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

Station:

KVBG

Date/Time:

20 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 Tue 45 45 SW 7 4915 9500 0 Blue 0
6 AM Tue 49 49 SW 7 6209 9500 0 Blue 0
7 AM Tue 52 52 SW 7 7370 9500 0 Blue 0
8 AM Tue 56 56 SW 7 8857 9500 0 Blue 0
9 AM Tue 61 63 SW 7 13482 10274 774 Blue 3
10 AM Tue 65 69 SW 7 17926 15769 6269 Blue 9
11 AM Tue 69 74 NE 7 21318 18942 9442 Blue 14
12 Noon Tue 71 78 NE 7 23777 21714 12214 Blue 18
1 PM Tue 73 80 NE 7 24851 22937 13437 Blue 20
2 PM Tue 75 82 NW 7 26371 24053 14553 Blue 22
3 PM Tue 76 82 NW 7 26371 24053 14553 Blue 22
4 PM Tue 76 80 NW 7 24851 22937 13437 Blue 20
5 PM Tue 75 77 W 9 23206 21051 11551 Blue 17
6 PM Tue 72 73 W 9 20611 18362 8862 Blue 13
7 PM Tue 68 68 W 9 17290 15027 5527 Blue 8
8 PM Tue 64 64 W 8 14359 11334 1834 Blue 4
9 PM Tue 62 62 W 8 12510 9926 426 Blue 2
10 PM Tue 60 60 W 8 10281 9500 0 Blue 0
11 PM Tue 58 58 SW 7 9576 9500 0 Blue 0
12 Midnight Wed 56 56 SW 7 8857 9500 0 Blue 0
1 AM Wed 54 54 SW 7 8122 9500 0 Blue 0
2 AM Wed 51 51 SW 7 6988 9500 0 Blue 0
3 AM Wed 50 50 SW 7 6601 9500 0 Blue 0
4 AM Wed 49 49 SW 7 6209 9500 0 Blue 0
5 AM Wed 48 48 SW 6 5812 9500 0 Blue 0
6 AM Wed 50 50 SW 6 6601 9500 0 Blue 0
7 AM Wed 52 52 SW 6 7370 9500 0 Blue 0
8 AM Wed 55 55 S 6 8491 9500 0 Blue 0
9 AM Wed 58 60 S 6 10281 9500 0 Blue 0
10 AM Wed 62 65 S 6 15165 12416 2916 Blue 5
11 AM Wed 64 69 E 8 17926 15769 6269 Blue 9
12 Noon Wed 67 73 E 8 20611 18362 8862 Blue 13
1 PM Wed 68 75 E 8 21982 19582 10082 Blue 15
2 PM Wed 69 75 W 10 21982 19582 10082 Blue 15
3 PM Wed 70 75 W 10 21982 19582 10082 Blue 15
4 PM Wed 70 74 W 10 21318 18942 9442 Blue 14
5 PM Wed 68 70 W 12 18535 16467 6967 Blue 10
6 PM Wed 66 67 W 12 16622 14232 4732 Blue 7
7 PM Wed 63 63 W 12 13482 10274 774 Blue 3
8 PM Wed 60 60 W 10 10281 9500 0 Blue 0
9 PM Wed 58 58 W 10 9576 9500 0 Blue 0
10 PM Wed 56 56 W 10 8857 9500 0 Blue 0
11 PM Wed 54 54 SW 7 8122 9500 0 Blue 0
12 Midnight Thu 53 53 SW 7 7748 9500 0 Blue 0
1 AM Thu 52 52 SW 7 7370 9500 0 Blue 0
2 AM Thu 51 51 SW 7 6988 9500 0 Blue 0
3 AM Thu 50 50 SW 7 6601 9500 0 Blue 0
4 AM Thu 48 48 SW 7 5812 9500 0 Blue 0
5 AM Thu 48 48 W 6 5812 9500 0 Blue 0
6 AM Thu 49 49 W 6 6209 9500 0 Blue 0
7 AM Thu 51 51 W 6 6988 9500 0 Blue 0
8 AM Thu 53 53 SE 6 7748 9500 0 Blue 0
9 AM Thu 56 57 SE 6 9218 9500 0 Blue 0
10 AM Thu 59 62 SE 6 12510 9926 426 Blue 2
11 AM Thu 61 66 N 7 15916 13369 3869 Blue 6
12 Noon Thu 64 70 N 7 18535 16467 6967 Blue 10
1 PM Thu 67 73 N 7 20611 18362 8862 Blue 13
2 PM Thu 69 75 N 7 21982 19582 10082 Blue 15
3 PM Thu 69 74 N 7 21318 18942 9442 Blue 14
4 PM Thu 68 71 N 7 19120 17128 7628 Blue 11
5 PM Thu 67 69 N 10 17926 15769 6269 Blue 9
6 PM Thu 65 65 N 10 15165 12416 2916 Blue 5
7 PM Thu 62 62 N 10 12510 9926 426 Blue 2
8 PM Thu 59 59 N 10 9931 9500 0 Blue 0
9 PM Thu 57 57 N 10 9218 9500 0 Blue 0
10 PM Thu 56 56 N 10 8857 9500 0 Blue 0
11 PM Thu 55 55 E 5 8491 9500 0 Blue 0
12 Midnight Fri 53 53 E 5 7748 9500 0 Blue 0
1 AM Fri 51 51 E 5 6988 9500 0 Blue 0
2 AM Fri 49 49 E 5 6209 9500 0 Blue 0
3 AM Fri 48 48 E 5 5812 9500 0 Blue 0
4 AM Fri 47 47 E 5 5410 9500 0 Blue 0
5 AM Fri 47 47 S 6 5410 9500 0 Blue 0
6 AM Fri 48 48 S 6 5812 9500 0 Blue 0
7 AM Fri 51 51 S 6 6988 9500 0 Blue 0
8 AM Fri 54 54 S 6 8122 9500 0 Blue 0
9 AM Fri 58 60 S 6 10281 9500 0 Blue 0
10 AM Fri 63 66 S 6 15916 13369 3869 Blue 6
11 AM Fri 66 71 SE 9 19120 17128 7628 Blue 11
12 Noon Fri 68 75 SE 9 21982 19582 10082 Blue 15
1 PM Fri 69 76 SE 9 22610 20344 10844 Blue 16
2 PM Fri 70 77 SE 9 23206 21051 11551 Blue 17
3 PM Fri 71 77 SE 9 23206 21051 11551 Blue 17
4 PM Fri 72 76 SE 9 22610 20344 10844 Blue 16
5 PM Fri 71 73 NW 13 20611 18362 8862 Blue 13
6 PM Fri 67 68 NW 13 17290 15027 5527 Blue 8
7 PM Fri 63 63 NW 13 13482 10274 774 Blue 3
8 PM Fri 59 59 NW 13 9931 9500 0 Blue 0
9 PM Fri 57 57 NW 13 9218 9500 0 Blue 0
10 PM Fri 56 56 NW 13 8857 9500 0 Blue 0
11 PM Fri 55 55 SW 8 8491 9500 0 Blue 0
12 Midnight Sat 53 53 SW 8 7748 9500 0 Blue 0
1 AM Sat 51 51 SW 8 6988 9500 0 Blue 0
2 AM Sat 48 48 SW 8 5812 9500 0 Blue 0
3 AM Sat 47 47 SW 8 5410 9500 0 Blue 0
4 AM Sat 48 48 SW 8 5812 9500 0 Blue 0
5 AM Sat 48 48 SW 7 5812 9500 0 Blue 0
6 AM Sat 50 50 SW 7 6601 9500 0 Blue 0
7 AM Sat 52 52 SW 7 7370 9500 0 Blue 0
8 AM Sat 55 55 SW 7 8491 9500 0 Blue 0
9 AM Sat 59 61 SW 7 11401 9576 76 Blue 1
10 AM Sat 63 67 SW 7 16622 14232 4732 Blue 7
11 AM Sat 67 73 NE 13 20611 18362 8862 Blue 13
12 Noon Sat 70 77 NE 13 23206 21051 11551 Blue 17
1 PM Sat 71 78 NE 13 23777 21714 12214 Blue 18
2 PM Sat 72 79 NE 13 24324 22341 12841 Blue 19
3 PM Sat 72 78 NE 13 23777 21714 12214 Blue 18
4 PM Sat 71 75 NE 13 21982 19582 10082 Blue 15
5 PM Sat 70 72 W 13 19849 17758 8258 Blue 12
6 PM Sat 66 66 W 13 15916 13369 3869 Blue 6
7 PM Sat 63 63 W 13 13482 10274 774 Blue 3
8 PM Sat 60 60 W 13 10281 9500 0 Blue 0
9 PM Sat 59 59 W 13 9931 9500 0 Blue 0
10 PM Sat 58 58 W 13 9576 9500 0 Blue 0
11 PM Sat 57 57 SW 8 9218 9500 0 Blue 0
12 Midnight Sun 55 55 SW 8 8491 9500 0 Blue 0
1 AM Sun 52 52 SW 8 7370 9500 0 Blue 0
2 AM Sun 50 50 SW 8 6601 9500 0 Blue 0
3 AM Sun 48 48 SW 8 5812 9500 0 Blue 0
4 AM Sun 48 48 SW 8 5812 9500 0 Blue 0
5 AM Sun 48 48 SW 6 5812 9500 0 Blue 0
6 AM Sun 50 50 SW 6 6601 9500 0 Blue 0
7 AM Sun 52 52 SW 6 7370 9500 0 Blue 0
8 AM Sun 55 55 SW 6 8491 9500 0 Blue 0
9 AM Sun 58 60 SW 6 10281 9500 0 Blue 0
10 AM Sun 62 66 SW 6 15916 13369 3869 Blue 6
11 AM Sun 66 72 NW 12 19849 17758 8258 Blue 12
12 Noon Sun 68 75 NW 12 21982 19582 10082 Blue 15
1 PM Sun 69 76 NW 12 22610 20344 10844 Blue 16
2 PM Sun 70 77 NW 12 23206 21051 11551 Blue 17
3 PM Sun 70 76 NW 12 22610 20344 10844 Blue 16
4 PM Sun 69 73 NW 12 20611 18362 8862 Blue 13
5 PM Sun 68 70 W 13 18535 16467 6967 Blue 10
6 PM Sun 65 66 W 13 15916 13369 3869 Blue 6
7 PM Sun 63 63 W 13 13482 10274 774 Blue 3
8 PM Sun 60 60 W 13 10281 9500 0 Blue 0
9 PM Sun 58 58 W 13 9576 9500 0 Blue 0
10 PM Sun 57 57 W 13 9218 9500 0 Blue 0
11 PM Sun 56 56 SW 7 8857 9500 0 Blue 0
12 Midnight Mon 54 54 SW 7 8122 9500 0 Blue 0
1 AM Mon 52 52 SW 7 7370 9500 0 Blue 0
2 AM Mon 50 50 SW 7 6601 9500 0 Blue 0
3 AM Mon 49 49 SW 7 6209 9500 0 Blue 0
4 AM Mon 47 47 SW 7 5410 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