Detailed Predictions for: Sweetwater
Launch Altitude (f): 9500
LZ Altitude (f): 7400
Sounding

Station:

KVBG

Date/Time:

2 DEC 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 25 25 S 2 5394 9500 0 Blue 0
5 AM Wed 25 25 S 2 5394 9500 0 Blue 0
6 AM Wed 25 25 S 2 5394 9500 0 Blue 0
7 AM Wed 25 25 NE 5 5394 9500 0 Blue 0
8 AM Wed 29 29 NE 5 5394 9500 0 Blue 0
9 AM Wed 34 34 NE 5 5394 9500 0 Blue 0
10 AM Wed 37 38 SW 5 5394 9500 0 Blue 0
11 AM Wed 39 41 SW 5 6578 9500 0 Blue 0
12 Noon Wed 40 42 SW 5 6985 9500 0 Blue 0
1 PM Wed 40 41 NW 3 6578 9500 0 Blue 0
2 PM Wed 40 41 NW 3 6578 9500 0 Blue 0
3 PM Wed 38 38 NW 3 5394 9500 0 Blue 0
4 PM Wed 34 34 E 7 5394 9500 0 Blue 0
5 PM Wed 31 31 E 7 5394 9500 0 Blue 0
6 PM Wed 27 27 E 7 5394 9500 0 Blue 0
7 PM Wed 25 25 SE 9 5394 9500 0 Blue 0
8 PM Wed 24 24 SE 9 5394 9500 0 Blue 0
9 PM Wed 23 23 SE 9 5394 9500 0 Blue 0
10 PM Wed 23 23 SE 12 5394 9500 0 Blue 0
11 PM Wed 24 24 SE 12 5394 9500 0 Blue 0
12 Midnight Thu 23 23 SE 12 5394 9500 0 Blue 0
1 AM Thu 22 22 SE 6 5394 9500 0 Blue 0
2 AM Thu 22 22 SE 6 5394 9500 0 Blue 0
3 AM Thu 21 21 SE 6 5394 9500 0 Blue 0
4 AM Thu 22 22 SE 7 5394 9500 0 Blue 0
5 AM Thu 22 22 SE 7 5394 9500 0 Blue 0
6 AM Thu 22 22 SE 7 5394 9500 0 Blue 0
7 AM Thu 22 22 S 6 5394 9500 0 Blue 0
8 AM Thu 25 25 S 6 5394 9500 0 Blue 0
9 AM Thu 31 31 S 6 5394 9500 0 Blue 0
10 AM Thu 33 34 S 5 5394 9500 0 Blue 0
11 AM Thu 34 35 S 5 5394 9500 0 Blue 0
12 Noon Thu 36 37 S 5 5394 9500 0 Blue 0
1 PM Thu 36 37 E 8 5394 9500 0 Blue 0
2 PM Thu 35 36 E 8 5394 9500 0 Blue 0
3 PM Thu 33 33 E 8 5394 9500 0 Blue 0
4 PM Thu 30 30 NE 8 5394 9500 0 Blue 0
5 PM Thu 27 27 NE 8 5394 9500 0 Blue 0
6 PM Thu 24 24 NE 8 5394 9500 0 Blue 0
7 PM Thu 22 22 S 6 5394 9500 0 Blue 0
8 PM Thu 21 21 S 6 5394 9500 0 Blue 0
9 PM Thu 20 20 S 6 5394 9500 0 Blue 0
10 PM Thu 20 20 S 6 5394 9500 0 Blue 0
11 PM Thu 20 20 S 6 5394 9500 0 Blue 0
12 Midnight Fri 20 20 S 6 5394 9500 0 Blue 0
1 AM Fri 20 20 S 7 5394 9500 0 Blue 0
2 AM Fri 20 20 S 7 5394 9500 0 Blue 0
3 AM Fri 20 20 S 7 5394 9500 0 Blue 0
4 AM Fri 19 19 S 6 5394 9500 0 Blue 0
5 AM Fri 18 18 S 6 5394 9500 0 Blue 0
6 AM Fri 17 17 S 6 5394 9500 0 Blue 0
7 AM Fri 18 18 S 6 5394 9500 0 Blue 0
8 AM Fri 22 22 S 6 5394 9500 0 Blue 0
9 AM Fri 26 26 S 6 5394 9500 0 Blue 0
10 AM Fri 31 32 E 7 5394 9500 0 Blue 0
11 AM Fri 35 37 E 7 5394 9500 0 Blue 0
12 Noon Fri 37 39 E 7 5745 9500 0 Blue 0
1 PM Fri 38 40 E 8 6164 9500 0 Blue 0
2 PM Fri 37 38 E 8 5394 9500 0 Blue 0
3 PM Fri 35 35 E 8 5394 9500 0 Blue 0
4 PM Fri 33 33 NE 8 5394 9500 0 Blue 0
5 PM Fri 30 30 NE 8 5394 9500 0 Blue 0
6 PM Fri 27 27 NE 8 5394 9500 0 Blue 0
7 PM Fri 24 24 E 8 5394 9500 0 Blue 0
8 PM Fri 23 23 E 8 5394 9500 0 Blue 0
9 PM Fri 22 22 E 8 5394 9500 0 Blue 0
10 PM Fri 22 22 SE 8 5394 9500 0 Blue 0
11 PM Fri 22 22 SE 8 5394 9500 0 Blue 0
12 Midnight Sat 21 21 SE 8 5394 9500 0 Blue 0
1 AM Sat 22 22 S 9 5394 9500 0 Blue 0
2 AM Sat 22 22 S 9 5394 9500 0 Blue 0
3 AM Sat 22 22 S 9 5394 9500 0 Blue 0
4 AM Sat 22 22 S 7 5394 9500 0 Blue 0
5 AM Sat 20 20 S 7 5394 9500 0 Blue 0
6 AM Sat 19 19 S 7 5394 9500 0 Blue 0
7 AM Sat 20 20 S 6 5394 9500 0 Blue 0
8 AM Sat 24 24 S 6 5394 9500 0 Blue 0
9 AM Sat 29 29 S 6 5394 9500 0 Blue 0
10 AM Sat 34 35 SW 6 5394 9500 0 Blue 0
11 AM Sat 37 39 SW 6 5745 9500 0 Blue 0
12 Noon Sat 39 41 SW 6 6578 9500 0 Blue 0
1 PM Sat 40 41 N 6 6578 9500 0 Blue 0
2 PM Sat 39 40 N 6 6164 9500 0 Blue 0
3 PM Sat 37 37 N 6 5394 9500 0 Blue 0
4 PM Sat 34 34 N 6 5394 9500 0 Blue 0
5 PM Sat 31 31 N 6 5394 9500 0 Blue 0
6 PM Sat 28 28 N 6 5394 9500 0 Blue 0
7 PM Sat 26 26 SW 6 5394 9500 0 Blue 0
8 PM Sat 24 24 SW 6 5394 9500 0 Blue 0
9 PM Sat 24 24 SW 6 5394 9500 0 Blue 0
10 PM Sat 24 24 SW 7 5394 9500 0 Blue 0
11 PM Sat 24 24 SW 7 5394 9500 0 Blue 0
12 Midnight Sun 24 24 SW 7 5394 9500 0 Blue 0
1 AM Sun 23 23 W 7 5394 9500 0 Blue 0
2 AM Sun 23 23 W 7 5394 9500 0 Blue 0
3 AM Sun 23 23 W 7 5394 9500 0 Blue 0
4 AM Sun 22 22 W 6 5394 9500 0 Blue 0
5 AM Sun 22 22 W 6 5394 9500 0 Blue 0
6 AM Sun 22 22 W 6 5394 9500 0 Blue 0
7 AM Sun 23 23 SW 7 5394 9500 0 Blue 0
8 AM Sun 27 27 SW 7 5394 9500 0 Blue 0
9 AM Sun 32 32 SW 7 5394 9500 0 Blue 0
10 AM Sun 36 37 W 7 5394 9500 0 Blue 0
11 AM Sun 39 41 W 7 6578 9500 0 Blue 0
12 Noon Sun 40 42 W 7 6985 9500 0 Blue 0
1 PM Sun 40 42 N 9 6985 9500 0 Blue 0
2 PM Sun 38 39 N 9 5745 9500 0 Blue 0
3 PM Sun 37 37 N 9 5394 9500 0 Blue 0
4 PM Sun 34 34 NE 9 5394 9500 0 Blue 0
5 PM Sun 31 31 NE 9 5394 9500 0 Blue 0
6 PM Sun 28 28 NE 9 5394 9500 0 Blue 0
7 PM Sun 25 25 NE 6 5394 9500 0 Blue 0
8 PM Sun 23 23 NE 6 5394 9500 0 Blue 0
9 PM Sun 22 22 NE 6 5394 9500 0 Blue 0
10 PM Sun 21 21 NE 6 5394 9500 0 Blue 0
11 PM Sun 21 21 NE 6 5394 9500 0 Blue 0
12 Midnight Mon 21 21 NE 6 5394 9500 0 Blue 0
1 AM Mon 21 21 NE 7 5394 9500 0 Blue 0
2 AM Mon 22 22 NE 7 5394 9500 0 Blue 0
3 AM Mon 22 22 NE 7 5394 9500 0 Blue 0
4 AM Mon 21 21 N 7 5394 9500 0 Blue 0
5 AM Mon 21 21 N 7 5394 9500 0 Blue 0
6 AM Mon 20 20 N 7 5394 9500 0 Blue 0
7 AM Mon 21 21 NE 7 5394 9500 0 Blue 0
8 AM Mon 23 23 NE 7 5394 9500 0 Blue 0
9 AM Mon 27 27 NE 7 5394 9500 0 Blue 0
10 AM Mon 30 31 NE 7 5394 9500 0 Blue 0
11 AM Mon 33 35 NE 7 5394 9500 0 Blue 0
12 Noon Mon 34 36 NE 7 5394 9500 0 Blue 0
1 PM Mon 35 36 NE 10 5394 9500 0 Blue 0
2 PM Mon 35 36 NE 10 5394 9500 0 Blue 0
3 PM Mon 33 33 NE 10 5394 9500 0 Blue 0
4 PM Mon 31 31 NE 9 5394 9500 0 Blue 0
5 PM Mon 28 28 NE 9 5394 9500 0 Blue 0
6 PM Mon 26 26 NE 9 5394 9500 0 Blue 0
7 PM Mon 24 24 E 7 5394 9500 0 Blue 0
8 PM Mon 23 23 E 7 5394 9500 0 Blue 0
9 PM Mon 22 22 E 7 5394 9500 0 Blue 0
10 PM Mon 22 22 S 7 5394 9500 0 Blue 0
11 PM Mon 22 22 S 7 5394 9500 0 Blue 0
12 Midnight Tue 22 22 S 7 5394 9500 0 Blue 0
1 AM Tue 22 22 S 7 5394 9500 0 Blue 0
2 AM Tue 22 22 S 7 5394 9500 0 Blue 0
3 AM Tue 22 22 S 7 5394 9500 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