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

Station:

KOTX

Date/Time:

16 OCT 2018

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 Tue 38 38 N 2 2444 3820 0 Blue 4
6 AM Tue 36 36 N 2 2413 3820 0 Blue 2
7 AM Tue 35 35 N 3 2397 3820 0 Blue 1
8 AM Tue 36 36 N 3 2413 3820 0 Blue 2
9 AM Tue 39 39 NE 3 2460 3820 0 Blue 5
10 AM Tue 44 45 NE 2 2726 3820 0 Blue 11
11 AM Tue 49 51 NE 2 2866 3820 0 Blue 17
12 Noon Tue 53 55 E 2 3261 3820 0 Blue 20
1 PM Tue 57 59 E 3 4473 3820 0 Blue 24
2 PM Tue 60 62 E 3 4765 4466 646 Blue 27
3 PM Tue 61 62 E 3 4765 4466 646 Blue 27
4 PM Tue 62 63 E 3 4858 4564 744 Blue 28
5 PM Tue 61 61 E 3 4670 4161 341 Blue 26
6 PM Tue 58 58 E 3 4183 3820 0 Blue 23
7 PM Tue 55 55 E 3 3261 3820 0 Blue 20
8 PM Tue 51 51 E 2 2866 3820 0 Blue 17
9 PM Tue 49 49 NE 2 2819 3820 0 Blue 15
10 PM Tue 48 48 N 3 2796 3820 0 Blue 14
11 PM Tue 47 47 NW 3 2773 3820 0 Blue 13
12 Midnight Wed 46 46 NW 3 2750 3820 0 Blue 12
1 AM Wed 45 45 N 3 2726 3820 0 Blue 11
2 AM Wed 44 44 N 3 2661 3820 0 Blue 10
3 AM Wed 43 43 N 3 2595 3820 0 Blue 9
4 AM Wed 43 43 N 3 2595 3820 0 Blue 9
5 AM Wed 42 42 N 3 2528 3820 0 Blue 8
6 AM Wed 40 40 N 3 2475 3820 0 Blue 6
7 AM Wed 38 38 N 3 2444 3820 0 Blue 4
8 AM Wed 38 38 N 3 2444 3820 0 Blue 4
9 AM Wed 42 42 N 3 2528 3820 0 Blue 8
10 AM Wed 47 48 NE 2 2796 3820 0 Blue 14
11 AM Wed 53 55 NE 2 3261 3820 0 Blue 20
12 Noon Wed 56 58 E 2 4183 3820 0 Blue 23
1 PM Wed 59 61 E 2 4670 4161 341 Blue 26
2 PM Wed 61 63 SE 2 4858 4564 744 Blue 28
3 PM Wed 63 64 SE 2 4951 4662 842 Blue 29
4 PM Wed 64 65 SE 3 5044 4757 937 Blue 30
5 PM Wed 63 63 SE 3 4858 4564 744 Blue 28
6 PM Wed 60 60 S 3 4572 3838 18 Blue 25
7 PM Wed 56 56 W 2 3527 3820 0 Blue 21
8 PM Wed 52 52 W 2 2889 3820 0 Blue 18
9 PM Wed 49 49 W 2 2819 3820 0 Blue 15
10 PM Wed 48 48 NW 2 2796 3820 0 Blue 14
11 PM Wed 47 47 NW 2 2773 3820 0 Blue 13
12 Midnight Thu 45 45 NW 2 2726 3820 0 Blue 11
1 AM Thu 44 44 NW 3 2661 3820 0 Blue 10
2 AM Thu 43 43 NW 3 2595 3820 0 Blue 9
3 AM Thu 42 42 NW 3 2528 3820 0 Blue 8
4 AM Thu 41 41 NW 2 2491 3820 0 Blue 7
5 AM Thu 40 40 NW 2 2475 3820 0 Blue 6
6 AM Thu 38 38 N 2 2444 3820 0 Blue 4
7 AM Thu 37 37 N 2 2428 3820 0 Blue 3
8 AM Thu 38 38 N 2 2444 3820 0 Blue 4
9 AM Thu 41 41 N 2 2491 3820 0 Blue 7
10 AM Thu 46 46 NE 3 2750 3820 0 Blue 12
11 AM Thu 51 52 E 3 2889 3820 0 Blue 18
12 Noon Thu 56 58 E 3 4183 3820 0 Blue 23
1 PM Thu 59 61 SE 3 4670 4161 341 Blue 26
2 PM Thu 62 64 SE 3 4951 4662 842 Blue 29
3 PM Thu 63 64 SE 3 4951 4662 842 Blue 29
4 PM Thu 64 64 SE 5 4951 4662 842 Blue 29
5 PM Thu 63 63 SE 5 4858 4564 744 Blue 28
6 PM Thu 60 60 SE 3 4572 3838 18 Blue 25
7 PM Thu 56 56 SE 3 3527 3820 0 Blue 21
8 PM Thu 52 52 E 2 2889 3820 0 Blue 18
9 PM Thu 50 50 E 2 2843 3820 0 Blue 16
10 PM Thu 49 49 N 2 2819 3820 0 Blue 15
11 PM Thu 49 49 NW 2 2819 3820 0 Blue 15
12 Midnight Fri 48 48 NW 2 2796 3820 0 Blue 14
1 AM Fri 46 46 NW 3 2750 3820 0 Blue 12
2 AM Fri 45 45 NW 3 2726 3820 0 Blue 11
3 AM Fri 45 45 NW 3 2726 3820 0 Blue 11
4 AM Fri 44 44 N 3 2661 3820 0 Blue 10
5 AM Fri 43 43 N 3 2595 3820 0 Blue 9
6 AM Fri 41 41 N 3 2491 3820 0 Blue 7
7 AM Fri 40 40 N 3 2475 3820 0 Blue 6
8 AM Fri 41 41 N 5 2491 3820 0 Blue 7
9 AM Fri 44 44 NE 5 2661 3820 0 Blue 10
10 AM Fri 49 50 NE 5 2843 3820 0 Blue 16
11 AM Fri 54 55 E 5 3261 3820 0 Blue 20
12 Noon Fri 57 59 E 5 4473 3820 0 Blue 24
1 PM Fri 60 62 E 5 4765 4466 646 Blue 27
2 PM Fri 62 64 E 5 4951 4662 842 Blue 29
3 PM Fri 64 65 SE 5 5044 4757 937 Blue 30
4 PM Fri 65 65 SE 3 5044 4757 937 Blue 30
5 PM Fri 64 64 SE 3 4951 4662 842 Blue 29
6 PM Fri 61 61 SE 3 4670 4161 341 Blue 26
7 PM Fri 57 57 SE 3 3856 3820 0 Blue 22
8 PM Fri 53 53 SE 3 2997 3820 0 Blue 18
9 PM Fri 51 51 SE 3 2866 3820 0 Blue 17
10 PM Fri 49 49 SE 3 2819 3820 0 Blue 15
11 PM Fri 48 48 NW 3 2796 3820 0 Blue 14
12 Midnight Sat 47 47 NW 3 2773 3820 0 Blue 13
1 AM Sat 46 46 NW 3 2750 3820 0 Blue 12
2 AM Sat 45 45 NW 3 2726 3820 0 Blue 11
3 AM Sat 44 44 NW 3 2661 3820 0 Blue 10
4 AM Sat 43 43 NW 3 2595 3820 0 Blue 9
5 AM Sat 42 42 NW 2 2528 3820 0 Blue 8
6 AM Sat 40 40 NW 2 2475 3820 0 Blue 6
7 AM Sat 39 39 NW 2 2460 3820 0 Blue 5
8 AM Sat 40 40 NW 2 2475 3820 0 Blue 6
9 AM Sat 43 43 NW 2 2595 3820 0 Blue 9
10 AM Sat 48 49 NW 2 2819 3820 0 Blue 15
11 AM Sat 53 55 E 3 3261 3820 0 Blue 20
12 Noon Sat 58 60 E 3 4572 3838 18 Blue 25
1 PM Sat 61 63 E 3 4858 4564 744 Blue 28
2 PM Sat 63 65 E 3 5044 4757 937 Blue 30
3 PM Sat 65 66 E 3 5137 4849 1029 Blue 31
4 PM Sat 65 66 E 3 5137 4849 1029 Blue 31
5 PM Sat 63 63 SE 5 4858 4564 744 Blue 28
6 PM Sat 59 59 SE 5 4473 3820 0 Blue 24
7 PM Sat 55 55 SE 5 3261 3820 0 Blue 20
8 PM Sat 51 51 SE 5 2866 3820 0 Blue 17
9 PM Sat 49 49 SE 5 2819 3820 0 Blue 15
10 PM Sat 48 48 SE 5 2796 3820 0 Blue 14
11 PM Sat 48 48 NW 3 2796 3820 0 Blue 14
12 Midnight Sun 47 47 NW 3 2773 3820 0 Blue 13
1 AM Sun 45 45 NW 3 2726 3820 0 Blue 11
2 AM Sun 44 44 NW 3 2661 3820 0 Blue 10
3 AM Sun 43 43 NW 3 2595 3820 0 Blue 9
4 AM Sun 42 42 NW 3 2528 3820 0 Blue 8
5 AM Sun 41 41 NW 3 2491 3820 0 Blue 7
6 AM Sun 39 39 NW 3 2460 3820 0 Blue 5
7 AM Sun 38 38 NW 3 2444 3820 0 Blue 4
8 AM Sun 38 38 NW 3 2444 3820 0 Blue 4
9 AM Sun 41 41 NW 3 2491 3820 0 Blue 7
10 AM Sun 46 47 NW 3 2773 3820 0 Blue 13
11 AM Sun 52 54 NE 5 3129 3820 0 Blue 19
12 Noon Sun 56 58 NE 5 4183 3820 0 Blue 23
1 PM Sun 60 62 NE 5 4765 4466 646 Blue 27
2 PM Sun 63 65 NE 5 5044 4757 937 Blue 30
3 PM Sun 65 66 NE 5 5137 4849 1029 Blue 31
4 PM Sun 65 66 NE 5 5137 4849 1029 Blue 31
5 PM Sun 63 63 E 5 4858 4564 744 Blue 28
6 PM Sun 60 60 E 5 4572 3838 18 Blue 25
7 PM Sun 56 56 E 5 3527 3820 0 Blue 21
8 PM Sun 52 52 E 5 2889 3820 0 Blue 18
9 PM Sun 50 50 E 5 2843 3820 0 Blue 16
10 PM Sun 50 50 E 5 2843 3820 0 Blue 16
11 PM Sun 49 49 NW 5 2819 3820 0 Blue 15
12 Midnight Mon 48 48 NW 5 2796 3820 0 Blue 14
1 AM Mon 47 47 NW 5 2773 3820 0 Blue 13
2 AM Mon 45 45 NW 5 2726 3820 0 Blue 11
3 AM Mon 44 44 NW 5 2661 3820 0 Blue 10
4 AM Mon 44 44 NW 5 2661 3820 0 Blue 10

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