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:

 260118/1200

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 Sun 55 55 N 2 8 2627 4000 0 Blue 0
1 AM Sun 54 54 NE 2 9 2627 4000 0 Blue 0
2 AM Sun 54 54 NE 2 9 2627 4000 0 Blue 0
3 AM Sun 54 54 NE 2 9 2627 4000 0 Blue 0
4 AM Sun 53 53 E 1 9 2627 4000 0 Blue 0
5 AM Sun 52 52 E 1 9 2627 4000 0 Blue 0
6 AM Sun 52 52 E 1 9 2627 4000 0 Blue 0
7 AM Sun 50 50 ENE 3 10 2627 4000 0 Blue 0
8 AM Sun 52 52 ENE 3 10 2627 4000 0 Blue 0
9 AM Sun 54 54 ENE 3 10 2627 4000 0 Blue 0
10 AM Sun 57 58 WNW 1 2 2627 4000 0 Blue 0
11 AM Sun 61 62 WNW 1 2 2627 4000 0 Blue 0
12 Noon Sun 64 65 WNW 1 2 2627 4000 0 Blue 0
1 PM Sun 66 67 W 1 4 2627 4000 0 Blue 0
2 PM Sun 65 66 W 1 4 2627 4000 0 Blue 0
3 PM Sun 66 66 W 1 4 2627 4000 0 Blue 0
4 PM Sun 64 64 N 3 5 2627 4000 0 Blue 0
5 PM Sun 61 61 N 3 5 2627 4000 0 Blue 0
6 PM Sun 59 59 N 3 5 2627 4000 0 Blue 0
7 PM Sun 56 56 N 5 11 2627 4000 0 Blue 0
8 PM Sun 56 56 N 5 11 2627 4000 0 Blue 0
9 PM Sun 56 56 N 5 11 2627 4000 0 Blue 0
10 PM Sun 56 56 NNE 4 12 2627 4000 0 Blue 0
11 PM Sun 55 55 NNE 4 12 2627 4000 0 Blue 0
12 Midnight Mon 55 55 NNE 4 12 2627 4000 0 Blue 0
1 AM Mon 55 55 NNE 2 12 2627 4000 0 Blue 0
2 AM Mon 55 55 NNE 2 12 2627 4000 0 Blue 0
3 AM Mon 55 55 NNE 2 12 2627 4000 0 Blue 0
4 AM Mon 55 55 NNE 5 11 2627 4000 0 Blue 0
5 AM Mon 52 52 NNE 5 11 2627 4000 0 Blue 0
6 AM Mon 53 53 NNE 5 11 2627 4000 0 Blue 0
7 AM Mon 53 53 N 8 11 2627 4000 0 Blue 0
8 AM Mon 51 51 N 8 11 2627 4000 0 Blue 0
9 AM Mon 56 56 N 8 11 2627 4000 0 Blue 0
10 AM Mon 58 59 ENE 5 16 2627 4000 0 Blue 0
11 AM Mon 61 62 ENE 5 16 2627 4000 0 Blue 0
12 Noon Mon 64 66 ENE 5 16 2627 4000 0 Blue 0
1 PM Mon 67 69 SW 2 11 3131 4000 0 Blue 1
2 PM Mon 67 68 SW 2 11 2919 4000 0 Blue 0
3 PM Mon 66 66 SW 2 11 2627 4000 0 Blue 0
4 PM Mon 64 64 N 1 4 2627 4000 0 Blue 0
5 PM Mon 61 61 N 1 4 2627 4000 0 Blue 0
6 PM Mon 58 58 N 1 4 2627 4000 0 Blue 0
7 PM Mon 56 56 NNE 3 9 2627 4000 0 Blue 0
8 PM Mon 55 55 NNE 3 9 2627 4000 0 Blue 0
9 PM Mon 54 54 NNE 3 9 2627 4000 0 Blue 0
10 PM Mon 54 54 NE 4 10 2627 4000 0 Blue 0
11 PM Mon 54 54 NE 4 10 2627 4000 0 Blue 0
12 Midnight Tue 53 53 NE 4 10 2627 4000 0 Blue 0
1 AM Tue 53 53 NE 4 9 2627 4000 0 Blue 0
2 AM Tue 52 52 NE 4 9 2627 4000 0 Blue 0
3 AM Tue 52 52 NE 4 9 2627 4000 0 Blue 0
4 AM Tue 51 51 NE 4 10 2627 4000 0 Blue 0
5 AM Tue 50 50 NE 4 10 2627 4000 0 Blue 0
6 AM Tue 49 49 NE 4 10 2627 4000 0 Blue 0
7 AM Tue 49 49 NE 4 8 2627 4000 0 Blue 0
8 AM Tue 50 50 NE 4 8 2627 4000 0 Blue 0
9 AM Tue 53 53 NE 4 8 2627 4000 0 Blue 0
10 AM Tue 56 57 NE 3 9 2627 4000 0 Blue 0
11 AM Tue 59 60 NE 3 9 2627 4000 0 Blue 0
12 Noon Tue 62 63 NE 3 9 2627 4000 0 Blue 0
1 PM Tue 64 65 SSW 2 5 2627 4000 0 Blue 0
2 PM Tue 65 66 SSW 2 5 2627 4000 0 Blue 0
3 PM Tue 64 64 SSW 2 5 2627 4000 0 Blue 0
4 PM Tue 62 62 SW 1 4 2627 4000 0 Blue 0
5 PM Tue 59 59 SW 1 4 2627 4000 0 Blue 0
6 PM Tue 56 56 SW 1 4 2627 4000 0 Blue 0
7 PM Tue 54 54 NNE 2 5 2627 4000 0 Blue 0
8 PM Tue 53 53 NNE 2 5 2627 4000 0 Blue 0
9 PM Tue 53 53 NNE 2 5 2627 4000 0 Blue 0
10 PM Tue 53 53 NNE 3 8 2627 4000 0 Blue 0
11 PM Tue 53 53 NNE 3 8 2627 4000 0 Blue 0
12 Midnight Wed 52 52 NNE 3 8 2627 4000 0 Blue 0
1 AM Wed 52 52 NE 3 6 2627 4000 0 Blue 0
2 AM Wed 52 52 NE 3 6 2627 4000 0 Blue 0
3 AM Wed 51 51 NE 3 6 2627 4000 0 Blue 0
4 AM Wed 51 51 NE 2 6 2627 4000 0 Blue 0
5 AM Wed 50 50 NE 2 6 2627 4000 0 Blue 0
6 AM Wed 49 49 NE 2 6 2627 4000 0 Blue 0
7 AM Wed 49 49 NE 2 6 2627 4000 0 Blue 0
8 AM Wed 50 50 NE 2 6 2627 4000 0 Blue 0
9 AM Wed 52 52 NE 2 6 2627 4000 0 Blue 0
10 AM Wed 54 54 NE 2 5 2627 4000 0 Blue 0
11 AM Wed 57 58 NE 2 5 2627 4000 0 Blue 0
12 Noon Wed 60 61 NE 2 5 2627 4000 0 Blue 0
1 PM Wed 62 63 WSW 2 5 2627 4000 0 Blue 0
2 PM Wed 63 63 WSW 2 5 2627 4000 0 Blue 0
3 PM Wed 62 62 WSW 2 5 2627 4000 0 Blue 0
4 PM Wed 60 60 NW 1 5 2627 4000 0 Blue 0
5 PM Wed 57 57 NW 1 5 2627 4000 0 Blue 0
6 PM Wed 54 54 NW 1 5 2627 4000 0 Blue 0
7 PM Wed 52 52 NW 1 5 2627 4000 0 Blue 0
8 PM Wed 51 51 NW 1 5 2627 4000 0 Blue 0
9 PM Wed 50 50 NW 1 5 2627 4000 0 Blue 0
10 PM Wed 50 50 N 3 6 2627 4000 0 Blue 0
11 PM Wed 50 50 N 3 6 2627 4000 0 Blue 0
12 Midnight Thu 51 51 N 3 6 2627 4000 0 Blue 0
1 AM Thu 51 51 N 3 6 2627 4000 0 Blue 0
2 AM Thu 50 50 N 3 6 2627 4000 0 Blue 0
3 AM Thu 49 49 N 3 6 2627 4000 0 Blue 0
4 AM Thu 48 48 NNE 3 6 2627 4000 0 Blue 0
5 AM Thu 47 47 NNE 3 6 2627 4000 0 Blue 0
6 AM Thu 47 47 NNE 3 6 2627 4000 0 Blue 0
7 AM Thu 47 47 NNE 3 6 2627 4000 0 Blue 0
8 AM Thu 49 49 NNE 3 6 2627 4000 0 Blue 0
9 AM Thu 51 51 NNE 3 6 2627 4000 0 Blue 0
10 AM Thu 53 54 W 3 6 2627 4000 0 Blue 0
11 AM Thu 55 56 W 3 6 2627 4000 0 Blue 0
12 Noon Thu 58 60 W 3 6 2627 4000 0 Blue 0
1 PM Thu 59 60 W 3 6 2627 4000 0 Blue 0
2 PM Thu 60 61 W 3 6 2627 4000 0 Blue 0
3 PM Thu 59 59 W 3 6 2627 4000 0 Blue 0
4 PM Thu 58 58 WNW 2 8 2627 4000 0 Blue 0
5 PM Thu 55 55 WNW 2 8 2627 4000 0 Blue 0
6 PM Thu 52 52 WNW 2 8 2627 4000 0 Blue 0
7 PM Thu 50 50 WNW 2 8 2627 4000 0 Blue 0
8 PM Thu 49 49 WNW 2 8 2627 4000 0 Blue 0
9 PM Thu 48 48 WNW 2 8 2627 4000 0 Blue 0
10 PM Thu 48 48 N 3 8 2627 4000 0 Blue 0
11 PM Thu 48 48 N 3 8 2627 4000 0 Blue 0
12 Midnight Fri 48 48 N 3 8 2627 4000 0 Blue 0
1 AM Fri 48 48 N 3 8 2627 4000 0 Blue 0
2 AM Fri 47 47 N 3 8 2627 4000 0 Blue 0
3 AM Fri 47 47 N 3 8 2627 4000 0 Blue 0
4 AM Fri 46 46 N 3 6 2627 4000 0 Blue 0
5 AM Fri 45 45 N 3 6 2627 4000 0 Blue 0
6 AM Fri 45 45 N 3 6 2627 4000 0 Blue 0
7 AM Fri 45 45 N 3 6 2627 4000 0 Blue 0
8 AM Fri 47 47 N 3 6 2627 4000 0 Blue 0
9 AM Fri 49 49 N 3 6 2627 4000 0 Blue 0
10 AM Fri 51 52 WNW 3 9 2627 4000 0 Blue 0
11 AM Fri 53 54 WNW 3 9 2627 4000 0 Blue 0
12 Noon Fri 55 57 WNW 3 9 2627 4000 0 Blue 0
1 PM Fri 56 58 WNW 3 9 2627 4000 0 Blue 0
2 PM Fri 57 58 WNW 3 9 2627 4000 0 Blue 0
3 PM Fri 57 57 WNW 3 9 2627 4000 0 Blue 0
4 PM Fri 56 56 WNW 3 11 2627 4000 0 Blue 0
5 PM Fri 53 53 WNW 3 11 2627 4000 0 Blue 0
6 PM Fri 50 50 WNW 3 11 2627 4000 0 Blue 0
7 PM Fri 48 48 WNW 3 11 2627 4000 0 Blue 0
8 PM Fri 47 47 WNW 3 11 2627 4000 0 Blue 0
9 PM Fri 47 47 WNW 3 11 2627 4000 0 Blue 0
10 PM Fri 47 47 N 2 9 2627 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]