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

Station:

KOAK

Date/Time:

15 JUN 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 Sat 64 64 NW 7 2821 2620 620 Blue 12
6 AM Sat 64 64 NW 6 2821 2620 620 Blue 12
7 AM Sat 68 68 NW 2 3079 2884 884 Blue 16
8 AM Sat 74 75 W 3 3299 3225 1225 Blue 23
9 AM Sat 77 80 W 6 3397 3345 1345 Blue 28
10 AM Sat 80 85 W 8 3468 3424 1424 Blue 33
11 AM Sat 82 89 W 9 3694 3481 1481 Blue 37
12 Noon Sat 85 93 W 9 5014 3834 1834 Blue 41
1 PM Sat 88 97 W 10 8294 5293 3293 Blue 44
2 PM Sat 89 97 W 10 8294 5293 3293 Blue 44
3 PM Sat 90 97 W 10 8294 5293 3293 Blue 44
4 PM Sat 91 96 W 12 7304 4975 2975 Blue 43
5 PM Sat 91 94 NW 12 5336 4168 2168 Blue 42
6 PM Sat 90 91 NW 12 4353 3546 1546 Blue 39
7 PM Sat 87 87 NW 12 3507 3453 1453 Blue 35
8 PM Sat 82 82 NW 10 3425 3382 1382 Blue 30
9 PM Sat 77 77 NW 10 3347 3273 1273 Blue 25
10 PM Sat 75 75 NW 10 3299 3225 1225 Blue 23
11 PM Sat 72 72 NW 9 3227 3125 1125 Blue 20
12 Midnight Sun 70 70 NW 9 3176 3016 1016 Blue 18
1 AM Sun 68 68 NW 9 3079 2884 884 Blue 16
2 AM Sun 66 66 NW 10 2954 2752 752 Blue 14
3 AM Sun 66 66 NW 10 2954 2752 752 Blue 14
4 AM Sun 64 64 NW 10 2821 2620 620 Blue 12
5 AM Sun 63 63 NW 3 2755 2554 554 Blue 11
6 AM Sun 63 63 N 3 2755 2554 554 Blue 11
7 AM Sun 67 67 NW 3 3020 2818 818 Blue 15
8 AM Sun 73 74 W 2 3275 3201 1201 Blue 22
9 AM Sun 76 79 W 3 3383 3321 1321 Blue 27
10 AM Sun 79 84 W 6 3454 3410 1410 Blue 32
11 AM Sun 81 88 W 6 3550 3467 1467 Blue 36
12 Noon Sun 84 92 W 6 4781 3681 1681 Blue 40
1 PM Sun 87 96 W 6 7304 4975 2975 Blue 43
2 PM Sun 89 97 W 6 8294 5293 3293 Blue 44
3 PM Sun 91 98 W 7 8929 5609 3609 Blue 45
4 PM Sun 92 97 W 8 8294 5293 3293 Blue 44
5 PM Sun 92 95 W 8 5654 4759 2759 Blue 42
6 PM Sun 90 91 W 8 4353 3546 1546 Blue 39
7 PM Sun 87 87 NW 7 3507 3453 1453 Blue 35
8 PM Sun 84 84 NW 6 3454 3410 1410 Blue 32
9 PM Sun 81 81 NW 5 3411 3368 1368 Blue 29
10 PM Sun 78 78 NW 5 3369 3297 1297 Blue 26
11 PM Sun 75 75 NW 3 3299 3225 1225 Blue 23
12 Midnight Mon 73 73 NW 3 3251 3173 1173 Blue 21
1 AM Mon 71 71 N 3 3203 3076 1076 Blue 19
2 AM Mon 70 70 N 3 3176 3016 1016 Blue 18
3 AM Mon 68 68 N 3 3079 2884 884 Blue 16
4 AM Mon 67 67 NE 2 3020 2818 818 Blue 15
5 AM Mon 67 67 NE 2 3020 2818 818 Blue 15
6 AM Mon 69 69 N 2 3128 2950 950 Blue 17
7 AM Mon 73 73 W 2 3251 3173 1173 Blue 21
8 AM Mon 77 78 SW 2 3369 3297 1297 Blue 26
9 AM Mon 80 83 SW 3 3440 3396 1396 Blue 31
10 AM Mon 83 88 SW 5 3550 3467 1467 Blue 36
11 AM Mon 86 92 SW 6 4781 3681 1681 Blue 40
12 Noon Mon 88 95 SW 6 5654 4759 2759 Blue 42
1 PM Mon 90 97 W 6 8294 5293 3293 Blue 44
2 PM Mon 92 99 W 6 9520 7042 5042 Blue 46
3 PM Mon 93 99 W 6 9520 7042 5042 Blue 46
4 PM Mon 94 98 NW 6 8929 5609 3609 Blue 45
5 PM Mon 94 97 NW 6 8294 5293 3293 Blue 44
6 PM Mon 93 94 NW 6 5336 4168 2168 Blue 42
7 PM Mon 91 91 NW 5 4353 3546 1546 Blue 39
8 PM Mon 88 88 NW 5 3550 3467 1467 Blue 36
9 PM Mon 85 85 NW 5 3468 3424 1424 Blue 33
10 PM Mon 82 82 NW 3 3425 3382 1382 Blue 30
11 PM Mon 79 79 NW 3 3383 3321 1321 Blue 27
12 Midnight Tue 77 77 N 3 3347 3273 1273 Blue 25
1 AM Tue 75 75 N 3 3299 3225 1225 Blue 23
2 AM Tue 74 74 NE 3 3275 3201 1201 Blue 22
3 AM Tue 72 72 NE 3 3227 3125 1125 Blue 20
4 AM Tue 71 71 NE 3 3203 3076 1076 Blue 19
5 AM Tue 71 71 NE 3 3203 3076 1076 Blue 19
6 AM Tue 73 73 NE 3 3251 3173 1173 Blue 21
7 AM Tue 77 77 N 2 3347 3273 1273 Blue 25
8 AM Tue 81 82 NW 2 3425 3382 1382 Blue 30
9 AM Tue 84 87 NW 3 3507 3453 1453 Blue 35
10 AM Tue 87 92 W 5 4781 3681 1681 Blue 40
11 AM Tue 89 96 W 6 7304 4975 2975 Blue 43
12 Noon Tue 92 100 W 6 10090 8140 6140 Blue 47
1 PM Tue 94 103 W 6 12403 9928 7928 Blue 50
2 PM Tue 96 104 W 6 12711 10457 8457 Blue 51
3 PM Tue 98 105 W 6 13271 11323 9323 Blue 52
4 PM Tue 98 103 W 7 12403 9928 7928 Blue 50
5 PM Tue 98 101 W 7 10607 8778 6778 Blue 48
6 PM Tue 96 97 W 7 8294 5293 3293 Blue 44
7 PM Tue 93 93 W 7 5014 3834 1834 Blue 41
8 PM Tue 90 90 W 7 3847 3504 1504 Blue 38
9 PM Tue 87 87 W 7 3507 3453 1453 Blue 35
10 PM Tue 83 83 W 7 3440 3396 1396 Blue 31
11 PM Tue 80 80 NW 3 3397 3345 1345 Blue 28
12 Midnight Wed 78 78 NW 3 3369 3297 1297 Blue 26
1 AM Wed 76 76 NW 3 3323 3249 1249 Blue 24
2 AM Wed 75 75 NW 3 3299 3225 1225 Blue 23
3 AM Wed 73 73 NW 3 3251 3173 1173 Blue 21
4 AM Wed 71 71 NW 3 3203 3076 1076 Blue 19
5 AM Wed 71 71 W 2 3203 3076 1076 Blue 19
6 AM Wed 73 73 W 2 3251 3173 1173 Blue 21
7 AM Wed 76 76 W 2 3323 3249 1249 Blue 24
8 AM Wed 80 81 W 2 3411 3368 1368 Blue 29
9 AM Wed 84 87 W 2 3507 3453 1453 Blue 35
10 AM Wed 87 92 W 2 4781 3681 1681 Blue 40
11 AM Wed 90 97 W 6 8294 5293 3293 Blue 44
12 Noon Wed 92 100 W 6 10090 8140 6140 Blue 47
1 PM Wed 94 103 W 6 12403 9928 7928 Blue 50
2 PM Wed 95 103 W 6 12403 9928 7928 Blue 50
3 PM Wed 97 104 W 6 12711 10457 8457 Blue 51
4 PM Wed 98 103 W 6 12403 9928 7928 Blue 50
5 PM Wed 98 101 W 7 10607 8778 6778 Blue 48
6 PM Wed 96 97 W 7 8294 5293 3293 Blue 44
7 PM Wed 93 93 W 7 5014 3834 1834 Blue 41
8 PM Wed 89 89 W 7 3694 3481 1481 Blue 37
9 PM Wed 86 86 W 7 3482 3439 1439 Blue 34
10 PM Wed 82 82 W 7 3425 3382 1382 Blue 30
11 PM Wed 79 79 N 3 3383 3321 1321 Blue 27
12 Midnight Thu 77 77 N 3 3347 3273 1273 Blue 25
1 AM Thu 75 75 N 3 3299 3225 1225 Blue 23
2 AM Thu 73 73 N 3 3251 3173 1173 Blue 21
3 AM Thu 71 71 N 3 3203 3076 1076 Blue 19
4 AM Thu 70 70 N 3 3176 3016 1016 Blue 18
5 AM Thu 70 70 NW 2 3176 3016 1016 Blue 18
6 AM Thu 72 72 NW 2 3227 3125 1125 Blue 20
7 AM Thu 75 75 NW 2 3299 3225 1225 Blue 23
8 AM Thu 79 80 NW 2 3397 3345 1345 Blue 28
9 AM Thu 82 85 NW 2 3468 3424 1424 Blue 33
10 AM Thu 85 90 NW 2 3847 3504 1504 Blue 38
11 AM Thu 88 95 W 6 5654 4759 2759 Blue 42
12 Noon Thu 90 98 W 6 8929 5609 3609 Blue 45
1 PM Thu 92 101 W 6 10607 8778 6778 Blue 48
2 PM Thu 93 101 W 6 10607 8778 6778 Blue 48
3 PM Thu 94 101 W 6 10607 8778 6778 Blue 48
4 PM Thu 95 100 W 6 10090 8140 6140 Blue 47
5 PM Thu 95 98 W 6 8929 5609 3609 Blue 45
6 PM Thu 93 94 W 6 5336 4168 2168 Blue 42
7 PM Thu 90 90 W 6 3847 3504 1504 Blue 38
8 PM Thu 87 87 W 6 3507 3453 1453 Blue 35
9 PM Thu 83 83 W 6 3440 3396 1396 Blue 31
10 PM Thu 79 79 W 6 3383 3321 1321 Blue 27
11 PM Thu 76 76 NW 3 3323 3249 1249 Blue 24
12 Midnight Fri 74 74 NW 3 3275 3201 1201 Blue 22
1 AM Fri 72 72 NW 3 3227 3125 1125 Blue 20
2 AM Fri 71 71 NW 3 3203 3076 1076 Blue 19
3 AM Fri 69 69 NW 3 3128 2950 950 Blue 17
4 AM Fri 67 67 NW 3 3020 2818 818 Blue 15

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 ac_soaring@yahoo.com