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

Station:

KOAK

Date/Time:

12 MAY 2021

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 Wed 62 62 N 5 6 2566 4000 0 Blue 0
1 AM Wed 62 62 N 5 6 2566 4000 0 Blue 0
2 AM Wed 62 62 NNE 4 5 2566 4000 0 Blue 0
3 AM Wed 62 62 NNE 4 5 2566 4000 0 Blue 0
4 AM Wed 62 62 NNE 4 5 2566 4000 0 Blue 0
5 AM Wed 62 62 ENE 6 8 2566 4000 0 Blue 0
6 AM Wed 66 66 ENE 6 8 2566 4000 0 Blue 0
7 AM Wed 69 69 ENE 6 8 2566 4000 0 Blue 0
8 AM Wed 72 73 S 3 4 2974 4000 0 Blue 0
9 AM Wed 75 77 S 3 4 5415 4000 0 Blue 1
10 AM Wed 78 82 S 3 4 8394 5949 1949 Blue 6
11 AM Wed 81 86 S 8 10 9765 8751 4751 Blue 10
12 Noon Wed 83 89 S 8 10 12192 9592 5592 Blue 13
1 PM Wed 84 91 S 8 10 13599 11180 7180 Blue 15
2 PM Wed 85 91 SW 6 9 13599 11180 7180 Blue 15
3 PM Wed 85 90 SW 6 9 12918 10333 6333 Blue 14
4 PM Wed 84 88 SW 6 9 11411 9316 5316 Blue 12
5 PM Wed 83 85 WSW 10 12 9338 8335 4335 Blue 9
6 PM Wed 81 82 WSW 10 12 8394 5949 1949 Blue 6
7 PM Wed 78 78 WSW 10 12 5698 4000 0 Blue 2
8 PM Wed 75 75 WNW 6 9 3646 4000 0 Blue 0
9 PM Wed 71 71 WNW 6 9 2566 4000 0 Blue 0
10 PM Wed 68 68 WNW 6 9 2566 4000 0 Blue 0
11 PM Wed 65 65 NNW 5 6 2566 4000 0 Blue 0
12 Midnight Thu 63 63 NNW 5 6 2566 4000 0 Blue 0
1 AM Thu 62 62 NNW 5 6 2566 4000 0 Blue 0
2 AM Thu 61 61 NNW 5 6 2566 4000 0 Blue 0
3 AM Thu 61 61 NNW 5 6 2566 4000 0 Blue 0
4 AM Thu 62 62 NNW 5 6 2566 4000 0 Blue 0
5 AM Thu 63 63 NNE 3 4 2566 4000 0 Blue 0
6 AM Thu 66 66 NNE 3 4 2566 4000 0 Blue 0
7 AM Thu 69 69 NNE 3 4 2566 4000 0 Blue 0
8 AM Thu 72 73 E 1 1 2974 4000 0 Blue 0
9 AM Thu 75 77 E 1 1 5415 4000 0 Blue 1
10 AM Thu 79 83 E 1 1 8855 6381 2381 Blue 7
11 AM Thu 81 87 SSW 5 6 10560 9215 5215 Blue 11
12 Noon Thu 83 90 SSW 5 6 12918 10333 6333 Blue 14
1 PM Thu 84 92 SSW 5 6 14244 11957 7957 Blue 16
2 PM Thu 85 92 WSW 8 10 14244 11957 7957 Blue 16
3 PM Thu 85 91 WSW 8 10 13599 11180 7180 Blue 15
4 PM Thu 84 88 WSW 8 10 11411 9316 5316 Blue 12
5 PM Thu 82 85 W 10 12 9338 8335 4335 Blue 9
6 PM Thu 80 81 W 10 12 7738 5671 1671 Blue 5
7 PM Thu 77 77 W 10 12 5415 4000 0 Blue 1
8 PM Thu 74 74 W 6 9 3311 4000 0 Blue 0
9 PM Thu 70 70 W 6 9 2566 4000 0 Blue 0
10 PM Thu 67 67 W 6 9 2566 4000 0 Blue 0
11 PM Thu 64 64 NNW 6 9 2566 4000 0 Blue 0
12 Midnight Fri 62 62 NNW 6 9 2566 4000 0 Blue 0
1 AM Fri 60 60 NNW 6 9 2566 4000 0 Blue 0
2 AM Fri 59 59 NNW 4 5 2566 4000 0 Blue 0
3 AM Fri 59 59 NNW 4 5 2566 4000 0 Blue 0
4 AM Fri 59 59 NNW 4 5 2566 4000 0 Blue 0
5 AM Fri 61 61 N 4 5 2566 4000 0 Blue 0
6 AM Fri 62 62 N 4 5 2566 4000 0 Blue 0
7 AM Fri 65 65 N 4 5 2566 4000 0 Blue 0
8 AM Fri 68 69 N 4 5 2566 4000 0 Blue 0
9 AM Fri 70 72 N 4 5 2633 4000 0 Blue 0
10 AM Fri 73 77 N 4 5 5415 4000 0 Blue 1
11 AM Fri 75 80 W 3 4 6539 5391 1391 Blue 4
12 Noon Fri 77 83 W 3 4 8855 6381 2381 Blue 7
1 PM Fri 78 84 W 3 4 9236 7563 3563 Blue 8
2 PM Fri 78 84 W 3 4 9236 7563 3563 Blue 8
3 PM Fri 78 83 W 3 4 8855 6381 2381 Blue 7
4 PM Fri 77 80 W 3 4 6539 5391 1391 Blue 4
5 PM Fri 75 77 W 8 10 5415 4000 0 Blue 1
6 PM Fri 73 74 W 8 10 3311 4000 0 Blue 0
7 PM Fri 70 70 W 8 10 2566 4000 0 Blue 0
8 PM Fri 67 67 W 8 10 2566 4000 0 Blue 0
9 PM Fri 64 64 W 8 10 2566 4000 0 Blue 0
10 PM Fri 61 61 W 8 10 2566 4000 0 Blue 0
11 PM Fri 59 59 N 4 5 2566 4000 0 Blue 0
12 Midnight Sat 57 57 N 4 5 2566 4000 0 Blue 0
1 AM Sat 56 56 N 4 5 2566 4000 0 Blue 0
2 AM Sat 56 56 N 4 5 2566 4000 0 Blue 0
3 AM Sat 56 56 N 4 5 2566 4000 0 Blue 0
4 AM Sat 57 57 N 4 5 2566 4000 0 Blue 0
5 AM Sat 58 58 N 4 5 2566 4000 0 Blue 0
6 AM Sat 60 60 N 4 5 2566 4000 0 Blue 0
7 AM Sat 62 62 N 4 5 2566 4000 0 Blue 0
8 AM Sat 64 65 N 4 5 2566 4000 0 Blue 0
9 AM Sat 67 69 N 4 5 2566 4000 0 Blue 0
10 AM Sat 69 73 N 4 5 2974 4000 0 Blue 0
11 AM Sat 72 78 NW 2 3 5698 4000 0 Blue 2
12 Noon Sat 74 81 NW 2 3 7738 5671 1671 Blue 5
1 PM Sat 76 83 NW 2 3 8855 6381 2381 Blue 7
2 PM Sat 78 85 NW 2 3 9338 8335 4335 Blue 9
3 PM Sat 79 85 NW 2 3 9338 8335 4335 Blue 9
4 PM Sat 79 83 NW 2 3 8855 6381 2381 Blue 7
5 PM Sat 78 80 W 5 6 6539 5391 1391 Blue 4
6 PM Sat 77 78 W 5 6 5698 4000 0 Blue 2
7 PM Sat 75 75 W 5 6 3646 4000 0 Blue 0
8 PM Sat 72 72 W 5 6 2633 4000 0 Blue 0
9 PM Sat 69 69 W 5 6 2566 4000 0 Blue 0
10 PM Sat 66 66 W 5 6 2566 4000 0 Blue 0
11 PM Sat 63 63 NNW 3 4 2566 4000 0 Blue 0
12 Midnight Sun 60 60 NNW 3 4 2566 4000 0 Blue 0
1 AM Sun 59 59 NNW 3 4 2566 4000 0 Blue 0
2 AM Sun 57 57 NNW 3 4 2566 4000 0 Blue 0
3 AM Sun 57 57 NNW 3 4 2566 4000 0 Blue 0
4 AM Sun 57 57 NNW 3 4 2566 4000 0 Blue 0
5 AM Sun 59 59 NNE 3 4 2566 4000 0 Blue 0
6 AM Sun 61 61 NNE 3 4 2566 4000 0 Blue 0
7 AM Sun 64 64 NNE 3 4 2566 4000 0 Blue 0
8 AM Sun 68 68 NNE 3 4 2566 4000 0 Blue 0
9 AM Sun 71 72 NNE 3 4 2633 4000 0 Blue 0
10 AM Sun 75 76 NNE 3 4 3977 4000 0 Blue 0
11 AM Sun 77 81 SSW 2 3 7738 5671 1671 Blue 5
12 Noon Sun 79 83 SSW 2 3 8855 6381 2381 Blue 7
1 PM Sun 81 86 SSW 2 3 9765 8751 4751 Blue 10
2 PM Sun 81 85 SSW 2 3 9338 8335 4335 Blue 9
3 PM Sun 81 85 SSW 2 3 9338 8335 4335 Blue 9
4 PM Sun 80 83 SSW 2 3 8855 6381 2381 Blue 7
5 PM Sun 78 79 WSW 8 10 5978 4000 0 Blue 3
6 PM Sun 75 75 WSW 8 10 3646 4000 0 Blue 0
7 PM Sun 73 73 WSW 8 10 2974 4000 0 Blue 0
8 PM Sun 69 69 WSW 8 10 2566 4000 0 Blue 0
9 PM Sun 66 66 WSW 8 10 2566 4000 0 Blue 0
10 PM Sun 63 63 WSW 8 10 2566 4000 0 Blue 0
11 PM Sun 61 61 WNW 3 4 2566 4000 0 Blue 0
12 Midnight Mon 58 58 WNW 3 4 2566 4000 0 Blue 0
1 AM Mon 57 57 WNW 3 4 2566 4000 0 Blue 0
2 AM Mon 56 56 WNW 3 4 2566 4000 0 Blue 0
3 AM Mon 55 55 WNW 3 4 2566 4000 0 Blue 0
4 AM Mon 55 55 WNW 3 4 2566 4000 0 Blue 0
5 AM Mon 56 56 NW 2 3 2566 4000 0 Blue 0
6 AM Mon 58 58 NW 2 3 2566 4000 0 Blue 0
7 AM Mon 60 60 NW 2 3 2566 4000 0 Blue 0
8 AM Mon 62 62 NW 2 3 2566 4000 0 Blue 0
9 AM Mon 65 66 NW 2 3 2566 4000 0 Blue 0
10 AM Mon 68 70 NW 2 3 2566 4000 0 Blue 0
11 AM Mon 70 75 WSW 3 4 3646 4000 0 Blue 0
12 Noon Mon 73 79 WSW 3 4 5978 4000 0 Blue 3
1 PM Mon 74 81 WSW 3 4 7738 5671 1671 Blue 5
2 PM Mon 76 82 WSW 3 4 8394 5949 1949 Blue 6
3 PM Mon 76 81 WSW 3 4 7738 5671 1671 Blue 5
4 PM Mon 75 79 WSW 3 4 5978 4000 0 Blue 3
5 PM Mon 74 77 W 8 10 5415 4000 0 Blue 1
6 PM Mon 71 72 W 8 10 2633 4000 0 Blue 0
7 PM Mon 68 68 W 8 10 2566 4000 0 Blue 0
8 PM Mon 64 64 W 8 10 2566 4000 0 Blue 0
9 PM Mon 60 60 W 8 10 2566 4000 0 Blue 0
10 PM Mon 56 56 W 8 10 2566 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 ac_soaring@yahoo.com