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:

 250322/1200

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 Sat 44 42 W 3 10 2690 3400 0 Blue 0
1 AM Sat 44 42 W 3 9 2690 3400 0 Blue 0
2 AM Sat 44 42 W 3 9 2690 3400 0 Blue 0
3 AM Sat 44 42 W 3 9 2690 3400 0 Blue 0
4 AM Sat 44 42 W 3 9 2690 3400 0 Blue 0
5 AM Sat 44 42 W 2 8 2690 3400 0 Blue 0
6 AM Sat 44 42 W 2 8 2690 3400 0 Blue 0
7 AM Sat 44 42 W 2 8 2690 3400 0 Blue 0
8 AM Sat 44 42 W 2 8 2690 3400 0 Blue 0
9 AM Sat 45 43 WNW 2 6 2690 3400 0 Blue 0
10 AM Sat 48 46 NW 2 6 2690 3400 0 Blue 0
11 AM Sat 49 48 NNW 2 6 2720 3400 0 Blue 0
12 Noon Sat 50 49 N 2 6 3005 3400 0 Blue 0
1 PM Sat 51 50 NW 3 8 3288 3400 0 Blue 1
2 PM Sat 51 50 NNW 4 8 3288 3400 0 Blue 1
3 PM Sat 51 50 NNW 4 9 3288 3400 0 Blue 1
4 PM Sat 51 50 NNW 3 9 3288 3400 0 Blue 1
5 PM Sat 52 50 NW 3 9 3288 3400 0 Blue 1
6 PM Sat 51 49 NW 2 9 3005 3400 0 Blue 0
7 PM Sat 49 47 WNW 2 8 2690 3400 0 Blue 0
8 PM Sat 48 46 W 2 6 2690 3400 0 Blue 0
9 PM Sat 47 45 WNW 2 6 2690 3400 0 Blue 0
10 PM Sat 47 45 WNW 3 8 2690 3400 0 Blue 0
11 PM Sat 46 44 WNW 3 9 2690 3400 0 Blue 0
12 Midnight Sun 46 44 WNW 3 9 2690 3400 0 Blue 0
1 AM Sun 46 44 W 4 10 2690 3400 0 Blue 0
2 AM Sun 45 43 W 4 11 2690 3400 0 Blue 0
3 AM Sun 45 43 W 4 11 2690 3400 0 Blue 0
4 AM Sun 46 44 W 4 11 2690 3400 0 Blue 0
5 AM Sun 44 42 W 4 11 2690 3400 0 Blue 0
6 AM Sun 46 44 W 4 11 2690 3400 0 Blue 0
7 AM Sun 46 44 W 4 11 2690 3400 0 Blue 0
8 AM Sun 46 44 NW 4 11 2690 3400 0 Blue 0
9 AM Sun 51 50 NW 4 11 3288 3400 0 Blue 1
10 AM Sun 55 55 NW 4 11 5749 3840 440 Blue 6
11 AM Sun 59 60 N 4 11 6625 6199 2799 Blue 11
12 Noon Sun 62 64 N 4 11 7614 6790 3390 Blue 15
1 PM Sun 64 67 N 4 11 8402 7572 4172 Blue 18
2 PM Sun 65 67 NNE 6 13 8402 7572 4172 Blue 18
3 PM Sun 66 67 NNE 6 13 8402 7572 4172 Blue 18
4 PM Sun 67 67 NNE 6 13 8402 7572 4172 Blue 18
5 PM Sun 66 65 NE 5 12 7875 7051 3651 Blue 16
6 PM Sun 64 62 NE 5 12 7088 6472 3072 Blue 13
7 PM Sun 61 59 NE 5 12 6489 6063 2663 Blue 10
8 PM Sun 59 57 NW 3 9 6215 5301 1901 Blue 8
9 PM Sun 57 55 NW 3 9 5749 3840 440 Blue 6
10 PM Sun 56 54 NW 3 9 5337 3563 163 Blue 5
11 PM Sun 56 54 NW 5 13 5337 3563 163 Blue 5
12 Midnight Mon 56 54 NW 5 13 5337 3563 163 Blue 5
1 AM Mon 56 54 NW 5 13 5337 3563 163 Blue 5
2 AM Mon 56 54 NNW 5 11 5337 3563 163 Blue 5
3 AM Mon 55 53 NNW 5 11 4762 3400 0 Blue 4
4 AM Mon 54 52 NNW 5 11 3850 3400 0 Blue 3
5 AM Mon 54 52 NNW 3 10 3850 3400 0 Blue 3
6 AM Mon 53 51 NNW 3 10 3570 3400 0 Blue 2
7 AM Mon 53 51 NNW 3 10 3570 3400 0 Blue 2
8 AM Mon 55 53 NNW 2 8 4762 3400 0 Blue 4
9 AM Mon 58 57 NNW 2 8 6215 5301 1901 Blue 8
10 AM Mon 63 63 NNW 2 8 7352 6608 3208 Blue 14
11 AM Mon 67 69 NNE 2 8 8930 8088 4688 Blue 20
12 Noon Mon 69 72 NNE 2 8 9712 8876 5476 Blue 23
1 PM Mon 70 73 NNE 2 8 9970 9136 5736 Blue 24
2 PM Mon 70 73 ENE 4 10 9970 9136 5736 Blue 24
3 PM Mon 71 73 ENE 4 10 9970 9136 5736 Blue 24
4 PM Mon 71 72 ENE 4 10 9712 8876 5476 Blue 23
5 PM Mon 69 68 ENE 4 9 8667 7831 4431 Blue 19
6 PM Mon 67 65 ENE 4 9 7875 7051 3651 Blue 16
7 PM Mon 64 62 ENE 4 9 7088 6472 3072 Blue 13
8 PM Mon 61 59 NNW 2 4 6489 6063 2663 Blue 10
9 PM Mon 60 58 NNW 2 4 6352 5709 2309 Blue 9
10 PM Mon 59 57 NNW 2 4 6215 5301 1901 Blue 8
11 PM Mon 59 57 NW 2 6 6215 5301 1901 Blue 8
12 Midnight Tue 58 56 NW 2 6 6078 4657 1257 Blue 7
1 AM Tue 58 56 NW 2 6 6078 4657 1257 Blue 7
2 AM Tue 57 55 NW 2 6 5749 3840 440 Blue 6
3 AM Tue 56 54 NW 2 6 5337 3563 163 Blue 5
4 AM Tue 55 53 NW 2 6 4762 3400 0 Blue 4
5 AM Tue 55 53 NNW 2 6 4762 3400 0 Blue 4
6 AM Tue 55 53 NNW 2 6 4762 3400 0 Blue 4
7 AM Tue 56 54 NNW 2 6 5337 3563 163 Blue 5
8 AM Tue 57 55 N 2 6 5749 3840 440 Blue 6
9 AM Tue 61 60 N 2 6 6625 6199 2799 Blue 11
10 AM Tue 65 65 N 2 6 7875 7051 3651 Blue 16
11 AM Tue 68 69 E 2 5 8930 8088 4688 Blue 20
12 Noon Tue 70 72 E 2 5 9712 8876 5476 Blue 23
1 PM Tue 71 74 E 2 5 10219 9395 5995 Blue 25
2 PM Tue 71 73 SE 5 12 9970 9136 5736 Blue 24
3 PM Tue 72 73 SE 5 12 9970 9136 5736 Blue 24
4 PM Tue 72 72 SE 5 12 9712 8876 5476 Blue 23
5 PM Tue 71 70 S 6 14 9192 8352 4952 Blue 21
6 PM Tue 68 66 S 6 14 8135 7312 3912 Blue 17
7 PM Tue 66 64 S 6 14 7614 6790 3390 Blue 15
8 PM Tue 63 61 WSW 3 10 6825 6336 2936 Blue 12
9 PM Tue 61 59 WSW 3 10 6489 6063 2663 Blue 10
10 PM Tue 60 58 WSW 3 10 6352 5709 2309 Blue 9
11 PM Tue 59 57 W 3 6 6215 5301 1901 Blue 8
12 Midnight Wed 58 56 W 3 6 6078 4657 1257 Blue 7
1 AM Wed 58 56 W 3 6 6078 4657 1257 Blue 7
2 AM Wed 57 55 W 3 6 5749 3840 440 Blue 6
3 AM Wed 56 54 W 3 6 5337 3563 163 Blue 5
4 AM Wed 54 52 W 3 6 3850 3400 0 Blue 3
5 AM Wed 53 51 W 3 8 3570 3400 0 Blue 2
6 AM Wed 53 51 W 3 8 3570 3400 0 Blue 2
7 AM Wed 53 51 W 3 8 3570 3400 0 Blue 2
8 AM Wed 53 51 W 4 11 3570 3400 0 Blue 2
9 AM Wed 56 54 W 4 11 5337 3563 163 Blue 5
10 AM Wed 58 57 W 4 11 6215 5301 1901 Blue 8
11 AM Wed 60 59 SSW 9 21 6489 6063 2663 Blue 10
12 Noon Wed 61 61 SSW 9 21 6825 6336 2936 Blue 12
1 PM Wed 62 62 SSW 9 21 7088 6472 3072 Blue 13
2 PM Wed 61 61 SW 14 32 6825 6336 2936 Blue 12
3 PM Wed 60 59 SW 14 32 6489 6063 2663 Blue 10
4 PM Wed 59 58 SW 14 32 6352 5709 2309 Blue 9
5 PM Wed 56 54 SW 16 36 5337 3563 163 Blue 5
6 PM Wed 54 52 SW 16 36 3850 3400 0 Blue 3
7 PM Wed 51 49 SW 16 36 3005 3400 0 Blue 0
8 PM Wed 49 47 WSW 14 35 2690 3400 0 Blue 0
9 PM Wed 48 46 WSW 14 35 2690 3400 0 Blue 0
10 PM Wed 48 46 WSW 14 35 2690 3400 0 Blue 0
11 PM Wed 48 46 WSW 12 29 2690 3400 0 Blue 0
12 Midnight Thu 47 45 WSW 12 29 2690 3400 0 Blue 0
1 AM Thu 47 45 WSW 12 29 2690 3400 0 Blue 0
2 AM Thu 46 44 WSW 10 25 2690 3400 0 Blue 0
3 AM Thu 45 43 WSW 10 25 2690 3400 0 Blue 0
4 AM Thu 44 42 WSW 10 25 2690 3400 0 Blue 0
5 AM Thu 43 41 WSW 9 21 2690 3400 0 Blue 0
6 AM Thu 42 40 WSW 9 21 2690 3400 0 Blue 0
7 AM Thu 41 39 WSW 9 21 2690 3400 0 Blue 0
8 AM Thu 42 40 WSW 6 19 2690 3400 0 Blue 0
9 AM Thu 43 41 WSW 6 19 2690 3400 0 Blue 0
10 AM Thu 45 43 WSW 6 19 2690 3400 0 Blue 0
11 AM Thu 47 46 WSW 10 24 2690 3400 0 Blue 0
12 Noon Thu 48 47 WSW 10 24 2690 3400 0 Blue 0
1 PM Thu 49 48 WSW 10 24 2720 3400 0 Blue 0
2 PM Thu 50 49 W 12 27 3005 3400 0 Blue 0
3 PM Thu 50 49 W 12 27 3005 3400 0 Blue 0
4 PM Thu 49 48 W 12 27 2720 3400 0 Blue 0
5 PM Thu 48 47 W 13 28 2690 3400 0 Blue 0
6 PM Thu 46 44 W 13 28 2690 3400 0 Blue 0
7 PM Thu 45 43 W 13 28 2690 3400 0 Blue 0
8 PM Thu 43 41 W 10 26 2690 3400 0 Blue 0
9 PM Thu 42 40 W 10 26 2690 3400 0 Blue 0
10 PM Thu 41 39 W 10 26 2690 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]