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

Station:

 KOAK

Date/Time:

 5 DEC 2023

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 Tue 50 50 N 2 3 2638 4000 0 Blue 0
1 AM Tue 51 51 N 4 5 2638 4000 0 Blue 0
2 AM Tue 50 50 N 4 5 2638 4000 0 Blue 0
3 AM Tue 50 50 N 4 5 2638 4000 0 Blue 0
4 AM Tue 50 50 NE 3 4 2638 4000 0 Blue 0
5 AM Tue 49 49 NE 3 4 2638 4000 0 Blue 0
6 AM Tue 54 54 NE 3 4 2638 4000 0 Blue 0
7 AM Tue 48 48 ESE 2 3 2638 4000 0 Blue 0
8 AM Tue 49 49 ESE 2 3 2638 4000 0 Blue 0
9 AM Tue 54 54 ESE 2 3 2638 4000 0 Blue 0
10 AM Tue 57 57 S 4 5 2673 4000 0 Blue 0
11 AM Tue 61 61 S 4 5 3613 4000 0 Blue 3
12 Noon Tue 62 62 S 4 5 3930 4000 0 Blue 4
1 PM Tue 63 63 S 4 6 4244 4000 0 Blue 5
2 PM Tue 63 63 S 4 6 4244 4000 0 Blue 5
3 PM Tue 62 62 S 4 6 3930 4000 0 Blue 4
4 PM Tue 60 60 S 3 5 3044 4000 0 Blue 2
5 PM Tue 55 55 S 3 5 2638 4000 0 Blue 0
6 PM Tue 53 53 S 3 5 2638 4000 0 Blue 0
7 PM Tue 52 52 SE 4 5 2638 4000 0 Blue 0
8 PM Tue 52 52 SE 4 5 2638 4000 0 Blue 0
9 PM Tue 51 51 SE 4 5 2638 4000 0 Blue 0
10 PM Tue 51 51 SE 5 6 2638 4000 0 Blue 0
11 PM Tue 49 49 SE 5 6 2638 4000 0 Blue 0
12 Midnight Wed 49 49 SE 5 6 2638 4000 0 Blue 0
1 AM Wed 49 49 SE 4 6 2638 4000 0 Blue 0
2 AM Wed 48 48 SE 4 6 2638 4000 0 Blue 0
3 AM Wed 48 48 SE 4 6 2638 4000 0 Blue 0
4 AM Wed 47 47 SSE 5 8 2638 4000 0 Blue 0
5 AM Wed 46 46 SSE 5 8 2638 4000 0 Blue 0
6 AM Wed 46 46 SSE 5 8 2638 4000 0 Blue 0
7 AM Wed 46 46 SSW 5 6 2638 4000 0 Blue 0
8 AM Wed 46 46 SSW 5 6 2638 4000 0 Blue 0
9 AM Wed 49 49 SSW 5 6 2638 4000 0 Blue 0
10 AM Wed 49 49 SSW 5 8 2638 4000 0 Blue 0
11 AM Wed 51 51 SSW 5 8 2638 4000 0 Blue 0
12 Noon Wed 51 51 SSW 5 8 2638 4000 0 Blue 0
1 PM Wed 51 51 WSW 10 13 2638 4000 0 Blue 0
2 PM Wed 50 50 WSW 10 13 2638 4000 0 Blue 0
3 PM Wed 49 49 WSW 10 13 2638 4000 0 Blue 0
4 PM Wed 48 48 W 10 14 2638 4000 0 Blue 0
5 PM Wed 47 47 W 10 14 2638 4000 0 Blue 0
6 PM Wed 46 46 W 10 14 2638 4000 0 Blue 0
7 PM Wed 44 44 W 8 11 2638 4000 0 Blue 0
8 PM Wed 43 43 W 8 11 2638 4000 0 Blue 0
9 PM Wed 43 43 W 8 11 2638 4000 0 Blue 0
10 PM Wed 43 43 W 8 10 2638 4000 0 Blue 0
11 PM Wed 43 43 W 8 10 2638 4000 0 Blue 0
12 Midnight Thu 43 43 W 8 10 2638 4000 0 Blue 0
1 AM Thu 43 43 WNW 6 9 2638 4000 0 Blue 0
2 AM Thu 42 42 WNW 6 9 2638 4000 0 Blue 0
3 AM Thu 42 42 WNW 6 9 2638 4000 0 Blue 0
4 AM Thu 41 41 NW 4 6 2638 4000 0 Blue 0
5 AM Thu 41 41 NW 4 6 2638 4000 0 Blue 0
6 AM Thu 40 40 NW 4 6 2638 4000 0 Blue 0
7 AM Thu 40 40 NW 3 4 2638 4000 0 Blue 0
8 AM Thu 41 41 NW 3 4 2638 4000 0 Blue 0
9 AM Thu 43 43 NW 3 4 2638 4000 0 Blue 0
10 AM Thu 45 45 W 6 10 2638 4000 0 Blue 0
11 AM Thu 46 46 W 6 10 2638 4000 0 Blue 0
12 Noon Thu 47 47 W 6 10 2638 4000 0 Blue 0
1 PM Thu 47 47 W 9 12 2638 4000 0 Blue 0
2 PM Thu 47 47 W 9 12 2638 4000 0 Blue 0
3 PM Thu 46 46 W 9 12 2638 4000 0 Blue 0
4 PM Thu 44 44 WNW 13 19 2638 4000 0 Blue 0
5 PM Thu 42 42 WNW 13 19 2638 4000 0 Blue 0
6 PM Thu 40 40 WNW 13 19 2638 4000 0 Blue 0
7 PM Thu 39 39 WNW 12 17 2638 4000 0 Blue 0
8 PM Thu 39 39 WNW 12 17 2638 4000 0 Blue 0
9 PM Thu 39 39 WNW 12 17 2638 4000 0 Blue 0
10 PM Thu 39 39 NW 12 19 2638 4000 0 Blue 0
11 PM Thu 39 39 NW 12 19 2638 4000 0 Blue 0
12 Midnight Fri 38 38 NW 12 19 2638 4000 0 Blue 0
1 AM Fri 38 38 NNW 10 14 2638 4000 0 Blue 0
2 AM Fri 37 37 NNW 10 14 2638 4000 0 Blue 0
3 AM Fri 36 36 NNW 10 14 2638 4000 0 Blue 0
4 AM Fri 35 35 N 9 13 2638 4000 0 Blue 0
5 AM Fri 34 34 N 9 13 2638 4000 0 Blue 0
6 AM Fri 33 33 N 9 13 2638 4000 0 Blue 0
7 AM Fri 34 34 NNE 5 9 2638 4000 0 Blue 0
8 AM Fri 36 36 NNE 5 9 2638 4000 0 Blue 0
9 AM Fri 39 39 NNE 5 9 2638 4000 0 Blue 0
10 AM Fri 43 44 N 5 10 2638 4000 0 Blue 0
11 AM Fri 46 47 N 5 10 2638 4000 0 Blue 0
12 Noon Fri 49 50 N 5 10 2638 4000 0 Blue 0
1 PM Fri 50 51 NW 6 10 2638 4000 0 Blue 0
2 PM Fri 50 51 NW 6 10 2638 4000 0 Blue 0
3 PM Fri 49 49 NW 6 10 2638 4000 0 Blue 0
4 PM Fri 46 46 NNW 6 10 2638 4000 0 Blue 0
5 PM Fri 44 44 NNW 6 10 2638 4000 0 Blue 0
6 PM Fri 41 41 NNW 6 10 2638 4000 0 Blue 0
7 PM Fri 39 39 NNW 6 10 2638 4000 0 Blue 0
8 PM Fri 38 38 NNW 6 10 2638 4000 0 Blue 0
9 PM Fri 38 38 NNW 6 10 2638 4000 0 Blue 0
10 PM Fri 38 38 NNE 5 8 2638 4000 0 Blue 0
11 PM Fri 38 38 NNE 5 8 2638 4000 0 Blue 0
12 Midnight Sat 39 39 NNE 5 8 2638 4000 0 Blue 0
1 AM Sat 39 39 NNE 5 8 2638 4000 0 Blue 0
2 AM Sat 40 40 NNE 5 8 2638 4000 0 Blue 0
3 AM Sat 41 41 NNE 5 8 2638 4000 0 Blue 0
4 AM Sat 41 41 N 4 5 2638 4000 0 Blue 0
5 AM Sat 40 40 N 4 5 2638 4000 0 Blue 0
6 AM Sat 39 39 N 4 5 2638 4000 0 Blue 0
7 AM Sat 39 39 N 4 5 2638 4000 0 Blue 0
8 AM Sat 41 41 N 4 5 2638 4000 0 Blue 0
9 AM Sat 44 44 N 4 5 2638 4000 0 Blue 0
10 AM Sat 47 47 WNW 5 10 2638 4000 0 Blue 0
11 AM Sat 49 49 WNW 5 10 2638 4000 0 Blue 0
12 Noon Sat 51 51 WNW 5 10 2638 4000 0 Blue 0
1 PM Sat 52 52 WNW 5 10 2638 4000 0 Blue 0
2 PM Sat 52 52 WNW 5 10 2638 4000 0 Blue 0
3 PM Sat 51 51 WNW 5 10 2638 4000 0 Blue 0
4 PM Sat 49 49 NW 5 9 2638 4000 0 Blue 0
5 PM Sat 47 47 NW 5 9 2638 4000 0 Blue 0
6 PM Sat 44 44 NW 5 9 2638 4000 0 Blue 0
7 PM Sat 43 43 NW 5 9 2638 4000 0 Blue 0
8 PM Sat 43 43 NW 5 9 2638 4000 0 Blue 0
9 PM Sat 44 44 NW 5 9 2638 4000 0 Blue 0
10 PM Sat 46 46 N 4 6 2638 4000 0 Blue 0
11 PM Sat 46 46 N 4 6 2638 4000 0 Blue 0
12 Midnight Sun 47 47 N 4 6 2638 4000 0 Blue 0
1 AM Sun 47 47 N 4 6 2638 4000 0 Blue 0
2 AM Sun 47 47 N 4 6 2638 4000 0 Blue 0
3 AM Sun 47 47 N 4 6 2638 4000 0 Blue 0
4 AM Sun 47 47 NNW 4 6 2638 4000 0 Blue 0
5 AM Sun 46 46 NNW 4 6 2638 4000 0 Blue 0
6 AM Sun 45 45 NNW 4 6 2638 4000 0 Blue 0
7 AM Sun 44 44 NNW 4 6 2638 4000 0 Blue 0
8 AM Sun 46 46 NNW 4 6 2638 4000 0 Blue 0
9 AM Sun 48 48 NNW 4 6 2638 4000 0 Blue 0
10 AM Sun 51 51 NW 6 11 2638 4000 0 Blue 0
11 AM Sun 53 53 NW 6 11 2638 4000 0 Blue 0
12 Noon Sun 55 55 NW 6 11 2638 4000 0 Blue 0
1 PM Sun 56 56 NW 6 11 2638 4000 0 Blue 0
2 PM Sun 56 56 NW 6 11 2638 4000 0 Blue 0
3 PM Sun 55 55 NW 6 11 2638 4000 0 Blue 0
4 PM Sun 53 53 NW 6 10 2638 4000 0 Blue 0
5 PM Sun 51 51 NW 6 10 2638 4000 0 Blue 0
6 PM Sun 49 49 NW 6 10 2638 4000 0 Blue 0
7 PM Sun 47 47 NW 6 10 2638 4000 0 Blue 0
8 PM Sun 46 46 NW 6 10 2638 4000 0 Blue 0
9 PM Sun 46 46 NW 6 10 2638 4000 0 Blue 0
10 PM Sun 47 47 N 5 8 2638 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]