Detailed Predictions for: Lake McClure
Launch Altitude (f): 2000
LZ Altitude (f): 500
Sounding

Station:

KOAK

Date/Time:

20 OCT 2019

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 53 53 NW 9 1168 2000 0 Blue 0
6 AM Sun 53 53 NW 7 1168 2000 0 Blue 0
7 AM Sun 52 52 NW 5 1168 2000 0 Blue 0
8 AM Sun 54 54 E 2 1168 2000 0 Blue 0
9 AM Sun 61 61 SE 3 1576 2000 0 Blue 3
10 AM Sun 66 67 S 5 3289 2086 86 Blue 9
11 AM Sun 69 72 SW 5 5578 4603 2603 Blue 14
12 Noon Sun 71 75 W 7 6470 5533 3533 Blue 17
1 PM Sun 72 76 W 12 6798 5833 3833 Blue 18
2 PM Sun 73 76 NW 14 6798 5833 3833 Blue 18
3 PM Sun 74 76 NW 15 6798 5833 3833 Blue 18
4 PM Sun 75 76 NW 16 6798 5833 3833 Blue 18
5 PM Sun 74 74 NW 15 6175 5216 3216 Blue 16
6 PM Sun 71 71 NW 13 5258 4057 2057 Blue 13
7 PM Sun 66 66 NW 8 2989 2000 0 Blue 8
8 PM Sun 63 63 NW 7 1790 2000 0 Blue 5
9 PM Sun 61 61 NW 6 1576 2000 0 Blue 3
10 PM Sun 60 60 NW 8 1515 2000 0 Blue 2
11 PM Sun 59 59 NW 9 1455 2000 0 Blue 1
12 Midnight Mon 57 57 N 8 1293 2000 0 Blue 0
1 AM Mon 56 56 N 6 1204 2000 0 Blue 0
2 AM Mon 56 56 N 3 1204 2000 0 Blue 0
3 AM Mon 56 56 E 5 1204 2000 0 Blue 0
4 AM Mon 54 54 E 6 1168 2000 0 Blue 0
5 AM Mon 53 53 E 7 1168 2000 0 Blue 0
6 AM Mon 53 53 E 7 1168 2000 0 Blue 0
7 AM Mon 52 52 E 7 1168 2000 0 Blue 0
8 AM Mon 54 54 E 8 1168 2000 0 Blue 0
9 AM Mon 62 62 SE 6 1636 2000 0 Blue 4
10 AM Mon 68 70 S 6 4964 3269 1269 Blue 12
11 AM Mon 71 74 S 5 6175 5216 3216 Blue 16
12 Noon Mon 74 78 S 5 7338 6419 4419 Blue 20
1 PM Mon 75 79 S 5 7500 6709 4709 Blue 21
2 PM Mon 77 81 SW 5 7823 7305 5305 Blue 23
3 PM Mon 78 81 SW 5 7823 7305 5305 Blue 23
4 PM Mon 79 80 SW 5 7662 7144 5144 Blue 22
5 PM Mon 78 78 W 3 7338 6419 4419 Blue 20
6 PM Mon 75 75 W 3 6470 5533 3533 Blue 17
7 PM Mon 70 70 W 3 4964 3269 1269 Blue 12
8 PM Mon 67 67 NE 2 3289 2086 86 Blue 9
9 PM Mon 65 65 NE 2 2680 2000 0 Blue 7
10 PM Mon 64 64 NE 2 2099 2000 0 Blue 6
11 PM Mon 63 63 NE 3 1790 2000 0 Blue 5
12 Midnight Tue 61 61 NE 3 1576 2000 0 Blue 3
1 AM Tue 60 60 NE 3 1515 2000 0 Blue 2
2 AM Tue 60 60 NE 5 1515 2000 0 Blue 2
3 AM Tue 60 60 NE 5 1515 2000 0 Blue 2
4 AM Tue 58 58 NE 5 1382 2000 0 Blue 0
5 AM Tue 57 57 NE 5 1293 2000 0 Blue 0
6 AM Tue 57 57 NE 5 1293 2000 0 Blue 0
7 AM Tue 56 56 NE 5 1204 2000 0 Blue 0
8 AM Tue 58 58 NE 5 1382 2000 0 Blue 0
9 AM Tue 67 67 NE 5 3289 2086 86 Blue 9
10 AM Tue 73 75 NE 5 6470 5533 3533 Blue 17
11 AM Tue 76 79 SW 5 7500 6709 4709 Blue 21
12 Noon Tue 79 83 SW 5 8146 7627 5627 Blue 25
1 PM Tue 80 84 SW 5 8492 7788 5788 Blue 26
2 PM Tue 82 86 W 6 9216 8109 6109 Blue 27
3 PM Tue 83 86 W 6 9216 8109 6109 Blue 27
4 PM Tue 84 85 W 6 8856 7948 5948 Blue 26
5 PM Tue 83 83 W 6 8146 7627 5627 Blue 25
6 PM Tue 80 80 W 6 7662 7144 5144 Blue 22
7 PM Tue 73 73 W 6 5878 4939 2939 Blue 15
8 PM Tue 70 70 NW 2 4964 3269 1269 Blue 12
9 PM Tue 68 68 NW 2 4278 2630 630 Blue 10
10 PM Tue 67 67 NW 2 3289 2086 86 Blue 9
11 PM Tue 65 65 NE 3 2680 2000 0 Blue 7
12 Midnight Wed 63 63 NE 3 1790 2000 0 Blue 5
1 AM Wed 62 62 NE 3 1636 2000 0 Blue 4
2 AM Wed 61 61 NE 5 1576 2000 0 Blue 3
3 AM Wed 61 61 NE 5 1576 2000 0 Blue 3
4 AM Wed 59 59 NE 5 1455 2000 0 Blue 1
5 AM Wed 59 59 NE 5 1455 2000 0 Blue 1
6 AM Wed 58 58 NE 5 1382 2000 0 Blue 0
7 AM Wed 57 57 NE 5 1293 2000 0 Blue 0
8 AM Wed 59 59 NE 5 1455 2000 0 Blue 1
9 AM Wed 67 67 NE 5 3289 2086 86 Blue 9
10 AM Wed 72 74 NE 5 6175 5216 3216 Blue 16
11 AM Wed 75 78 S 6 7338 6419 4419 Blue 20
12 Noon Wed 78 82 S 6 7985 7466 5466 Blue 24
1 PM Wed 79 83 S 6 8146 7627 5627 Blue 25
2 PM Wed 80 84 SW 5 8492 7788 5788 Blue 26
3 PM Wed 81 84 SW 5 8492 7788 5788 Blue 26
4 PM Wed 82 83 SW 5 8146 7627 5627 Blue 25
5 PM Wed 81 81 W 6 7823 7305 5305 Blue 23
6 PM Wed 78 78 W 6 7338 6419 4419 Blue 20
7 PM Wed 72 72 W 6 5578 4603 2603 Blue 14
8 PM Wed 69 69 NW 2 4652 2972 972 Blue 11
9 PM Wed 67 67 NW 2 3289 2086 86 Blue 9
10 PM Wed 66 66 NW 2 2989 2000 0 Blue 8
11 PM Wed 64 64 NE 5 2099 2000 0 Blue 6
12 Midnight Thu 62 62 NE 5 1636 2000 0 Blue 4
1 AM Thu 62 62 NE 5 1636 2000 0 Blue 4
2 AM Thu 61 61 NE 6 1576 2000 0 Blue 3
3 AM Thu 61 61 NE 6 1576 2000 0 Blue 3
4 AM Thu 59 59 NE 6 1455 2000 0 Blue 1
5 AM Thu 58 58 NE 6 1382 2000 0 Blue 0
6 AM Thu 58 58 NE 6 1382 2000 0 Blue 0
7 AM Thu 57 57 NE 6 1293 2000 0 Blue 0
8 AM Thu 59 59 NE 5 1455 2000 0 Blue 1
9 AM Thu 68 68 NE 5 4278 2630 630 Blue 10
10 AM Thu 74 75 NE 5 6470 5533 3533 Blue 17
11 AM Thu 77 79 S 5 7500 6709 4709 Blue 21
12 Noon Thu 80 83 S 5 8146 7627 5627 Blue 25
1 PM Thu 81 84 S 5 8492 7788 5788 Blue 26
2 PM Thu 83 86 S 5 9216 8109 6109 Blue 27
3 PM Thu 84 86 S 5 9216 8109 6109 Blue 27
4 PM Thu 85 86 S 5 9216 8109 6109 Blue 27
5 PM Thu 84 84 W 5 8492 7788 5788 Blue 26
6 PM Thu 80 80 W 5 7662 7144 5144 Blue 22
7 PM Thu 74 74 W 5 6175 5216 3216 Blue 16
8 PM Thu 70 70 NE 2 4964 3269 1269 Blue 12
9 PM Thu 68 68 NE 2 4278 2630 630 Blue 10
10 PM Thu 66 66 NE 2 2989 2000 0 Blue 8
11 PM Thu 64 64 NE 3 2099 2000 0 Blue 6
12 Midnight Fri 62 62 NE 3 1636 2000 0 Blue 4
1 AM Fri 61 61 NE 3 1576 2000 0 Blue 3
2 AM Fri 61 61 NE 5 1576 2000 0 Blue 3
3 AM Fri 61 61 NE 5 1576 2000 0 Blue 3
4 AM Fri 58 58 NE 5 1382 2000 0 Blue 0
5 AM Fri 58 58 NE 5 1382 2000 0 Blue 0
6 AM Fri 57 57 NE 5 1293 2000 0 Blue 0
7 AM Fri 56 56 NE 5 1204 2000 0 Blue 0
8 AM Fri 58 58 E 5 1382 2000 0 Blue 0
9 AM Fri 67 67 E 5 3289 2086 86 Blue 9
10 AM Fri 73 74 E 5 6175 5216 3216 Blue 16
11 AM Fri 76 79 S 5 7500 6709 4709 Blue 21
12 Noon Fri 79 82 S 5 7985 7466 5466 Blue 24
1 PM Fri 80 84 S 5 8492 7788 5788 Blue 26
2 PM Fri 82 85 W 5 8856 7948 5948 Blue 26
3 PM Fri 83 85 W 5 8856 7948 5948 Blue 26
4 PM Fri 84 85 W 5 8856 7948 5948 Blue 26
5 PM Fri 83 83 W 6 8146 7627 5627 Blue 25
6 PM Fri 79 79 W 6 7500 6709 4709 Blue 21
7 PM Fri 73 73 W 6 5878 4939 2939 Blue 15
8 PM Fri 69 69 NW 2 4652 2972 972 Blue 11
9 PM Fri 67 67 NW 2 3289 2086 86 Blue 9
10 PM Fri 65 65 NW 2 2680 2000 0 Blue 7
11 PM Fri 63 63 N 3 1790 2000 0 Blue 5
12 Midnight Sat 61 61 N 3 1576 2000 0 Blue 3
1 AM Sat 60 60 N 3 1515 2000 0 Blue 2
2 AM Sat 60 60 NE 5 1515 2000 0 Blue 2
3 AM Sat 60 60 NE 5 1515 2000 0 Blue 2
4 AM Sat 57 57 NE 5 1293 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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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]