Detailed Predictions for: Lake McClure
Launch Lat, Long, Altitude (f): 37.712452, -120.2343, 2000
LZ Altitude (f): 500
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 51 51 N 2 4 1783 2000 0 Blue 3
1 AM Sat 50 50 NNE 2 4 1578 2000 0 Blue 2
2 AM Sat 49 49 N 2 4 1336 2000 0 Blue 1
3 AM Sat 49 49 NNE 2 4 1336 2000 0 Blue 1
4 AM Sat 49 49 NNE 2 4 1336 2000 0 Blue 1
5 AM Sat 49 49 NNE 2 4 1336 2000 0 Blue 1
6 AM Sat 48 48 NNE 2 4 726 2000 0 Blue 0
7 AM Sat 49 49 NNE 2 3 1336 2000 0 Blue 1
8 AM Sat 49 49 NNE 2 4 1336 2000 0 Blue 1
9 AM Sat 52 52 NW 2 5 1919 2000 0 Blue 4
10 AM Sat 54 55 WNW 3 8 2324 2000 0 Blue 7
11 AM Sat 57 59 WNW 4 10 3339 2453 453 Blue 11
12 Noon Sat 60 61 WNW 5 12 3887 3045 1045 Blue 13
1 PM Sat 60 62 WNW 6 13 4906 3319 1319 Blue 14
2 PM Sat 61 62 WNW 6 13 4906 3319 1319 Blue 14
3 PM Sat 62 63 WNW 8 14 5361 3592 1592 Blue 15
4 PM Sat 61 61 NW 8 14 3887 3045 1045 Blue 13
5 PM Sat 61 61 NW 6 13 3887 3045 1045 Blue 13
6 PM Sat 60 60 NW 5 12 3614 2770 770 Blue 12
7 PM Sat 58 58 NW 5 11 3062 2319 319 Blue 10
8 PM Sat 57 57 NNW 4 9 2784 2185 185 Blue 9
9 PM Sat 56 56 NNW 3 8 2458 2050 50 Blue 8
10 PM Sat 54 54 NNW 2 6 2189 2000 0 Blue 6
11 PM Sat 53 53 N 2 5 2054 2000 0 Blue 5
12 Midnight Sun 52 52 N 2 4 1919 2000 0 Blue 4
1 AM Sun 51 51 NE 2 4 1783 2000 0 Blue 3
2 AM Sun 51 51 NE 2 3 1783 2000 0 Blue 3
3 AM Sun 50 50 NE 2 3 1578 2000 0 Blue 2
4 AM Sun 49 49 NE 2 4 1336 2000 0 Blue 1
5 AM Sun 49 49 NE 2 4 1336 2000 0 Blue 1
6 AM Sun 49 49 NE 2 4 1336 2000 0 Blue 1
7 AM Sun 49 49 NE 2 4 1336 2000 0 Blue 1
8 AM Sun 51 51 ENE 2 4 1783 2000 0 Blue 3
9 AM Sun 53 54 ENE 2 4 2189 2000 0 Blue 6
10 AM Sun 56 58 ENE 2 4 3062 2319 319 Blue 10
11 AM Sun 60 64 WSW 3 6 5590 3863 1863 White 16
12 Noon Sun 62 67 WSW 3 6 6228 5702 3702 White 19
1 PM Sun 64 69 WSW 3 6 6615 6191 4191 Blue 21
2 PM Sun 65 70 W 5 9 6799 6324 4324 Blue 22
3 PM Sun 67 71 W 5 9 7056 6457 4457 Blue 23
4 PM Sun 68 70 W 5 9 6799 6324 4324 Blue 22
5 PM Sun 68 69 WNW 5 9 6615 6191 4191 Blue 21
6 PM Sun 67 67 WNW 5 9 6228 5702 3702 White 19
7 PM Sun 64 64 WNW 5 9 5590 3863 1863 White 16
8 PM Sun 62 62 N 2 4 4906 3319 1319 Blue 14
9 PM Sun 60 60 N 2 4 3614 2770 770 Blue 12
10 PM Sun 59 59 N 2 4 3339 2453 453 Blue 11
11 PM Sun 58 58 ENE 2 4 3062 2319 319 Blue 10
12 Midnight Mon 57 57 ENE 2 4 2784 2185 185 Blue 9
1 AM Mon 56 56 ENE 2 4 2458 2050 50 Blue 8
2 AM Mon 56 56 ENE 2 4 2458 2050 50 Blue 8
3 AM Mon 55 55 ENE 2 4 2324 2000 0 Blue 7
4 AM Mon 55 55 ENE 2 4 2324 2000 0 Blue 7
5 AM Mon 55 55 ENE 2 5 2324 2000 0 Blue 7
6 AM Mon 55 55 ENE 2 5 2324 2000 0 Blue 7
7 AM Mon 55 55 ENE 2 5 2324 2000 0 Blue 7
8 AM Mon 56 56 ENE 2 5 2458 2050 50 Blue 8
9 AM Mon 60 61 ENE 2 5 3887 3045 1045 Blue 13
10 AM Mon 65 67 ENE 2 5 6228 5702 3702 White 19
11 AM Mon 69 73 SSW 2 5 7491 6751 4751 White 25
12 Noon Mon 72 77 SSW 2 5 8324 7768 5768 White 29
1 PM Mon 74 80 SSW 2 5 8946 8532 6532 White 32
2 PM Mon 75 80 WSW 4 9 8946 8532 6532 White 32
3 PM Mon 76 80 WSW 4 9 8946 8532 6532 White 32
4 PM Mon 77 80 WSW 4 9 8946 8532 6532 White 32
5 PM Mon 76 77 WNW 4 6 8324 7768 5768 White 29
6 PM Mon 74 74 WNW 4 6 7699 7006 5006 White 26
7 PM Mon 72 72 WNW 4 6 7281 6591 4591 White 24
8 PM Mon 69 69 N 2 4 6615 6191 4191 Blue 21
9 PM Mon 67 67 N 2 4 6228 5702 3702 White 19
10 PM Mon 65 65 N 2 4 5803 4723 2723 White 17
11 PM Mon 64 64 ENE 2 5 5590 3863 1863 White 16
12 Midnight Tue 62 62 ENE 2 5 4906 3319 1319 Blue 14
1 AM Tue 61 61 ENE 2 5 3887 3045 1045 Blue 13
2 AM Tue 60 60 ENE 2 5 3614 2770 770 Blue 12
3 AM Tue 59 59 ENE 2 5 3339 2453 453 Blue 11
4 AM Tue 58 58 ENE 2 5 3062 2319 319 Blue 10
5 AM Tue 58 58 ENE 3 6 3062 2319 319 Blue 10
6 AM Tue 58 58 ENE 3 6 3062 2319 319 Blue 10
7 AM Tue 58 58 ENE 3 6 3062 2319 319 Blue 10
8 AM Tue 60 60 ENE 2 5 3614 2770 770 Blue 12
9 AM Tue 64 65 ENE 2 5 5803 4723 2723 White 17
10 AM Tue 69 71 ENE 2 5 7056 6457 4457 Blue 23
11 AM Tue 73 77 SSW 2 5 8324 7768 5768 White 29
12 Noon Tue 76 81 SSW 2 5 9153 8788 6788 White 33
1 PM Tue 77 82 SSW 2 5 9360 9042 7042 White 34
2 PM Tue 78 82 WSW 4 9 9360 9042 7042 White 34
3 PM Tue 79 82 WSW 4 9 9360 9042 7042 White 34
4 PM Tue 80 82 WSW 4 9 9360 9042 7042 White 34
5 PM Tue 79 80 W 3 6 8946 8532 6532 White 32
6 PM Tue 77 77 W 3 6 8324 7768 5768 White 29
7 PM Tue 73 73 W 3 6 7491 6751 4751 White 25
8 PM Tue 70 70 NNE 2 5 6799 6324 4324 Blue 22
9 PM Tue 68 68 NNE 2 5 6440 6057 4057 White 20
10 PM Tue 66 66 NNE 2 5 6016 5305 3305 White 18
11 PM Tue 65 65 NE 2 5 5803 4723 2723 White 17
12 Midnight Wed 64 64 NE 2 5 5590 3863 1863 White 16
1 AM Wed 63 63 NE 2 5 5361 3592 1592 Blue 15
2 AM Wed 62 62 ENE 2 4 4906 3319 1319 Blue 14
3 AM Wed 61 61 ENE 2 4 3887 3045 1045 Blue 13
4 AM Wed 60 60 ENE 2 4 3614 2770 770 Blue 12
5 AM Wed 60 60 ENE 2 5 3614 2770 770 Blue 12
6 AM Wed 59 59 ENE 2 5 3339 2453 453 Blue 11
7 AM Wed 59 59 ENE 2 5 3339 2453 453 Blue 11
8 AM Wed 60 60 ENE 2 6 3614 2770 770 Blue 12
9 AM Wed 63 64 ENE 2 6 5590 3863 1863 White 16
10 AM Wed 66 68 ENE 2 6 6440 6057 4057 White 20
11 AM Wed 69 73 WSW 5 10 7491 6751 4751 White 25
12 Noon Wed 71 76 WSW 5 10 8116 7515 5515 White 28
1 PM Wed 72 77 WSW 5 10 8324 7768 5768 White 29
2 PM Wed 73 77 WSW 8 14 8324 7768 5768 White 29
3 PM Wed 73 76 WSW 8 14 8116 7515 5515 White 28
4 PM Wed 73 75 WSW 8 14 7908 7261 5261 White 27
5 PM Wed 72 72 W 9 16 7281 6591 4591 White 24
6 PM Wed 70 70 W 9 16 6799 6324 4324 Blue 22
7 PM Wed 68 68 W 9 16 6440 6057 4057 White 20
8 PM Wed 65 65 WNW 5 13 5803 4723 2723 White 17
9 PM Wed 63 63 WNW 5 13 5361 3592 1592 Blue 15
10 PM Wed 61 61 WNW 5 13 3887 3045 1045 Blue 13
11 PM Wed 60 60 NW 4 11 3614 2770 770 Blue 12
12 Midnight Thu 59 59 NW 4 11 3339 2453 453 Blue 11
1 AM Thu 58 58 NW 4 11 3062 2319 319 Blue 10
2 AM Thu 57 57 NW 4 10 2784 2185 185 Blue 9
3 AM Thu 56 56 NW 4 10 2458 2050 50 Blue 8
4 AM Thu 55 55 NW 4 10 2324 2000 0 Blue 7
5 AM Thu 54 54 NW 4 10 2189 2000 0 Blue 6
6 AM Thu 53 53 NW 4 10 2054 2000 0 Blue 5
7 AM Thu 52 52 NW 4 10 1919 2000 0 Blue 4
8 AM Thu 52 52 NW 4 11 1919 2000 0 Blue 4
9 AM Thu 53 53 NW 4 11 2054 2000 0 Blue 5
10 AM Thu 54 54 NW 4 11 2189 2000 0 Blue 6
11 AM Thu 55 57 WNW 6 14 2784 2185 185 Blue 9
12 Noon Thu 56 59 WNW 6 14 3339 2453 453 Blue 11
1 PM Thu 57 60 WNW 6 14 3614 2770 770 Blue 12
2 PM Thu 58 61 WNW 9 17 3887 3045 1045 Blue 13
3 PM Thu 58 60 WNW 9 17 3614 2770 770 Blue 12
4 PM Thu 58 59 WNW 9 17 3339 2453 453 Blue 11
5 PM Thu 58 58 WNW 9 17 3062 2319 319 Blue 10
6 PM Thu 57 57 WNW 9 17 2784 2185 185 Blue 9
7 PM Thu 55 55 WNW 9 17 2324 2000 0 Blue 7
8 PM Thu 54 54 NW 6 14 2189 2000 0 Blue 6
9 PM Thu 53 53 NW 6 14 2054 2000 0 Blue 5
10 PM Thu 52 52 NW 6 14 1919 2000 0 Blue 4

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]