Detailed Predictions for: Potato Hill
Launch Lat, Long, Altitude (f): 39.34098, -122.69, 3400
LZ Altitude (f): 1700
Sounding

Station:

 KOAK

Date/Time UTC:

 260911/1200

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 Fri 75 73 W 10 16 2585 3400 0 Blue 0
1 AM Fri 74 72 W 8 12 2585 3400 0 Blue 0
2 AM Fri 73 71 W 5 9 2585 3400 0 Blue 0
3 AM Fri 72 70 W 4 8 2585 3400 0 Blue 0
4 AM Fri 70 68 W 3 6 2585 3400 0 Blue 0
5 AM Fri 69 67 W 3 5 2585 3400 0 Blue 0
6 AM Fri 68 66 W 3 5 2585 3400 0 Blue 0
7 AM Fri 66 64 W 2 4 2585 3400 0 Blue 0
8 AM Fri 67 65 WNW 3 5 2585 3400 0 Blue 0
9 AM Fri 70 69 ENE 1 3 2585 3400 0 Blue 0
10 AM Fri 76 77 ENE 2 5 2943 3400 0 Blue 0
11 AM Fri 78 80 ENE 3 8 3728 3400 0 Blue 1
12 Noon Fri 80 83 E 4 10 4370 3721 321 Blue 4
1 PM Fri 83 87 ESE 4 13 7735 4584 1184 Blue 8
2 PM Fri 84 88 SW 5 16 7810 4871 1471 Blue 9
3 PM Fri 86 89 WSW 6 17 8032 6424 3024 Blue 10
4 PM Fri 84 85 WSW 6 17 4890 4151 751 Blue 6
5 PM Fri 83 83 W 6 16 4370 3721 321 Blue 4
6 PM Fri 81 79 W 5 14 3512 3400 0 Blue 0
7 PM Fri 76 74 W 6 13 2585 3400 0 Blue 0
8 PM Fri 71 69 W 9 17 2585 3400 0 Blue 0
9 PM Fri 70 68 W 10 17 2585 3400 0 Blue 0
10 PM Fri 70 68 W 9 16 2585 3400 0 Blue 0
11 PM Fri 70 68 W 9 16 2585 3400 0 Blue 0
12 Midnight Sat 69 67 W 9 16 2585 3400 0 Blue 0
1 AM Sat 69 67 W 9 14 2585 3400 0 Blue 0
2 AM Sat 68 66 W 8 14 2585 3400 0 Blue 0
3 AM Sat 67 65 W 8 13 2585 3400 0 Blue 0
4 AM Sat 66 64 W 6 11 2585 3400 0 Blue 0
5 AM Sat 64 62 W 4 10 2585 3400 0 Blue 0
6 AM Sat 63 61 W 4 10 2585 3400 0 Blue 0
7 AM Sat 62 60 W 4 10 2585 3400 0 Blue 0
8 AM Sat 62 60 WSW 4 9 2585 3400 0 Blue 0
9 AM Sat 65 64 WSW 4 9 2585 3400 0 Blue 0
10 AM Sat 70 70 WSW 4 9 2585 3400 0 Blue 0
11 AM Sat 71 73 SW 9 25 2585 3400 0 Blue 0
12 Noon Sat 73 76 SW 9 25 2654 3400 0 Blue 0
1 PM Sat 74 78 SW 9 25 3231 3400 0 Blue 0
2 PM Sat 74 77 WSW 17 33 2943 3400 0 Blue 0
3 PM Sat 75 77 WSW 17 33 2943 3400 0 Blue 0
4 PM Sat 72 73 WSW 17 33 2585 3400 0 Blue 0
5 PM Sat 69 69 W 20 37 2585 3400 0 Blue 0
6 PM Sat 66 64 W 20 37 2585 3400 0 Blue 0
7 PM Sat 61 59 W 20 37 2585 3400 0 Blue 0
8 PM Sat 56 54 W 18 33 2585 3400 0 Blue 0
9 PM Sat 55 53 W 18 33 2585 3400 0 Blue 0
10 PM Sat 55 53 W 18 33 2585 3400 0 Blue 0
11 PM Sat 55 53 W 12 26 2585 3400 0 Blue 0
12 Midnight Sun 54 52 W 12 26 2585 3400 0 Blue 0
1 AM Sun 52 50 W 12 26 2585 3400 0 Blue 0
2 AM Sun 50 48 WNW 8 14 2585 3400 0 Blue 0
3 AM Sun 49 47 WNW 8 14 2585 3400 0 Blue 0
4 AM Sun 49 47 WNW 8 14 2585 3400 0 Blue 0
5 AM Sun 48 46 NW 2 5 2585 3400 0 Blue 0
6 AM Sun 48 46 NW 2 5 2585 3400 0 Blue 0
7 AM Sun 49 47 NW 2 5 2585 3400 0 Blue 0
8 AM Sun 50 48 NW 2 5 2585 3400 0 Blue 0
9 AM Sun 54 53 NW 2 5 2585 3400 0 Blue 0
10 AM Sun 58 59 NW 2 5 2585 3400 0 Blue 0
11 AM Sun 62 64 NNE 5 11 2585 3400 0 Blue 0
12 Noon Sun 65 68 NNE 5 11 2585 3400 0 Blue 0
1 PM Sun 67 71 NNE 5 11 2585 3400 0 Blue 0
2 PM Sun 69 73 ENE 3 10 2585 3400 0 Blue 0
3 PM Sun 70 73 ENE 3 10 2585 3400 0 Blue 0
4 PM Sun 70 71 ENE 3 10 2585 3400 0 Blue 0
5 PM Sun 69 69 ENE 1 6 2585 3400 0 Blue 0
6 PM Sun 67 65 ENE 1 6 2585 3400 0 Blue 0
7 PM Sun 63 61 ENE 1 6 2585 3400 0 Blue 0
8 PM Sun 60 58 WNW 3 8 2585 3400 0 Blue 0
9 PM Sun 60 58 WNW 3 8 2585 3400 0 Blue 0
10 PM Sun 61 59 WNW 3 8 2585 3400 0 Blue 0
11 PM Sun 62 60 NW 4 9 2585 3400 0 Blue 0
12 Midnight Mon 62 60 NW 4 9 2585 3400 0 Blue 0
1 AM Mon 61 59 NW 4 9 2585 3400 0 Blue 0
2 AM Mon 60 58 WNW 6 14 2585 3400 0 Blue 0
3 AM Mon 59 57 WNW 6 14 2585 3400 0 Blue 0
4 AM Mon 58 56 WNW 6 14 2585 3400 0 Blue 0
5 AM Mon 58 56 NW 3 6 2585 3400 0 Blue 0
6 AM Mon 57 55 NW 3 6 2585 3400 0 Blue 0
7 AM Mon 57 55 NW 3 6 2585 3400 0 Blue 0
8 AM Mon 58 56 NW 1 4 2585 3400 0 Blue 0
9 AM Mon 61 60 NW 1 4 2585 3400 0 Blue 0
10 AM Mon 66 67 NW 1 4 2585 3400 0 Blue 0
11 AM Mon 70 72 ENE 4 9 2585 3400 0 Blue 0
12 Noon Mon 73 76 ENE 4 9 2654 3400 0 Blue 0
1 PM Mon 76 80 ENE 4 9 3728 3400 0 Blue 1
2 PM Mon 77 81 ESE 3 10 3944 3400 0 Blue 2
3 PM Mon 78 81 ESE 3 10 3944 3400 0 Blue 2
4 PM Mon 78 79 ESE 3 10 3512 3400 0 Blue 0
5 PM Mon 77 77 S 3 6 2943 3400 0 Blue 0
6 PM Mon 72 70 S 3 6 2585 3400 0 Blue 0
7 PM Mon 68 66 S 3 6 2585 3400 0 Blue 0
8 PM Mon 65 63 W 2 5 2585 3400 0 Blue 0
9 PM Mon 64 62 W 2 5 2585 3400 0 Blue 0
10 PM Mon 65 63 W 2 5 2585 3400 0 Blue 0
11 PM Mon 65 63 WNW 1 4 2585 3400 0 Blue 0
12 Midnight Tue 64 62 WNW 1 4 2585 3400 0 Blue 0
1 AM Tue 64 62 WNW 1 4 2585 3400 0 Blue 0
2 AM Tue 63 61 NW 1 4 2585 3400 0 Blue 0
3 AM Tue 62 60 NW 1 4 2585 3400 0 Blue 0
4 AM Tue 62 60 NW 1 4 2585 3400 0 Blue 0
5 AM Tue 61 59 N 0 3 2585 3400 0 Blue 0
6 AM Tue 60 58 N 0 3 2585 3400 0 Blue 0
7 AM Tue 59 57 N 0 3 2585 3400 0 Blue 0
8 AM Tue 60 58 N 1 3 2585 3400 0 Blue 0
9 AM Tue 63 62 N 1 3 2585 3400 0 Blue 0
10 AM Tue 67 67 N 1 3 2585 3400 0 Blue 0
11 AM Tue 71 73 E 5 9 2585 3400 0 Blue 0
12 Noon Tue 74 77 E 5 9 2943 3400 0 Blue 0
1 PM Tue 77 81 E 5 9 3944 3400 0 Blue 2
2 PM Tue 78 81 SE 5 10 3944 3400 0 Blue 2
3 PM Tue 79 81 SE 5 10 3944 3400 0 Blue 2
4 PM Tue 78 79 SE 5 10 3512 3400 0 Blue 0
5 PM Tue 76 75 SSE 4 9 2585 3400 0 Blue 0
6 PM Tue 72 70 SSE 4 9 2585 3400 0 Blue 0
7 PM Tue 68 66 SSE 4 9 2585 3400 0 Blue 0
8 PM Tue 65 63 W 1 3 2585 3400 0 Blue 0
9 PM Tue 64 62 W 1 3 2585 3400 0 Blue 0
10 PM Tue 65 63 W 1 3 2585 3400 0 Blue 0
11 PM Tue 65 63 N 0 3 2585 3400 0 Blue 0
12 Midnight Wed 64 62 N 0 3 2585 3400 0 Blue 0
1 AM Wed 64 62 N 0 3 2585 3400 0 Blue 0
2 AM Wed 63 61 N 0 3 2585 3400 0 Blue 0
3 AM Wed 62 60 N 0 3 2585 3400 0 Blue 0
4 AM Wed 62 60 N 0 3 2585 3400 0 Blue 0
5 AM Wed 61 59 N 0 3 2585 3400 0 Blue 0
6 AM Wed 60 58 N 0 3 2585 3400 0 Blue 0
7 AM Wed 59 57 N 0 3 2585 3400 0 Blue 0
8 AM Wed 60 58 NNE 1 3 2585 3400 0 Blue 0
9 AM Wed 63 62 NNE 1 3 2585 3400 0 Blue 0
10 AM Wed 66 66 NNE 1 3 2585 3400 0 Blue 0
11 AM Wed 70 72 E 5 9 2585 3400 0 Blue 0
12 Noon Wed 73 76 E 5 9 2654 3400 0 Blue 0
1 PM Wed 75 79 E 5 9 3512 3400 0 Blue 0
2 PM Wed 76 80 ESE 5 10 3728 3400 0 Blue 1
3 PM Wed 77 80 ESE 5 10 3728 3400 0 Blue 1
4 PM Wed 76 77 ESE 5 10 2943 3400 0 Blue 0
5 PM Wed 75 75 SE 3 6 2585 3400 0 Blue 0
6 PM Wed 72 70 SE 3 6 2585 3400 0 Blue 0
7 PM Wed 68 66 SE 3 6 2585 3400 0 Blue 0
8 PM Wed 65 63 SW 1 3 2585 3400 0 Blue 0
9 PM Wed 64 62 SW 1 3 2585 3400 0 Blue 0
10 PM Wed 64 62 SW 1 3 2585 3400 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]