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

Station:

KOAK

Date/Time:

16 OCT 2018

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 Tue 50 50 E 3 1033 2000 0 Blue 0
6 AM Tue 49 49 E 3 1033 2000 0 Blue 0
7 AM Tue 49 49 E 3 1033 2000 0 Blue 0
8 AM Tue 51 51 SE 3 1033 2000 0 Blue 0
9 AM Tue 56 56 SE 3 1033 2000 0 Blue 0
10 AM Tue 63 65 SE 3 1245 2000 0 Blue 0
11 AM Tue 70 73 SW 3 3036 2000 0 Blue 5
12 Noon Tue 73 77 SW 3 4569 3499 1499 Blue 9
1 PM Tue 75 79 SW 3 4755 4352 2352 Blue 11
2 PM Tue 77 81 W 6 5220 4652 2652 Blue 13
3 PM Tue 78 81 W 6 5220 4652 2652 Blue 13
4 PM Tue 78 79 W 6 4755 4352 2352 Blue 11
5 PM Tue 77 77 W 5 4569 3499 1499 Blue 9
6 PM Tue 73 73 W 5 3036 2000 0 Blue 5
7 PM Tue 68 68 W 5 1438 2000 0 Blue 0
8 PM Tue 64 64 NE 2 1181 2000 0 Blue 0
9 PM Tue 61 61 NE 2 1033 2000 0 Blue 0
10 PM Tue 59 59 NE 2 1033 2000 0 Blue 0
11 PM Tue 57 57 NE 5 1033 2000 0 Blue 0
12 Midnight Wed 56 56 NE 5 1033 2000 0 Blue 0
1 AM Wed 56 56 NE 5 1033 2000 0 Blue 0
2 AM Wed 55 55 NE 3 1033 2000 0 Blue 0
3 AM Wed 55 55 NE 3 1033 2000 0 Blue 0
4 AM Wed 54 54 NE 3 1033 2000 0 Blue 0
5 AM Wed 53 53 NE 5 1033 2000 0 Blue 0
6 AM Wed 52 52 NE 5 1033 2000 0 Blue 0
7 AM Wed 51 51 NE 5 1033 2000 0 Blue 0
8 AM Wed 53 53 NE 5 1033 2000 0 Blue 0
9 AM Wed 59 59 NE 5 1033 2000 0 Blue 0
10 AM Wed 67 69 NE 5 1558 2000 0 Blue 1
11 AM Wed 73 76 SW 3 4375 3007 1007 Blue 8
12 Noon Wed 77 81 SW 3 5220 4652 2652 Blue 13
1 PM Wed 78 82 SW 3 5477 4745 2745 Blue 14
2 PM Wed 79 83 SW 6 5878 4944 2944 Blue 15
3 PM Wed 80 83 SW 6 5878 4944 2944 Blue 15
4 PM Wed 80 81 SW 6 5220 4652 2652 Blue 13
5 PM Wed 79 79 W 2 4755 4352 2352 Blue 11
6 PM Wed 75 75 W 2 4022 2484 484 Blue 7
7 PM Wed 70 70 W 2 1712 2000 0 Blue 2
8 PM Wed 65 65 W 2 1245 2000 0 Blue 0
9 PM Wed 62 62 W 2 1053 2000 0 Blue 0
10 PM Wed 60 60 W 2 1033 2000 0 Blue 0
11 PM Wed 59 59 NE 3 1033 2000 0 Blue 0
12 Midnight Thu 58 58 NE 3 1033 2000 0 Blue 0
1 AM Thu 57 57 NE 3 1033 2000 0 Blue 0
2 AM Thu 56 56 NE 3 1033 2000 0 Blue 0
3 AM Thu 55 55 NE 3 1033 2000 0 Blue 0
4 AM Thu 54 54 NE 3 1033 2000 0 Blue 0
5 AM Thu 53 53 NE 3 1033 2000 0 Blue 0
6 AM Thu 52 52 NE 3 1033 2000 0 Blue 0
7 AM Thu 52 52 NE 3 1033 2000 0 Blue 0
8 AM Thu 54 54 NE 3 1033 2000 0 Blue 0
9 AM Thu 60 60 NE 3 1033 2000 0 Blue 0
10 AM Thu 68 70 NE 3 1712 2000 0 Blue 2
11 AM Thu 74 77 W 3 4569 3499 1499 Blue 9
12 Noon Thu 77 81 W 3 5220 4652 2652 Blue 13
1 PM Thu 79 83 W 3 5878 4944 2944 Blue 15
2 PM Thu 80 84 W 3 6901 5187 3187 Blue 16
3 PM Thu 81 84 W 3 6901 5187 3187 Blue 16
4 PM Thu 81 82 W 3 5477 4745 2745 Blue 14
5 PM Thu 80 80 NW 3 4972 4559 2559 Blue 12
6 PM Thu 76 76 NW 3 4375 3007 1007 Blue 8
7 PM Thu 70 70 NW 3 1712 2000 0 Blue 2
8 PM Thu 65 65 NW 3 1245 2000 0 Blue 0
9 PM Thu 62 62 NW 3 1053 2000 0 Blue 0
10 PM Thu 59 59 NW 3 1033 2000 0 Blue 0
11 PM Thu 58 58 N 3 1033 2000 0 Blue 0
12 Midnight Fri 57 57 N 3 1033 2000 0 Blue 0
1 AM Fri 56 56 N 3 1033 2000 0 Blue 0
2 AM Fri 56 56 N 3 1033 2000 0 Blue 0
3 AM Fri 55 55 N 3 1033 2000 0 Blue 0
4 AM Fri 54 54 N 3 1033 2000 0 Blue 0
5 AM Fri 53 53 NE 3 1033 2000 0 Blue 0
6 AM Fri 52 52 NE 3 1033 2000 0 Blue 0
7 AM Fri 52 52 NE 3 1033 2000 0 Blue 0
8 AM Fri 54 54 NE 3 1033 2000 0 Blue 0
9 AM Fri 60 60 NE 3 1033 2000 0 Blue 0
10 AM Fri 67 69 NE 3 1558 2000 0 Blue 1
11 AM Fri 74 77 SW 2 4569 3499 1499 Blue 9
12 Noon Fri 78 82 SW 2 5477 4745 2745 Blue 14
1 PM Fri 79 83 SW 2 5878 4944 2944 Blue 15
2 PM Fri 81 85 SW 2 7813 5442 3442 Blue 17
3 PM Fri 82 85 SW 2 7813 5442 3442 Blue 17
4 PM Fri 82 83 SW 2 5878 4944 2944 Blue 15
5 PM Fri 81 81 W 5 5220 4652 2652 Blue 13
6 PM Fri 77 77 W 5 4569 3499 1499 Blue 9
7 PM Fri 71 71 W 5 1932 2000 0 Blue 3
8 PM Fri 67 67 W 5 1374 2000 0 Blue 0
9 PM Fri 64 64 W 5 1181 2000 0 Blue 0
10 PM Fri 62 62 W 5 1053 2000 0 Blue 0
11 PM Fri 61 61 N 3 1033 2000 0 Blue 0
12 Midnight Sat 60 60 N 3 1033 2000 0 Blue 0
1 AM Sat 58 58 N 3 1033 2000 0 Blue 0
2 AM Sat 57 57 N 3 1033 2000 0 Blue 0
3 AM Sat 57 57 N 3 1033 2000 0 Blue 0
4 AM Sat 56 56 N 3 1033 2000 0 Blue 0
5 AM Sat 55 55 NE 5 1033 2000 0 Blue 0
6 AM Sat 54 54 NE 5 1033 2000 0 Blue 0
7 AM Sat 53 53 NE 5 1033 2000 0 Blue 0
8 AM Sat 55 55 NE 5 1033 2000 0 Blue 0
9 AM Sat 61 61 NE 5 1033 2000 0 Blue 0
10 AM Sat 68 70 NE 5 1712 2000 0 Blue 2
11 AM Sat 75 78 S 2 4662 3979 1979 Blue 10
12 Noon Sat 79 83 S 2 5878 4944 2944 Blue 15
1 PM Sat 81 85 S 2 7813 5442 3442 Blue 17
2 PM Sat 82 86 S 2 8505 5717 3717 Blue 18
3 PM Sat 84 87 S 2 8746 6726 4726 Blue 19
4 PM Sat 84 85 S 2 7813 5442 3442 Blue 17
5 PM Sat 83 83 W 3 5878 4944 2944 Blue 15
6 PM Sat 79 79 W 3 4755 4352 2352 Blue 11
7 PM Sat 73 73 W 3 3036 2000 0 Blue 5
8 PM Sat 69 69 W 3 1558 2000 0 Blue 1
9 PM Sat 66 66 W 3 1310 2000 0 Blue 0
10 PM Sat 64 64 W 3 1181 2000 0 Blue 0
11 PM Sat 63 63 NE 3 1117 2000 0 Blue 0
12 Midnight Sun 62 62 NE 3 1053 2000 0 Blue 0
1 AM Sun 60 60 NE 3 1033 2000 0 Blue 0
2 AM Sun 59 59 NE 3 1033 2000 0 Blue 0
3 AM Sun 59 59 NE 3 1033 2000 0 Blue 0
4 AM Sun 58 58 NE 3 1033 2000 0 Blue 0
5 AM Sun 57 57 NE 2 1033 2000 0 Blue 0
6 AM Sun 56 56 NE 2 1033 2000 0 Blue 0
7 AM Sun 55 55 NE 2 1033 2000 0 Blue 0
8 AM Sun 57 57 NE 2 1033 2000 0 Blue 0
9 AM Sun 62 62 NE 2 1053 2000 0 Blue 0
10 AM Sun 68 70 NE 2 1712 2000 0 Blue 2
11 AM Sun 74 77 S 2 4569 3499 1499 Blue 9
12 Noon Sun 78 82 S 2 5477 4745 2745 Blue 14
1 PM Sun 79 83 S 2 5878 4944 2944 Blue 15
2 PM Sun 81 85 S 2 7813 5442 3442 Blue 17
3 PM Sun 82 85 S 2 7813 5442 3442 Blue 17
4 PM Sun 82 83 S 2 5878 4944 2944 Blue 15
5 PM Sun 81 81 W 6 5220 4652 2652 Blue 13
6 PM Sun 77 77 W 6 4569 3499 1499 Blue 9
7 PM Sun 72 72 W 6 2507 2000 0 Blue 4
8 PM Sun 67 67 W 6 1374 2000 0 Blue 0
9 PM Sun 65 65 W 6 1245 2000 0 Blue 0
10 PM Sun 63 63 W 6 1117 2000 0 Blue 0
11 PM Sun 63 63 N 3 1117 2000 0 Blue 0
12 Midnight Mon 62 62 N 3 1053 2000 0 Blue 0
1 AM Mon 61 61 N 3 1033 2000 0 Blue 0
2 AM Mon 59 59 N 3 1033 2000 0 Blue 0
3 AM Mon 58 58 N 3 1033 2000 0 Blue 0
4 AM Mon 57 57 N 3 1033 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 ac_soaring@yahoo.com