Detailed Predictions for: Sweetwater
Launch Lat, Long, Altitude (f): 38.394, -119.370, 9500
LZ Altitude (f): 7400
Sounding

Station:

KVBG

Date/Time UTC:

250217/1200

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Mon 26 26 WSW 33 49 9130 9500 0 Blue 0
1 AM Mon 22 22 WSW 34 51 9130 9500 0 Blue 0
2 AM Mon 22 22 WSW 34 51 9130 9500 0 Blue 0
3 AM Mon 20 20 WSW 34 51 9130 9500 0 Blue 0
4 AM Mon 19 19 WSW 33 50 9130 9500 0 Blue 0
5 AM Mon 19 19 WSW 33 50 9130 9500 0 Blue 0
6 AM Mon 19 19 WSW 33 50 9130 9500 0 Blue 0
7 AM Mon 18 18 WSW 31 47 9130 9500 0 Blue 0
8 AM Mon 21 21 WSW 31 47 9130 9500 0 Blue 0
9 AM Mon 26 26 WSW 31 47 9130 9500 0 Blue 0
10 AM Mon 28 28 WSW 29 46 9130 9500 0 Blue 0
11 AM Mon 31 32 WSW 29 46 9130 9500 0 Blue 0
12 Noon Mon 31 32 WSW 29 46 9130 9500 0 Blue 0
1 PM Mon 31 31 W 27 41 9130 9500 0 Blue 0
2 PM Mon 31 31 W 27 41 9130 9500 0 Blue 0
3 PM Mon 32 32 W 27 41 9130 9500 0 Blue 0
4 PM Mon 30 30 W 23 34 9130 9500 0 Blue 0
5 PM Mon 28 28 W 23 34 9130 9500 0 Blue 0
6 PM Mon 27 27 W 23 34 9130 9500 0 Blue 0
7 PM Mon 24 24 WNW 17 25 9130 9500 0 Blue 0
8 PM Mon 24 24 WNW 17 25 9130 9500 0 Blue 0
9 PM Mon 22 22 WNW 17 25 9130 9500 0 Blue 0
10 PM Mon 21 21 NW 13 20 9130 9500 0 Blue 0
11 PM Mon 20 20 NW 13 20 9130 9500 0 Blue 0
12 Midnight Tue 19 19 NW 13 20 9130 9500 0 Blue 0
1 AM Tue 18 18 NNW 11 17 9130 9500 0 Blue 0
2 AM Tue 18 18 NNW 11 17 9130 9500 0 Blue 0
3 AM Tue 18 18 NNW 11 17 9130 9500 0 Blue 0
4 AM Tue 15 15 N 11 17 9130 9500 0 Blue 0
5 AM Tue 15 15 N 11 17 9130 9500 0 Blue 0
6 AM Tue 15 15 N 11 17 9130 9500 0 Blue 0
7 AM Tue 15 15 N 13 20 9130 9500 0 Blue 0
8 AM Tue 19 19 N 13 20 9130 9500 0 Blue 0
9 AM Tue 26 27 N 13 20 9130 9500 0 Blue 0
10 AM Tue 29 31 NNW 9 13 9130 9500 0 Blue 0
11 AM Tue 31 34 NNW 9 13 9130 9500 0 Blue 0
12 Noon Tue 33 36 NNW 9 13 9130 9500 0 Blue 0
1 PM Tue 34 36 NW 9 14 9130 9500 0 Blue 0
2 PM Tue 35 37 NW 9 14 9402 9500 0 Blue 0
3 PM Tue 36 37 NW 9 14 9402 9500 0 Blue 0
4 PM Tue 36 36 NW 10 16 9130 9500 0 Blue 0
5 PM Tue 34 34 NW 10 16 9130 9500 0 Blue 0
6 PM Tue 32 32 NW 10 16 9130 9500 0 Blue 0
7 PM Tue 30 30 W 11 17 9130 9500 0 Blue 0
8 PM Tue 29 29 W 11 17 9130 9500 0 Blue 0
9 PM Tue 28 28 W 11 17 9130 9500 0 Blue 0
10 PM Tue 28 28 WSW 12 19 9130 9500 0 Blue 0
11 PM Tue 28 28 WSW 12 19 9130 9500 0 Blue 0
12 Midnight Wed 28 28 WSW 12 19 9130 9500 0 Blue 0
1 AM Wed 28 28 SW 20 32 9130 9500 0 Blue 0
2 AM Wed 27 27 SW 20 32 9130 9500 0 Blue 0
3 AM Wed 26 26 SW 20 32 9130 9500 0 Blue 0
4 AM Wed 25 25 SW 25 42 9130 9500 0 Blue 0
5 AM Wed 25 25 SW 25 42 9130 9500 0 Blue 0
6 AM Wed 26 26 SW 25 42 9130 9500 0 Blue 0
7 AM Wed 27 27 SW 33 57 9130 9500 0 Blue 0
8 AM Wed 29 29 SW 33 57 9130 9500 0 Blue 0
9 AM Wed 32 32 SW 33 57 9130 9500 0 Blue 0
10 AM Wed 34 35 SW 39 66 9130 9500 0 Blue 0
11 AM Wed 35 36 SW 39 66 9130 9500 0 Blue 0
12 Noon Wed 35 36 SW 39 66 9130 9500 0 Blue 0
1 PM Wed 34 35 SW 40 69 9130 9500 0 Blue 0
2 PM Wed 33 34 SW 40 69 9130 9500 0 Blue 0
3 PM Wed 32 32 SW 40 69 9130 9500 0 Blue 0
4 PM Wed 31 31 WSW 35 60 9130 9500 0 Blue 0
5 PM Wed 29 29 WSW 35 60 9130 9500 0 Blue 0
6 PM Wed 28 28 WSW 35 60 9130 9500 0 Blue 0
7 PM Wed 26 26 WSW 28 48 9130 9500 0 Blue 0
8 PM Wed 25 25 WSW 28 48 9130 9500 0 Blue 0
9 PM Wed 24 24 WSW 28 48 9130 9500 0 Blue 0
10 PM Wed 23 23 WSW 21 36 9130 9500 0 Blue 0
11 PM Wed 22 22 WSW 21 36 9130 9500 0 Blue 0
12 Midnight Thu 20 20 WSW 21 36 9130 9500 0 Blue 0
1 AM Thu 19 19 W 13 20 9130 9500 0 Blue 0
2 AM Thu 17 17 W 13 20 9130 9500 0 Blue 0
3 AM Thu 15 15 W 13 20 9130 9500 0 Blue 0
4 AM Thu 14 14 W 14 23 9130 9500 0 Blue 0
5 AM Thu 14 14 W 14 23 9130 9500 0 Blue 0
6 AM Thu 15 15 W 14 23 9130 9500 0 Blue 0
7 AM Thu 17 17 W 10 14 9130 9500 0 Blue 0
8 AM Thu 20 20 W 10 14 9130 9500 0 Blue 0
9 AM Thu 25 26 W 10 14 9130 9500 0 Blue 0
10 AM Thu 28 30 N 10 14 9130 9500 0 Blue 0
11 AM Thu 30 33 N 10 14 9130 9500 0 Blue 0
12 Noon Thu 31 34 N 10 14 9130 9500 0 Blue 0
1 PM Thu 31 34 N 10 14 9130 9500 0 Blue 0
2 PM Thu 31 33 N 10 14 9130 9500 0 Blue 0
3 PM Thu 30 31 N 10 14 9130 9500 0 Blue 0
4 PM Thu 29 29 N 11 16 9130 9500 0 Blue 0
5 PM Thu 27 27 N 11 16 9130 9500 0 Blue 0
6 PM Thu 24 24 N 11 16 9130 9500 0 Blue 0
7 PM Thu 22 22 N 11 16 9130 9500 0 Blue 0
8 PM Thu 20 20 N 11 16 9130 9500 0 Blue 0
9 PM Thu 19 19 N 11 16 9130 9500 0 Blue 0
10 PM Thu 18 18 WSW 11 17 9130 9500 0 Blue 0
11 PM Thu 17 17 WSW 11 17 9130 9500 0 Blue 0
12 Midnight Fri 17 17 WSW 11 17 9130 9500 0 Blue 0
1 AM Fri 17 17 SW 12 18 9130 9500 0 Blue 0
2 AM Fri 17 17 SW 12 18 9130 9500 0 Blue 0
3 AM Fri 15 15 SW 12 18 9130 9500 0 Blue 0
4 AM Fri 15 15 SSW 13 20 9130 9500 0 Blue 0
5 AM Fri 14 14 SSW 13 20 9130 9500 0 Blue 0
6 AM Fri 13 13 SSW 13 20 9130 9500 0 Blue 0
7 AM Fri 14 14 SSW 11 17 9130 9500 0 Blue 0
8 AM Fri 19 19 SSW 11 17 9130 9500 0 Blue 0
9 AM Fri 25 26 SSW 11 17 9130 9500 0 Blue 0
10 AM Fri 30 32 SSE 9 13 9130 9500 0 Blue 0
11 AM Fri 33 36 SSE 9 13 9130 9500 0 Blue 0
12 Noon Fri 34 37 SSE 9 13 9402 9500 0 Blue 0
1 PM Fri 35 38 N 8 12 9731 9500 0 Blue 0
2 PM Fri 36 38 N 8 12 9731 9500 0 Blue 0
3 PM Fri 36 37 N 8 12 9402 9500 0 Blue 0
4 PM Fri 36 36 NW 6 10 9130 9500 0 Blue 0
5 PM Fri 34 34 NW 6 10 9130 9500 0 Blue 0
6 PM Fri 32 32 NW 6 10 9130 9500 0 Blue 0
7 PM Fri 30 30 SW 9 13 9130 9500 0 Blue 0
8 PM Fri 28 28 SW 9 13 9130 9500 0 Blue 0
9 PM Fri 26 26 SW 9 13 9130 9500 0 Blue 0
10 PM Fri 25 25 SW 11 17 9130 9500 0 Blue 0
11 PM Fri 25 25 SW 11 17 9130 9500 0 Blue 0
12 Midnight Sat 25 25 SW 11 17 9130 9500 0 Blue 0
1 AM Sat 25 25 SW 10 16 9130 9500 0 Blue 0
2 AM Sat 25 25 SW 10 16 9130 9500 0 Blue 0
3 AM Sat 24 24 SW 10 16 9130 9500 0 Blue 0
4 AM Sat 24 24 SW 9 13 9130 9500 0 Blue 0
5 AM Sat 24 24 SW 9 13 9130 9500 0 Blue 0
6 AM Sat 24 24 SW 9 13 9130 9500 0 Blue 0
7 AM Sat 25 25 WSW 13 20 9130 9500 0 Blue 0
8 AM Sat 29 29 WSW 13 20 9130 9500 0 Blue 0
9 AM Sat 34 34 WSW 13 20 9130 9500 0 Blue 0
10 AM Sat 38 40 SSW 17 26 10344 9500 0 Blue 1
11 AM Sat 40 42 SSW 17 26 11778 10052 552 Blue 3
12 Noon Sat 41 44 SSW 17 26 13714 10690 1190 Blue 5
1 PM Sat 41 43 WNW 16 23 12802 10335 835 Blue 4
2 PM Sat 41 43 WNW 16 23 12802 10335 835 Blue 4
3 PM Sat 40 41 WNW 16 23 10703 9729 229 Blue 2
4 PM Sat 39 39 W 13 20 10057 9500 0 Blue 0
5 PM Sat 37 37 W 13 20 9402 9500 0 Blue 0
6 PM Sat 34 34 W 13 20 9130 9500 0 Blue 0
7 PM Sat 32 32 SSW 11 17 9130 9500 0 Blue 0
8 PM Sat 31 31 SSW 11 17 9130 9500 0 Blue 0
9 PM Sat 30 30 SSW 11 17 9130 9500 0 Blue 0
10 PM Sat 30 30 SSW 10 14 9130 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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]