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

Station:

KOAK

Date/Time:

16 AUG 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 Thu 68 68 E 6 2592 4000 0 Blue 0
6 AM Thu 68 68 E 6 2592 4000 0 Blue 0
7 AM Thu 68 68 E 6 2592 4000 0 Blue 0
8 AM Thu 70 70 E 6 2592 4000 0 Blue 0
9 AM Thu 73 74 E 6 2592 4000 0 Blue 0
10 AM Thu 78 81 E 6 3683 4000 0 Blue 3
11 AM Thu 81 86 S 3 5950 4110 110 Blue 8
12 Noon Thu 84 90 S 3 8629 6359 2359 Blue 12
1 PM Thu 86 93 S 3 10106 8540 4540 Blue 15
2 PM Thu 88 95 SW 5 11918 9460 5460 Blue 17
3 PM Thu 89 95 SW 5 11918 9460 5460 Blue 17
4 PM Thu 89 93 SW 5 10106 8540 4540 Blue 15
5 PM Thu 88 91 W 7 9100 7466 3466 Blue 13
6 PM Thu 85 86 W 7 5950 4110 110 Blue 8
7 PM Thu 81 81 W 7 3683 4000 0 Blue 3
8 PM Thu 78 78 W 6 2921 4000 0 Blue 0
9 PM Thu 75 75 W 6 2612 4000 0 Blue 0
10 PM Thu 74 74 W 6 2592 4000 0 Blue 0
11 PM Thu 73 73 N 3 2592 4000 0 Blue 0
12 Midnight Fri 72 72 N 3 2592 4000 0 Blue 0
1 AM Fri 72 72 N 3 2592 4000 0 Blue 0
2 AM Fri 71 71 N 3 2592 4000 0 Blue 0
3 AM Fri 70 70 N 3 2592 4000 0 Blue 0
4 AM Fri 70 70 N 3 2592 4000 0 Blue 0
5 AM Fri 69 69 NE 3 2592 4000 0 Blue 0
6 AM Fri 69 69 NE 3 2592 4000 0 Blue 0
7 AM Fri 70 70 NE 3 2592 4000 0 Blue 0
8 AM Fri 72 72 NE 2 2592 4000 0 Blue 0
9 AM Fri 75 77 NE 2 2818 4000 0 Blue 0
10 AM Fri 80 83 NE 2 4120 4000 0 Blue 5
11 AM Fri 84 89 S 3 8129 5903 1903 Blue 11
12 Noon Fri 87 93 S 3 10106 8540 4540 Blue 15
1 PM Fri 89 96 S 3 12760 9938 5938 Blue 18
2 PM Fri 90 97 S 5 13535 10725 6725 Blue 19
3 PM Fri 91 97 S 5 13535 10725 6725 Blue 19
4 PM Fri 91 96 S 5 12760 9938 5938 Blue 18
5 PM Fri 89 92 W 7 9560 8041 4041 Blue 14
6 PM Fri 86 87 W 7 6412 4986 986 Blue 9
7 PM Fri 82 82 W 7 3902 4000 0 Blue 4
8 PM Fri 78 78 W 7 2921 4000 0 Blue 0
9 PM Fri 76 76 W 7 2715 4000 0 Blue 0
10 PM Fri 74 74 W 7 2592 4000 0 Blue 0
11 PM Fri 73 73 NE 3 2592 4000 0 Blue 0
12 Midnight Sat 72 72 NE 3 2592 4000 0 Blue 0
1 AM Sat 71 71 NE 3 2592 4000 0 Blue 0
2 AM Sat 70 70 NE 3 2592 4000 0 Blue 0
3 AM Sat 69 69 NE 3 2592 4000 0 Blue 0
4 AM Sat 68 68 NE 3 2592 4000 0 Blue 0
5 AM Sat 68 68 NE 5 2592 4000 0 Blue 0
6 AM Sat 68 68 NE 5 2592 4000 0 Blue 0
7 AM Sat 69 69 NE 5 2592 4000 0 Blue 0
8 AM Sat 72 72 NE 5 2592 4000 0 Blue 0
9 AM Sat 76 78 NE 5 2921 4000 0 Blue 0
10 AM Sat 82 85 NE 5 5478 4000 0 Blue 7
11 AM Sat 87 92 SW 2 9560 8041 4041 Blue 14
12 Noon Sat 91 98 SW 2 14080 11656 7656 Blue 20
1 PM Sat 93 100 SW 2 15233 13271 9271 Blue 22
2 PM Sat 94 101 SW 2 15556 13939 9939 Blue 23
3 PM Sat 95 101 SW 2 15556 13939 9939 Blue 23
4 PM Sat 95 100 SW 2 15233 13271 9271 Blue 22
5 PM Sat 93 96 W 8 12760 9938 5938 Blue 18
6 PM Sat 90 91 W 8 9100 7466 3466 Blue 13
7 PM Sat 85 85 W 8 5478 4000 0 Blue 7
8 PM Sat 80 80 W 8 3463 4000 0 Blue 2
9 PM Sat 77 77 W 8 2818 4000 0 Blue 0
10 PM Sat 74 74 W 8 2592 4000 0 Blue 0
11 PM Sat 73 73 N 5 2592 4000 0 Blue 0
12 Midnight Sun 72 72 N 5 2592 4000 0 Blue 0
1 AM Sun 72 72 N 5 2592 4000 0 Blue 0
2 AM Sun 71 71 N 5 2592 4000 0 Blue 0
3 AM Sun 70 70 N 5 2592 4000 0 Blue 0
4 AM Sun 69 69 N 5 2592 4000 0 Blue 0
5 AM Sun 68 68 NE 5 2592 4000 0 Blue 0
6 AM Sun 68 68 NE 5 2592 4000 0 Blue 0
7 AM Sun 69 69 NE 5 2592 4000 0 Blue 0
8 AM Sun 71 71 NE 5 2592 4000 0 Blue 0
9 AM Sun 74 76 NE 5 2715 4000 0 Blue 0
10 AM Sun 78 81 NE 5 3683 4000 0 Blue 3
11 AM Sun 82 87 S 3 6412 4986 986 Blue 9
12 Noon Sun 86 93 S 3 10106 8540 4540 Blue 15
1 PM Sun 88 95 S 3 11918 9460 5460 Blue 17
2 PM Sun 90 97 S 3 13535 10725 6725 Blue 19
3 PM Sun 91 97 S 3 13535 10725 6725 Blue 19
4 PM Sun 91 96 S 3 12760 9938 5938 Blue 18
5 PM Sun 89 92 W 9 9560 8041 4041 Blue 14
6 PM Sun 86 87 W 9 6412 4986 986 Blue 9
7 PM Sun 81 81 W 9 3683 4000 0 Blue 3
8 PM Sun 78 78 W 9 2921 4000 0 Blue 0
9 PM Sun 75 75 W 9 2612 4000 0 Blue 0
10 PM Sun 74 74 W 9 2592 4000 0 Blue 0
11 PM Sun 73 73 NW 5 2592 4000 0 Blue 0
12 Midnight Mon 72 72 NW 5 2592 4000 0 Blue 0
1 AM Mon 71 71 NW 5 2592 4000 0 Blue 0
2 AM Mon 70 70 NW 5 2592 4000 0 Blue 0
3 AM Mon 69 69 NW 5 2592 4000 0 Blue 0
4 AM Mon 69 69 NW 5 2592 4000 0 Blue 0
5 AM Mon 68 68 N 6 2592 4000 0 Blue 0
6 AM Mon 68 68 N 6 2592 4000 0 Blue 0
7 AM Mon 69 69 N 6 2592 4000 0 Blue 0
8 AM Mon 71 71 N 6 2592 4000 0 Blue 0
9 AM Mon 75 77 N 6 2818 4000 0 Blue 0
10 AM Mon 79 82 N 6 3902 4000 0 Blue 4
11 AM Mon 84 89 E 5 8129 5903 1903 Blue 11
12 Noon Mon 87 94 E 5 10986 9005 5005 Blue 16
1 PM Mon 89 96 E 5 12760 9938 5938 Blue 18
2 PM Mon 90 97 E 5 13535 10725 6725 Blue 19
3 PM Mon 91 97 E 5 13535 10725 6725 Blue 19
4 PM Mon 91 96 E 5 12760 9938 5938 Blue 18
5 PM Mon 90 93 SW 7 10106 8540 4540 Blue 15
6 PM Mon 87 88 SW 7 7605 5437 1437 Blue 10
7 PM Mon 83 83 SW 7 4120 4000 0 Blue 5
8 PM Mon 80 80 SW 7 3463 4000 0 Blue 2
9 PM Mon 78 78 SW 7 2921 4000 0 Blue 0
10 PM Mon 76 76 SW 7 2715 4000 0 Blue 0
11 PM Mon 75 75 NW 3 2612 4000 0 Blue 0
12 Midnight Tue 74 74 NW 3 2592 4000 0 Blue 0
1 AM Tue 73 73 NW 3 2592 4000 0 Blue 0
2 AM Tue 73 73 NW 3 2592 4000 0 Blue 0
3 AM Tue 72 72 NW 3 2592 4000 0 Blue 0
4 AM Tue 72 72 NW 3 2592 4000 0 Blue 0
5 AM Tue 71 71 NE 5 2592 4000 0 Blue 0
6 AM Tue 71 71 NE 5 2592 4000 0 Blue 0
7 AM Tue 71 71 NE 5 2592 4000 0 Blue 0
8 AM Tue 73 73 NE 5 2592 4000 0 Blue 0
9 AM Tue 76 78 NE 5 2921 4000 0 Blue 0
10 AM Tue 80 83 NE 5 4120 4000 0 Blue 5
11 AM Tue 84 89 SE 5 8129 5903 1903 Blue 11
12 Noon Tue 87 94 SE 5 10986 9005 5005 Blue 16
1 PM Tue 90 97 SE 5 13535 10725 6725 Blue 19
2 PM Tue 91 98 SE 5 14080 11656 7656 Blue 20
3 PM Tue 92 98 SE 5 14080 11656 7656 Blue 20
4 PM Tue 92 97 SE 5 13535 10725 6725 Blue 19
5 PM Tue 90 93 SW 7 10106 8540 4540 Blue 15
6 PM Tue 88 89 SW 7 8129 5903 1903 Blue 11
7 PM Tue 84 84 SW 7 5003 4000 0 Blue 6
8 PM Tue 81 81 SW 7 3683 4000 0 Blue 3
9 PM Tue 79 79 SW 7 3243 4000 0 Blue 1
10 PM Tue 77 77 SW 7 2818 4000 0 Blue 0
11 PM Tue 76 76 NW 3 2715 4000 0 Blue 0
12 Midnight Wed 75 75 NW 3 2612 4000 0 Blue 0
1 AM Wed 74 74 NW 3 2592 4000 0 Blue 0
2 AM Wed 74 74 NW 3 2592 4000 0 Blue 0
3 AM Wed 73 73 NW 3 2592 4000 0 Blue 0
4 AM Wed 73 73 NW 3 2592 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