Detailed Predictions for: Potato Hill
Launch Lat, Long, Altitude (f): 39.34098, -122.69, 3400
LZ Altitude (f): 1700
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 52 50 W 3 3 2638 3400 0 Blue 0
1 AM Tue 51 49 W 2 3 2638 3400 0 Blue 0
2 AM Tue 50 48 WNW 2 3 2638 3400 0 Blue 0
3 AM Tue 50 48 WNW 1 1 2638 3400 0 Blue 0
4 AM Tue 50 48 WNW 0 0 2638 3400 0 Blue 0
5 AM Tue 49 47 WNW 1 1 2638 3400 0 Blue 0
6 AM Tue 49 47 W 1 1 2638 3400 0 Blue 0
7 AM Tue 49 47 WSW 1 2 2638 3400 0 Blue 0
8 AM Tue 49 47 WSW 1 2 2638 3400 0 Blue 0
9 AM Tue 52 50 SSW 2 2 2638 3400 0 Blue 0
10 AM Tue 54 52 ESE 2 3 2638 3400 0 Blue 0
11 AM Tue 56 55 E 3 5 2638 3400 0 Blue 0
12 Noon Tue 57 55 E 5 8 2638 3400 0 Blue 0
1 PM Tue 58 56 E 5 9 2638 3400 0 Blue 0
2 PM Tue 58 56 ESE 5 8 2638 3400 0 Blue 0
3 PM Tue 57 55 SE 5 8 2638 3400 0 Blue 0
4 PM Tue 55 53 S 4 6 2638 3400 0 Blue 0
5 PM Tue 53 51 SW 3 5 2638 3400 0 Blue 0
6 PM Tue 52 50 WSW 4 5 2638 3400 0 Blue 0
7 PM Tue 52 50 WSW 4 6 2638 3400 0 Blue 0
8 PM Tue 52 50 WSW 4 6 2638 3400 0 Blue 0
9 PM Tue 51 49 W 5 8 2638 3400 0 Blue 0
10 PM Tue 51 49 WSW 5 8 2638 3400 0 Blue 0
11 PM Tue 51 49 WSW 5 8 2638 3400 0 Blue 0
12 Midnight Wed 50 48 WSW 5 8 2638 3400 0 Blue 0
1 AM Wed 50 48 WSW 5 8 2638 3400 0 Blue 0
2 AM Wed 50 48 WSW 6 10 2638 3400 0 Blue 0
3 AM Wed 49 47 WSW 9 13 2638 3400 0 Blue 0
4 AM Wed 49 47 WSW 14 27 2638 3400 0 Blue 0
5 AM Wed 49 47 WSW 14 27 2638 3400 0 Blue 0
6 AM Wed 48 46 WSW 14 27 2638 3400 0 Blue 0
7 AM Wed 47 45 WSW 18 28 2638 3400 0 Blue 0
8 AM Wed 46 44 WSW 18 28 2638 3400 0 Blue 0
9 AM Wed 47 45 WSW 18 28 2638 3400 0 Blue 0
10 AM Wed 48 46 SW 17 25 2638 3400 0 Blue 0
11 AM Wed 48 46 SW 17 25 2638 3400 0 Blue 0
12 Noon Wed 48 46 SW 17 25 2638 3400 0 Blue 0
1 PM Wed 47 45 WSW 21 32 2638 3400 0 Blue 0
2 PM Wed 46 44 WSW 21 32 2638 3400 0 Blue 0
3 PM Wed 46 44 WSW 21 32 2638 3400 0 Blue 0
4 PM Wed 45 43 W 21 32 2638 3400 0 Blue 0
5 PM Wed 45 43 W 21 32 2638 3400 0 Blue 0
6 PM Wed 44 42 W 21 32 2638 3400 0 Blue 0
7 PM Wed 44 42 W 14 23 2638 3400 0 Blue 0
8 PM Wed 43 41 W 14 23 2638 3400 0 Blue 0
9 PM Wed 43 41 W 14 23 2638 3400 0 Blue 0
10 PM Wed 42 40 W 11 18 2638 3400 0 Blue 0
11 PM Wed 42 40 W 11 18 2638 3400 0 Blue 0
12 Midnight Thu 42 40 W 11 18 2638 3400 0 Blue 0
1 AM Thu 42 40 W 11 17 2638 3400 0 Blue 0
2 AM Thu 41 39 W 11 17 2638 3400 0 Blue 0
3 AM Thu 41 39 W 11 17 2638 3400 0 Blue 0
4 AM Thu 40 38 W 9 13 2638 3400 0 Blue 0
5 AM Thu 39 37 W 9 13 2638 3400 0 Blue 0
6 AM Thu 39 37 W 9 13 2638 3400 0 Blue 0
7 AM Thu 39 37 W 6 10 2638 3400 0 Blue 0
8 AM Thu 39 37 W 6 10 2638 3400 0 Blue 0
9 AM Thu 40 38 W 6 10 2638 3400 0 Blue 0
10 AM Thu 41 39 W 9 13 2638 3400 0 Blue 0
11 AM Thu 42 40 W 9 13 2638 3400 0 Blue 0
12 Noon Thu 43 41 W 9 13 2638 3400 0 Blue 0
1 PM Thu 43 41 W 12 18 2638 3400 0 Blue 0
2 PM Thu 43 41 W 12 18 2638 3400 0 Blue 0
3 PM Thu 42 40 W 12 18 2638 3400 0 Blue 0
4 PM Thu 41 39 W 14 23 2638 3400 0 Blue 0
5 PM Thu 40 38 W 14 23 2638 3400 0 Blue 0
6 PM Thu 40 38 W 14 23 2638 3400 0 Blue 0
7 PM Thu 39 37 WNW 10 17 2638 3400 0 Blue 0
8 PM Thu 38 36 WNW 10 17 2638 3400 0 Blue 0
9 PM Thu 38 36 WNW 10 17 2638 3400 0 Blue 0
10 PM Thu 37 35 WNW 10 16 2638 3400 0 Blue 0
11 PM Thu 37 35 WNW 10 16 2638 3400 0 Blue 0
12 Midnight Fri 36 34 WNW 10 16 2638 3400 0 Blue 0
1 AM Fri 36 34 NW 9 12 2638 3400 0 Blue 0
2 AM Fri 35 33 NW 9 12 2638 3400 0 Blue 0
3 AM Fri 35 33 NW 9 12 2638 3400 0 Blue 0
4 AM Fri 34 32 NW 5 9 2638 3400 0 Blue 0
5 AM Fri 34 32 NW 5 9 2638 3400 0 Blue 0
6 AM Fri 33 31 NW 5 9 2638 3400 0 Blue 0
7 AM Fri 34 32 NNW 6 10 2638 3400 0 Blue 0
8 AM Fri 36 34 NNW 6 10 2638 3400 0 Blue 0
9 AM Fri 38 36 NNW 6 10 2638 3400 0 Blue 0
10 AM Fri 40 39 N 9 13 2638 3400 0 Blue 0
11 AM Fri 42 41 N 9 13 2638 3400 0 Blue 0
12 Noon Fri 43 42 N 9 13 2638 3400 0 Blue 0
1 PM Fri 44 43 N 10 14 2638 3400 0 Blue 0
2 PM Fri 44 43 N 10 14 2638 3400 0 Blue 0
3 PM Fri 43 41 N 10 14 2638 3400 0 Blue 0
4 PM Fri 42 40 N 9 13 2638 3400 0 Blue 0
5 PM Fri 41 39 N 9 13 2638 3400 0 Blue 0
6 PM Fri 40 38 N 9 13 2638 3400 0 Blue 0
7 PM Fri 39 37 NW 6 11 2638 3400 0 Blue 0
8 PM Fri 39 37 NW 6 11 2638 3400 0 Blue 0
9 PM Fri 39 37 NW 6 11 2638 3400 0 Blue 0
10 PM Fri 39 37 NW 6 11 2638 3400 0 Blue 0
11 PM Fri 39 37 NW 6 11 2638 3400 0 Blue 0
12 Midnight Sat 40 38 NW 6 11 2638 3400 0 Blue 0
1 AM Sat 40 38 NW 6 10 2638 3400 0 Blue 0
2 AM Sat 40 38 NW 6 10 2638 3400 0 Blue 0
3 AM Sat 40 38 NW 6 10 2638 3400 0 Blue 0
4 AM Sat 40 38 WNW 5 9 2638 3400 0 Blue 0
5 AM Sat 39 37 WNW 5 9 2638 3400 0 Blue 0
6 AM Sat 39 37 WNW 5 9 2638 3400 0 Blue 0
7 AM Sat 39 37 WNW 5 9 2638 3400 0 Blue 0
8 AM Sat 40 38 WNW 5 9 2638 3400 0 Blue 0
9 AM Sat 41 39 WNW 5 9 2638 3400 0 Blue 0
10 AM Sat 43 41 WNW 6 10 2638 3400 0 Blue 0
11 AM Sat 44 42 WNW 6 10 2638 3400 0 Blue 0
12 Noon Sat 45 43 WNW 6 10 2638 3400 0 Blue 0
1 PM Sat 46 44 WSW 8 11 2638 3400 0 Blue 0
2 PM Sat 46 44 WSW 8 11 2638 3400 0 Blue 0
3 PM Sat 45 43 WSW 8 11 2638 3400 0 Blue 0
4 PM Sat 44 42 W 6 11 2638 3400 0 Blue 0
5 PM Sat 43 41 W 6 11 2638 3400 0 Blue 0
6 PM Sat 43 41 W 6 11 2638 3400 0 Blue 0
7 PM Sat 43 41 WNW 5 9 2638 3400 0 Blue 0
8 PM Sat 43 41 WNW 5 9 2638 3400 0 Blue 0
9 PM Sat 44 42 WNW 5 9 2638 3400 0 Blue 0
10 PM Sat 44 42 NW 5 9 2638 3400 0 Blue 0
11 PM Sat 44 42 NW 5 9 2638 3400 0 Blue 0
12 Midnight Sun 45 43 NW 5 9 2638 3400 0 Blue 0
1 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
2 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
3 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
4 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
5 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
6 AM Sun 45 43 WNW 5 9 2638 3400 0 Blue 0
7 AM Sun 45 43 NW 5 8 2638 3400 0 Blue 0
8 AM Sun 46 44 NW 5 8 2638 3400 0 Blue 0
9 AM Sun 46 44 NW 5 8 2638 3400 0 Blue 0
10 AM Sun 47 45 NNW 6 10 2638 3400 0 Blue 0
11 AM Sun 48 46 NNW 6 10 2638 3400 0 Blue 0
12 Noon Sun 48 46 NNW 6 10 2638 3400 0 Blue 0
1 PM Sun 49 47 NNW 9 12 2638 3400 0 Blue 0
2 PM Sun 49 47 NNW 9 12 2638 3400 0 Blue 0
3 PM Sun 49 47 NNW 9 12 2638 3400 0 Blue 0
4 PM Sun 49 47 NNW 8 12 2638 3400 0 Blue 0
5 PM Sun 48 46 NNW 8 12 2638 3400 0 Blue 0
6 PM Sun 48 46 NNW 8 12 2638 3400 0 Blue 0
7 PM Sun 47 45 NW 6 11 2638 3400 0 Blue 0
8 PM Sun 47 45 NW 6 11 2638 3400 0 Blue 0
9 PM Sun 46 44 NW 6 11 2638 3400 0 Blue 0
10 PM Sun 46 44 NW 6 11 2638 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]