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)
5 AM Mon 35 35 N 2 N/A N/A N/A N/A N/A
6 AM Mon 35 35 N 2 N/A N/A N/A N/A N/A
7 AM Mon 34 34 N 2 N/A N/A N/A N/A N/A
8 AM Mon 34 34 N 2 N/A N/A N/A N/A N/A
9 AM Mon 36 36 N 2 N/A N/A N/A N/A N/A
10 AM Mon 40 40 N 2 N/A N/A N/A N/A N/A
11 AM Mon 42 42 NE 3 N/A N/A N/A N/A N/A
12 Noon Mon 48 49 NE 3 N/A N/A N/A N/A N/A
1 PM Mon 50 51 NE 3 N/A N/A N/A N/A N/A
2 PM Mon 52 53 NE 4 N/A N/A N/A N/A N/A
3 PM Mon 53 53 NE 4 N/A N/A N/A N/A N/A
4 PM Mon 53 53 NE 4 N/A N/A N/A N/A N/A
5 PM Mon 53 53 N 1 N/A N/A N/A N/A N/A
6 PM Mon 50 50 N 1 N/A N/A N/A N/A N/A
7 PM Mon 46 46 N 1 N/A N/A N/A N/A N/A
8 PM Mon 41 41 N 4 N/A N/A N/A N/A N/A
9 PM Mon 39 39 N 4 N/A N/A N/A N/A N/A
10 PM Mon 37 37 N 4 N/A N/A N/A N/A N/A
11 PM Mon 36 36 NE 3 N/A N/A N/A N/A N/A
12 Midnight Tue 36 36 NE 3 N/A N/A N/A N/A N/A
1 AM Tue 35 35 NE 3 N/A N/A N/A N/A N/A
2 AM Tue 36 36 NE 3 N/A N/A N/A N/A N/A
3 AM Tue 35 35 NE 3 N/A N/A N/A N/A N/A
4 AM Tue 35 35 NE 3 N/A N/A N/A N/A N/A
5 AM Tue 34 34 NE 3 N/A N/A N/A N/A N/A
6 AM Tue 34 34 NE 3 N/A N/A N/A N/A N/A
7 AM Tue 33 33 NE 3 N/A N/A N/A N/A N/A
8 AM Tue 33 33 NE 3 N/A N/A N/A N/A N/A
9 AM Tue 36 36 NE 3 N/A N/A N/A N/A N/A
10 AM Tue 39 39 NE 3 N/A N/A N/A N/A N/A
11 AM Tue 42 42 S 5 N/A N/A N/A N/A N/A
12 Noon Tue 49 49 S 5 N/A N/A N/A N/A N/A
1 PM Tue 52 52 S 5 N/A N/A N/A N/A N/A
2 PM Tue 54 54 SW 8 N/A N/A N/A N/A N/A
3 PM Tue 55 55 SW 8 N/A N/A N/A N/A N/A
4 PM Tue 55 55 SW 8 N/A N/A N/A N/A N/A
5 PM Tue 55 55 W 9 N/A N/A N/A N/A N/A
6 PM Tue 52 52 W 9 N/A N/A N/A N/A N/A
7 PM Tue 47 47 W 9 N/A N/A N/A N/A N/A
8 PM Tue 42 42 W 9 N/A N/A N/A N/A N/A
9 PM Tue 40 40 W 9 N/A N/A N/A N/A N/A
10 PM Tue 38 38 W 9 N/A N/A N/A N/A N/A
11 PM Tue 37 37 W 6 N/A N/A N/A N/A N/A
12 Midnight Wed 37 37 W 6 N/A N/A N/A N/A N/A
1 AM Wed 35 35 W 6 N/A N/A N/A N/A N/A
2 AM Wed 37 37 W 8 N/A N/A N/A N/A N/A
3 AM Wed 35 35 W 8 N/A N/A N/A N/A N/A
4 AM Wed 35 35 W 8 N/A N/A N/A N/A N/A
5 AM Wed 34 34 W 5 N/A N/A N/A N/A N/A
6 AM Wed 34 34 W 5 N/A N/A N/A N/A N/A
7 AM Wed 33 33 W 5 N/A N/A N/A N/A N/A
8 AM Wed 33 33 W 5 N/A N/A N/A N/A N/A
9 AM Wed 35 35 W 5 N/A N/A N/A N/A N/A
10 AM Wed 39 40 W 5 N/A N/A N/A N/A N/A
11 AM Wed 41 42 W 11 N/A N/A N/A N/A N/A
12 Noon Wed 47 49 W 11 N/A N/A N/A N/A N/A
1 PM Wed 49 51 W 11 N/A N/A N/A N/A N/A
2 PM Wed 51 53 W 11 N/A N/A N/A N/A N/A
3 PM Wed 52 53 W 11 N/A N/A N/A N/A N/A
4 PM Wed 52 53 W 11 N/A N/A N/A N/A N/A
5 PM Wed 52 52 W 10 N/A N/A N/A N/A N/A
6 PM Wed 49 49 W 10 N/A N/A N/A N/A N/A
7 PM Wed 45 45 W 10 N/A N/A N/A N/A N/A
8 PM Wed 40 40 W 10 N/A N/A N/A N/A N/A
9 PM Wed 38 38 W 10 N/A N/A N/A N/A N/A
10 PM Wed 36 36 W 10 N/A N/A N/A N/A N/A
11 PM Wed 35 35 W 6 N/A N/A N/A N/A N/A
12 Midnight Thu 35 35 W 6 N/A N/A N/A N/A N/A
1 AM Thu 34 34 W 6 N/A N/A N/A N/A N/A
2 AM Thu 35 35 W 6 N/A N/A N/A N/A N/A
3 AM Thu 34 34 W 6 N/A N/A N/A N/A N/A
4 AM Thu 34 34 W 6 N/A N/A N/A N/A N/A
5 AM Thu 33 33 NW 6 N/A N/A N/A N/A N/A
6 AM Thu 33 33 NW 6 N/A N/A N/A N/A N/A
7 AM Thu 32 32 NW 6 N/A N/A N/A N/A N/A
8 AM Thu 32 32 NW 6 N/A N/A N/A N/A N/A
9 AM Thu 35 35 NW 6 N/A N/A N/A N/A N/A
10 AM Thu 38 39 NW 6 N/A N/A N/A N/A N/A
11 AM Thu 41 43 N 5 N/A N/A N/A N/A N/A
12 Noon Thu 47 49 N 5 N/A N/A N/A N/A N/A
1 PM Thu 50 53 N 5 N/A N/A N/A N/A N/A
2 PM Thu 52 54 N 5 N/A N/A N/A N/A N/A
3 PM Thu 53 55 N 5 N/A N/A N/A N/A N/A
4 PM Thu 53 54 N 5 N/A N/A N/A N/A N/A
5 PM Thu 53 53 N 3 N/A N/A N/A N/A N/A
6 PM Thu 50 50 N 3 N/A N/A N/A N/A N/A
7 PM Thu 46 46 N 3 N/A N/A N/A N/A N/A
8 PM Thu 41 41 N 3 N/A N/A N/A N/A N/A
9 PM Thu 39 39 N 3 N/A N/A N/A N/A N/A
10 PM Thu 36 36 N 3 N/A N/A N/A N/A N/A
11 PM Thu 35 35 NW 3 N/A N/A N/A N/A N/A
12 Midnight Fri 36 36 NW 3 N/A N/A N/A N/A N/A
1 AM Fri 34 34 NW 3 N/A N/A N/A N/A N/A
2 AM Fri 35 35 NW 3 N/A N/A N/A N/A N/A
3 AM Fri 34 34 NW 3 N/A N/A N/A N/A N/A
4 AM Fri 34 34 NW 3 N/A N/A N/A N/A N/A
5 AM Fri 33 33 N 4 N/A N/A N/A N/A N/A
6 AM Fri 33 33 N 4 N/A N/A N/A N/A N/A
7 AM Fri 32 32 N 4 N/A N/A N/A N/A N/A
8 AM Fri 32 32 N 4 N/A N/A N/A N/A N/A
9 AM Fri 35 35 N 4 N/A N/A N/A N/A N/A
10 AM Fri 38 39 N 4 N/A N/A N/A N/A N/A
11 AM Fri 40 42 NE 7 N/A N/A N/A N/A N/A
12 Noon Fri 47 49 NE 7 N/A N/A N/A N/A N/A
1 PM Fri 49 51 NE 7 N/A N/A N/A N/A N/A
2 PM Fri 51 53 NE 7 N/A N/A N/A N/A N/A
3 PM Fri 52 54 NE 7 N/A N/A N/A N/A N/A
4 PM Fri 52 53 NE 7 N/A N/A N/A N/A N/A
5 PM Fri 52 52 NE 4 N/A N/A N/A N/A N/A
6 PM Fri 49 49 NE 4 N/A N/A N/A N/A N/A
7 PM Fri 45 45 NE 4 N/A N/A N/A N/A N/A
8 PM Fri 41 41 NE 4 N/A N/A N/A N/A N/A
9 PM Fri 39 39 NE 4 N/A N/A N/A N/A N/A
10 PM Fri 37 37 NE 4 N/A N/A N/A N/A N/A
11 PM Fri 36 36 N 2 N/A N/A N/A N/A N/A
12 Midnight Sat 36 36 N 2 N/A N/A N/A N/A N/A
1 AM Sat 35 35 N 2 N/A N/A N/A N/A N/A
2 AM Sat 36 36 N 2 N/A N/A N/A N/A N/A
3 AM Sat 34 34 N 2 N/A N/A N/A N/A N/A
4 AM Sat 35 35 N 2 N/A N/A N/A N/A N/A
5 AM Sat 34 34 N 2 N/A N/A N/A N/A N/A
6 AM Sat 34 34 N 2 N/A N/A N/A N/A N/A
7 AM Sat 33 33 N 2 N/A N/A N/A N/A N/A
8 AM Sat 33 33 N 2 N/A N/A N/A N/A N/A
9 AM Sat 36 36 N 2 N/A N/A N/A N/A N/A
10 AM Sat 39 40 N 2 N/A N/A N/A N/A N/A
11 AM Sat 42 44 E 3 N/A N/A N/A N/A N/A
12 Noon Sat 48 50 E 3 N/A N/A N/A N/A N/A
1 PM Sat 51 53 E 3 N/A N/A N/A N/A N/A
2 PM Sat 53 55 E 3 N/A N/A N/A N/A N/A
3 PM Sat 54 56 E 3 N/A N/A N/A N/A N/A
4 PM Sat 54 55 E 3 N/A N/A N/A N/A N/A
5 PM Sat 54 54 SW 2 N/A N/A N/A N/A N/A
6 PM Sat 51 51 SW 2 N/A N/A N/A N/A N/A
7 PM Sat 47 47 SW 2 N/A N/A N/A N/A N/A
8 PM Sat 42 42 SW 2 N/A N/A N/A N/A N/A
9 PM Sat 40 40 SW 2 N/A N/A N/A N/A N/A
10 PM Sat 37 37 SW 2 N/A N/A N/A N/A N/A
11 PM Sat 36 36 W 4 N/A N/A N/A N/A N/A
12 Midnight Sun 37 37 W 4 N/A N/A N/A N/A N/A
1 AM Sun 35 35 W 4 N/A N/A N/A N/A N/A
2 AM Sun 36 36 W 4 N/A N/A N/A N/A N/A
3 AM Sun 35 35 W 4 N/A N/A N/A N/A N/A
4 AM Sun 35 35 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