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

Station:

KOAK

Date/Time:

25 NOV 2020

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)
4 AM Wed 44 44 NE 2 1132 2000 0 Blue 0
5 AM Wed 44 44 E 3 1132 2000 0 Blue 0
6 AM Wed 42 42 N 3 1132 2000 0 Blue 0
7 AM Wed 42 42 N 6 1132 2000 0 Blue 0
8 AM Wed 46 46 NW 7 1132 2000 0 Blue 0
9 AM Wed 52 52 NW 6 2193 2000 0 Blue 1
10 AM Wed 54 55 NW 8 3356 2188 188 Blue 4
11 AM Wed 55 57 NW 10 3603 2721 721 Blue 6
12 Noon Wed 55 57 NW 12 3603 2721 721 Blue 6
1 PM Wed 56 58 NW 10 3727 3324 1324 Blue 7
2 PM Wed 55 56 NW 12 3479 2338 338 Blue 5
3 PM Wed 55 55 NW 12 3356 2188 188 Blue 4
4 PM Wed 54 54 NW 12 2752 2000 0 Blue 3
5 PM Wed 50 50 NW 8 1479 2000 0 Blue 0
6 PM Wed 48 48 NW 7 1132 2000 0 Blue 0
7 PM Wed 46 46 N 8 1132 2000 0 Blue 0
8 PM Wed 45 45 NW 9 1132 2000 0 Blue 0
9 PM Wed 43 43 N 9 1132 2000 0 Blue 0
10 PM Wed 43 43 N 9 1132 2000 0 Blue 0
11 PM Wed 42 42 N 9 1132 2000 0 Blue 0
12 Midnight Thu 42 42 N 9 1132 2000 0 Blue 0
1 AM Thu 41 41 NW 8 1132 2000 0 Blue 0
2 AM Thu 40 40 NW 7 1132 2000 0 Blue 0
3 AM Thu 40 40 NE 5 1132 2000 0 Blue 0
4 AM Thu 39 39 N 2 1132 2000 0 Blue 0
5 AM Thu 38 38 E 2 1132 2000 0 Blue 0
6 AM Thu 37 37 E 3 1132 2000 0 Blue 0
7 AM Thu 37 37 E 5 1132 2000 0 Blue 0
8 AM Thu 41 41 E 5 1132 2000 0 Blue 0
9 AM Thu 45 45 SE 7 1132 2000 0 Blue 0
10 AM Thu 48 49 SE 7 1132 2000 0 Blue 0
11 AM Thu 50 52 SE 7 2193 2000 0 Blue 1
12 Noon Thu 52 54 SE 7 2752 2000 0 Blue 3
1 PM Thu 53 55 SW 6 3356 2188 188 Blue 4
2 PM Thu 54 55 SW 6 3356 2188 188 Blue 4
3 PM Thu 54 54 SW 6 2752 2000 0 Blue 3
4 PM Thu 53 53 SW 3 2344 2000 0 Blue 2
5 PM Thu 50 50 SW 3 1479 2000 0 Blue 0
6 PM Thu 47 47 SW 3 1132 2000 0 Blue 0
7 PM Thu 44 44 NE 5 1132 2000 0 Blue 0
8 PM Thu 42 42 NE 5 1132 2000 0 Blue 0
9 PM Thu 42 42 NE 5 1132 2000 0 Blue 0
10 PM Thu 41 41 NE 6 1132 2000 0 Blue 0
11 PM Thu 40 40 NE 6 1132 2000 0 Blue 0
12 Midnight Fri 40 40 NE 6 1132 2000 0 Blue 0
1 AM Fri 40 40 N 3 1132 2000 0 Blue 0
2 AM Fri 40 40 N 3 1132 2000 0 Blue 0
3 AM Fri 40 40 N 3 1132 2000 0 Blue 0
4 AM Fri 40 40 NE 5 1132 2000 0 Blue 0
5 AM Fri 39 39 NE 5 1132 2000 0 Blue 0
6 AM Fri 38 38 NE 5 1132 2000 0 Blue 0
7 AM Fri 38 38 NE 5 1132 2000 0 Blue 0
8 AM Fri 42 42 NE 5 1132 2000 0 Blue 0
9 AM Fri 46 46 NE 5 1132 2000 0 Blue 0
10 AM Fri 51 52 S 5 2193 2000 0 Blue 1
11 AM Fri 54 56 S 5 3479 2338 338 Blue 5
12 Noon Fri 55 57 S 5 3603 2721 721 Blue 6
1 PM Fri 56 58 S 5 3727 3324 1324 Blue 7
2 PM Fri 57 58 S 5 3727 3324 1324 Blue 7
3 PM Fri 56 56 S 5 3479 2338 338 Blue 5
4 PM Fri 55 55 SW 3 3356 2188 188 Blue 4
5 PM Fri 52 52 SW 3 2193 2000 0 Blue 1
6 PM Fri 49 49 SW 3 1132 2000 0 Blue 0
7 PM Fri 46 46 NE 2 1132 2000 0 Blue 0
8 PM Fri 44 44 NE 2 1132 2000 0 Blue 0
9 PM Fri 43 43 NE 2 1132 2000 0 Blue 0
10 PM Fri 42 42 NE 3 1132 2000 0 Blue 0
11 PM Fri 42 42 NE 3 1132 2000 0 Blue 0
12 Midnight Sat 42 42 NE 3 1132 2000 0 Blue 0
1 AM Sat 42 42 NE 3 1132 2000 0 Blue 0
2 AM Sat 42 42 NE 3 1132 2000 0 Blue 0
3 AM Sat 41 41 NE 3 1132 2000 0 Blue 0
4 AM Sat 41 41 NE 3 1132 2000 0 Blue 0
5 AM Sat 40 40 NE 3 1132 2000 0 Blue 0
6 AM Sat 39 39 NE 3 1132 2000 0 Blue 0
7 AM Sat 40 40 NE 3 1132 2000 0 Blue 0
8 AM Sat 44 44 NE 3 1132 2000 0 Blue 0
9 AM Sat 49 49 NE 3 1132 2000 0 Blue 0
10 AM Sat 53 54 SW 3 2752 2000 0 Blue 3
11 AM Sat 56 58 SW 3 3727 3324 1324 Blue 7
12 Noon Sat 57 59 SW 3 3850 3470 1470 Blue 8
1 PM Sat 58 60 W 5 3974 3593 1593 Blue 9
2 PM Sat 58 59 W 5 3850 3470 1470 Blue 8
3 PM Sat 58 58 W 5 3727 3324 1324 Blue 7
4 PM Sat 56 56 W 3 3479 2338 338 Blue 5
5 PM Sat 53 53 W 3 2344 2000 0 Blue 2
6 PM Sat 50 50 W 3 1479 2000 0 Blue 0
7 PM Sat 47 47 NE 2 1132 2000 0 Blue 0
8 PM Sat 45 45 NE 2 1132 2000 0 Blue 0
9 PM Sat 44 44 NE 2 1132 2000 0 Blue 0
10 PM Sat 43 43 NE 2 1132 2000 0 Blue 0
11 PM Sat 42 42 NE 2 1132 2000 0 Blue 0
12 Midnight Sun 42 42 NE 2 1132 2000 0 Blue 0
1 AM Sun 42 42 NE 2 1132 2000 0 Blue 0
2 AM Sun 42 42 NE 2 1132 2000 0 Blue 0
3 AM Sun 41 41 NE 2 1132 2000 0 Blue 0
4 AM Sun 41 41 NE 3 1132 2000 0 Blue 0
5 AM Sun 40 40 NE 3 1132 2000 0 Blue 0
6 AM Sun 39 39 NE 3 1132 2000 0 Blue 0
7 AM Sun 40 40 E 3 1132 2000 0 Blue 0
8 AM Sun 44 44 E 3 1132 2000 0 Blue 0
9 AM Sun 48 48 E 3 1132 2000 0 Blue 0
10 AM Sun 53 54 S 3 2752 2000 0 Blue 3
11 AM Sun 56 57 S 3 3603 2721 721 Blue 6
12 Noon Sun 58 59 S 3 3850 3470 1470 Blue 8
1 PM Sun 59 60 SW 3 3974 3593 1593 Blue 9
2 PM Sun 59 60 SW 3 3974 3593 1593 Blue 9
3 PM Sun 59 59 SW 3 3850 3470 1470 Blue 8
4 PM Sun 57 57 W 3 3603 2721 721 Blue 6
5 PM Sun 55 55 W 3 3356 2188 188 Blue 4
6 PM Sun 52 52 W 3 2193 2000 0 Blue 1
7 PM Sun 49 49 NE 2 1132 2000 0 Blue 0
8 PM Sun 47 47 NE 2 1132 2000 0 Blue 0
9 PM Sun 46 46 NE 2 1132 2000 0 Blue 0
10 PM Sun 45 45 NE 2 1132 2000 0 Blue 0
11 PM Sun 44 44 NE 2 1132 2000 0 Blue 0
12 Midnight Mon 44 44 NE 2 1132 2000 0 Blue 0
1 AM Mon 44 44 NE 3 1132 2000 0 Blue 0
2 AM Mon 44 44 NE 3 1132 2000 0 Blue 0
3 AM Mon 44 44 NE 3 1132 2000 0 Blue 0
4 AM Mon 44 44 NE 3 1132 2000 0 Blue 0
5 AM Mon 43 43 NE 3 1132 2000 0 Blue 0
6 AM Mon 42 42 NE 3 1132 2000 0 Blue 0
7 AM Mon 42 42 NE 2 1132 2000 0 Blue 0
8 AM Mon 45 45 NE 2 1132 2000 0 Blue 0
9 AM Mon 50 50 NE 2 1479 2000 0 Blue 0
10 AM Mon 54 55 SW 3 3356 2188 188 Blue 4
11 AM Mon 56 57 SW 3 3603 2721 721 Blue 6
12 Noon Mon 57 58 SW 3 3727 3324 1324 Blue 7
1 PM Mon 58 59 W 5 3850 3470 1470 Blue 8
2 PM Mon 58 59 W 5 3850 3470 1470 Blue 8
3 PM Mon 58 58 W 5 3727 3324 1324 Blue 7
4 PM Mon 57 57 W 5 3603 2721 721 Blue 6
5 PM Mon 54 54 W 5 2752 2000 0 Blue 3
6 PM Mon 51 51 W 5 1949 2000 0 Blue 0
7 PM Mon 48 48 N 2 1132 2000 0 Blue 0
8 PM Mon 46 46 N 2 1132 2000 0 Blue 0
9 PM Mon 45 45 N 2 1132 2000 0 Blue 0
10 PM Mon 44 44 N 2 1132 2000 0 Blue 0
11 PM Mon 43 43 N 2 1132 2000 0 Blue 0
12 Midnight Tue 42 42 N 2 1132 2000 0 Blue 0
1 AM Tue 42 42 NE 3 1132 2000 0 Blue 0
2 AM Tue 42 42 NE 3 1132 2000 0 Blue 0
3 AM Tue 41 41 NE 3 1132 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