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

Station:

KOAK

Date/Time:

23 MAY 2024

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 Thu 55 55 N 11 23 2520 4000 0 Blue 0
1 AM Thu 53 53 N 11 23 2520 4000 0 Blue 0
2 AM Thu 52 52 N 8 12 2520 4000 0 Blue 0
3 AM Thu 51 51 N 8 12 2520 4000 0 Blue 0
4 AM Thu 50 50 N 8 12 2520 4000 0 Blue 0
5 AM Thu 51 51 N 5 14 2520 4000 0 Blue 0
6 AM Thu 49 49 N 5 14 2520 4000 0 Blue 0
7 AM Thu 52 52 N 5 14 2520 4000 0 Blue 0
8 AM Thu 56 57 N 5 10 2520 4000 0 Blue 0
9 AM Thu 61 64 N 5 10 4348 4000 0 Blue 5
10 AM Thu 67 72 N 5 10 6209 5924 1924 Blue 13
11 AM Thu 69 75 WNW 5 10 6601 6203 2203 Blue 16
12 Noon Thu 71 79 WNW 5 10 7675 6759 2759 Blue 20
1 PM Thu 71 79 WNW 5 10 7675 6759 2759 Blue 20
2 PM Thu 74 82 W 6 12 10276 7605 3605 Blue 23
3 PM Thu 74 81 W 6 12 9861 7325 3325 Blue 22
4 PM Thu 73 78 W 6 12 7368 6579 2579 Blue 19
5 PM Thu 74 77 W 8 11 7084 6402 2402 Blue 18
6 PM Thu 70 71 W 8 11 6156 5375 1375 Blue 12
7 PM Thu 67 67 W 8 11 4844 4339 339 Blue 8
8 PM Thu 62 62 WNW 6 9 3973 4000 0 Blue 3
9 PM Thu 57 57 WNW 6 9 2520 4000 0 Blue 0
10 PM Thu 56 56 WNW 6 9 2520 4000 0 Blue 0
11 PM Thu 55 55 NNW 5 10 2520 4000 0 Blue 0
12 Midnight Fri 55 55 NNW 5 10 2520 4000 0 Blue 0
1 AM Fri 54 54 NNW 5 10 2520 4000 0 Blue 0
2 AM Fri 54 54 NNW 5 10 2520 4000 0 Blue 0
3 AM Fri 51 51 NNW 5 10 2520 4000 0 Blue 0
4 AM Fri 50 50 NNW 5 10 2520 4000 0 Blue 0
5 AM Fri 49 49 NNW 5 10 2520 4000 0 Blue 0
6 AM Fri 48 48 NNW 5 10 2520 4000 0 Blue 0
7 AM Fri 50 50 NNW 5 10 2520 4000 0 Blue 0
8 AM Fri 54 55 NNW 4 9 2520 4000 0 Blue 0
9 AM Fri 58 61 NNW 4 9 3422 4000 0 Blue 2
10 AM Fri 62 66 NNW 4 9 4658 4200 200 Blue 7
11 AM Fri 66 70 WNW 5 11 6102 4831 831 Blue 11
12 Noon Fri 67 72 WNW 5 11 6209 5924 1924 Blue 13
1 PM Fri 68 74 WNW 5 11 6424 6150 2150 Blue 15
2 PM Fri 68 73 W 10 14 6262 6096 2096 Blue 14
3 PM Fri 68 72 W 10 14 6209 5924 1924 Blue 13
4 PM Fri 67 70 W 10 14 6102 4831 831 Blue 11
5 PM Fri 65 67 W 10 12 4844 4339 339 Blue 8
6 PM Fri 62 63 W 10 12 4206 4000 0 Blue 4
7 PM Fri 57 57 W 10 12 2520 4000 0 Blue 0
8 PM Fri 54 54 WNW 10 11 2520 4000 0 Blue 0
9 PM Fri 52 52 WNW 10 11 2520 4000 0 Blue 0
10 PM Fri 51 51 WNW 10 11 2520 4000 0 Blue 0
11 PM Fri 51 51 NW 8 9 2520 4000 0 Blue 0
12 Midnight Sat 50 50 NW 8 9 2520 4000 0 Blue 0
1 AM Sat 50 50 NW 8 9 2520 4000 0 Blue 0
2 AM Sat 49 49 NW 5 13 2520 4000 0 Blue 0
3 AM Sat 49 49 NW 5 13 2520 4000 0 Blue 0
4 AM Sat 48 48 NW 5 13 2520 4000 0 Blue 0
5 AM Sat 48 48 NW 4 10 2520 4000 0 Blue 0
6 AM Sat 48 48 NW 4 10 2520 4000 0 Blue 0
7 AM Sat 50 50 NW 4 10 2520 4000 0 Blue 0
8 AM Sat 52 53 NW 3 9 2520 4000 0 Blue 0
9 AM Sat 55 57 NW 3 9 2520 4000 0 Blue 0
10 AM Sat 58 62 NW 3 9 3973 4000 0 Blue 3
11 AM Sat 62 68 WSW 3 10 5432 4494 494 Blue 9
12 Noon Sat 64 71 WSW 3 10 6156 5375 1375 Blue 12
1 PM Sat 65 73 WSW 3 10 6262 6096 2096 Blue 14
2 PM Sat 66 73 WSW 6 13 6262 6096 2096 Blue 14
3 PM Sat 67 73 WSW 6 13 6262 6096 2096 Blue 14
4 PM Sat 67 71 WSW 6 13 6156 5375 1375 Blue 12
5 PM Sat 66 69 W 6 16 5955 4648 648 Blue 10
6 PM Sat 64 65 W 6 16 4503 4000 0 Blue 6
7 PM Sat 60 60 W 6 16 2987 4000 0 Blue 1
8 PM Sat 56 56 W 5 13 2520 4000 0 Blue 0
9 PM Sat 54 54 W 5 13 2520 4000 0 Blue 0
10 PM Sat 52 52 W 5 13 2520 4000 0 Blue 0
11 PM Sat 51 51 NW 3 9 2520 4000 0 Blue 0
12 Midnight Sun 50 50 NW 3 9 2520 4000 0 Blue 0
1 AM Sun 50 50 NW 3 9 2520 4000 0 Blue 0
2 AM Sun 50 50 N 2 6 2520 4000 0 Blue 0
3 AM Sun 49 49 N 2 6 2520 4000 0 Blue 0
4 AM Sun 48 48 N 2 6 2520 4000 0 Blue 0
5 AM Sun 49 49 NNE 2 6 2520 4000 0 Blue 0
6 AM Sun 51 51 NNE 2 6 2520 4000 0 Blue 0
7 AM Sun 54 54 NNE 2 6 2520 4000 0 Blue 0
8 AM Sun 57 58 NE 2 5 2675 4000 0 Blue 0
9 AM Sun 62 65 NE 2 5 4503 4000 0 Blue 6
10 AM Sun 66 71 NE 2 5 6156 5375 1375 Blue 12
11 AM Sun 70 77 SSW 3 8 7084 6402 2402 Blue 18
12 Noon Sun 73 81 SSW 3 8 9861 7325 3325 Blue 22
1 PM Sun 75 83 SSW 3 8 10792 8097 4097 Blue 24
2 PM Sun 76 84 WSW 5 12 11294 9685 5685 Blue 25
3 PM Sun 77 84 WSW 5 12 11294 9685 5685 Blue 25
4 PM Sun 77 82 WSW 5 12 10276 7605 3605 Blue 23
5 PM Sun 76 79 W 6 14 7675 6759 2759 Blue 20
6 PM Sun 73 74 W 6 14 6424 6150 2150 Blue 15
7 PM Sun 69 69 W 6 14 5955 4648 648 Blue 10
8 PM Sun 65 65 W 6 14 4503 4000 0 Blue 6
9 PM Sun 62 62 W 6 14 3973 4000 0 Blue 3
10 PM Sun 59 59 W 6 14 2843 4000 0 Blue 0
11 PM Sun 57 57 NNW 3 10 2520 4000 0 Blue 0
12 Midnight Mon 57 57 NNW 3 10 2520 4000 0 Blue 0
1 AM Mon 57 57 NNW 3 10 2520 4000 0 Blue 0
2 AM Mon 57 57 NNW 3 10 2520 4000 0 Blue 0
3 AM Mon 56 56 NNW 3 10 2520 4000 0 Blue 0
4 AM Mon 55 55 NNW 3 10 2520 4000 0 Blue 0
5 AM Mon 55 55 NNE 2 6 2520 4000 0 Blue 0
6 AM Mon 57 57 NNE 2 6 2520 4000 0 Blue 0
7 AM Mon 60 60 NNE 2 6 2987 4000 0 Blue 1
8 AM Mon 64 65 NNE 2 6 4503 4000 0 Blue 6
9 AM Mon 69 72 NNE 2 6 6209 5924 1924 Blue 13
10 AM Mon 73 78 NNE 2 6 7368 6579 2579 Blue 19
11 AM Mon 77 84 WSW 5 13 11294 9685 5685 Blue 25
12 Noon Mon 80 88 WSW 5 13 13611 11636 7636 Blue 29
1 PM Mon 81 89 WSW 5 13 13805 11963 7963 Blue 30
2 PM Mon 82 90 WSW 5 13 14190 12699 8699 Blue 31
3 PM Mon 83 90 WSW 5 13 14190 12699 8699 Blue 31
4 PM Mon 82 87 WSW 5 13 13416 11153 7153 Blue 28
5 PM Mon 81 84 W 6 16 11294 9685 5685 Blue 25
6 PM Mon 77 78 W 6 16 7368 6579 2579 Blue 19
7 PM Mon 72 72 W 6 16 6209 5924 1924 Blue 13
8 PM Mon 68 68 W 6 16 5432 4494 494 Blue 9
9 PM Mon 65 65 W 6 16 4503 4000 0 Blue 6
10 PM Mon 63 63 W 6 16 4206 4000 0 Blue 4
11 PM Mon 61 61 NNW 3 10 3422 4000 0 Blue 2
12 Midnight Tue 61 61 NNW 3 10 3422 4000 0 Blue 2
1 AM Tue 60 60 NNW 3 10 2987 4000 0 Blue 1
2 AM Tue 60 60 NNW 3 10 2987 4000 0 Blue 1
3 AM Tue 59 59 NNW 3 10 2843 4000 0 Blue 0
4 AM Tue 58 58 NNW 3 10 2675 4000 0 Blue 0
5 AM Tue 58 58 NNW 3 8 2675 4000 0 Blue 0
6 AM Tue 58 58 NNW 3 8 2675 4000 0 Blue 0
7 AM Tue 60 60 NNW 3 8 2987 4000 0 Blue 1
8 AM Tue 63 64 NNW 3 8 4348 4000 0 Blue 5
9 AM Tue 66 68 NNW 3 8 5432 4494 494 Blue 9
10 AM Tue 71 75 NNW 3 8 6601 6203 2203 Blue 16
11 AM Tue 74 79 W 6 17 7675 6759 2759 Blue 20
12 Noon Tue 77 83 W 6 17 10792 8097 4097 Blue 24
1 PM Tue 78 85 W 6 17 11740 10146 6146 Blue 26
2 PM Tue 79 85 W 6 17 11740 10146 6146 Blue 26
3 PM Tue 80 85 W 6 17 11740 10146 6146 Blue 26
4 PM Tue 80 84 W 6 17 11294 9685 5685 Blue 25
5 PM Tue 78 80 W 9 20 8186 7043 3043 Blue 21
6 PM Tue 74 75 W 9 20 6601 6203 2203 Blue 16
7 PM Tue 69 69 W 9 20 5955 4648 648 Blue 10
8 PM Tue 64 64 W 9 20 4348 4000 0 Blue 5
9 PM Tue 61 61 W 9 20 3422 4000 0 Blue 2
10 PM Tue 60 60 W 9 20 2987 4000 0 Blue 1

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]