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

Station:

 KVBG

Date/Time:

 25 APR 2024

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 Thu 30 30 NW 9 13 9019 9500 0 Blue 0
1 AM Thu 31 31 NW 9 13 9019 9500 0 Blue 0
2 AM Thu 30 30 NW 10 14 9019 9500 0 Blue 0
3 AM Thu 29 29 NW 10 14 9019 9500 0 Blue 0
4 AM Thu 28 28 NW 10 14 9019 9500 0 Blue 0
5 AM Thu 27 27 NW 8 11 9019 9500 0 Blue 0
6 AM Thu 28 28 NW 8 11 9019 9500 0 Blue 0
7 AM Thu 29 29 NW 8 11 9019 9500 0 Blue 0
8 AM Thu 33 34 W 9 13 9645 9500 0 Blue 0
9 AM Thu 38 40 W 9 13 12843 11048 1548 Blue 5
10 AM Thu 41 45 W 9 13 16175 14249 4749 Blue 10
11 AM Thu 42 46 W 13 20 16567 14876 5376 Blue 11
12 Noon Thu 43 48 W 13 20 17235 16049 6549 Blue 13
1 PM Thu 44 49 W 13 20 17564 16487 6987 Blue 14
2 PM Thu 42 46 W 18 27 16567 14876 5376 Blue 11
3 PM Thu 42 45 W 18 27 16175 14249 4749 Blue 10
4 PM Thu 41 43 W 18 27 14987 12723 3223 Blue 8
5 PM Thu 38 39 WSW 21 32 11951 10394 894 Blue 4
6 PM Thu 37 37 WSW 21 32 11088 9644 144 Blue 2
7 PM Thu 35 35 WSW 21 32 10100 9500 0 Blue 0
8 PM Thu 33 33 WSW 25 36 9139 9500 0 Blue 0
9 PM Thu 32 32 WSW 25 36 9019 9500 0 Blue 0
10 PM Thu 31 31 WSW 25 36 9019 9500 0 Blue 0
11 PM Thu 30 30 WSW 25 36 9019 9500 0 Blue 0
12 Midnight Fri 30 30 WSW 25 36 9019 9500 0 Blue 0
1 AM Fri 31 31 WSW 25 36 9019 9500 0 Blue 0
2 AM Fri 30 30 WSW 25 37 9019 9500 0 Blue 0
3 AM Fri 30 30 WSW 25 37 9019 9500 0 Blue 0
4 AM Fri 29 29 WSW 25 37 9019 9500 0 Blue 0
5 AM Fri 29 29 WSW 24 36 9019 9500 0 Blue 0
6 AM Fri 29 29 WSW 24 36 9019 9500 0 Blue 0
7 AM Fri 28 28 WSW 24 36 9019 9500 0 Blue 0
8 AM Fri 30 30 WSW 24 36 9019 9500 0 Blue 0
9 AM Fri 33 34 WSW 24 36 9645 9500 0 Blue 0
10 AM Fri 34 35 WSW 24 36 10100 9500 0 Blue 0
11 AM Fri 35 36 W 19 29 10402 9500 0 Blue 1
12 Noon Fri 35 36 W 19 29 10402 9500 0 Blue 1
1 PM Fri 35 37 W 19 29 11088 9644 144 Blue 2
2 PM Fri 35 36 W 20 32 10402 9500 0 Blue 1
3 PM Fri 34 35 W 20 32 10100 9500 0 Blue 0
4 PM Fri 33 34 W 20 32 9645 9500 0 Blue 0
5 PM Fri 32 33 WNW 19 29 9139 9500 0 Blue 0
6 PM Fri 30 30 WNW 19 29 9019 9500 0 Blue 0
7 PM Fri 29 29 WNW 19 29 9019 9500 0 Blue 0
8 PM Fri 27 27 WNW 18 28 9019 9500 0 Blue 0
9 PM Fri 26 26 WNW 18 28 9019 9500 0 Blue 0
10 PM Fri 25 25 WNW 18 28 9019 9500 0 Blue 0
11 PM Fri 25 25 WNW 19 28 9019 9500 0 Blue 0
12 Midnight Sat 25 25 WNW 19 28 9019 9500 0 Blue 0
1 AM Sat 24 24 WNW 19 28 9019 9500 0 Blue 0
2 AM Sat 24 24 W 16 24 9019 9500 0 Blue 0
3 AM Sat 23 23 W 16 24 9019 9500 0 Blue 0
4 AM Sat 23 23 W 16 24 9019 9500 0 Blue 0
5 AM Sat 23 23 SW 10 16 9019 9500 0 Blue 0
6 AM Sat 24 24 SW 10 16 9019 9500 0 Blue 0
7 AM Sat 25 25 SW 10 16 9019 9500 0 Blue 0
8 AM Sat 28 29 WSW 12 19 9019 9500 0 Blue 0
9 AM Sat 31 33 WSW 12 19 9139 9500 0 Blue 0
10 AM Sat 35 39 WSW 12 19 11951 10394 894 Blue 4
11 AM Sat 38 44 WNW 13 20 15593 13591 4091 Blue 9
12 Noon Sat 41 48 WNW 13 20 17235 16049 6549 Blue 13
1 PM Sat 42 49 WNW 13 20 17564 16487 6987 Blue 14
2 PM Sat 43 49 WNW 16 24 17564 16487 6987 Blue 14
3 PM Sat 43 48 WNW 16 24 17235 16049 6549 Blue 13
4 PM Sat 43 46 WNW 16 24 16567 14876 5376 Blue 11
5 PM Sat 42 43 W 19 28 14987 12723 3223 Blue 8
6 PM Sat 40 40 W 19 28 12843 11048 1548 Blue 5
7 PM Sat 38 38 W 19 28 11767 10095 595 Blue 3
8 PM Sat 36 36 WSW 18 27 10402 9500 0 Blue 1
9 PM Sat 34 34 WSW 18 27 9645 9500 0 Blue 0
10 PM Sat 32 32 WSW 18 27 9019 9500 0 Blue 0
11 PM Sat 31 31 SW 12 19 9019 9500 0 Blue 0
12 Midnight Sun 30 30 SW 12 19 9019 9500 0 Blue 0
1 AM Sun 30 30 SW 12 19 9019 9500 0 Blue 0
2 AM Sun 29 29 SW 10 14 9019 9500 0 Blue 0
3 AM Sun 28 28 SW 10 14 9019 9500 0 Blue 0
4 AM Sun 27 27 SW 10 14 9019 9500 0 Blue 0
5 AM Sun 27 27 SW 10 16 9019 9500 0 Blue 0
6 AM Sun 29 29 SW 10 16 9019 9500 0 Blue 0
7 AM Sun 31 31 SW 10 16 9019 9500 0 Blue 0
8 AM Sun 34 35 SW 11 17 10100 9500 0 Blue 0
9 AM Sun 37 39 SW 11 17 11951 10394 894 Blue 4
10 AM Sun 41 45 SW 11 17 16175 14249 4749 Blue 10
11 AM Sun 45 51 WSW 12 18 18210 17149 7649 Blue 16
12 Noon Sun 47 54 WSW 12 18 20698 18116 8616 White 19
1 PM Sun 48 55 WSW 12 18 20901 18477 8977 White 20
2 PM Sun 49 55 W 13 20 20901 18477 8977 White 20
3 PM Sun 49 54 W 13 20 20698 18116 8616 White 19
4 PM Sun 48 51 W 13 20 18210 17149 7649 Blue 16
5 PM Sun 47 49 W 16 23 17564 16487 6987 Blue 14
6 PM Sun 45 45 W 16 23 16175 14249 4749 Blue 10
7 PM Sun 42 42 W 16 23 14352 11937 2437 Blue 7
8 PM Sun 40 40 WSW 13 20 12843 11048 1548 Blue 5
9 PM Sun 38 38 WSW 13 20 11767 10095 595 Blue 3
10 PM Sun 36 36 WSW 13 20 10402 9500 0 Blue 1
11 PM Sun 34 34 SW 12 18 9645 9500 0 Blue 0
12 Midnight Mon 33 33 SW 12 18 9139 9500 0 Blue 0
1 AM Mon 32 32 SW 12 18 9019 9500 0 Blue 0
2 AM Mon 31 31 SW 12 18 9019 9500 0 Blue 0
3 AM Mon 30 30 SW 12 18 9019 9500 0 Blue 0
4 AM Mon 29 29 SW 12 18 9019 9500 0 Blue 0
5 AM Mon 29 29 SW 12 19 9019 9500 0 Blue 0
6 AM Mon 31 31 SW 12 19 9019 9500 0 Blue 0
7 AM Mon 33 33 SW 12 19 9139 9500 0 Blue 0
8 AM Mon 36 37 SW 11 16 11088 9644 144 Blue 2
9 AM Mon 40 42 SW 11 16 14352 11937 2437 Blue 7
10 AM Mon 44 48 SW 11 16 17235 16049 6549 Blue 13
11 AM Mon 48 54 WSW 10 14 20698 18116 8616 White 19
12 Noon Mon 50 57 WSW 10 14 21307 21307 11807 White 22
1 PM Mon 51 58 WSW 10 14 21509 21509 12009 White 23
2 PM Mon 52 59 WSW 12 18 21711 21711 12211 White 24
3 PM Mon 52 57 WSW 12 18 21307 21307 11807 White 22
4 PM Mon 52 56 WSW 12 18 21105 20147 10647 White 21
5 PM Mon 50 52 WSW 13 19 18901 17475 7975 Blue 17
6 PM Mon 48 48 WSW 13 19 17235 16049 6549 Blue 13
7 PM Mon 46 46 WSW 13 19 16567 14876 5376 Blue 11
8 PM Mon 43 43 WSW 12 19 14987 12723 3223 Blue 8
9 PM Mon 41 41 WSW 12 19 13683 11754 2254 Blue 6
10 PM Mon 39 39 WSW 12 19 11951 10394 894 Blue 4
11 PM Mon 37 37 SW 13 19 11088 9644 144 Blue 2
12 Midnight Tue 36 36 SW 13 19 10402 9500 0 Blue 1
1 AM Tue 35 35 SW 13 19 10100 9500 0 Blue 0
2 AM Tue 34 34 SW 12 18 9645 9500 0 Blue 0
3 AM Tue 33 33 SW 12 18 9139 9500 0 Blue 0
4 AM Tue 32 32 SW 12 18 9019 9500 0 Blue 0
5 AM Tue 32 32 SW 12 18 9019 9500 0 Blue 0
6 AM Tue 33 33 SW 12 18 9139 9500 0 Blue 0
7 AM Tue 36 36 SW 12 18 10402 9500 0 Blue 1
8 AM Tue 39 40 SW 11 17 12843 11048 1548 Blue 5
9 AM Tue 44 46 SW 11 17 16567 14876 5376 Blue 11
10 AM Tue 48 52 SW 11 17 18901 17475 7975 Blue 17
11 AM Tue 52 58 WSW 12 18 21509 21509 12009 White 23
12 Noon Tue 54 61 WSW 12 18 22114 22114 12614 White 26
1 PM Tue 55 62 WSW 12 18 22315 22315 12815 White 27
2 PM Tue 55 61 WSW 17 25 22114 22114 12614 White 26
3 PM Tue 55 60 WSW 17 25 21913 21913 12413 White 25
4 PM Tue 54 57 WSW 17 25 21307 21307 11807 White 22
5 PM Tue 53 55 WSW 19 29 20901 18477 8977 White 20
6 PM Tue 50 50 WSW 19 29 17889 16820 7320 Blue 15
7 PM Tue 47 47 WSW 19 29 16903 15474 5974 Blue 12
8 PM Tue 44 44 WSW 19 29 15593 13591 4091 Blue 9
9 PM Tue 42 42 WSW 19 29 14352 11937 2437 Blue 7
10 PM Tue 40 40 WSW 19 29 12843 11048 1548 Blue 5

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]