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

Station:

KOAK

Date/Time:

25 APR 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 Thu 44 41 SW 1 4967 6188 0 Blue 0
6 AM Thu 45 42 SW 1 4967 6188 0 Blue 0
7 AM Thu 47 44 SW 1 4967 6188 0 Blue 0
8 AM Thu 50 48 S 1 4967 6188 0 Blue 0
9 AM Thu 53 52 S 1 4967 6188 0 Blue 0
10 AM Thu 57 58 S 1 4967 6188 0 Blue 0
11 AM Thu 60 62 S 7 7731 6188 0 Blue 1
12 Noon Thu 63 66 S 7 11433 8591 2403 Blue 5
1 PM Thu 66 70 S 7 13136 11909 5721 Blue 9
2 PM Thu 67 70 SW 8 13136 11909 5721 Blue 9
3 PM Thu 67 69 SW 8 12917 11333 5145 Blue 8
4 PM Thu 66 66 SW 8 11433 8591 2403 Blue 5
5 PM Thu 64 63 SW 13 8651 6188 0 Blue 2
6 PM Thu 61 58 SW 13 4967 6188 0 Blue 0
7 PM Thu 58 55 SW 13 4967 6188 0 Blue 0
8 PM Thu 54 51 SW 13 4967 6188 0 Blue 0
9 PM Thu 52 49 SW 13 4967 6188 0 Blue 0
10 PM Thu 51 48 SW 13 4967 6188 0 Blue 0
11 PM Thu 50 47 SW 5 4967 6188 0 Blue 0
12 Midnight Fri 49 46 SW 5 4967 6188 0 Blue 0
1 AM Fri 48 45 SW 5 4967 6188 0 Blue 0
2 AM Fri 48 45 SW 5 4967 6188 0 Blue 0
3 AM Fri 47 44 SW 5 4967 6188 0 Blue 0
4 AM Fri 46 43 SW 5 4967 6188 0 Blue 0
5 AM Fri 46 43 SW 5 4967 6188 0 Blue 0
6 AM Fri 46 43 SW 5 4967 6188 0 Blue 0
7 AM Fri 48 45 SW 5 4967 6188 0 Blue 0
8 AM Fri 50 47 SW 5 4967 6188 0 Blue 0
9 AM Fri 52 51 SW 5 4967 6188 0 Blue 0
10 AM Fri 54 54 SW 5 4967 6188 0 Blue 0
11 AM Fri 57 57 SW 12 4967 6188 0 Blue 0
12 Noon Fri 60 61 SW 12 6499 6188 0 Blue 0
1 PM Fri 62 63 SW 12 8651 6188 0 Blue 2
2 PM Fri 63 64 SW 13 9393 6475 287 Blue 3
3 PM Fri 63 63 SW 13 8651 6188 0 Blue 2
4 PM Fri 62 61 SW 13 6499 6188 0 Blue 0
5 PM Fri 61 59 W 9 4967 6188 0 Blue 0
6 PM Fri 59 56 W 9 4967 6188 0 Blue 0
7 PM Fri 57 54 W 9 4967 6188 0 Blue 0
8 PM Fri 54 51 W 9 4967 6188 0 Blue 0
9 PM Fri 52 49 W 9 4967 6188 0 Blue 0
10 PM Fri 49 46 W 9 4967 6188 0 Blue 0
11 PM Fri 48 45 N 3 4967 6188 0 Blue 0
12 Midnight Sat 47 44 N 3 4967 6188 0 Blue 0
1 AM Sat 47 44 N 3 4967 6188 0 Blue 0
2 AM Sat 47 44 N 3 4967 6188 0 Blue 0
3 AM Sat 45 42 N 3 4967 6188 0 Blue 0
4 AM Sat 43 40 N 3 4967 6188 0 Blue 0
5 AM Sat 42 39 E 2 4967 6188 0 Blue 0
6 AM Sat 43 40 E 2 4967 6188 0 Blue 0
7 AM Sat 45 42 E 2 4967 6188 0 Blue 0
8 AM Sat 47 45 E 2 4967 6188 0 Blue 0
9 AM Sat 50 49 E 2 4967 6188 0 Blue 0
10 AM Sat 53 54 E 2 4967 6188 0 Blue 0
11 AM Sat 56 59 SW 10 4967 6188 0 Blue 0
12 Noon Sat 59 63 SW 10 8651 6188 0 Blue 2
1 PM Sat 61 65 SW 10 10093 7681 1493 Blue 4
2 PM Sat 62 66 SW 10 11433 8591 2403 Blue 5
3 PM Sat 63 65 SW 10 10093 7681 1493 Blue 4
4 PM Sat 62 63 SW 10 8651 6188 0 Blue 2
5 PM Sat 61 60 SW 14 4967 6188 0 Blue 0
6 PM Sat 58 55 SW 14 4967 6188 0 Blue 0
7 PM Sat 54 51 SW 14 4967 6188 0 Blue 0
8 PM Sat 51 48 SW 14 4967 6188 0 Blue 0
9 PM Sat 48 45 SW 14 4967 6188 0 Blue 0
10 PM Sat 46 43 SW 14 4967 6188 0 Blue 0
11 PM Sat 45 42 E 7 4967 6188 0 Blue 0
12 Midnight Sun 45 42 E 7 4967 6188 0 Blue 0
1 AM Sun 44 41 E 7 4967 6188 0 Blue 0
2 AM Sun 44 41 E 7 4967 6188 0 Blue 0
3 AM Sun 42 39 E 7 4967 6188 0 Blue 0
4 AM Sun 41 38 E 7 4967 6188 0 Blue 0
5 AM Sun 40 37 SW 3 4967 6188 0 Blue 0
6 AM Sun 41 38 SW 3 4967 6188 0 Blue 0
7 AM Sun 43 40 SW 3 4967 6188 0 Blue 0
8 AM Sun 46 44 SW 3 4967 6188 0 Blue 0
9 AM Sun 50 49 SW 3 4967 6188 0 Blue 0
10 AM Sun 54 54 SW 3 4967 6188 0 Blue 0
11 AM Sun 57 59 SW 8 4967 6188 0 Blue 0
12 Noon Sun 58 61 SW 8 6499 6188 0 Blue 0
1 PM Sun 59 62 SW 8 7731 6188 0 Blue 1
2 PM Sun 59 62 SW 8 7731 6188 0 Blue 1
3 PM Sun 60 62 SW 8 7731 6188 0 Blue 1
4 PM Sun 60 60 SW 8 4967 6188 0 Blue 0
5 PM Sun 60 59 SW 10 4967 6188 0 Blue 0
6 PM Sun 58 55 SW 10 4967 6188 0 Blue 0
7 PM Sun 56 53 SW 10 4967 6188 0 Blue 0
8 PM Sun 52 49 SW 10 4967 6188 0 Blue 0
9 PM Sun 50 47 SW 10 4967 6188 0 Blue 0
10 PM Sun 47 44 SW 10 4967 6188 0 Blue 0
11 PM Sun 46 43 W 5 4967 6188 0 Blue 0
12 Midnight Mon 45 42 W 5 4967 6188 0 Blue 0
1 AM Mon 45 42 W 5 4967 6188 0 Blue 0
2 AM Mon 44 41 W 5 4967 6188 0 Blue 0
3 AM Mon 42 39 W 5 4967 6188 0 Blue 0
4 AM Mon 41 38 W 5 4967 6188 0 Blue 0
5 AM Mon 40 37 SE 5 4967 6188 0 Blue 0
6 AM Mon 41 38 SE 5 4967 6188 0 Blue 0
7 AM Mon 43 40 SE 5 4967 6188 0 Blue 0
8 AM Mon 46 43 SE 5 4967 6188 0 Blue 0
9 AM Mon 49 48 SE 5 4967 6188 0 Blue 0
10 AM Mon 52 52 SE 5 4967 6188 0 Blue 0
11 AM Mon 55 55 SW 9 4967 6188 0 Blue 0
12 Noon Mon 57 58 SW 9 4967 6188 0 Blue 0
1 PM Mon 59 60 SW 9 4967 6188 0 Blue 0
2 PM Mon 59 60 SW 9 4967 6188 0 Blue 0
3 PM Mon 59 59 SW 9 4967 6188 0 Blue 0
4 PM Mon 58 57 SW 9 4967 6188 0 Blue 0
5 PM Mon 57 55 W 12 4967 6188 0 Blue 0
6 PM Mon 56 53 W 12 4967 6188 0 Blue 0
7 PM Mon 54 51 W 12 4967 6188 0 Blue 0
8 PM Mon 51 48 W 12 4967 6188 0 Blue 0
9 PM Mon 49 46 W 12 4967 6188 0 Blue 0
10 PM Mon 46 43 W 12 4967 6188 0 Blue 0
11 PM Mon 45 42 SW 6 4967 6188 0 Blue 0
12 Midnight Tue 44 41 SW 6 4967 6188 0 Blue 0
1 AM Tue 44 41 SW 6 4967 6188 0 Blue 0
2 AM Tue 44 41 SW 6 4967 6188 0 Blue 0
3 AM Tue 42 39 SW 6 4967 6188 0 Blue 0
4 AM Tue 40 37 SW 6 4967 6188 0 Blue 0
5 AM Tue 39 36 W 8 4967 6188 0 Blue 0
6 AM Tue 40 37 W 8 4967 6188 0 Blue 0
7 AM Tue 42 39 W 8 4967 6188 0 Blue 0
8 AM Tue 44 41 W 8 4967 6188 0 Blue 0
9 AM Tue 45 43 W 8 4967 6188 0 Blue 0
10 AM Tue 45 43 W 8 4967 6188 0 Blue 0
11 AM Tue 46 45 NE 13 4967 6188 0 Blue 0
12 Noon Tue 48 47 NE 13 4967 6188 0 Blue 0
1 PM Tue 49 48 NE 13 4967 6188 0 Blue 0
2 PM Tue 50 49 NE 13 4967 6188 0 Blue 0
3 PM Tue 50 48 NE 13 4967 6188 0 Blue 0
4 PM Tue 49 47 NE 13 4967 6188 0 Blue 0
5 PM Tue 47 45 NE 12 4967 6188 0 Blue 0
6 PM Tue 46 43 NE 12 4967 6188 0 Blue 0
7 PM Tue 45 42 NE 12 4967 6188 0 Blue 0
8 PM Tue 43 40 NE 12 4967 6188 0 Blue 0
9 PM Tue 42 39 NE 12 4967 6188 0 Blue 0
10 PM Tue 40 37 NE 12 4967 6188 0 Blue 0
11 PM Tue 39 36 N 6 4967 6188 0 Blue 0
12 Midnight Wed 39 36 N 6 4967 6188 0 Blue 0
1 AM Wed 39 36 N 6 4967 6188 0 Blue 0
2 AM Wed 39 36 N 6 4967 6188 0 Blue 0
3 AM Wed 38 35 N 6 4967 6188 0 Blue 0
4 AM Wed 36 33 N 6 4967 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