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

Station:

KOAK

Date/Time:

16 FEB 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)
4 AM Sat 40 40 SE 5 1161 2000 0 Blue 0
5 AM Sat 40 40 SE 5 1161 2000 0 Blue 0
6 AM Sat 39 39 SE 5 1161 2000 0 Blue 0
7 AM Sat 38 38 SE 6 1161 2000 0 Blue 0
8 AM Sat 38 38 SE 6 1161 2000 0 Blue 0
9 AM Sat 40 40 SE 6 1161 2000 0 Blue 0
10 AM Sat 42 42 SE 6 1161 2000 0 Blue 0
11 AM Sat 43 43 SE 6 1243 2000 0 Blue 0
12 Noon Sat 44 44 SE 6 2155 2000 0 Blue 1
1 PM Sat 44 44 W 6 2155 2000 0 Blue 1
2 PM Sat 44 44 W 6 2155 2000 0 Blue 1
3 PM Sat 44 44 W 6 2155 2000 0 Blue 1
4 PM Sat 44 44 NW 6 2155 2000 0 Blue 1
5 PM Sat 44 44 NW 6 2155 2000 0 Blue 1
6 PM Sat 42 42 NW 6 1161 2000 0 Blue 0
7 PM Sat 41 41 E 2 1161 2000 0 Blue 0
8 PM Sat 40 40 E 2 1161 2000 0 Blue 0
9 PM Sat 40 40 E 2 1161 2000 0 Blue 0
10 PM Sat 40 40 E 3 1161 2000 0 Blue 0
11 PM Sat 40 40 E 3 1161 2000 0 Blue 0
12 Midnight Sun 39 39 E 3 1161 2000 0 Blue 0
1 AM Sun 39 39 SE 3 1161 2000 0 Blue 0
2 AM Sun 38 38 SE 3 1161 2000 0 Blue 0
3 AM Sun 38 38 SE 3 1161 2000 0 Blue 0
4 AM Sun 38 38 SE 6 1161 2000 0 Blue 0
5 AM Sun 37 37 SE 6 1161 2000 0 Blue 0
6 AM Sun 37 37 SE 6 1161 2000 0 Blue 0
7 AM Sun 36 36 SE 5 1161 2000 0 Blue 0
8 AM Sun 36 36 SE 5 1161 2000 0 Blue 0
9 AM Sun 37 37 SE 5 1161 2000 0 Blue 0
10 AM Sun 39 39 SW 6 1161 2000 0 Blue 0
11 AM Sun 40 40 SW 6 1161 2000 0 Blue 0
12 Noon Sun 41 41 SW 6 1161 2000 0 Blue 0
1 PM Sun 42 42 NW 6 1161 2000 0 Blue 0
2 PM Sun 43 43 NW 6 1243 2000 0 Blue 0
3 PM Sun 43 43 NW 6 1243 2000 0 Blue 0
4 PM Sun 43 43 NW 6 1243 2000 0 Blue 0
5 PM Sun 42 42 NW 6 1161 2000 0 Blue 0
6 PM Sun 40 40 NW 6 1161 2000 0 Blue 0
7 PM Sun 38 38 NW 5 1161 2000 0 Blue 0
8 PM Sun 37 37 NW 5 1161 2000 0 Blue 0
9 PM Sun 37 37 NW 5 1161 2000 0 Blue 0
10 PM Sun 36 36 N 5 1161 2000 0 Blue 0
11 PM Sun 35 35 N 5 1161 2000 0 Blue 0
12 Midnight Mon 34 34 N 5 1161 2000 0 Blue 0
1 AM Mon 33 33 NE 5 1161 2000 0 Blue 0
2 AM Mon 33 33 NE 5 1161 2000 0 Blue 0
3 AM Mon 32 32 NE 5 1161 2000 0 Blue 0
4 AM Mon 32 32 NE 5 1161 2000 0 Blue 0
5 AM Mon 31 31 NE 5 1161 2000 0 Blue 0
6 AM Mon 30 30 NE 5 1161 2000 0 Blue 0
7 AM Mon 31 31 NE 6 1161 2000 0 Blue 0
8 AM Mon 34 34 NE 6 1161 2000 0 Blue 0
9 AM Mon 38 39 NE 6 1161 2000 0 Blue 0
10 AM Mon 42 44 SE 3 2155 2000 0 Blue 1
11 AM Mon 44 46 S 3 3261 2000 0 White 3
12 Noon Mon 45 48 W 5 3692 2699 699 White 5
1 PM Mon 45 48 W 6 3692 2699 699 White 5
2 PM Mon 46 48 W 7 3692 2699 699 White 5
3 PM Mon 46 47 W 7 3477 2137 137 White 4
4 PM Mon 46 46 W 7 3261 2000 0 White 3
5 PM Mon 44 44 NW 6 2155 2000 0 Blue 1
6 PM Mon 41 41 N 5 1161 2000 0 Blue 0
7 PM Mon 39 39 NE 3 1161 2000 0 Blue 0
8 PM Mon 38 38 NE 3 1161 2000 0 Blue 0
9 PM Mon 37 37 NE 3 1161 2000 0 Blue 0
10 PM Mon 36 36 NE 5 1161 2000 0 Blue 0
11 PM Mon 35 35 NE 5 1161 2000 0 Blue 0
12 Midnight Tue 35 35 NE 6 1161 2000 0 Blue 0
1 AM Tue 34 34 NE 6 1161 2000 0 Blue 0
2 AM Tue 33 33 NE 6 1161 2000 0 Blue 0
3 AM Tue 33 33 NE 6 1161 2000 0 Blue 0
4 AM Tue 32 32 NE 6 1161 2000 0 Blue 0
5 AM Tue 31 31 NE 6 1161 2000 0 Blue 0
6 AM Tue 31 31 NE 5 1161 2000 0 Blue 0
7 AM Tue 32 32 NE 5 1161 2000 0 Blue 0
8 AM Tue 35 35 E 5 1161 2000 0 Blue 0
9 AM Tue 39 40 SE 5 1161 2000 0 Blue 0
10 AM Tue 43 45 SE 5 3047 2000 0 White 2
11 AM Tue 45 48 S 5 3692 2699 699 White 5
12 Noon Tue 46 49 SW 5 3906 3738 1738 White 6
1 PM Tue 47 50 W 5 4119 4046 2046 White 7
2 PM Tue 48 50 W 5 4119 4046 2046 White 7
3 PM Tue 48 49 NW 5 3906 3738 1738 White 6
4 PM Tue 48 48 NW 3 3692 2699 699 White 5
5 PM Tue 46 46 NW 3 3261 2000 0 White 3
6 PM Tue 43 43 NW 3 1243 2000 0 Blue 0
7 PM Tue 40 40 NW 3 1161 2000 0 Blue 0
8 PM Tue 38 38 NW 3 1161 2000 0 Blue 0
9 PM Tue 38 38 NW 3 1161 2000 0 Blue 0
10 PM Tue 37 37 NE 5 1161 2000 0 Blue 0
11 PM Tue 36 36 NE 5 1161 2000 0 Blue 0
12 Midnight Wed 36 36 NE 5 1161 2000 0 Blue 0
1 AM Wed 36 36 NE 5 1161 2000 0 Blue 0
2 AM Wed 36 36 NE 5 1161 2000 0 Blue 0
3 AM Wed 36 36 NE 5 1161 2000 0 Blue 0
4 AM Wed 36 36 E 5 1161 2000 0 Blue 0
5 AM Wed 35 35 E 5 1161 2000 0 Blue 0
6 AM Wed 34 34 E 5 1161 2000 0 Blue 0
7 AM Wed 35 35 E 5 1161 2000 0 Blue 0
8 AM Wed 38 38 E 5 1161 2000 0 Blue 0
9 AM Wed 42 42 E 5 1161 2000 0 Blue 0
10 AM Wed 46 48 S 6 3692 2699 699 White 5
11 AM Wed 47 49 S 6 3906 3738 1738 White 6
12 Noon Wed 48 51 S 6 4333 4333 2333 White 8
1 PM Wed 48 50 S 6 4119 4046 2046 White 7
2 PM Wed 48 50 S 6 4119 4046 2046 White 7
3 PM Wed 49 50 S 6 4119 4046 2046 White 7
4 PM Wed 48 48 NW 5 3692 2699 699 White 5
5 PM Wed 46 46 NW 5 3261 2000 0 White 3
6 PM Wed 44 44 NW 5 2155 2000 0 Blue 1
7 PM Wed 42 42 NW 5 1161 2000 0 Blue 0
8 PM Wed 41 41 NW 5 1161 2000 0 Blue 0
9 PM Wed 40 40 NW 5 1161 2000 0 Blue 0
10 PM Wed 40 40 E 6 1161 2000 0 Blue 0
11 PM Wed 40 40 E 6 1161 2000 0 Blue 0
12 Midnight Thu 39 39 E 6 1161 2000 0 Blue 0
1 AM Thu 39 39 E 6 1161 2000 0 Blue 0
2 AM Thu 39 39 E 6 1161 2000 0 Blue 0
3 AM Thu 38 38 E 6 1161 2000 0 Blue 0
4 AM Thu 38 38 E 6 1161 2000 0 Blue 0
5 AM Thu 37 37 E 6 1161 2000 0 Blue 0
6 AM Thu 36 36 E 6 1161 2000 0 Blue 0
7 AM Thu 36 36 E 6 1161 2000 0 Blue 0
8 AM Thu 38 38 E 6 1161 2000 0 Blue 0
9 AM Thu 40 40 E 6 1161 2000 0 Blue 0
10 AM Thu 42 43 W 6 1243 2000 0 Blue 0
11 AM Thu 43 44 W 6 2155 2000 0 Blue 1
12 Noon Thu 44 45 W 6 3047 2000 0 White 2
1 PM Thu 45 46 W 6 3261 2000 0 White 3
2 PM Thu 46 47 W 6 3477 2137 137 White 4
3 PM Thu 46 46 W 6 3261 2000 0 White 3
4 PM Thu 45 45 NW 6 3047 2000 0 White 2
5 PM Thu 43 43 NW 6 1243 2000 0 Blue 0
6 PM Thu 41 41 NW 6 1161 2000 0 Blue 0
7 PM Thu 39 39 NW 6 1161 2000 0 Blue 0
8 PM Thu 38 38 NW 6 1161 2000 0 Blue 0
9 PM Thu 38 38 NW 6 1161 2000 0 Blue 0
10 PM Thu 38 38 E 7 1161 2000 0 Blue 0
11 PM Thu 37 37 E 7 1161 2000 0 Blue 0
12 Midnight Fri 36 36 E 7 1161 2000 0 Blue 0
1 AM Fri 35 35 E 7 1161 2000 0 Blue 0
2 AM Fri 35 35 E 7 1161 2000 0 Blue 0
3 AM Fri 34 34 E 7 1161 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