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

Station:

KVBG

Date/Time:

N/A

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 Thu 28 28 SW 47 N/A N/A N/A N/A N/A
5 AM Thu 27 27 SW 47 N/A N/A N/A N/A N/A
6 AM Thu 27 27 SW 47 N/A N/A N/A N/A N/A
7 AM Thu 23 23 SW 55 N/A N/A N/A N/A N/A
8 AM Thu 23 23 SW 55 N/A N/A N/A N/A N/A
9 AM Thu 23 23 SW 55 N/A N/A N/A N/A N/A
10 AM Thu 23 23 SW 47 N/A N/A N/A N/A N/A
11 AM Thu 23 23 SW 47 N/A N/A N/A N/A N/A
12 Noon Thu 22 22 SW 47 N/A N/A N/A N/A N/A
1 PM Thu 21 21 SW 54 N/A N/A N/A N/A N/A
2 PM Thu 21 21 SW 54 N/A N/A N/A N/A N/A
3 PM Thu 20 20 SW 54 N/A N/A N/A N/A N/A
4 PM Thu 19 19 SW 53 N/A N/A N/A N/A N/A
5 PM Thu 18 18 SW 53 N/A N/A N/A N/A N/A
6 PM Thu 18 18 SW 53 N/A N/A N/A N/A N/A
7 PM Thu 18 18 SW 49 N/A N/A N/A N/A N/A
8 PM Thu 17 17 SW 49 N/A N/A N/A N/A N/A
9 PM Thu 17 17 SW 49 N/A N/A N/A N/A N/A
10 PM Thu 17 17 SW 44 N/A N/A N/A N/A N/A
11 PM Thu 17 17 SW 44 N/A N/A N/A N/A N/A
12 Midnight Fri 17 17 SW 44 N/A N/A N/A N/A N/A
1 AM Fri 17 17 W 41 N/A N/A N/A N/A N/A
2 AM Fri 18 18 W 41 N/A N/A N/A N/A N/A
3 AM Fri 19 19 W 41 N/A N/A N/A N/A N/A
4 AM Fri 19 19 W 38 N/A N/A N/A N/A N/A
5 AM Fri 19 19 W 38 N/A N/A N/A N/A N/A
6 AM Fri 19 19 W 38 N/A N/A N/A N/A N/A
7 AM Fri 19 19 W 38 N/A N/A N/A N/A N/A
8 AM Fri 21 21 W 38 N/A N/A N/A N/A N/A
9 AM Fri 23 23 W 38 N/A N/A N/A N/A N/A
10 AM Fri 25 25 W 38 N/A N/A N/A N/A N/A
11 AM Fri 27 28 W 38 N/A N/A N/A N/A N/A
12 Noon Fri 28 29 W 38 N/A N/A N/A N/A N/A
1 PM Fri 29 30 W 36 N/A N/A N/A N/A N/A
2 PM Fri 30 30 W 36 N/A N/A N/A N/A N/A
3 PM Fri 30 30 W 36 N/A N/A N/A N/A N/A
4 PM Fri 29 29 W 35 N/A N/A N/A N/A N/A
5 PM Fri 29 29 W 35 N/A N/A N/A N/A N/A
6 PM Fri 28 28 W 35 N/A N/A N/A N/A N/A
7 PM Fri 28 28 W 35 N/A N/A N/A N/A N/A
8 PM Fri 28 28 W 35 N/A N/A N/A N/A N/A
9 PM Fri 27 27 W 35 N/A N/A N/A N/A N/A
10 PM Fri 27 27 W 31 N/A N/A N/A N/A N/A
11 PM Fri 28 28 W 31 N/A N/A N/A N/A N/A
12 Midnight Sat 28 28 W 31 N/A N/A N/A N/A N/A
1 AM Sat 28 28 W 31 N/A N/A N/A N/A N/A
2 AM Sat 28 28 W 31 N/A N/A N/A N/A N/A
3 AM Sat 27 27 W 31 N/A N/A N/A N/A N/A
4 AM Sat 27 27 W 20 N/A N/A N/A N/A N/A
5 AM Sat 27 27 W 20 N/A N/A N/A N/A N/A
6 AM Sat 27 27 W 20 N/A N/A N/A N/A N/A
7 AM Sat 28 28 W 20 N/A N/A N/A N/A N/A
8 AM Sat 30 30 W 20 N/A N/A N/A N/A N/A
9 AM Sat 33 33 W 20 N/A N/A N/A N/A N/A
10 AM Sat 35 35 SW 15 N/A N/A N/A N/A N/A
11 AM Sat 36 37 SW 15 N/A N/A N/A N/A N/A
12 Noon Sat 36 37 SW 15 N/A N/A N/A N/A N/A
1 PM Sat 36 37 SW 15 N/A N/A N/A N/A N/A
2 PM Sat 36 37 SW 15 N/A N/A N/A N/A N/A
3 PM Sat 36 36 SW 15 N/A N/A N/A N/A N/A
4 PM Sat 35 35 SW 12 N/A N/A N/A N/A N/A
5 PM Sat 33 33 SW 12 N/A N/A N/A N/A N/A
6 PM Sat 30 30 SW 12 N/A N/A N/A N/A N/A
7 PM Sat 28 28 SW 12 N/A N/A N/A N/A N/A
8 PM Sat 27 27 SW 12 N/A N/A N/A N/A N/A
9 PM Sat 27 27 SW 12 N/A N/A N/A N/A N/A
10 PM Sat 27 27 SW 17 N/A N/A N/A N/A N/A
11 PM Sat 27 27 SW 17 N/A N/A N/A N/A N/A
12 Midnight Sun 27 27 SW 17 N/A N/A N/A N/A N/A
1 AM Sun 28 28 SW 17 N/A N/A N/A N/A N/A
2 AM Sun 27 27 SW 17 N/A N/A N/A N/A N/A
3 AM Sun 26 26 SW 17 N/A N/A N/A N/A N/A
4 AM Sun 26 26 SW 31 N/A N/A N/A N/A N/A
5 AM Sun 26 26 SW 31 N/A N/A N/A N/A N/A
6 AM Sun 27 27 SW 31 N/A N/A N/A N/A N/A
7 AM Sun 27 27 SW 31 N/A N/A N/A N/A N/A
8 AM Sun 28 28 SW 31 N/A N/A N/A N/A N/A
9 AM Sun 29 29 SW 31 N/A N/A N/A N/A N/A
10 AM Sun 31 31 SW 39 N/A N/A N/A N/A N/A
11 AM Sun 32 32 SW 39 N/A N/A N/A N/A N/A
12 Noon Sun 34 34 SW 39 N/A N/A N/A N/A N/A
1 PM Sun 34 34 SW 39 N/A N/A N/A N/A N/A
2 PM Sun 33 33 SW 39 N/A N/A N/A N/A N/A
3 PM Sun 31 31 SW 39 N/A N/A N/A N/A N/A
4 PM Sun 30 30 SW 45 N/A N/A N/A N/A N/A
5 PM Sun 30 30 SW 45 N/A N/A N/A N/A N/A
6 PM Sun 30 30 SW 45 N/A N/A N/A N/A N/A
7 PM Sun 29 29 SW 45 N/A N/A N/A N/A N/A
8 PM Sun 26 26 SW 45 N/A N/A N/A N/A N/A
9 PM Sun 23 23 SW 45 N/A N/A N/A N/A N/A
10 PM Sun 20 20 SW 44 N/A N/A N/A N/A N/A
11 PM Sun 20 20 SW 44 N/A N/A N/A N/A N/A
12 Midnight Mon 22 22 SW 44 N/A N/A N/A N/A N/A
1 AM Mon 23 23 SW 44 N/A N/A N/A N/A N/A
2 AM Mon 22 22 SW 44 N/A N/A N/A N/A N/A
3 AM Mon 20 20 SW 44 N/A N/A N/A N/A N/A
4 AM Mon 19 19 NW 25 N/A N/A N/A N/A N/A
5 AM Mon 18 18 NW 25 N/A N/A N/A N/A N/A
6 AM Mon 18 18 NW 25 N/A N/A N/A N/A N/A
7 AM Mon 18 18 NW 25 N/A N/A N/A N/A N/A
8 AM Mon 19 19 NW 25 N/A N/A N/A N/A N/A
9 AM Mon 19 19 NW 25 N/A N/A N/A N/A N/A
10 AM Mon 20 21 N 23 N/A N/A N/A N/A N/A
11 AM Mon 22 23 N 23 N/A N/A N/A N/A N/A
12 Noon Mon 25 26 N 23 N/A N/A N/A N/A N/A
1 PM Mon 26 27 N 23 N/A N/A N/A N/A N/A
2 PM Mon 26 27 N 23 N/A N/A N/A N/A N/A
3 PM Mon 24 24 N 23 N/A N/A N/A N/A N/A
4 PM Mon 23 23 N 29 N/A N/A N/A N/A N/A
5 PM Mon 21 21 N 29 N/A N/A N/A N/A N/A
6 PM Mon 20 20 N 29 N/A N/A N/A N/A N/A
7 PM Mon 19 19 N 29 N/A N/A N/A N/A N/A
8 PM Mon 19 19 N 29 N/A N/A N/A N/A N/A
9 PM Mon 19 19 N 29 N/A N/A N/A N/A N/A
10 PM Mon 18 18 NE 23 N/A N/A N/A N/A N/A
11 PM Mon 18 18 NE 23 N/A N/A N/A N/A N/A
12 Midnight Tue 17 17 NE 23 N/A N/A N/A N/A N/A
1 AM Tue 18 18 NE 23 N/A N/A N/A N/A N/A
2 AM Tue 19 19 NE 23 N/A N/A N/A N/A N/A
3 AM Tue 20 20 NE 23 N/A N/A N/A N/A N/A
4 AM Tue 20 20 NE 14 N/A N/A N/A N/A N/A
5 AM Tue 19 19 NE 14 N/A N/A N/A N/A N/A
6 AM Tue 18 18 NE 14 N/A N/A N/A N/A N/A
7 AM Tue 18 18 NE 14 N/A N/A N/A N/A N/A
8 AM Tue 22 22 NE 14 N/A N/A N/A N/A N/A
9 AM Tue 26 26 NE 14 N/A N/A N/A N/A N/A
10 AM Tue 30 31 E 9 N/A N/A N/A N/A N/A
11 AM Tue 30 31 E 9 N/A N/A N/A N/A N/A
12 Noon Tue 29 31 E 9 N/A N/A N/A N/A N/A
1 PM Tue 29 30 E 9 N/A N/A N/A N/A N/A
2 PM Tue 30 31 E 9 N/A N/A N/A N/A N/A
3 PM Tue 31 31 E 9 N/A N/A N/A N/A N/A
4 PM Tue 31 31 NE 9 N/A N/A N/A N/A N/A
5 PM Tue 28 28 NE 9 N/A N/A N/A N/A N/A
6 PM Tue 25 25 NE 9 N/A N/A N/A N/A N/A
7 PM Tue 22 22 NE 9 N/A N/A N/A N/A N/A
8 PM Tue 22 22 NE 9 N/A N/A N/A N/A N/A
9 PM Tue 24 24 NE 9 N/A N/A N/A N/A N/A
10 PM Tue 25 25 E 7 N/A N/A N/A N/A N/A
11 PM Tue 24 24 E 7 N/A N/A N/A N/A N/A
12 Midnight Wed 21 21 E 7 N/A N/A N/A N/A N/A
1 AM Wed 20 20 E 7 N/A N/A N/A N/A N/A
2 AM Wed 21 21 E 7 N/A N/A N/A N/A N/A
3 AM Wed 23 23 E 7 N/A N/A N/A N/A N/A

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