Detailed Predictions for: Elk Mountain
Launch Altitude (f): 4000
LZ Altitude (f): 1600
Sounding

Station:

KOAK

Date/Time:

15 JUL 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 Mon 66 66 N 8 2648 4000 0 Blue 0
6 AM Mon 66 66 N 8 2648 4000 0 Blue 0
7 AM Mon 67 67 N 8 2648 4000 0 Blue 0
8 AM Mon 72 73 NW 7 2648 4000 0 Blue 0
9 AM Mon 77 79 NW 7 3737 4000 0 Blue 2
10 AM Mon 83 87 NW 7 7654 6097 2097 Blue 10
11 AM Mon 84 90 W 10 9144 7576 3576 Blue 13
12 Noon Mon 84 91 W 10 9876 7903 3903 Blue 14
1 PM Mon 87 94 W 10 11627 9713 5713 Blue 17
2 PM Mon 88 95 W 14 12142 10397 6397 Blue 18
3 PM Mon 87 93 W 14 11096 8966 4966 Blue 16
4 PM Mon 87 92 W 14 10546 8197 4197 Blue 15
5 PM Mon 84 87 NW 14 7654 6097 2097 Blue 10
6 PM Mon 82 83 NW 14 5769 4201 201 Blue 6
7 PM Mon 77 77 NW 14 2797 4000 0 Blue 0
8 PM Mon 72 72 NW 10 2648 4000 0 Blue 0
9 PM Mon 67 67 NW 10 2648 4000 0 Blue 0
10 PM Mon 70 70 NW 10 2648 4000 0 Blue 0
11 PM Mon 70 70 NW 9 2648 4000 0 Blue 0
12 Midnight Tue 68 68 NW 9 2648 4000 0 Blue 0
1 AM Tue 70 70 NW 9 2648 4000 0 Blue 0
2 AM Tue 68 68 N 8 2648 4000 0 Blue 0
3 AM Tue 70 70 N 8 2648 4000 0 Blue 0
4 AM Tue 68 68 N 8 2648 4000 0 Blue 0
5 AM Tue 68 68 N 7 2648 4000 0 Blue 0
6 AM Tue 66 66 N 7 2648 4000 0 Blue 0
7 AM Tue 68 68 N 7 2648 4000 0 Blue 0
8 AM Tue 73 74 NW 6 2648 4000 0 Blue 0
9 AM Tue 78 80 NW 6 4224 4000 0 Blue 3
10 AM Tue 81 85 NW 6 6500 5171 1171 Blue 8
11 AM Tue 82 88 NW 8 7953 6457 2457 Blue 11
12 Noon Tue 84 91 NW 8 9876 7903 3903 Blue 14
1 PM Tue 85 93 NW 8 11096 8966 4966 Blue 16
2 PM Tue 87 95 W 13 12142 10397 6397 Blue 18
3 PM Tue 87 94 W 13 11627 9713 5713 Blue 17
4 PM Tue 86 91 W 13 9876 7903 3903 Blue 14
5 PM Tue 83 86 NW 13 6974 5733 1733 Blue 9
6 PM Tue 78 80 NW 13 4224 4000 0 Blue 3
7 PM Tue 72 72 NW 13 2648 4000 0 Blue 0
8 PM Tue 68 68 NW 13 2648 4000 0 Blue 0
9 PM Tue 66 66 NW 13 2648 4000 0 Blue 0
10 PM Tue 65 65 NW 13 2648 4000 0 Blue 0
11 PM Tue 65 65 N 6 2648 4000 0 Blue 0
12 Midnight Wed 66 66 N 6 2648 4000 0 Blue 0
1 AM Wed 66 66 N 6 2648 4000 0 Blue 0
2 AM Wed 65 65 N 6 2648 4000 0 Blue 0
3 AM Wed 65 65 N 6 2648 4000 0 Blue 0
4 AM Wed 65 65 N 6 2648 4000 0 Blue 0
5 AM Wed 65 65 N 6 2648 4000 0 Blue 0
6 AM Wed 67 67 N 6 2648 4000 0 Blue 0
7 AM Wed 69 69 N 6 2648 4000 0 Blue 0
8 AM Wed 72 73 N 6 2648 4000 0 Blue 0
9 AM Wed 76 78 N 6 3239 4000 0 Blue 1
10 AM Wed 81 85 N 6 6500 5171 1171 Blue 8
11 AM Wed 85 91 SW 8 9876 7903 3903 Blue 14
12 Noon Wed 88 95 SW 8 12142 10397 6397 Blue 18
1 PM Wed 89 97 SW 8 13744 11476 7476 Blue 20
2 PM Wed 90 97 SW 8 13744 11476 7476 Blue 20
3 PM Wed 91 97 SW 8 13744 11476 7476 Blue 20
4 PM Wed 91 96 SW 8 12642 10950 6950 Blue 19
5 PM Wed 89 92 W 9 10546 8197 4197 Blue 15
6 PM Wed 84 85 W 9 6500 5171 1171 Blue 8
7 PM Wed 78 78 W 9 3239 4000 0 Blue 1
8 PM Wed 73 73 W 9 2648 4000 0 Blue 0
9 PM Wed 70 70 W 9 2648 4000 0 Blue 0
10 PM Wed 69 69 W 9 2648 4000 0 Blue 0
11 PM Wed 69 69 N 6 2648 4000 0 Blue 0
12 Midnight Thu 68 68 N 6 2648 4000 0 Blue 0
1 AM Thu 68 68 N 6 2648 4000 0 Blue 0
2 AM Thu 67 67 N 6 2648 4000 0 Blue 0
3 AM Thu 67 67 N 6 2648 4000 0 Blue 0
4 AM Thu 67 67 N 6 2648 4000 0 Blue 0
5 AM Thu 67 67 N 6 2648 4000 0 Blue 0
6 AM Thu 68 68 N 6 2648 4000 0 Blue 0
7 AM Thu 69 69 N 6 2648 4000 0 Blue 0
8 AM Thu 71 72 N 6 2648 4000 0 Blue 0
9 AM Thu 74 76 N 6 2648 4000 0 Blue 0
10 AM Thu 79 83 N 6 5769 4201 201 Blue 6
11 AM Thu 83 89 S 7 8249 6877 2877 Blue 12
12 Noon Thu 86 94 S 7 11627 9713 5713 Blue 17
1 PM Thu 88 96 S 7 12642 10950 6950 Blue 19
2 PM Thu 89 97 S 7 13744 11476 7476 Blue 20
3 PM Thu 89 96 S 7 12642 10950 6950 Blue 19
4 PM Thu 88 94 S 7 11627 9713 5713 Blue 17
5 PM Thu 86 90 SW 10 9144 7576 3576 Blue 13
6 PM Thu 82 84 SW 10 6137 4671 671 Blue 7
7 PM Thu 77 77 SW 10 2797 4000 0 Blue 0
8 PM Thu 73 73 SW 10 2648 4000 0 Blue 0
9 PM Thu 71 71 SW 10 2648 4000 0 Blue 0
10 PM Thu 70 70 SW 10 2648 4000 0 Blue 0
11 PM Thu 70 70 W 5 2648 4000 0 Blue 0
12 Midnight Fri 69 69 W 5 2648 4000 0 Blue 0
1 AM Fri 68 68 W 5 2648 4000 0 Blue 0
2 AM Fri 67 67 W 5 2648 4000 0 Blue 0
3 AM Fri 66 66 W 5 2648 4000 0 Blue 0
4 AM Fri 66 66 W 5 2648 4000 0 Blue 0
5 AM Fri 67 67 SE 5 2648 4000 0 Blue 0
6 AM Fri 67 67 SE 5 2648 4000 0 Blue 0
7 AM Fri 69 69 SE 5 2648 4000 0 Blue 0
8 AM Fri 71 72 SE 5 2648 4000 0 Blue 0
9 AM Fri 74 76 SE 5 2648 4000 0 Blue 0
10 AM Fri 78 82 SE 5 5227 4000 0 Blue 5
11 AM Fri 81 87 S 9 7654 6097 2097 Blue 10
12 Noon Fri 83 90 S 9 9144 7576 3576 Blue 13
1 PM Fri 84 92 S 9 10546 8197 4197 Blue 15
2 PM Fri 85 93 S 9 11096 8966 4966 Blue 16
3 PM Fri 86 93 S 9 11096 8966 4966 Blue 16
4 PM Fri 86 91 S 9 9876 7903 3903 Blue 14
5 PM Fri 84 87 SW 10 7654 6097 2097 Blue 10
6 PM Fri 80 81 SW 10 4700 4000 0 Blue 4
7 PM Fri 75 75 SW 10 2648 4000 0 Blue 0
8 PM Fri 71 71 SW 10 2648 4000 0 Blue 0
9 PM Fri 68 68 SW 10 2648 4000 0 Blue 0
10 PM Fri 67 67 SW 10 2648 4000 0 Blue 0
11 PM Fri 67 67 E 6 2648 4000 0 Blue 0
12 Midnight Sat 66 66 E 6 2648 4000 0 Blue 0
1 AM Sat 65 65 E 6 2648 4000 0 Blue 0
2 AM Sat 64 64 E 6 2648 4000 0 Blue 0
3 AM Sat 64 64 E 6 2648 4000 0 Blue 0
4 AM Sat 64 64 E 6 2648 4000 0 Blue 0
5 AM Sat 64 64 E 6 2648 4000 0 Blue 0
6 AM Sat 65 65 E 6 2648 4000 0 Blue 0
7 AM Sat 67 67 E 6 2648 4000 0 Blue 0
8 AM Sat 69 70 E 6 2648 4000 0 Blue 0
9 AM Sat 73 75 E 6 2648 4000 0 Blue 0
10 AM Sat 76 80 E 6 4224 4000 0 Blue 3
11 AM Sat 80 85 S 8 6500 5171 1171 Blue 8
12 Noon Sat 82 89 S 8 8249 6877 2877 Blue 12
1 PM Sat 84 91 S 8 9876 7903 3903 Blue 14
2 PM Sat 85 92 S 8 10546 8197 4197 Blue 15
3 PM Sat 85 91 S 8 9876 7903 3903 Blue 14
4 PM Sat 84 89 S 8 8249 6877 2877 Blue 12
5 PM Sat 82 85 W 10 6500 5171 1171 Blue 8
6 PM Sat 78 80 W 10 4224 4000 0 Blue 3
7 PM Sat 73 73 W 10 2648 4000 0 Blue 0
8 PM Sat 69 69 W 10 2648 4000 0 Blue 0
9 PM Sat 67 67 W 10 2648 4000 0 Blue 0
10 PM Sat 66 66 W 10 2648 4000 0 Blue 0
11 PM Sat 65 65 SW 6 2648 4000 0 Blue 0
12 Midnight Sun 65 65 SW 6 2648 4000 0 Blue 0
1 AM Sun 65 65 SW 6 2648 4000 0 Blue 0
2 AM Sun 64 64 SW 6 2648 4000 0 Blue 0
3 AM Sun 64 64 SW 6 2648 4000 0 Blue 0
4 AM Sun 63 63 SW 6 2648 4000 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