Detailed Predictions for: Elk Mountain
Launch Lat, Long, Altitude (f): 39.2820, -122.93, 4000
LZ Altitude (f): 1600
Sounding

Station:

 KOAK

Date/Time UTC:

 260912/1200

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Wind
 Gust		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
12 Midnight Sat 68 68 NNW 9 11 2527 4000 0 Blue 0
1 AM Sat 68 68 NNW 9 11 2527 4000 0 Blue 0
2 AM Sat 67 67 NNW 9 11 2526 4000 0 Blue 0
3 AM Sat 66 66 NNW 9 11 2526 4000 0 Blue 0
4 AM Sat 65 65 NNW 9 11 2526 4000 0 Blue 0
5 AM Sat 64 64 NNW 9 10 2526 4000 0 Blue 0
6 AM Sat 63 63 NNW 9 10 2526 4000 0 Blue 0
7 AM Sat 62 62 NNW 9 10 2526 4000 0 Blue 0
8 AM Sat 64 64 WNW 6 8 2526 4000 0 Blue 0
9 AM Sat 68 69 WNW 6 8 2660 4000 0 Blue 0
10 AM Sat 71 73 WNW 6 8 3248 4000 0 Blue 2
11 AM Sat 73 75 W 12 14 3614 4000 0 Blue 4
12 Noon Sat 73 76 W 12 14 3718 4000 0 Blue 5
1 PM Sat 75 79 W 12 14 4078 4000 0 Blue 8
2 PM Sat 74 77 W 14 20 3802 4000 0 Blue 6
3 PM Sat 74 76 W 14 20 3718 4000 0 Blue 5
4 PM Sat 74 76 W 14 20 3718 4000 0 Blue 5
5 PM Sat 70 71 WNW 17 24 2927 4000 0 Blue 0
6 PM Sat 68 68 WNW 17 24 2527 4000 0 Blue 0
7 PM Sat 63 63 WNW 17 24 2526 4000 0 Blue 0
8 PM Sat 53 53 NW 13 25 2526 4000 0 Blue 0
9 PM Sat 52 52 NW 13 25 2526 4000 0 Blue 0
10 PM Sat 53 53 NW 13 25 2526 4000 0 Blue 0
11 PM Sat 52 52 NNW 10 23 2526 4000 0 Blue 0
12 Midnight Sun 53 53 NNW 10 23 2526 4000 0 Blue 0
1 AM Sun 52 52 NNW 10 23 2526 4000 0 Blue 0
2 AM Sun 52 52 N 10 20 2526 4000 0 Blue 0
3 AM Sun 51 51 N 10 20 2526 4000 0 Blue 0
4 AM Sun 50 50 N 10 20 2526 4000 0 Blue 0
5 AM Sun 49 49 N 12 20 2526 4000 0 Blue 0
6 AM Sun 49 49 N 12 20 2526 4000 0 Blue 0
7 AM Sun 48 48 N 12 20 2526 4000 0 Blue 0
8 AM Sun 51 51 N 9 14 2526 4000 0 Blue 0
9 AM Sun 55 56 N 9 14 2526 4000 0 Blue 0
10 AM Sun 61 63 N 9 14 2526 4000 0 Blue 0
11 AM Sun 66 70 NW 6 10 2794 4000 0 Blue 0
12 Noon Sun 67 72 NW 6 10 3064 4000 0 Blue 1
1 PM Sun 69 74 NW 6 10 3431 4000 0 Blue 3
2 PM Sun 72 76 NW 10 17 3718 4000 0 Blue 5
3 PM Sun 73 77 NW 10 17 3802 4000 0 Blue 6
4 PM Sun 73 76 NW 10 17 3718 4000 0 Blue 5
5 PM Sun 71 72 W 10 17 3064 4000 0 Blue 1
6 PM Sun 67 67 W 10 17 2526 4000 0 Blue 0
7 PM Sun 61 61 W 10 17 2526 4000 0 Blue 0
8 PM Sun 57 57 NW 4 10 2526 4000 0 Blue 0
9 PM Sun 56 56 NW 4 10 2526 4000 0 Blue 0
10 PM Sun 56 56 NW 4 10 2526 4000 0 Blue 0
11 PM Sun 57 57 N 4 10 2526 4000 0 Blue 0
12 Midnight Mon 57 57 N 4 10 2526 4000 0 Blue 0
1 AM Mon 57 57 N 4 10 2526 4000 0 Blue 0
2 AM Mon 57 57 N 4 9 2526 4000 0 Blue 0
3 AM Mon 57 57 N 4 9 2526 4000 0 Blue 0
4 AM Mon 56 56 N 4 9 2526 4000 0 Blue 0
5 AM Mon 56 56 N 4 8 2526 4000 0 Blue 0
6 AM Mon 56 56 N 4 8 2526 4000 0 Blue 0
7 AM Mon 56 56 N 4 8 2526 4000 0 Blue 0
8 AM Mon 58 58 N 3 6 2526 4000 0 Blue 0
9 AM Mon 63 64 N 3 6 2526 4000 0 Blue 0
10 AM Mon 69 71 N 3 6 2927 4000 0 Blue 0
11 AM Mon 75 79 SW 3 5 4078 4000 0 Blue 8
12 Noon Mon 78 83 SW 3 5 4372 4151 151 Blue 11
1 PM Mon 79 85 SW 3 5 5011 4291 291 Blue 13
2 PM Mon 80 86 WSW 5 12 5500 4368 368 Blue 14
3 PM Mon 81 86 WSW 5 12 5500 4368 368 Blue 14
4 PM Mon 82 85 WSW 5 12 5011 4291 291 Blue 13
5 PM Mon 80 82 W 6 14 4295 4070 70 Blue 10
6 PM Mon 75 75 W 6 14 3614 4000 0 Blue 4
7 PM Mon 68 68 W 6 14 2527 4000 0 Blue 0
8 PM Mon 63 63 WNW 2 8 2526 4000 0 Blue 0
9 PM Mon 62 62 WNW 2 8 2526 4000 0 Blue 0
10 PM Mon 62 62 WNW 2 8 2526 4000 0 Blue 0
11 PM Mon 63 63 N 3 9 2526 4000 0 Blue 0
12 Midnight Tue 63 63 N 3 9 2526 4000 0 Blue 0
1 AM Tue 63 63 N 3 9 2526 4000 0 Blue 0
2 AM Tue 63 63 NNE 3 6 2526 4000 0 Blue 0
3 AM Tue 63 63 NNE 3 6 2526 4000 0 Blue 0
4 AM Tue 62 62 NNE 3 6 2526 4000 0 Blue 0
5 AM Tue 62 62 NE 3 5 2526 4000 0 Blue 0
6 AM Tue 61 61 NE 3 5 2526 4000 0 Blue 0
7 AM Tue 61 61 NE 3 5 2526 4000 0 Blue 0
8 AM Tue 63 63 NE 3 6 2526 4000 0 Blue 0
9 AM Tue 67 68 NE 3 6 2527 4000 0 Blue 0
10 AM Tue 73 75 NE 3 6 3614 4000 0 Blue 4
11 AM Tue 78 82 S 3 6 4295 4070 70 Blue 10
12 Noon Tue 81 86 S 3 6 5500 4368 368 Blue 14
1 PM Tue 82 88 S 3 6 8176 4983 983 Blue 16
2 PM Tue 83 89 SW 5 12 10294 5455 1455 Blue 17
3 PM Tue 84 89 SW 5 12 10294 5455 1455 Blue 17
4 PM Tue 85 88 SW 5 12 8176 4983 983 Blue 16
5 PM Tue 83 84 WSW 8 16 4644 4214 214 Blue 12
6 PM Tue 76 76 WSW 8 16 3718 4000 0 Blue 5
7 PM Tue 69 69 WSW 8 16 2660 4000 0 Blue 0
8 PM Tue 65 65 W 3 5 2526 4000 0 Blue 0
9 PM Tue 64 64 W 3 5 2526 4000 0 Blue 0
10 PM Tue 64 64 W 3 5 2526 4000 0 Blue 0
11 PM Tue 65 65 N 3 6 2526 4000 0 Blue 0
12 Midnight Wed 64 64 N 3 6 2526 4000 0 Blue 0
1 AM Wed 64 64 N 3 6 2526 4000 0 Blue 0
2 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
3 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
4 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
5 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
6 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
7 AM Wed 63 63 NE 3 5 2526 4000 0 Blue 0
8 AM Wed 64 64 ENE 4 8 2526 4000 0 Blue 0
9 AM Wed 68 69 ENE 4 8 2660 4000 0 Blue 0
10 AM Wed 73 75 ENE 4 8 3614 4000 0 Blue 4
11 AM Wed 78 82 S 4 9 4295 4070 70 Blue 10
12 Noon Wed 81 86 S 4 9 5500 4368 368 Blue 14
1 PM Wed 82 88 S 4 9 8176 4983 983 Blue 16
2 PM Wed 83 89 S 5 13 10294 5455 1455 Blue 17
3 PM Wed 84 89 S 5 13 10294 5455 1455 Blue 17
4 PM Wed 85 88 S 5 13 8176 4983 983 Blue 16
5 PM Wed 83 85 SW 6 14 5011 4291 291 Blue 13
6 PM Wed 77 77 SW 6 14 3802 4000 0 Blue 6
7 PM Wed 70 70 SW 6 14 2794 4000 0 Blue 0
8 PM Wed 64 64 W 3 4 2526 4000 0 Blue 0
9 PM Wed 63 63 W 3 4 2526 4000 0 Blue 0
10 PM Wed 64 64 W 3 4 2526 4000 0 Blue 0
11 PM Wed 65 65 NNW 2 5 2526 4000 0 Blue 0
12 Midnight Thu 65 65 NNW 2 5 2526 4000 0 Blue 0
1 AM Thu 64 64 NNW 2 5 2526 4000 0 Blue 0
2 AM Thu 63 63 NNE 2 4 2526 4000 0 Blue 0
3 AM Thu 62 62 NNE 2 4 2526 4000 0 Blue 0
4 AM Thu 62 62 NNE 2 4 2526 4000 0 Blue 0
5 AM Thu 62 62 NE 2 5 2526 4000 0 Blue 0
6 AM Thu 62 62 NE 2 5 2526 4000 0 Blue 0
7 AM Thu 63 63 NE 2 5 2526 4000 0 Blue 0
8 AM Thu 65 65 E 3 6 2526 4000 0 Blue 0
9 AM Thu 69 70 E 3 6 2794 4000 0 Blue 0
10 AM Thu 74 76 E 3 6 3718 4000 0 Blue 5
11 AM Thu 78 82 S 4 9 4295 4070 70 Blue 10
12 Noon Thu 81 86 S 4 9 5500 4368 368 Blue 14
1 PM Thu 82 88 S 4 9 8176 4983 983 Blue 16
2 PM Thu 83 88 SSW 6 14 8176 4983 983 Blue 16
3 PM Thu 84 88 SSW 6 14 8176 4983 983 Blue 16
4 PM Thu 84 87 SSW 6 14 7283 4622 622 Blue 15
5 PM Thu 82 83 WSW 6 14 4372 4151 151 Blue 11
6 PM Thu 77 77 WSW 6 14 3802 4000 0 Blue 6
7 PM Thu 70 70 WSW 6 14 2794 4000 0 Blue 0
8 PM Thu 65 65 W 4 6 2526 4000 0 Blue 0
9 PM Thu 63 63 W 4 6 2526 4000 0 Blue 0
10 PM Thu 64 64 W 4 6 2526 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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]