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

Station:

KOTX

Date/Time:

19 OCT 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 40 40 W 3 0 3820 0 Blue 0
6 AM Sat 39 39 W 3 0 3820 0 Blue 0
7 AM Sat 38 38 NW 3 0 3820 0 Blue 0
8 AM Sat 38 38 NW 3 0 3820 0 Blue 0
9 AM Sat 40 40 NW 3 0 3820 0 Blue 0
10 AM Sat 42 42 W 5 2139 3820 0 White 0
11 AM Sat 44 44 W 5 2242 3820 0 White 0
12 Noon Sat 46 46 W 7 2682 3820 0 White 3
1 PM Sat 47 47 W 9 2905 3820 0 White 4
2 PM Sat 48 48 W 12 3126 3820 0 White 5
3 PM Sat 49 49 W 13 3348 3820 0 White 6
4 PM Sat 49 49 W 14 3348 3820 0 White 6
5 PM Sat 48 48 W 14 3126 3820 0 White 5
6 PM Sat 47 47 W 14 2905 3820 0 White 4
7 PM Sat 45 45 W 13 2460 3820 0 White 2
8 PM Sat 44 44 W 12 2242 3820 0 White 0
9 PM Sat 43 43 W 10 2139 3820 0 White 0
10 PM Sat 43 43 W 10 2139 3820 0 White 0
11 PM Sat 42 42 W 9 2139 3820 0 White 0
12 Midnight Sun 42 42 W 9 2139 3820 0 White 0
1 AM Sun 41 41 W 8 0 3820 0 Blue 0
2 AM Sun 40 40 W 8 0 3820 0 Blue 0
3 AM Sun 39 39 W 8 0 3820 0 Blue 0
4 AM Sun 38 38 W 7 0 3820 0 Blue 0
5 AM Sun 37 37 W 5 0 3820 0 Blue 0
6 AM Sun 37 37 W 5 0 3820 0 Blue 0
7 AM Sun 36 36 W 3 0 3820 0 Blue 0
8 AM Sun 36 36 W 3 0 3820 0 Blue 0
9 AM Sun 38 38 W 3 0 3820 0 Blue 0
10 AM Sun 40 40 W 3 0 3820 0 Blue 0
11 AM Sun 42 42 W 3 2139 3820 0 White 0
12 Noon Sun 44 44 SW 3 2242 3820 0 White 0
1 PM Sun 45 45 S 2 2460 3820 0 White 2
2 PM Sun 46 46 SE 5 2682 3820 0 White 3
3 PM Sun 46 46 SE 6 2682 3820 0 White 3
4 PM Sun 46 46 SE 6 2682 3820 0 White 3
5 PM Sun 45 45 S 7 2460 3820 0 White 2
6 PM Sun 44 44 S 6 2242 3820 0 White 0
7 PM Sun 43 43 S 2 2139 3820 0 White 0
8 PM Sun 42 42 SW 1 2139 3820 0 White 0
9 PM Sun 42 42 W 2 2139 3820 0 White 0
10 PM Sun 41 41 W 2 0 3820 0 Blue 0
11 PM Sun 41 41 W 2 0 3820 0 Blue 0
12 Midnight Mon 40 40 W 2 0 3820 0 Blue 0
1 AM Mon 39 39 W 2 0 3820 0 Blue 0
2 AM Mon 38 38 W 2 0 3820 0 Blue 0
3 AM Mon 38 38 W 2 0 3820 0 Blue 0
4 AM Mon 38 38 W 2 0 3820 0 Blue 0
5 AM Mon 38 38 W 2 0 3820 0 Blue 0
6 AM Mon 39 39 W 2 0 3820 0 Blue 0
7 AM Mon 39 39 W 2 0 3820 0 Blue 0
8 AM Mon 40 40 W 2 0 3820 0 Blue 0
9 AM Mon 42 42 SW 2 2139 3820 0 White 0
10 AM Mon 44 44 SW 2 2242 3820 0 White 0
11 AM Mon 47 47 S 2 2905 3820 0 White 4
12 Noon Mon 48 48 S 3 3126 3820 0 White 5
1 PM Mon 50 50 S 5 3570 3820 0 White 7
2 PM Mon 50 50 S 5 3570 3820 0 White 7
3 PM Mon 50 50 S 6 3570 3820 0 White 7
4 PM Mon 49 49 S 6 3348 3820 0 White 6
5 PM Mon 48 48 S 6 3126 3820 0 White 5
6 PM Mon 47 47 S 5 2905 3820 0 White 4
7 PM Mon 46 46 S 5 2682 3820 0 White 3
8 PM Mon 45 45 S 5 2460 3820 0 White 2
9 PM Mon 45 45 S 5 2460 3820 0 White 2
10 PM Mon 45 45 S 3 2460 3820 0 White 2
11 PM Mon 45 45 S 3 2460 3820 0 White 2
12 Midnight Tue 45 45 S 3 2460 3820 0 White 2
1 AM Tue 44 44 SW 3 2242 3820 0 White 0
2 AM Tue 44 44 SW 2 2242 3820 0 White 0
3 AM Tue 43 43 SW 2 2139 3820 0 White 0
4 AM Tue 43 43 SW 2 2139 3820 0 White 0
5 AM Tue 42 42 SW 2 2139 3820 0 White 0
6 AM Tue 41 41 SW 2 0 3820 0 Blue 0
7 AM Tue 41 41 W 2 0 3820 0 Blue 0
8 AM Tue 42 42 W 3 2139 3820 0 White 0
9 AM Tue 44 44 W 6 2242 3820 0 White 0
10 AM Tue 48 48 W 8 3126 3820 0 White 5
11 AM Tue 51 52 W 8 4011 4011 191 White 9
12 Noon Tue 53 54 W 8 4452 4452 632 White 11
1 PM Tue 55 56 W 9 4882 4882 1062 White 13
2 PM Tue 56 57 W 12 5095 5095 1275 White 14
3 PM Tue 56 57 W 13 5095 5095 1275 White 14
4 PM Tue 55 55 W 14 4668 4668 848 White 12
5 PM Tue 54 54 W 14 4452 4452 632 White 11
6 PM Tue 51 51 W 14 3790 3820 0 White 8
7 PM Tue 49 49 W 14 3348 3820 0 White 6
8 PM Tue 46 46 W 14 2682 3820 0 White 3
9 PM Tue 45 45 W 14 2460 3820 0 White 2
10 PM Tue 44 44 W 14 2242 3820 0 White 0
11 PM Tue 43 43 NW 12 2139 3820 0 White 0
12 Midnight Wed 43 43 NW 12 2139 3820 0 White 0
1 AM Wed 42 42 NW 12 2139 3820 0 White 0
2 AM Wed 41 41 NW 12 0 3820 0 Blue 0
3 AM Wed 41 41 NW 12 0 3820 0 Blue 0
4 AM Wed 40 40 NW 12 0 3820 0 Blue 0
5 AM Wed 39 39 NW 10 0 3820 0 Blue 0
6 AM Wed 38 38 NW 10 0 3820 0 Blue 0
7 AM Wed 37 37 NW 10 0 3820 0 Blue 0
8 AM Wed 37 37 NW 10 0 3820 0 Blue 0
9 AM Wed 39 39 NW 10 0 3820 0 Blue 0
10 AM Wed 42 42 NW 10 2139 3820 0 White 0
11 AM Wed 45 46 NW 6 2682 3820 0 White 3
12 Noon Wed 48 49 NW 6 3348 3820 0 White 6
1 PM Wed 50 52 NW 6 4011 4011 191 White 9
2 PM Wed 52 53 NW 6 4232 4232 412 White 10
3 PM Wed 53 54 NW 6 4452 4452 632 White 11
4 PM Wed 53 53 NW 6 4232 4232 412 White 10
5 PM Wed 52 52 W 5 4011 4011 191 White 9
6 PM Wed 49 49 W 5 3348 3820 0 White 6
7 PM Wed 46 46 W 5 2682 3820 0 White 3
8 PM Wed 43 43 W 5 2139 3820 0 White 0
9 PM Wed 42 42 W 5 2139 3820 0 White 0
10 PM Wed 41 41 W 5 0 3820 0 Blue 0
11 PM Wed 41 41 NW 2 0 3820 0 Blue 0
12 Midnight Thu 40 40 NW 2 0 3820 0 Blue 0
1 AM Thu 39 39 NW 2 0 3820 0 Blue 0
2 AM Thu 39 39 NW 2 0 3820 0 Blue 0
3 AM Thu 38 38 NW 2 0 3820 0 Blue 0
4 AM Thu 38 38 NW 2 0 3820 0 Blue 0
5 AM Thu 38 38 NW 1 0 3820 0 Blue 0
6 AM Thu 37 37 NW 1 0 3820 0 Blue 0
7 AM Thu 36 36 NW 1 0 3820 0 Blue 0
8 AM Thu 36 36 NW 1 0 3820 0 Blue 0
9 AM Thu 39 39 NW 1 0 3820 0 Blue 0
10 AM Thu 42 42 NW 1 2139 3820 0 White 0
11 AM Thu 45 46 E 2 2682 3820 0 White 3
12 Noon Thu 47 48 E 2 3126 3820 0 White 5
1 PM Thu 49 50 E 2 3570 3820 0 White 7
2 PM Thu 50 51 E 2 3790 3820 0 White 8
3 PM Thu 51 52 E 2 4011 4011 191 White 9
4 PM Thu 51 51 E 2 3790 3820 0 White 8
5 PM Thu 49 49 S 2 3348 3820 0 White 6
6 PM Thu 47 47 S 2 2905 3820 0 White 4
7 PM Thu 45 45 S 2 2460 3820 0 White 2
8 PM Thu 42 42 S 2 2139 3820 0 White 0
9 PM Thu 41 41 S 2 0 3820 0 Blue 0
10 PM Thu 41 41 S 2 0 3820 0 Blue 0
11 PM Thu 40 40 W 1 0 3820 0 Blue 0
12 Midnight Fri 40 40 W 1 0 3820 0 Blue 0
1 AM Fri 39 39 W 1 0 3820 0 Blue 0
2 AM Fri 38 38 W 1 0 3820 0 Blue 0
3 AM Fri 38 38 W 1 0 3820 0 Blue 0
4 AM Fri 38 38 W 1 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 [email protected]