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

Station:

KGEG

Date/Time:

N/A

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
7 AM Wed 26 26 NW 2 N/A N/A N/A N/A N/A
8 AM Wed 28 28 NW 2 N/A N/A N/A N/A N/A
9 AM Wed 30 30 NW 2 N/A N/A N/A N/A N/A
10 AM Wed 32 33 SW 3 N/A N/A N/A N/A N/A
11 AM Wed 37 39 SW 3 N/A N/A N/A N/A N/A
12 Noon Wed 40 42 SW 3 N/A N/A N/A N/A N/A
1 PM Wed 42 44 SW 7 N/A N/A N/A N/A N/A
2 PM Wed 43 44 SW 7 N/A N/A N/A N/A N/A
3 PM Wed 44 45 SW 7 N/A N/A N/A N/A N/A
4 PM Wed 44 44 W 8 N/A N/A N/A N/A N/A
5 PM Wed 41 41 W 8 N/A N/A N/A N/A N/A
6 PM Wed 37 37 W 8 N/A N/A N/A N/A N/A
7 PM Wed 34 34 W 3 N/A N/A N/A N/A N/A
8 PM Wed 32 32 W 3 N/A N/A N/A N/A N/A
9 PM Wed 30 30 W 3 N/A N/A N/A N/A N/A
10 PM Wed 29 29 NW 4 N/A N/A N/A N/A N/A
11 PM Wed 28 28 NW 4 N/A N/A N/A N/A N/A
12 Midnight Thu 28 28 NW 4 N/A N/A N/A N/A N/A
1 AM Thu 29 29 NW 4 N/A N/A N/A N/A N/A
2 AM Thu 27 27 NW 4 N/A N/A N/A N/A N/A
3 AM Thu 27 27 NW 4 N/A N/A N/A N/A N/A
4 AM Thu 27 27 SW 2 N/A N/A N/A N/A N/A
5 AM Thu 27 27 SW 2 N/A N/A N/A N/A N/A
6 AM Thu 26 26 SW 2 N/A N/A N/A N/A N/A
7 AM Thu 26 26 S 2 N/A N/A N/A N/A N/A
8 AM Thu 27 27 S 2 N/A N/A N/A N/A N/A
9 AM Thu 29 29 S 2 N/A N/A N/A N/A N/A
10 AM Thu 31 31 SE 5 N/A N/A N/A N/A N/A
11 AM Thu 35 35 SE 5 N/A N/A N/A N/A N/A
12 Noon Thu 37 37 SE 5 N/A N/A N/A N/A N/A
1 PM Thu 38 38 S 4 N/A N/A N/A N/A N/A
2 PM Thu 40 40 S 4 N/A N/A N/A N/A N/A
3 PM Thu 40 40 S 4 N/A N/A N/A N/A N/A
4 PM Thu 40 40 S 5 N/A N/A N/A N/A N/A
5 PM Thu 39 39 S 5 N/A N/A N/A N/A N/A
6 PM Thu 37 37 S 5 N/A N/A N/A N/A N/A
7 PM Thu 36 36 S 5 N/A N/A N/A N/A N/A
8 PM Thu 35 35 S 5 N/A N/A N/A N/A N/A
9 PM Thu 34 34 S 5 N/A N/A N/A N/A N/A
10 PM Thu 34 34 SW 2 N/A N/A N/A N/A N/A
11 PM Thu 34 34 SW 2 N/A N/A N/A N/A N/A
12 Midnight Fri 34 34 SW 2 N/A N/A N/A N/A N/A
1 AM Fri 34 34 SW 2 N/A N/A N/A N/A N/A
2 AM Fri 33 33 SW 2 N/A N/A N/A N/A N/A
3 AM Fri 34 34 SW 2 N/A N/A N/A N/A N/A
4 AM Fri 33 33 S 4 N/A N/A N/A N/A N/A
5 AM Fri 33 33 S 4 N/A N/A N/A N/A N/A
6 AM Fri 33 33 S 4 N/A N/A N/A N/A N/A
7 AM Fri 33 33 S 4 N/A N/A N/A N/A N/A
8 AM Fri 34 34 S 4 N/A N/A N/A N/A N/A
9 AM Fri 36 36 S 4 N/A N/A N/A N/A N/A
10 AM Fri 37 37 S 10 N/A N/A N/A N/A N/A
11 AM Fri 41 41 S 10 N/A N/A N/A N/A N/A
12 Noon Fri 43 43 S 10 N/A N/A N/A N/A N/A
1 PM Fri 44 44 S 10 N/A N/A N/A N/A N/A
2 PM Fri 46 46 S 10 N/A N/A N/A N/A N/A
3 PM Fri 46 46 S 10 N/A N/A N/A N/A N/A
4 PM Fri 46 46 SW 3 N/A N/A N/A N/A N/A
5 PM Fri 44 44 SW 3 N/A N/A N/A N/A N/A
6 PM Fri 40 40 SW 3 N/A N/A N/A N/A N/A
7 PM Fri 38 38 SW 3 N/A N/A N/A N/A N/A
8 PM Fri 36 36 SW 3 N/A N/A N/A N/A N/A
9 PM Fri 35 35 SW 3 N/A N/A N/A N/A N/A
10 PM Fri 34 34 SW 4 N/A N/A N/A N/A N/A
11 PM Fri 34 34 SW 4 N/A N/A N/A N/A N/A
12 Midnight Sat 34 34 SW 4 N/A N/A N/A N/A N/A
1 AM Sat 34 34 SW 4 N/A N/A N/A N/A N/A
2 AM Sat 33 33 SW 4 N/A N/A N/A N/A N/A
3 AM Sat 33 33 SW 4 N/A N/A N/A N/A N/A
4 AM Sat 33 33 SW 6 N/A N/A N/A N/A N/A
5 AM Sat 32 32 SW 6 N/A N/A N/A N/A N/A
6 AM Sat 32 32 SW 6 N/A N/A N/A N/A N/A
7 AM Sat 32 32 SW 6 N/A N/A N/A N/A N/A
8 AM Sat 33 33 SW 6 N/A N/A N/A N/A N/A
9 AM Sat 35 35 SW 6 N/A N/A N/A N/A N/A
10 AM Sat 36 37 W 5 N/A N/A N/A N/A N/A
11 AM Sat 40 41 W 5 N/A N/A N/A N/A N/A
12 Noon Sat 42 43 W 5 N/A N/A N/A N/A N/A
1 PM Sat 43 44 W 5 N/A N/A N/A N/A N/A
2 PM Sat 45 46 W 5 N/A N/A N/A N/A N/A
3 PM Sat 45 45 W 5 N/A N/A N/A N/A N/A
4 PM Sat 45 45 W 3 N/A N/A N/A N/A N/A
5 PM Sat 42 42 W 3 N/A N/A N/A N/A N/A
6 PM Sat 39 39 W 3 N/A N/A N/A N/A N/A
7 PM Sat 36 36 W 3 N/A N/A N/A N/A N/A
8 PM Sat 35 35 W 3 N/A N/A N/A N/A N/A
9 PM Sat 33 33 W 3 N/A N/A N/A N/A N/A
10 PM Sat 32 32 E 2 N/A N/A N/A N/A N/A
11 PM Sat 32 32 E 2 N/A N/A N/A N/A N/A
12 Midnight Sun 32 32 E 2 N/A N/A N/A N/A N/A
1 AM Sun 32 32 E 2 N/A N/A N/A N/A N/A
2 AM Sun 31 31 E 2 N/A N/A N/A N/A N/A
3 AM Sun 31 31 E 2 N/A N/A N/A N/A N/A
4 AM Sun 31 31 E 3 N/A N/A N/A N/A N/A
5 AM Sun 30 30 E 3 N/A N/A N/A N/A N/A
6 AM Sun 30 30 E 3 N/A N/A N/A N/A N/A
7 AM Sun 30 30 E 3 N/A N/A N/A N/A N/A
8 AM Sun 31 31 E 3 N/A N/A N/A N/A N/A
9 AM Sun 34 34 E 3 N/A N/A N/A N/A N/A
10 AM Sun 35 36 E 4 N/A N/A N/A N/A N/A
11 AM Sun 40 41 E 4 N/A N/A N/A N/A N/A
12 Noon Sun 42 43 E 4 N/A N/A N/A N/A N/A
1 PM Sun 44 45 E 4 N/A N/A N/A N/A N/A
2 PM Sun 46 47 E 4 N/A N/A N/A N/A N/A
3 PM Sun 46 46 E 4 N/A N/A N/A N/A N/A
4 PM Sun 46 46 SE 3 N/A N/A N/A N/A N/A
5 PM Sun 44 44 SE 3 N/A N/A N/A N/A N/A
6 PM Sun 40 40 SE 3 N/A N/A N/A N/A N/A
7 PM Sun 38 38 SE 3 N/A N/A N/A N/A N/A
8 PM Sun 36 36 SE 3 N/A N/A N/A N/A N/A
9 PM Sun 35 35 SE 3 N/A N/A N/A N/A N/A
10 PM Sun 34 34 NE 1 N/A N/A N/A N/A N/A
11 PM Sun 34 34 NE 1 N/A N/A N/A N/A N/A
12 Midnight Mon 34 34 NE 1 N/A N/A N/A N/A N/A
1 AM Mon 34 34 NE 1 N/A N/A N/A N/A N/A
2 AM Mon 33 33 NE 1 N/A N/A N/A N/A N/A
3 AM Mon 33 33 NE 1 N/A N/A N/A N/A N/A
4 AM Mon 33 33 N 3 N/A N/A N/A N/A N/A
5 AM Mon 32 32 N 3 N/A N/A N/A N/A N/A
6 AM Mon 32 32 N 3 N/A N/A N/A N/A N/A
7 AM Mon 32 32 N 3 N/A N/A N/A N/A N/A
8 AM Mon 34 34 N 3 N/A N/A N/A N/A N/A
9 AM Mon 37 37 N 3 N/A N/A N/A N/A N/A
10 AM Mon 39 40 SE 3 N/A N/A N/A N/A N/A
11 AM Mon 45 46 SE 3 N/A N/A N/A N/A N/A
12 Noon Mon 48 50 SE 3 N/A N/A N/A N/A N/A
1 PM Mon 50 51 SE 3 N/A N/A N/A N/A N/A
2 PM Mon 52 53 SE 3 N/A N/A N/A N/A N/A
3 PM Mon 53 53 SE 3 N/A N/A N/A N/A N/A
4 PM Mon 53 53 S 4 N/A N/A N/A N/A N/A
5 PM Mon 50 50 S 4 N/A N/A N/A N/A N/A
6 PM Mon 46 46 S 4 N/A N/A N/A N/A N/A
7 PM Mon 43 43 S 4 N/A N/A N/A N/A N/A
8 PM Mon 41 41 S 4 N/A N/A N/A N/A N/A
9 PM Mon 40 40 S 4 N/A N/A N/A N/A N/A
10 PM Mon 39 39 W 5 N/A N/A N/A N/A N/A
11 PM Mon 38 38 W 5 N/A N/A N/A N/A N/A
12 Midnight Tue 38 38 W 5 N/A N/A N/A N/A N/A
1 AM Tue 39 39 W 5 N/A N/A N/A N/A N/A
2 AM Tue 37 37 W 5 N/A N/A N/A N/A N/A
3 AM Tue 37 37 W 5 N/A N/A N/A N/A N/A
4 AM Tue 37 37 W 4 N/A N/A N/A N/A N/A
5 AM Tue 37 37 W 4 N/A N/A N/A N/A N/A
6 AM Tue 36 36 W 4 N/A N/A N/A N/A N/A

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