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

Station:

KVBG

Date/Time:

21 AUG 2019

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)
5 AM Wed 48 48 S 6 5902 9500 0 Blue 0
6 AM Wed 50 50 S 6 5902 9500 0 Blue 0
7 AM Wed 52 52 S 6 5902 9500 0 Blue 0
8 AM Wed 55 55 S 7 5902 9500 0 Blue 0
9 AM Wed 59 61 S 7 10087 9500 0 Blue 0
10 AM Wed 62 65 S 7 12669 10733 1233 Blue 4
11 AM Wed 65 70 SE 7 15244 13716 4216 Blue 8
12 Noon Wed 68 74 SE 7 17041 15618 6118 Blue 12
1 PM Wed 69 75 SE 7 17468 16067 6567 Blue 13
2 PM Wed 71 77 W 8 18321 16938 7438 Blue 15
3 PM Wed 71 76 W 8 17887 16507 7007 Blue 14
4 PM Wed 71 74 W 8 17041 15618 6118 Blue 12
5 PM Wed 69 71 W 13 15708 14209 4709 Blue 9
6 PM Wed 67 67 W 13 13782 12011 2511 Blue 5
7 PM Wed 64 64 W 13 12059 10076 576 Blue 3
8 PM Wed 60 60 W 8 9418 9500 0 Blue 0
9 PM Wed 58 58 W 8 7978 9500 0 Blue 0
10 PM Wed 56 56 W 8 6355 9500 0 Blue 0
11 PM Wed 55 55 SW 8 5902 9500 0 Blue 0
12 Midnight Thu 54 54 SW 8 5902 9500 0 Blue 0
1 AM Thu 52 52 SW 8 5902 9500 0 Blue 0
2 AM Thu 51 51 SW 6 5902 9500 0 Blue 0
3 AM Thu 49 49 SW 6 5902 9500 0 Blue 0
4 AM Thu 47 47 SW 6 5902 9500 0 Blue 0
5 AM Thu 47 47 SE 7 5902 9500 0 Blue 0
6 AM Thu 49 49 SE 7 5902 9500 0 Blue 0
7 AM Thu 52 52 SE 7 5902 9500 0 Blue 0
8 AM Thu 55 55 SE 8 5902 9500 0 Blue 0
9 AM Thu 58 59 SE 8 8717 9500 0 Blue 0
10 AM Thu 62 65 SE 8 12669 10733 1233 Blue 4
11 AM Thu 65 70 N 9 15244 13716 4216 Blue 8
12 Noon Thu 68 74 N 9 17041 15618 6118 Blue 12
1 PM Thu 71 78 N 9 18750 17360 7860 Blue 16
2 PM Thu 72 78 NW 9 18750 17360 7860 Blue 16
3 PM Thu 73 78 NW 9 18750 17360 7860 Blue 16
4 PM Thu 73 77 NW 9 18321 16938 7438 Blue 15
5 PM Thu 71 73 NW 10 16606 15160 5660 Blue 11
6 PM Thu 69 70 NW 10 15244 13716 4216 Blue 8
7 PM Thu 67 67 NW 10 13782 12011 2511 Blue 5
8 PM Thu 64 64 NW 10 12059 10076 576 Blue 3
9 PM Thu 62 62 NW 10 10758 9500 0 Blue 1
10 PM Thu 60 60 NW 10 9418 9500 0 Blue 0
11 PM Thu 58 58 SE 5 7978 9500 0 Blue 0
12 Midnight Fri 56 56 SE 5 6355 9500 0 Blue 0
1 AM Fri 54 54 SE 5 5902 9500 0 Blue 0
2 AM Fri 52 52 SE 5 5902 9500 0 Blue 0
3 AM Fri 50 50 SE 5 5902 9500 0 Blue 0
4 AM Fri 49 49 SE 5 5902 9500 0 Blue 0
5 AM Fri 49 49 SE 7 5902 9500 0 Blue 0
6 AM Fri 49 49 SE 7 5902 9500 0 Blue 0
7 AM Fri 52 52 SE 7 5902 9500 0 Blue 0
8 AM Fri 55 55 SE 7 5902 9500 0 Blue 0
9 AM Fri 58 60 SE 7 9418 9500 0 Blue 0
10 AM Fri 61 64 SE 7 12059 10076 576 Blue 3
11 AM Fri 64 69 SE 7 14769 13190 3690 Blue 7
12 Noon Fri 67 73 SE 7 16606 15160 5660 Blue 11
1 PM Fri 69 75 SE 7 17468 16067 6567 Blue 13
2 PM Fri 71 77 SE 7 18321 16938 7438 Blue 15
3 PM Fri 71 76 SE 7 17887 16507 7007 Blue 14
4 PM Fri 70 73 SE 7 16606 15160 5660 Blue 11
5 PM Fri 68 70 W 13 15244 13716 4216 Blue 8
6 PM Fri 66 66 W 13 13256 11386 1886 Blue 4
7 PM Fri 63 63 W 13 11423 9500 0 Blue 2
8 PM Fri 60 60 W 13 9418 9500 0 Blue 0
9 PM Fri 58 58 W 13 7978 9500 0 Blue 0
10 PM Fri 57 57 W 13 7194 9500 0 Blue 0
11 PM Fri 57 57 SW 8 7194 9500 0 Blue 0
12 Midnight Sat 55 55 SW 8 5902 9500 0 Blue 0
1 AM Sat 53 53 SW 8 5902 9500 0 Blue 0
2 AM Sat 51 51 SW 8 5902 9500 0 Blue 0
3 AM Sat 50 50 SW 8 5902 9500 0 Blue 0
4 AM Sat 49 49 SW 8 5902 9500 0 Blue 0
5 AM Sat 49 49 SW 7 5902 9500 0 Blue 0
6 AM Sat 50 50 SW 7 5902 9500 0 Blue 0
7 AM Sat 52 52 SW 7 5902 9500 0 Blue 0
8 AM Sat 55 55 SW 7 5902 9500 0 Blue 0
9 AM Sat 59 61 SW 7 10087 9500 0 Blue 0
10 AM Sat 63 67 SW 7 13782 12011 2511 Blue 5
11 AM Sat 67 72 SE 9 16162 14690 5190 Blue 10
12 Noon Sat 69 76 SE 9 17887 16507 7007 Blue 14
1 PM Sat 69 76 SE 9 17887 16507 7007 Blue 14
2 PM Sat 70 77 SE 9 18321 16938 7438 Blue 15
3 PM Sat 71 77 SE 9 18321 16938 7438 Blue 15
4 PM Sat 71 75 SE 9 17468 16067 6567 Blue 13
5 PM Sat 70 72 W 14 16162 14690 5190 Blue 10
6 PM Sat 67 67 W 14 13782 12011 2511 Blue 5
7 PM Sat 63 63 W 14 11423 9500 0 Blue 2
8 PM Sat 60 60 W 14 9418 9500 0 Blue 0
9 PM Sat 58 58 W 14 7978 9500 0 Blue 0
10 PM Sat 56 56 W 14 6355 9500 0 Blue 0
11 PM Sat 55 55 SW 6 5902 9500 0 Blue 0
12 Midnight Sun 53 53 SW 6 5902 9500 0 Blue 0
1 AM Sun 51 51 SW 6 5902 9500 0 Blue 0
2 AM Sun 50 50 SW 6 5902 9500 0 Blue 0
3 AM Sun 48 48 SW 6 5902 9500 0 Blue 0
4 AM Sun 48 48 SW 6 5902 9500 0 Blue 0
5 AM Sun 48 48 SW 6 5902 9500 0 Blue 0
6 AM Sun 49 49 SW 6 5902 9500 0 Blue 0
7 AM Sun 51 51 SW 6 5902 9500 0 Blue 0
8 AM Sun 54 54 SW 6 5902 9500 0 Blue 0
9 AM Sun 58 60 SW 6 9418 9500 0 Blue 0
10 AM Sun 62 66 SW 6 13256 11386 1886 Blue 4
11 AM Sun 65 70 SW 9 15244 13716 4216 Blue 8
12 Noon Sun 67 74 SW 9 17041 15618 6118 Blue 12
1 PM Sun 69 76 SW 9 17887 16507 7007 Blue 14
2 PM Sun 70 77 SW 9 18321 16938 7438 Blue 15
3 PM Sun 70 76 SW 9 17887 16507 7007 Blue 14
4 PM Sun 70 74 SW 9 17041 15618 6118 Blue 12
5 PM Sun 68 70 W 14 15244 13716 4216 Blue 8
6 PM Sun 66 67 W 14 13782 12011 2511 Blue 5
7 PM Sun 63 63 W 14 11423 9500 0 Blue 2
8 PM Sun 60 60 W 14 9418 9500 0 Blue 0
9 PM Sun 58 58 W 14 7978 9500 0 Blue 0
10 PM Sun 56 56 W 14 6355 9500 0 Blue 0
11 PM Sun 55 55 SW 5 5902 9500 0 Blue 0
12 Midnight Mon 54 54 SW 5 5902 9500 0 Blue 0
1 AM Mon 52 52 SW 5 5902 9500 0 Blue 0
2 AM Mon 50 50 SW 5 5902 9500 0 Blue 0
3 AM Mon 48 48 SW 5 5902 9500 0 Blue 0
4 AM Mon 46 46 SW 5 5902 9500 0 Blue 0
5 AM Mon 46 46 SW 6 5902 9500 0 Blue 0
6 AM Mon 48 48 SW 6 5902 9500 0 Blue 0
7 AM Mon 51 51 SW 6 5902 9500 0 Blue 0
8 AM Mon 55 55 SW 6 5902 9500 0 Blue 0
9 AM Mon 59 61 SW 6 10087 9500 0 Blue 0
10 AM Mon 62 66 SW 6 13256 11386 1886 Blue 4
11 AM Mon 65 70 W 8 15244 13716 4216 Blue 8
12 Noon Mon 68 74 W 8 17041 15618 6118 Blue 12
1 PM Mon 70 76 W 8 17887 16507 7007 Blue 14
2 PM Mon 71 77 W 8 18321 16938 7438 Blue 15
3 PM Mon 71 76 W 8 17887 16507 7007 Blue 14
4 PM Mon 70 74 W 8 17041 15618 6118 Blue 12
5 PM Mon 69 71 W 10 15708 14209 4709 Blue 9
6 PM Mon 67 67 W 10 13782 12011 2511 Blue 5
7 PM Mon 64 64 W 10 12059 10076 576 Blue 3
8 PM Mon 62 62 W 10 10758 9500 0 Blue 1
9 PM Mon 59 59 W 10 8717 9500 0 Blue 0
10 PM Mon 58 58 W 10 7978 9500 0 Blue 0
11 PM Mon 56 56 SW 6 6355 9500 0 Blue 0
12 Midnight Tue 55 55 SW 6 5902 9500 0 Blue 0
1 AM Tue 54 54 SW 6 5902 9500 0 Blue 0
2 AM Tue 52 52 SW 6 5902 9500 0 Blue 0
3 AM Tue 50 50 SW 6 5902 9500 0 Blue 0
4 AM Tue 48 48 SW 6 5902 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