 3820 0 Blue 12
3 AM Sun 63 63 W 2 2659 3820 0 Blue 11
4 AM Sun 61 61 W 2 2538 3820 0 Blue 9
5 AM Sun 61 61 W 2 2538 3820 0 Blue 9
6 AM Sun 63 63 W 2 2659 3820 0 Blue 11
7 AM Sun 66 66 W 2 2841 3820 0 Blue 14
8 AM Sun 69 70 W 2 3025 3820 0 Blue 18
9 AM Sun 72 75 W 2 3905 3820 0 Blue 23
10 AM Sun 75 79 W 2 6002 4306 486 Blue 27
11 AM Sun 78 83 W 2 10605 6591 2771 White 31
12 Noon Sun 81 86 W 2 11221 11221 7401 White 34
1 PM Sun 84 89 SW 3 11832 11832 8012 White 37
2 PM Sun 85 90 SW 3 12035 12035 8215 White 38
3 PM Sun 86 90 SW 5 12035 12035 8215 White 38
4 PM Sun 86 89 W 5 11832 11832 8012 White 37
5 PM Sun 85 87 W 6 11425 11425 7605 White 35
6 PM Sun 84 85 W 6 11016 9863 6043 White 33
7 PM Sun 82 82 W 6 10398 5917 2097 White 30
8 PM Sun 79 79 W 6 6002 4306 486 Blue 27
9 PM Sun 76 76 W 6 4335 3820 0 Blue 24
10 PM Sun 72 72 W 6 3111 3820 0 Blue 20
11 PM Sun 69 69 W 6 2982 3820 0 Blue 17
12 Midnight Mon 67 67 W 6 2896 3820 0 Blue 15
1 AM Mon 66 66 W 5 2841 3820 0 Blue 14
2 AM Mon 64 64 W 5 2720 3820 0 Blue 12
3 AM Mon 63 63 W 5 2659 3820 0 Blue 11
4 AM Mon 61 61 W 3 2538 3820 0 Blue 9
5 AM Mon 61 61 W 3 2538 3820 0 Blue 9
6 AM Mon 62 62 W 3 2598 3820 0 Blue 10
7 AM Mon 64 64 W 3 2720 3820 0 Blue 12
8 AM Mon 67 68 W 3 2939 3820 0 Blue 16
9 AM Mon 71 74 W 3 3467 3820 0 Blue 22
10 AM Mon 74 78 W 3 5311 3881 61 Blue 26
11 AM Mon 77 83 W 3 10605 6591 2771 White 31
12 Noon Mon 80 87 W 5 11425 11425 7605 White 35
1 PM Mon 82 89 W 5 11832 11832 8012 White 37
2 PM Mon 83 89 W 6 11832 11832 8012 White 37
3 PM Mon 85 90 W 7 12035 12035 8215 White 38
4 PM Mon 85 89 W 7 11832 11832 8012 White 37
5 PM Mon 85 87 W 8 11425 11425 7605 White 35
6 PM Mon 83 84 W 8 10811 8227 4407 White 32
7 PM Mon 81 81 W 9 8625 5251 1431 Blue 29
8 PM Mon 78 78 W 9 5311 3881 61 Blue 26
9 PM Mon 74 74 W 9 3467 3820 0 Blue 22
10 PM Mon 71 71 W 9 3068 3820 0 Blue 19
11 PM Mon 68 68 W 9 2939 3820 0 Blue 16
12 Midnight Tue 66 66 W 8 2841 3820 0 Blue 14
1 AM Tue 64 64 W 7 2720 3820 0 Blue 12
2 AM Tue 62 62 W 6 2598 3820 0 Blue 10
3 AM Tue 61 61 W 6 2538 3820 0 Blue 9
4 AM Tue 59 59 W 6 2469 3820 0 Blue 7
5 AM Tue 59 59 W 8 2469 3820 0 Blue 7
6 AM Tue 60 60 W 8 2499 3820 0 Blue 8
7 AM Tue 63 63 W 8 2659 3820 0 Blue 11
8 AM Tue 66 67 W 8 2896 3820 0 Blue 15
9 AM Tue 69 72 W 8 3111 3820 0 Blue 20
10 AM Tue 72 76 W 8 4335 3820 0 Blue 24
11 AM Tue 75 81 W 13 8625 5251 1431 Blue 29
12 Noon Tue 77 84 W 13 10811 8227 4407 White 32
1 PM Tue 78 85 W 13 11016 9863 6043 White 33
2 PM Tue 79 86 W 13 11221 11221 7401 White 34
3 PM Tue 80 86 W 13 11221 11221 7401 White 34
4 PM Tue 80 84 W 13 10811 8227 4407 White 32
5 PM Tue 79 82 W 13 10398 5917 2097 White 30
6 PM Tue 77 78 W 13 5311 3881 61 Blue 26
7 PM Tue 74 74 W 13 3467 3820 0 Blue 22
8 PM Tue 71 71 W 13 3068 3820 0 Blue 19
9 PM Tue 68 68 W 13 2939 3820 0 Blue 16
10 PM Tue 65 65 W 13 2780 3820 0 Blue 13
11 PM Tue 62 62 W 10 2598 3820 0 Blue 10
12 Midnight Wed 60 60 W 10 2499 3820 0 Blue 8
1 AM Wed 59 59 W 10 2469 3820 0 Blue 7
2 AM Wed 57 57 W 10 2416 3820 0 Blue 5
3 AM Wed 56 56 W 10 2411 3820 0 Blue 4
4 AM Wed 54 54 W 10 2399 3820 0 Blue 2
5 AM Wed 54 54 W 7 2399 3820 0 Blue 2
6 AM Wed 55 55 W 7 2405 3820 0 Blue 3
7 AM Wed 57 57 W 7 2416 3820 0 Blue 5
8 AM Wed 60 61 W 7 2538 3820 0 Blue 9
9 AM Wed 63 66 W 7 2841 3820 0 Blue 14
10 AM Wed 65 69 W 7 2982 3820 0 Blue 17
11 AM Wed 68 74 W 15 3467 3820 0 Blue 22
12 Noon Wed 69 76 W 15 4335 3820 0 Blue 24
1 PM Wed 71 78 W 15 5311 3881 61 Blue 26
2 PM Wed 72 79 W 15 6002 4306 486 Blue 27
3 PM Wed 72 78 W 15 5311 3881 61 Blue 26
4 PM Wed 72 76 W 15 4335 3820 0 Blue 24
5 PM Wed 71 74 W 16 3467 3820 0 Blue 22
6 PM Wed 69 70 W 16 3025 3820 0 Blue 18
7 PM Wed 67 67 W 16 2896 3820 0 Blue 15
8 PM Wed 64 64 W 16 2720 3820 0 Blue 12
9 PM Wed 61 61 W 16 2538 3820 0 Blue 9
10 PM Wed 58 58 W 16 2439 3820 0 Blue 6
11 PM Wed 56 56 W 9 2411 3820 0 Blue 4
12 Midnight Thu 55 55 W 9 2405 3820 0 Blue 3
1 AM Thu 54 54 W 9 2399 3820 0 Blue 2
2 AM Thu 53 53 W 9 2394 3820 0 Blue 1
3 AM Thu 52 52 W 9 0 3820 0 Blue 0
4 AM Thu 50 50 W 9 0 3820 0 Blue 0
5 AM Thu 50 50 W 7 0 3820 0 Blue 0
6 AM Thu 51 51 W 7 0 3820 0 Blue 0
7 AM Thu 54 54 W 7 2399 3820 0 Blue 2
8 AM Thu 57 58 W 7 2439 3820 0 Blue 6
9 AM Thu 59 62 W 7 2598 3820 0 Blue 10
10 AM Thu 62 66 W 7 2841 3820 0 Blue 14
11 AM Thu 65 70 W 10 3025 3820 0 Blue 18
12 Noon Thu 67 73 W 10 3208 3820 0 Blue 21
1 PM Thu 69 75 W 10 3905 3820 0 Blue 23
2 PM Thu 71 77 W 10 4758 3820 0 Blue 25
3 PM Thu 72 77 W 10 4758 3820 0 Blue 25
4 PM Thu 72 76 W 10 4335 3820 0 Blue 24
5 PM Thu 71 73 W 9 3208 3820 0 Blue 21
6 PM Thu 70 71 W 9 3068 3820 0 Blue 19
7 PM Thu 68 68 W 9 2939 3820 0 Blue 16
8 PM Thu 65 65 W 9 2780 3820 0 Blue 13
9 PM Thu 63 63 W 9 2659 3820 0 Blue 11
10 PM Thu 60 60 W 9 2499 3820 0 Blue 8
11 PM Thu 58 58 W 7 2439 3820 0 Blue 6
12 Midnight Fri 57 57 W 7 2416 3820 0 Blue 5
1 AM Fri 56 56 W 7 2411 3820 0 Blue 4
2 AM Fri 55 55 W 7 2405 3820 0 Blue 3
3 AM Fri 53 53 W 7 2394 3820 0 Blue 1
4 AM Fri 51 51 W 7 0 3820 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