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

Station:

KVBG

Date/Time:

16 DEC 2017

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 27 27 N 21 8963 9500 0 Blue 0
5 AM Sat 26 26 N 21 8963 9500 0 Blue 0
6 AM Sat 25 25 N 21 8963 9500 0 Blue 0
7 AM Sat 26 26 N 24 8963 9500 0 Blue 0
8 AM Sat 24 24 N 24 8963 9500 0 Blue 0
9 AM Sat 24 24 N 24 8963 9500 0 Blue 0
10 AM Sat 26 27 N 30 8963 9500 0 Blue 0
11 AM Sat 27 28 N 30 8963 9500 0 Blue 0
12 Noon Sat 27 28 N 30 8963 9500 0 Blue 0
1 PM Sat 27 28 N 30 8963 9500 0 Blue 0
2 PM Sat 27 28 N 30 8963 9500 0 Blue 0
3 PM Sat 26 26 N 30 8963 9500 0 Blue 0
4 PM Sat 26 26 N 24 8963 9500 0 Blue 0
5 PM Sat 25 25 N 24 8963 9500 0 Blue 0
6 PM Sat 24 24 N 24 8963 9500 0 Blue 0
7 PM Sat 23 23 N 24 8963 9500 0 Blue 0
8 PM Sat 23 23 N 24 8963 9500 0 Blue 0
9 PM Sat 23 23 N 24 8963 9500 0 Blue 0
10 PM Sat 24 24 NE 38 8963 9500 0 Blue 0
11 PM Sat 24 24 NE 38 8963 9500 0 Blue 0
12 Midnight Sun 24 24 NE 38 8963 9500 0 Blue 0
1 AM Sun 24 24 NE 38 8963 9500 0 Blue 0
2 AM Sun 25 25 NE 38 8963 9500 0 Blue 0
3 AM Sun 25 25 NE 38 8963 9500 0 Blue 0
4 AM Sun 25 25 NE 32 8963 9500 0 Blue 0
5 AM Sun 25 25 NE 32 8963 9500 0 Blue 0
6 AM Sun 25 25 NE 32 8963 9500 0 Blue 0
7 AM Sun 25 25 NE 32 8963 9500 0 Blue 0
8 AM Sun 26 26 NE 32 8963 9500 0 Blue 0
9 AM Sun 27 27 NE 32 8963 9500 0 Blue 0
10 AM Sun 29 30 NE 30 8963 9500 0 Blue 0
11 AM Sun 30 31 NE 30 8963 9500 0 Blue 0
12 Noon Sun 30 31 NE 30 8963 9500 0 Blue 0
1 PM Sun 30 31 NE 30 8963 9500 0 Blue 0
2 PM Sun 30 31 NE 30 8963 9500 0 Blue 0
3 PM Sun 30 30 NE 30 8963 9500 0 Blue 0
4 PM Sun 29 29 NE 21 8963 9500 0 Blue 0
5 PM Sun 29 29 NE 21 8963 9500 0 Blue 0
6 PM Sun 28 28 NE 21 8963 9500 0 Blue 0
7 PM Sun 28 28 NE 21 8963 9500 0 Blue 0
8 PM Sun 28 28 NE 21 8963 9500 0 Blue 0
9 PM Sun 28 28 NE 21 8963 9500 0 Blue 0
10 PM Sun 29 29 N 12 8963 9500 0 Blue 0
11 PM Sun 29 29 N 12 8963 9500 0 Blue 0
12 Midnight Mon 29 29 N 12 8963 9500 0 Blue 0
1 AM Mon 29 29 N 12 8963 9500 0 Blue 0
2 AM Mon 29 29 N 12 8963 9500 0 Blue 0
3 AM Mon 29 29 N 12 8963 9500 0 Blue 0
4 AM Mon 29 29 N 13 8963 9500 0 Blue 0
5 AM Mon 29 29 N 13 8963 9500 0 Blue 0
6 AM Mon 29 29 N 13 8963 9500 0 Blue 0
7 AM Mon 30 30 N 13 8963 9500 0 Blue 0
8 AM Mon 32 32 N 13 8963 9500 0 Blue 0
9 AM Mon 35 35 N 13 8983 9500 0 Blue 0
10 AM Mon 38 39 NW 8 16270 12680 3180 Blue 4
11 AM Mon 40 41 NW 8 17416 15710 6210 Blue 6
12 Noon Mon 41 42 NW 8 18503 16167 6667 Blue 7
1 PM Mon 41 42 NW 8 18503 16167 6667 Blue 7
2 PM Mon 41 41 NW 8 17416 15710 6210 Blue 6
3 PM Mon 39 39 NW 8 16270 12680 3180 Blue 4
4 PM Mon 37 37 NW 6 15060 9500 0 Blue 2
5 PM Mon 34 34 NW 6 8963 9500 0 Blue 0
6 PM Mon 32 32 NW 6 8963 9500 0 Blue 0
7 PM Mon 30 30 NW 6 8963 9500 0 Blue 0
8 PM Mon 30 30 NW 6 8963 9500 0 Blue 0
9 PM Mon 31 31 NW 6 8963 9500 0 Blue 0
10 PM Mon 32 32 E 6 8963 9500 0 Blue 0
11 PM Mon 32 32 E 6 8963 9500 0 Blue 0
12 Midnight Tue 31 31 E 6 8963 9500 0 Blue 0
1 AM Tue 31 31 E 6 8963 9500 0 Blue 0
2 AM Tue 31 31 E 6 8963 9500 0 Blue 0
3 AM Tue 30 30 E 6 8963 9500 0 Blue 0
4 AM Tue 30 30 SW 7 8963 9500 0 Blue 0
5 AM Tue 29 29 SW 7 8963 9500 0 Blue 0
6 AM Tue 29 29 SW 7 8963 9500 0 Blue 0
7 AM Tue 30 30 SW 7 8963 9500 0 Blue 0
8 AM Tue 33 33 SW 7 8963 9500 0 Blue 0
9 AM Tue 37 37 SW 7 15060 9500 0 Blue 2
10 AM Tue 40 40 SW 17 16721 14772 5272 Blue 5
11 AM Tue 42 43 SW 17 18958 16613 7113 Blue 8
12 Noon Tue 43 44 SW 17 19402 17068 7568 Blue 9
1 PM Tue 43 44 SW 17 19402 17068 7568 Blue 9
2 PM Tue 42 42 SW 17 18503 16167 6667 Blue 7
3 PM Tue 40 40 SW 17 16721 14772 5272 Blue 5
4 PM Tue 38 38 SW 17 15808 9500 0 Blue 3
5 PM Tue 35 35 SW 17 8983 9500 0 Blue 0
6 PM Tue 32 32 SW 17 8963 9500 0 Blue 0
7 PM Tue 30 30 SW 17 8963 9500 0 Blue 0
8 PM Tue 30 30 SW 17 8963 9500 0 Blue 0
9 PM Tue 30 30 SW 17 8963 9500 0 Blue 0
10 PM Tue 30 30 SW 46 8963 9500 0 Blue 0
11 PM Tue 31 31 SW 46 8963 9500 0 Blue 0
12 Midnight Wed 31 31 SW 46 8963 9500 0 Blue 0
1 AM Wed 30 30 SW 46 8963 9500 0 Blue 0
2 AM Wed 30 30 SW 46 8963 9500 0 Blue 0
3 AM Wed 29 29 SW 46 8963 9500 0 Blue 0
4 AM Wed 28 28 W 49 8963 9500 0 Blue 0
5 AM Wed 28 28 W 49 8963 9500 0 Blue 0
6 AM Wed 29 29 W 49 8963 9500 0 Blue 0
7 AM Wed 30 30 W 49 8963 9500 0 Blue 0
8 AM Wed 32 32 W 49 8963 9500 0 Blue 0
9 AM Wed 33 33 W 49 8963 9500 0 Blue 0
10 AM Wed 34 34 W 55 8963 9500 0 Blue 0
11 AM Wed 36 37 W 55 15060 9500 0 Blue 2
12 Noon Wed 36 37 W 55 15060 9500 0 Blue 2
1 PM Wed 35 36 W 55 13002 9500 0 Blue 1
2 PM Wed 33 33 W 55 8963 9500 0 Blue 0
3 PM Wed 30 30 W 55 8963 9500 0 Blue 0
4 PM Wed 27 27 NW 39 8963 9500 0 Blue 0
5 PM Wed 24 24 NW 39 8963 9500 0 Blue 0
6 PM Wed 23 23 NW 39 8963 9500 0 Blue 0
7 PM Wed 22 22 NW 39 8963 9500 0 Blue 0
8 PM Wed 21 21 NW 39 8963 9500 0 Blue 0
9 PM Wed 21 21 NW 39 8963 9500 0 Blue 0
10 PM Wed 21 21 NE 23 8963 9500 0 Blue 0
11 PM Wed 21 21 NE 23 8963 9500 0 Blue 0
12 Midnight Thu 22 22 NE 23 8963 9500 0 Blue 0
1 AM Thu 22 22 NE 23 8963 9500 0 Blue 0
2 AM Thu 22 22 NE 23 8963 9500 0 Blue 0
3 AM Thu 21 21 NE 23 8963 9500 0 Blue 0
4 AM Thu 21 21 NE 36 8963 9500 0 Blue 0
5 AM Thu 20 20 NE 36 8963 9500 0 Blue 0
6 AM Thu 19 19 NE 36 8963 9500 0 Blue 0
7 AM Thu 19 19 NE 36 8963 9500 0 Blue 0
8 AM Thu 21 21 NE 36 8963 9500 0 Blue 0
9 AM Thu 23 23 NE 36 8963 9500 0 Blue 0
10 AM Thu 25 26 N 37 8963 9500 0 Blue 0
11 AM Thu 26 27 N 37 8963 9500 0 Blue 0
12 Noon Thu 26 27 N 37 8963 9500 0 Blue 0
1 PM Thu 26 27 N 37 8963 9500 0 Blue 0
2 PM Thu 27 28 N 37 8963 9500 0 Blue 0
3 PM Thu 27 27 N 37 8963 9500 0 Blue 0
4 PM Thu 26 26 NE 21 8963 9500 0 Blue 0
5 PM Thu 24 24 NE 21 8963 9500 0 Blue 0
6 PM Thu 21 21 NE 21 8963 9500 0 Blue 0
7 PM Thu 19 19 NE 21 8963 9500 0 Blue 0
8 PM Thu 19 19 NE 21 8963 9500 0 Blue 0
9 PM Thu 21 21 NE 21 8963 9500 0 Blue 0
10 PM Thu 22 22 NE 24 8963 9500 0 Blue 0
11 PM Thu 22 22 NE 24 8963 9500 0 Blue 0
12 Midnight Fri 20 20 NE 24 8963 9500 0 Blue 0
1 AM Fri 20 20 NE 24 8963 9500 0 Blue 0
2 AM Fri 21 21 NE 24 8963 9500 0 Blue 0
3 AM Fri 23 23 NE 24 8963 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