Detailed Predictions for: Lake McClure
Launch Lat, Long, Altitude (f): 37.3803, -120.0769, 2000
LZ Altitude (f): 500
Sounding

Station:

KOAK

Date/Time:

21 SEP 2021

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 69 69 N 3 3 758 2000 0 Blue 0
1 AM Tue 70 70 NNE 4 5 758 2000 0 Blue 0
2 AM Tue 71 71 NE 4 5 758 2000 0 Blue 0
3 AM Tue 70 70 ENE 3 3 758 2000 0 Blue 0
4 AM Tue 70 70 ENE 3 3 758 2000 0 Blue 0
5 AM Tue 70 70 SE 3 4 758 2000 0 Blue 0
6 AM Tue 68 68 ENE 5 8 758 2000 0 Blue 0
7 AM Tue 69 69 E 5 8 758 2000 0 Blue 0
8 AM Tue 72 72 SSW 2 3 758 2000 0 Blue 0
9 AM Tue 80 81 NE 2 3 2912 2000 0 Blue 2
10 AM Tue 83 86 S 4 5 4529 3863 1863 Blue 7
11 AM Tue 86 90 SSW 5 8 4960 4625 2625 Blue 11
12 Noon Tue 88 93 WSW 5 8 5276 4948 2948 Blue 14
1 PM Tue 90 96 WSW 6 9 6853 5207 3207 Blue 17
2 PM Tue 92 97 W 8 10 7101 5741 3741 Blue 18
3 PM Tue 92 96 W 8 10 6853 5207 3207 Blue 17
4 PM Tue 93 96 W 6 9 6853 5207 3207 Blue 17
5 PM Tue 93 94 NW 5 8 5817 5038 3038 Blue 15
6 PM Tue 91 91 N 5 8 5045 4733 2733 Blue 12
7 PM Tue 86 86 NNE 9 12 4529 3863 1863 Blue 7
8 PM Tue 83 83 NNE 9 12 3869 2071 71 Blue 4
9 PM Tue 81 81 NNE 10 13 2912 2000 0 Blue 2
10 PM Tue 78 78 N 8 10 1405 2000 0 Blue 0
11 PM Tue 77 77 NNW 4 5 1085 2000 0 Blue 0
12 Midnight Wed 75 75 NNE 3 4 758 2000 0 Blue 0
1 AM Wed 74 74 NNE 5 8 758 2000 0 Blue 0
2 AM Wed 73 73 NE 8 10 758 2000 0 Blue 0
3 AM Wed 73 73 ENE 9 12 758 2000 0 Blue 0
4 AM Wed 72 72 ENE 6 9 758 2000 0 Blue 0
5 AM Wed 72 72 ENE 4 5 758 2000 0 Blue 0
6 AM Wed 71 71 ENE 8 10 758 2000 0 Blue 0
7 AM Wed 70 70 ENE 11 14 758 2000 0 Blue 0
8 AM Wed 74 74 E 10 13 758 2000 0 Blue 0
9 AM Wed 82 83 E 8 10 3869 2071 71 Blue 4
10 AM Wed 84 87 S 8 10 4637 3937 1937 Blue 8
11 AM Wed 86 90 SSW 9 12 4960 4625 2625 Blue 11
12 Noon Wed 88 93 SSW 9 12 5276 4948 2948 Blue 14
1 PM Wed 89 94 SSW 9 12 5817 5038 3038 Blue 15
2 PM Wed 90 95 SW 9 12 6343 5097 3097 Blue 16
3 PM Wed 91 95 WSW 9 12 6343 5097 3097 Blue 16
4 PM Wed 92 94 WSW 8 10 5817 5038 3038 Blue 15
5 PM Wed 91 92 W 10 13 5105 4840 2840 Blue 13
6 PM Wed 88 88 WNW 11 14 4745 4186 2186 Blue 9
7 PM Wed 85 85 NW 10 13 4218 3788 1788 Blue 6
8 PM Wed 81 81 N 9 12 2912 2000 0 Blue 2
9 PM Wed 78 78 N 8 10 1405 2000 0 Blue 0
10 PM Wed 76 76 NNW 9 12 763 2000 0 Blue 0
11 PM Wed 74 74 N 4 5 758 2000 0 Blue 0
12 Midnight Thu 72 72 N 4 5 758 2000 0 Blue 0
1 AM Thu 71 71 N 4 5 758 2000 0 Blue 0
2 AM Thu 70 70 NNE 3 4 758 2000 0 Blue 0
3 AM Thu 69 69 NNE 3 4 758 2000 0 Blue 0
4 AM Thu 69 69 NNE 3 4 758 2000 0 Blue 0
5 AM Thu 69 69 NE 3 3 758 2000 0 Blue 0
6 AM Thu 69 69 NE 3 3 758 2000 0 Blue 0
7 AM Thu 69 69 NE 3 3 758 2000 0 Blue 0
8 AM Thu 70 70 NE 3 4 758 2000 0 Blue 0
9 AM Thu 73 74 NE 3 4 758 2000 0 Blue 0
10 AM Thu 77 79 NE 3 4 1722 2000 0 Blue 0
11 AM Thu 81 85 WSW 5 10 4218 3788 1788 Blue 6
12 Noon Thu 84 89 WSW 5 10 4853 4518 2518 Blue 10
1 PM Thu 86 92 WSW 5 10 5105 4840 2840 Blue 13
2 PM Thu 87 92 W 6 13 5105 4840 2840 Blue 13
3 PM Thu 88 92 W 6 13 5105 4840 2840 Blue 13
4 PM Thu 89 91 W 6 13 5045 4733 2733 Blue 12
5 PM Thu 88 89 WNW 6 13 4853 4518 2518 Blue 10
6 PM Thu 86 86 WNW 6 13 4529 3863 1863 Blue 7
7 PM Thu 82 82 WNW 6 13 3794 2000 0 Blue 3
8 PM Thu 79 79 N 3 4 1722 2000 0 Blue 0
9 PM Thu 77 77 N 3 4 1085 2000 0 Blue 0
10 PM Thu 75 75 N 3 4 758 2000 0 Blue 0
11 PM Thu 74 74 NE 3 3 758 2000 0 Blue 0
12 Midnight Fri 73 73 NE 3 3 758 2000 0 Blue 0
1 AM Fri 72 72 NE 3 3 758 2000 0 Blue 0
2 AM Fri 72 72 ENE 4 4 758 2000 0 Blue 0
3 AM Fri 71 71 ENE 4 4 758 2000 0 Blue 0
4 AM Fri 71 71 ENE 4 4 758 2000 0 Blue 0
5 AM Fri 71 71 ENE 4 4 758 2000 0 Blue 0
6 AM Fri 71 71 ENE 4 4 758 2000 0 Blue 0
7 AM Fri 71 71 ENE 4 4 758 2000 0 Blue 0
8 AM Fri 73 73 ENE 3 4 758 2000 0 Blue 0
9 AM Fri 77 78 ENE 3 4 1405 2000 0 Blue 0
10 AM Fri 82 84 ENE 3 4 3944 2846 846 Blue 5
11 AM Fri 86 90 SW 5 9 4960 4625 2625 Blue 11
12 Noon Fri 88 93 SW 5 9 5276 4948 2948 Blue 14
1 PM Fri 89 95 SW 5 9 6343 5097 3097 Blue 16
2 PM Fri 90 95 WSW 5 13 6343 5097 3097 Blue 16
3 PM Fri 91 95 WSW 5 13 6343 5097 3097 Blue 16
4 PM Fri 92 95 WSW 5 13 6343 5097 3097 Blue 16
5 PM Fri 92 93 W 6 12 5276 4948 2948 Blue 14
6 PM Fri 90 90 W 6 12 4960 4625 2625 Blue 11
7 PM Fri 86 86 W 6 12 4529 3863 1863 Blue 7
8 PM Fri 82 82 NNW 3 4 3794 2000 0 Blue 3
9 PM Fri 79 79 NNW 3 4 1722 2000 0 Blue 0
10 PM Fri 76 76 NNW 3 4 763 2000 0 Blue 0
11 PM Fri 74 74 N 2 4 758 2000 0 Blue 0
12 Midnight Sat 73 73 N 2 4 758 2000 0 Blue 0
1 AM Sat 72 72 N 2 4 758 2000 0 Blue 0
2 AM Sat 72 72 NNE 2 3 758 2000 0 Blue 0
3 AM Sat 71 71 NNE 2 3 758 2000 0 Blue 0
4 AM Sat 71 71 NNE 2 3 758 2000 0 Blue 0
5 AM Sat 71 71 NE 3 4 758 2000 0 Blue 0
6 AM Sat 71 71 NE 3 4 758 2000 0 Blue 0
7 AM Sat 72 72 NE 3 4 758 2000 0 Blue 0
8 AM Sat 73 73 NE 2 3 758 2000 0 Blue 0
9 AM Sat 76 77 NE 2 3 1085 2000 0 Blue 0
10 AM Sat 80 82 NE 2 3 3794 2000 0 Blue 3
11 AM Sat 83 87 SW 5 9 4637 3937 1937 Blue 8
12 Noon Sat 85 90 SW 5 9 4960 4625 2625 Blue 11
1 PM Sat 86 91 SW 5 9 5045 4733 2733 Blue 12
2 PM Sat 87 92 W 6 13 5105 4840 2840 Blue 13
3 PM Sat 88 92 W 6 13 5105 4840 2840 Blue 13
4 PM Sat 89 91 W 6 13 5045 4733 2733 Blue 12
5 PM Sat 89 90 W 6 14 4960 4625 2625 Blue 11
6 PM Sat 86 86 W 6 14 4529 3863 1863 Blue 7
7 PM Sat 83 83 W 6 14 3869 2071 71 Blue 4
8 PM Sat 79 79 NNW 4 6 1722 2000 0 Blue 0
9 PM Sat 76 76 NNW 4 6 763 2000 0 Blue 0
10 PM Sat 74 74 NNW 4 6 758 2000 0 Blue 0
11 PM Sat 73 73 N 2 5 758 2000 0 Blue 0
12 Midnight Sun 72 72 N 2 5 758 2000 0 Blue 0
1 AM Sun 71 71 N 2 5 758 2000 0 Blue 0
2 AM Sun 71 71 N 3 4 758 2000 0 Blue 0
3 AM Sun 70 70 N 3 4 758 2000 0 Blue 0
4 AM Sun 69 69 N 3 4 758 2000 0 Blue 0
5 AM Sun 69 69 NNE 2 4 758 2000 0 Blue 0
6 AM Sun 69 69 NNE 2 4 758 2000 0 Blue 0
7 AM Sun 70 70 NNE 2 4 758 2000 0 Blue 0
8 AM Sun 71 71 ENE 2 4 758 2000 0 Blue 0
9 AM Sun 74 75 ENE 2 4 758 2000 0 Blue 0
10 AM Sun 77 79 ENE 2 4 1722 2000 0 Blue 0
11 AM Sun 80 83 SW 5 9 3869 2071 71 Blue 4
12 Noon Sun 82 86 SW 5 9 4529 3863 1863 Blue 7
1 PM Sun 83 87 SW 5 9 4637 3937 1937 Blue 8
2 PM Sun 84 88 W 6 13 4745 4186 2186 Blue 9
3 PM Sun 85 88 W 6 13 4745 4186 2186 Blue 9
4 PM Sun 86 88 W 6 13 4745 4186 2186 Blue 9
5 PM Sun 85 86 W 6 14 4529 3863 1863 Blue 7
6 PM Sun 83 83 W 6 14 3869 2071 71 Blue 4
7 PM Sun 80 80 W 6 14 1849 2000 0 Blue 1
8 PM Sun 77 77 NW 3 5 1085 2000 0 Blue 0
9 PM Sun 75 75 NW 3 5 758 2000 0 Blue 0
10 PM Sun 73 73 NW 3 5 758 2000 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]