Detailed Predictions for: Burn Launch
Launch Altitude (f): 6188
LZ Altitude (f): 3540
Sounding

Station:

KOAK

Date/Time:

26 APR 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 Thu 47 44 SE 2 6129 6188 0 Blue 0
6 AM Thu 47 44 SE 2 6129 6188 0 Blue 0
7 AM Thu 48 45 SE 2 6129 6188 0 Blue 0
8 AM Thu 51 48 SE 2 6129 6188 0 Blue 0
9 AM Thu 56 54 SE 2 6129 6188 0 Blue 0
10 AM Thu 61 61 SE 2 9325 7303 1115 Blue 5
11 AM Thu 66 66 E 9 11430 9986 3798 Blue 10
12 Noon Thu 69 70 E 9 13413 12164 5976 Blue 14
1 PM Thu 70 71 E 9 13545 12756 6568 Blue 15
2 PM Thu 70 71 SE 8 13545 12756 6568 Blue 15
3 PM Thu 70 70 SE 8 13413 12164 5976 Blue 14
4 PM Thu 68 67 SE 8 12285 10213 4025 Blue 11
5 PM Thu 66 64 SW 12 10510 9278 3090 Blue 8
6 PM Thu 64 61 SW 12 9325 7303 1115 Blue 5
7 PM Thu 61 58 SW 12 7310 6188 0 Blue 2
8 PM Thu 59 56 SW 10 6575 6188 0 Blue 0
9 PM Thu 56 53 SW 10 6129 6188 0 Blue 0
10 PM Thu 55 52 SW 10 6129 6188 0 Blue 0
11 PM Thu 54 51 SW 3 6129 6188 0 Blue 0
12 Midnight Fri 53 50 SW 3 6129 6188 0 Blue 0
1 AM Fri 53 50 SW 3 6129 6188 0 Blue 0
2 AM Fri 52 49 SW 10 6129 6188 0 Blue 0
3 AM Fri 51 48 SW 10 6129 6188 0 Blue 0
4 AM Fri 50 47 SW 10 6129 6188 0 Blue 0
5 AM Fri 48 45 S 7 6129 6188 0 Blue 0
6 AM Fri 47 44 S 7 6129 6188 0 Blue 0
7 AM Fri 47 44 S 7 6129 6188 0 Blue 0
8 AM Fri 47 44 S 10 6129 6188 0 Blue 0
9 AM Fri 48 46 S 10 6129 6188 0 Blue 0
10 AM Fri 49 48 S 10 6129 6188 0 Blue 0
11 AM Fri 50 51 SW 18 6129 6188 0 Blue 0
12 Noon Fri 51 53 SW 18 6129 6188 0 Blue 0
1 PM Fri 49 51 SW 18 6129 6188 0 Blue 0
2 PM Fri 49 51 SW 18 6129 6188 0 Blue 0
3 PM Fri 49 50 SW 18 6129 6188 0 Blue 0
4 PM Fri 49 49 SW 18 6129 6188 0 Blue 0
5 PM Fri 47 45 SW 17 6129 6188 0 Blue 0
6 PM Fri 45 42 SW 17 6129 6188 0 Blue 0
7 PM Fri 42 39 SW 17 6129 6188 0 Blue 0
8 PM Fri 40 37 SW 17 6129 6188 0 Blue 0
9 PM Fri 38 35 SW 17 6129 6188 0 Blue 0
10 PM Fri 37 34 SW 17 6129 6188 0 Blue 0
11 PM Fri 37 34 SW 8 6129 6188 0 Blue 0
12 Midnight Sat 36 33 SW 8 6129 6188 0 Blue 0
1 AM Sat 35 32 SW 8 6129 6188 0 Blue 0
2 AM Sat 34 31 SW 8 6129 6188 0 Blue 0
3 AM Sat 34 31 SW 8 6129 6188 0 Blue 0
4 AM Sat 34 31 SW 8 6129 6188 0 Blue 0
5 AM Sat 34 31 S 6 6129 6188 0 Blue 0
6 AM Sat 34 31 S 6 6129 6188 0 Blue 0
7 AM Sat 33 30 S 6 6129 6188 0 Blue 0
8 AM Sat 34 31 S 6 6129 6188 0 Blue 0
9 AM Sat 36 34 S 6 6129 6188 0 Blue 0
10 AM Sat 39 37 S 6 6129 6188 0 Blue 0
11 AM Sat 42 41 SW 9 6129 6188 0 Blue 0
12 Noon Sat 44 43 SW 9 6129 6188 0 Blue 0
1 PM Sat 44 43 SW 9 6129 6188 0 Blue 0
2 PM Sat 44 43 SW 9 6129 6188 0 Blue 0
3 PM Sat 44 43 SW 9 6129 6188 0 Blue 0
4 PM Sat 43 41 SW 9 6129 6188 0 Blue 0
5 PM Sat 42 39 SW 13 6129 6188 0 Blue 0
6 PM Sat 41 38 SW 13 6129 6188 0 Blue 0
7 PM Sat 40 37 SW 13 6129 6188 0 Blue 0
8 PM Sat 39 36 SW 13 6129 6188 0 Blue 0
9 PM Sat 38 35 SW 13 6129 6188 0 Blue 0
10 PM Sat 37 34 SW 13 6129 6188 0 Blue 0
11 PM Sat 36 33 SW 7 6129 6188 0 Blue 0
12 Midnight Sun 36 33 SW 7 6129 6188 0 Blue 0
1 AM Sun 35 32 SW 7 6129 6188 0 Blue 0
2 AM Sun 35 32 SW 7 6129 6188 0 Blue 0
3 AM Sun 35 32 SW 7 6129 6188 0 Blue 0
4 AM Sun 34 31 SW 7 6129 6188 0 Blue 0
5 AM Sun 34 31 SW 7 6129 6188 0 Blue 0
6 AM Sun 34 31 SW 7 6129 6188 0 Blue 0
7 AM Sun 35 32 SW 7 6129 6188 0 Blue 0
8 AM Sun 37 34 SW 7 6129 6188 0 Blue 0
9 AM Sun 39 36 SW 7 6129 6188 0 Blue 0
10 AM Sun 41 39 SW 7 6129 6188 0 Blue 0
11 AM Sun 42 40 SW 9 6129 6188 0 Blue 0
12 Noon Sun 44 43 SW 9 6129 6188 0 Blue 0
1 PM Sun 44 43 SW 9 6129 6188 0 Blue 0
2 PM Sun 44 43 SW 9 6129 6188 0 Blue 0
3 PM Sun 43 41 SW 9 6129 6188 0 Blue 0
4 PM Sun 42 40 SW 9 6129 6188 0 Blue 0
5 PM Sun 42 39 W 10 6129 6188 0 Blue 0
6 PM Sun 42 39 W 10 6129 6188 0 Blue 0
7 PM Sun 43 40 W 10 6129 6188 0 Blue 0
8 PM Sun 42 39 W 10 6129 6188 0 Blue 0
9 PM Sun 40 37 W 10 6129 6188 0 Blue 0
10 PM Sun 38 35 W 10 6129 6188 0 Blue 0
11 PM Sun 36 33 W 5 6129 6188 0 Blue 0
12 Midnight Mon 36 33 W 5 6129 6188 0 Blue 0
1 AM Mon 36 33 W 5 6129 6188 0 Blue 0
2 AM Mon 36 33 W 5 6129 6188 0 Blue 0
3 AM Mon 35 32 W 5 6129 6188 0 Blue 0
4 AM Mon 34 31 W 5 6129 6188 0 Blue 0
5 AM Mon 33 30 NW 5 6129 6188 0 Blue 0
6 AM Mon 34 31 NW 5 6129 6188 0 Blue 0
7 AM Mon 36 33 NW 5 6129 6188 0 Blue 0
8 AM Mon 38 35 NW 5 6129 6188 0 Blue 0
9 AM Mon 40 37 NW 5 6129 6188 0 Blue 0
10 AM Mon 42 40 NW 5 6129 6188 0 Blue 0
11 AM Mon 44 43 NW 7 6129 6188 0 Blue 0
12 Noon Mon 46 46 NW 7 6129 6188 0 Blue 0
1 PM Mon 49 49 NW 7 6129 6188 0 Blue 0
2 PM Mon 50 50 NW 7 6129 6188 0 Blue 0
3 PM Mon 49 48 NW 7 6129 6188 0 Blue 0
4 PM Mon 48 46 NW 7 6129 6188 0 Blue 0
5 PM Mon 47 45 NW 9 6129 6188 0 Blue 0
6 PM Mon 47 44 NW 9 6129 6188 0 Blue 0
7 PM Mon 47 44 NW 9 6129 6188 0 Blue 0
8 PM Mon 46 43 NW 9 6129 6188 0 Blue 0
9 PM Mon 43 40 NW 9 6129 6188 0 Blue 0
10 PM Mon 41 38 NW 9 6129 6188 0 Blue 0
11 PM Mon 38 35 N 7 6129 6188 0 Blue 0
12 Midnight Tue 38 35 N 7 6129 6188 0 Blue 0
1 AM Tue 38 35 N 7 6129 6188 0 Blue 0
2 AM Tue 37 34 N 7 6129 6188 0 Blue 0
3 AM Tue 35 32 N 7 6129 6188 0 Blue 0
4 AM Tue 33 30 N 7 6129 6188 0 Blue 0
5 AM Tue 32 29 NE 8 6129 6188 0 Blue 0
6 AM Tue 33 30 NE 8 6129 6188 0 Blue 0
7 AM Tue 35 32 NE 8 6129 6188 0 Blue 0
8 AM Tue 38 35 NE 8 6129 6188 0 Blue 0
9 AM Tue 41 39 NE 8 6129 6188 0 Blue 0
10 AM Tue 44 43 NE 8 6129 6188 0 Blue 0
11 AM Tue 47 47 NE 9 6129 6188 0 Blue 0
12 Noon Tue 50 51 NE 9 6129 6188 0 Blue 0
1 PM Tue 52 53 NE 9 6129 6188 0 Blue 0
2 PM Tue 53 54 NE 9 6129 6188 0 Blue 0
3 PM Tue 54 54 NE 9 6129 6188 0 Blue 0
4 PM Tue 55 54 NE 9 6129 6188 0 Blue 0
5 PM Tue 54 52 N 9 6129 6188 0 Blue 0
6 PM Tue 53 50 N 9 6129 6188 0 Blue 0
7 PM Tue 50 47 N 9 6129 6188 0 Blue 0
8 PM Tue 48 45 N 9 6129 6188 0 Blue 0
9 PM Tue 46 43 N 9 6129 6188 0 Blue 0
10 PM Tue 44 41 N 9 6129 6188 0 Blue 0
11 PM Tue 42 39 N 6 6129 6188 0 Blue 0
12 Midnight Wed 42 39 N 6 6129 6188 0 Blue 0
1 AM Wed 41 38 N 6 6129 6188 0 Blue 0
2 AM Wed 41 38 N 6 6129 6188 0 Blue 0
3 AM Wed 40 37 N 6 6129 6188 0 Blue 0
4 AM Wed 38 35 N 6 6129 6188 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