Detailed Predictions for: Mammoth
Launch Altitude (f): 10973
LZ Altitude (f): 7850
Sounding

Station:

KVBG

Date/Time:

20 AUG 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 Tue 51 51 S 7 7584 10973 0 Blue 0
6 AM Tue 54 54 S 7 8703 10973 0 Blue 0
7 AM Tue 56 56 S 7 9428 10973 0 Blue 0
8 AM Tue 58 58 SW 7 10139 10973 0 Blue 0
9 AM Tue 61 63 SW 7 14871 12018 1045 Blue 4
10 AM Tue 64 68 SW 7 18328 16224 5251 Blue 9
11 AM Tue 67 73 SW 9 21776 19320 8347 Blue 14
12 Noon Tue 69 76 SW 9 23608 21513 10540 Blue 17
1 PM Tue 72 80 SW 9 26172 23898 12925 Blue 21
2 PM Tue 74 81 SW 10 26685 24433 13460 White 22
3 PM Tue 74 80 SW 10 26172 23898 12925 Blue 21
4 PM Tue 73 77 SW 10 24165 22154 11181 Blue 18
5 PM Tue 70 72 SW 12 21095 18752 7779 Blue 13
6 PM Tue 67 68 SW 12 18328 16224 5251 Blue 9
7 PM Tue 63 63 SW 12 14871 12018 1045 Blue 4
8 PM Tue 60 60 SW 10 12094 10973 0 Blue 1
9 PM Tue 59 59 SW 10 10903 10973 0 Blue 0
10 PM Tue 58 58 SW 10 10139 10973 0 Blue 0
11 PM Tue 57 57 N 9 9786 10973 0 Blue 0
12 Midnight Wed 56 56 N 9 9428 10973 0 Blue 0
1 AM Wed 54 54 N 9 8703 10973 0 Blue 0
2 AM Wed 52 52 N 7 7961 10973 0 Blue 0
3 AM Wed 50 50 N 7 7202 10973 0 Blue 0
4 AM Wed 49 49 N 7 6816 10973 0 Blue 0
5 AM Wed 49 49 N 6 6816 10973 0 Blue 0
6 AM Wed 51 51 N 6 7584 10973 0 Blue 0
7 AM Wed 54 54 N 6 8703 10973 0 Blue 0
8 AM Wed 56 56 NE 6 9428 10973 0 Blue 0
9 AM Wed 59 61 NE 6 13120 10973 0 Blue 2
10 AM Wed 61 64 NE 6 15646 13022 2049 Blue 5
11 AM Wed 64 69 SW 7 18923 16902 5929 Blue 10
12 Noon Wed 66 73 SW 7 21776 19320 8347 Blue 14
1 PM Wed 69 76 SW 7 23608 21513 10540 Blue 17
2 PM Wed 70 77 SW 9 24165 22154 11181 Blue 18
3 PM Wed 70 76 SW 9 23608 21513 10540 Blue 17
4 PM Wed 68 72 SW 9 21095 18752 7779 Blue 13
5 PM Wed 66 68 SW 13 18328 16224 5251 Blue 9
6 PM Wed 64 65 SW 13 16371 13921 2948 Blue 6
7 PM Wed 62 62 SW 13 14035 10973 0 Blue 3
8 PM Wed 60 60 SW 10 12094 10973 0 Blue 1
9 PM Wed 58 58 SW 10 10139 10973 0 Blue 0
10 PM Wed 57 57 SW 10 9786 10973 0 Blue 0
11 PM Wed 56 56 SW 8 9428 10973 0 Blue 0
12 Midnight Thu 56 56 SW 8 9428 10973 0 Blue 0
1 AM Thu 55 55 SW 8 9067 10973 0 Blue 0
2 AM Thu 55 55 E 8 9067 10973 0 Blue 0
3 AM Thu 54 54 E 8 8703 10973 0 Blue 0
4 AM Thu 53 53 E 8 8334 10973 0 Blue 0
5 AM Thu 52 52 S 7 7961 10973 0 Blue 0
6 AM Thu 53 53 S 7 8334 10973 0 Blue 0
7 AM Thu 56 56 S 7 9428 10973 0 Blue 0
8 AM Thu 58 58 W 7 10139 10973 0 Blue 0
9 AM Thu 60 62 W 7 14035 10973 0 Blue 3
10 AM Thu 63 66 W 7 17056 14744 3771 Blue 7
11 AM Thu 65 70 SW 8 19579 17546 6573 Blue 11
12 Noon Thu 68 74 SW 8 22418 20106 9133 Blue 15
1 PM Thu 70 77 SW 8 24165 22154 11181 Blue 18
2 PM Thu 72 78 SW 8 24700 22762 11789 Blue 19
3 PM Thu 72 77 SW 8 24165 22154 11181 Blue 18
4 PM Thu 71 75 SW 8 23027 20834 9861 Blue 16
5 PM Thu 68 70 NW 9 19579 17546 6573 Blue 11
6 PM Thu 65 66 NW 9 17056 14744 3771 Blue 7
7 PM Thu 61 61 NW 9 13120 10973 0 Blue 2
8 PM Thu 58 58 NW 9 10139 10973 0 Blue 0
9 PM Thu 57 57 NW 9 9786 10973 0 Blue 0
10 PM Thu 57 57 NW 9 9786 10973 0 Blue 0
11 PM Thu 57 57 NE 7 9786 10973 0 Blue 0
12 Midnight Fri 56 56 NE 7 9428 10973 0 Blue 0
1 AM Fri 55 55 NE 7 9067 10973 0 Blue 0
2 AM Fri 54 54 NE 7 8703 10973 0 Blue 0
3 AM Fri 53 53 NE 7 8334 10973 0 Blue 0
4 AM Fri 53 53 NE 7 8334 10973 0 Blue 0
5 AM Fri 53 53 E 7 8334 10973 0 Blue 0
6 AM Fri 53 53 E 7 8334 10973 0 Blue 0
7 AM Fri 54 54 E 7 8703 10973 0 Blue 0
8 AM Fri 56 56 E 7 9428 10973 0 Blue 0
9 AM Fri 59 61 E 7 13120 10973 0 Blue 2
10 AM Fri 63 66 E 7 17056 14744 3771 Blue 7
11 AM Fri 66 72 SE 14 21095 18752 7779 Blue 13
12 Noon Fri 68 75 SE 14 23027 20834 9861 Blue 16
1 PM Fri 68 75 SE 14 23027 20834 9861 Blue 16
2 PM Fri 69 76 SE 14 23608 21513 10540 Blue 17
3 PM Fri 70 76 SE 14 23608 21513 10540 Blue 17
4 PM Fri 70 74 SE 14 22418 20106 9133 Blue 15
5 PM Fri 69 71 SW 13 20367 18161 7188 Blue 12
6 PM Fri 65 65 SW 13 16371 13921 2948 Blue 6
7 PM Fri 60 60 SW 13 12094 10973 0 Blue 1
8 PM Fri 56 56 SW 13 9428 10973 0 Blue 0
9 PM Fri 54 54 SW 13 8703 10973 0 Blue 0
10 PM Fri 55 55 SW 13 9067 10973 0 Blue 0
11 PM Fri 56 56 S 8 9428 10973 0 Blue 0
12 Midnight Sat 55 55 S 8 9067 10973 0 Blue 0
1 AM Sat 54 54 S 8 8703 10973 0 Blue 0
2 AM Sat 53 53 S 8 8334 10973 0 Blue 0
3 AM Sat 52 52 S 8 7961 10973 0 Blue 0
4 AM Sat 51 51 S 8 7584 10973 0 Blue 0
5 AM Sat 51 51 SE 6 7584 10973 0 Blue 0
6 AM Sat 52 52 SE 6 7961 10973 0 Blue 0
7 AM Sat 53 53 SE 6 8334 10973 0 Blue 0
8 AM Sat 55 55 SE 6 9067 10973 0 Blue 0
9 AM Sat 59 61 SE 6 13120 10973 0 Blue 2
10 AM Sat 63 67 SE 6 17706 15508 4535 Blue 8
11 AM Sat 66 72 SW 13 21095 18752 7779 Blue 13
12 Noon Sat 67 74 SW 13 22418 20106 9133 Blue 15
1 PM Sat 68 76 SW 13 23608 21513 10540 Blue 17
2 PM Sat 69 76 SW 13 23608 21513 10540 Blue 17
3 PM Sat 69 75 SW 13 23027 20834 9861 Blue 16
4 PM Sat 69 73 SW 13 21776 19320 8347 Blue 14
5 PM Sat 67 69 SW 13 18923 16902 5929 Blue 10
6 PM Sat 64 65 SW 13 16371 13921 2948 Blue 6
7 PM Sat 61 61 SW 13 13120 10973 0 Blue 2
8 PM Sat 58 58 SW 13 10139 10973 0 Blue 0
9 PM Sat 57 57 SW 13 9786 10973 0 Blue 0
10 PM Sat 56 56 SW 13 9428 10973 0 Blue 0
11 PM Sat 57 57 S 8 9786 10973 0 Blue 0
12 Midnight Sun 57 57 S 8 9786 10973 0 Blue 0
1 AM Sun 56 56 S 8 9428 10973 0 Blue 0
2 AM Sun 55 55 S 8 9067 10973 0 Blue 0
3 AM Sun 54 54 S 8 8703 10973 0 Blue 0
4 AM Sun 53 53 S 8 8334 10973 0 Blue 0
5 AM Sun 53 53 SW 6 8334 10973 0 Blue 0
6 AM Sun 54 54 SW 6 8703 10973 0 Blue 0
7 AM Sun 56 56 SW 6 9428 10973 0 Blue 0
8 AM Sun 58 58 SW 6 10139 10973 0 Blue 0
9 AM Sun 60 62 SW 6 14035 10973 0 Blue 3
10 AM Sun 61 65 SW 6 16371 13921 2948 Blue 6
11 AM Sun 63 69 SW 12 18923 16902 5929 Blue 10
12 Noon Sun 65 72 SW 12 21095 18752 7779 Blue 13
1 PM Sun 66 74 SW 12 22418 20106 9133 Blue 15
2 PM Sun 68 75 SW 12 23027 20834 9861 Blue 16
3 PM Sun 68 74 SW 12 22418 20106 9133 Blue 15
4 PM Sun 68 72 SW 12 21095 18752 7779 Blue 13
5 PM Sun 66 68 SW 12 18328 16224 5251 Blue 9
6 PM Sun 64 64 SW 12 15646 13022 2049 Blue 5
7 PM Sun 62 62 SW 12 14035 10973 0 Blue 3
8 PM Sun 59 59 SW 12 10903 10973 0 Blue 0
9 PM Sun 57 57 SW 12 9786 10973 0 Blue 0
10 PM Sun 56 56 SW 12 9428 10973 0 Blue 0
11 PM Sun 56 56 SW 9 9428 10973 0 Blue 0
12 Midnight Mon 57 57 SW 9 9786 10973 0 Blue 0
1 AM Mon 57 57 SW 9 9786 10973 0 Blue 0
2 AM Mon 57 57 SW 9 9786 10973 0 Blue 0
3 AM Mon 55 55 SW 9 9067 10973 0 Blue 0
4 AM Mon 52 52 SW 9 7961 10973 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