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

Station:

KVBG

Date/Time:

17 SEP 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 27 27 W 12 8589 9500 0 Blue 0
6 AM Tue 28 28 W 12 8589 9500 0 Blue 0
7 AM Tue 31 31 W 12 8589 9500 0 Blue 0
8 AM Tue 34 34 W 7 8589 9500 0 Blue 0
9 AM Tue 37 38 W 7 8589 9500 0 Blue 0
10 AM Tue 41 43 W 7 8589 9500 0 Blue 0
11 AM Tue 44 48 W 13 9514 9500 0 Blue 0
12 Noon Tue 46 51 W 13 11522 9515 15 Blue 2
1 PM Tue 49 55 W 13 13266 12173 2673 Blue 6
2 PM Tue 50 55 W 14 13266 12173 2673 Blue 6
3 PM Tue 51 55 W 14 13266 12173 2673 Blue 6
4 PM Tue 50 53 W 14 12875 10740 1240 Blue 4
5 PM Tue 49 50 SW 14 10769 9500 0 Blue 1
6 PM Tue 47 47 SW 14 8968 9500 0 Blue 0
7 PM Tue 45 45 SW 14 8589 9500 0 Blue 0
8 PM Tue 43 43 SW 7 8589 9500 0 Blue 0
9 PM Tue 41 41 SW 7 8589 9500 0 Blue 0
10 PM Tue 39 39 SW 7 8589 9500 0 Blue 0
11 PM Tue 38 38 SW 8 8589 9500 0 Blue 0
12 Midnight Wed 37 37 SW 8 8589 9500 0 Blue 0
1 AM Wed 36 36 SW 8 8589 9500 0 Blue 0
2 AM Wed 35 35 SW 10 8589 9500 0 Blue 0
3 AM Wed 34 34 SW 10 8589 9500 0 Blue 0
4 AM Wed 32 32 SW 10 8589 9500 0 Blue 0
5 AM Wed 32 32 SW 15 8589 9500 0 Blue 0
6 AM Wed 33 33 SW 15 8589 9500 0 Blue 0
7 AM Wed 35 35 SW 15 8589 9500 0 Blue 0
8 AM Wed 38 38 SW 15 8589 9500 0 Blue 0
9 AM Wed 41 42 SW 15 8589 9500 0 Blue 0
10 AM Wed 44 47 SW 15 8968 9500 0 Blue 0
11 AM Wed 47 51 SW 31 11522 9515 15 Blue 2
12 Noon Wed 48 53 SW 31 12875 10740 1240 Blue 4
1 PM Wed 48 53 SW 31 12875 10740 1240 Blue 4
2 PM Wed 48 53 SW 32 12875 10740 1240 Blue 4
3 PM Wed 47 51 SW 32 11522 9515 15 Blue 2
4 PM Wed 46 48 SW 32 9514 9500 0 Blue 0
5 PM Wed 44 45 SW 32 8589 9500 0 Blue 0
6 PM Wed 42 42 SW 32 8589 9500 0 Blue 0
7 PM Wed 41 41 SW 32 8589 9500 0 Blue 0
8 PM Wed 39 39 SW 32 8589 9500 0 Blue 0
9 PM Wed 38 38 SW 32 8589 9500 0 Blue 0
10 PM Wed 36 36 SW 32 8589 9500 0 Blue 0
11 PM Wed 35 35 SW 15 8589 9500 0 Blue 0
12 Midnight Thu 34 34 SW 15 8589 9500 0 Blue 0
1 AM Thu 32 32 SW 15 8589 9500 0 Blue 0
2 AM Thu 31 31 SW 15 8589 9500 0 Blue 0
3 AM Thu 30 30 SW 15 8589 9500 0 Blue 0
4 AM Thu 29 29 SW 15 8589 9500 0 Blue 0
5 AM Thu 29 29 SW 12 8589 9500 0 Blue 0
6 AM Thu 29 29 SW 12 8589 9500 0 Blue 0
7 AM Thu 30 30 SW 12 8589 9500 0 Blue 0
8 AM Thu 32 32 SW 12 8589 9500 0 Blue 0
9 AM Thu 34 35 SW 12 8589 9500 0 Blue 0
10 AM Thu 36 38 SW 12 8589 9500 0 Blue 0
11 AM Thu 38 40 NW 18 8589 9500 0 Blue 0
12 Noon Thu 39 42 NW 18 8589 9500 0 Blue 0
1 PM Thu 39 42 NW 18 8589 9500 0 Blue 0
2 PM Thu 40 43 NW 18 8589 9500 0 Blue 0
3 PM Thu 39 41 NW 18 8589 9500 0 Blue 0
4 PM Thu 39 40 NW 18 8589 9500 0 Blue 0
5 PM Thu 38 38 NW 16 8589 9500 0 Blue 0
6 PM Thu 37 37 NW 16 8589 9500 0 Blue 0
7 PM Thu 36 36 NW 16 8589 9500 0 Blue 0
8 PM Thu 35 35 NW 16 8589 9500 0 Blue 0
9 PM Thu 33 33 NW 16 8589 9500 0 Blue 0
10 PM Thu 32 32 NW 16 8589 9500 0 Blue 0
11 PM Thu 31 31 SW 7 8589 9500 0 Blue 0
12 Midnight Fri 30 30 SW 7 8589 9500 0 Blue 0
1 AM Fri 29 29 SW 7 8589 9500 0 Blue 0
2 AM Fri 29 29 SW 7 8589 9500 0 Blue 0
3 AM Fri 29 29 SW 7 8589 9500 0 Blue 0
4 AM Fri 29 29 SW 7 8589 9500 0 Blue 0
5 AM Fri 28 28 SE 7 8589 9500 0 Blue 0
6 AM Fri 28 28 SE 7 8589 9500 0 Blue 0
7 AM Fri 29 29 SE 7 8589 9500 0 Blue 0
8 AM Fri 31 31 SE 7 8589 9500 0 Blue 0
9 AM Fri 35 36 SE 7 8589 9500 0 Blue 0
10 AM Fri 40 43 SE 7 8589 9500 0 Blue 0
11 AM Fri 43 47 NE 9 8968 9500 0 Blue 0
12 Noon Fri 45 50 NE 9 10769 9500 0 Blue 1
1 PM Fri 45 51 NE 9 11522 9515 15 Blue 2
2 PM Fri 45 50 NE 9 10769 9500 0 Blue 1
3 PM Fri 47 51 NE 9 11522 9515 15 Blue 2
4 PM Fri 48 51 NE 9 11522 9515 15 Blue 2
5 PM Fri 48 49 N 10 10046 9500 0 Blue 0
6 PM Fri 46 46 N 10 8589 9500 0 Blue 0
7 PM Fri 42 42 N 10 8589 9500 0 Blue 0
8 PM Fri 39 39 N 10 8589 9500 0 Blue 0
9 PM Fri 38 38 N 10 8589 9500 0 Blue 0
10 PM Fri 38 38 N 10 8589 9500 0 Blue 0
11 PM Fri 37 37 E 5 8589 9500 0 Blue 0
12 Midnight Sat 35 35 E 5 8589 9500 0 Blue 0
1 AM Sat 32 32 E 5 8589 9500 0 Blue 0
2 AM Sat 30 30 E 5 8589 9500 0 Blue 0
3 AM Sat 29 29 E 5 8589 9500 0 Blue 0
4 AM Sat 29 29 E 5 8589 9500 0 Blue 0
5 AM Sat 30 30 SE 5 8589 9500 0 Blue 0
6 AM Sat 30 30 SE 5 8589 9500 0 Blue 0
7 AM Sat 31 31 SE 5 8589 9500 0 Blue 0
8 AM Sat 34 34 SE 5 8589 9500 0 Blue 0
9 AM Sat 39 40 SE 5 8589 9500 0 Blue 0
10 AM Sat 44 47 SE 5 8968 9500 0 Blue 0
11 AM Sat 48 52 NE 7 12231 10038 538 Blue 3
12 Noon Sat 50 55 NE 7 13266 12173 2673 Blue 6
1 PM Sat 50 56 NE 7 13432 12810 3310 Blue 7
2 PM Sat 50 55 NE 7 13266 12173 2673 Blue 6
3 PM Sat 52 56 NE 7 13432 12810 3310 Blue 7
4 PM Sat 54 57 NE 7 13599 13080 3580 Blue 8
5 PM Sat 54 55 N 9 13266 12173 2673 Blue 6
6 PM Sat 51 51 N 9 11522 9515 15 Blue 2
7 PM Sat 47 47 N 9 8968 9500 0 Blue 0
8 PM Sat 44 44 N 9 8589 9500 0 Blue 0
9 PM Sat 42 42 N 9 8589 9500 0 Blue 0
10 PM Sat 42 42 N 9 8589 9500 0 Blue 0
11 PM Sat 42 42 S 5 8589 9500 0 Blue 0
12 Midnight Sun 40 40 S 5 8589 9500 0 Blue 0
1 AM Sun 37 37 S 5 8589 9500 0 Blue 0
2 AM Sun 35 35 S 5 8589 9500 0 Blue 0
3 AM Sun 34 34 S 5 8589 9500 0 Blue 0
4 AM Sun 35 35 S 5 8589 9500 0 Blue 0
5 AM Sun 35 35 S 7 8589 9500 0 Blue 0
6 AM Sun 35 35 S 7 8589 9500 0 Blue 0
7 AM Sun 36 36 S 7 8589 9500 0 Blue 0
8 AM Sun 39 39 S 7 8589 9500 0 Blue 0
9 AM Sun 45 46 S 7 8589 9500 0 Blue 0
10 AM Sun 50 53 S 7 12875 10740 1240 Blue 4
11 AM Sun 55 59 W 14 14115 13412 3912 Blue 10
12 Noon Sun 56 61 W 14 15009 13750 4250 Blue 12
1 PM Sun 56 61 W 14 15009 13750 4250 Blue 12
2 PM Sun 55 60 W 14 14543 13577 4077 Blue 11
3 PM Sun 56 60 W 14 14543 13577 4077 Blue 11
4 PM Sun 56 58 W 14 13775 13246 3746 Blue 9
5 PM Sun 56 56 W 17 13432 12810 3310 Blue 7
6 PM Sun 53 53 W 17 12875 10740 1240 Blue 4
7 PM Sun 49 49 W 17 10046 9500 0 Blue 0
8 PM Sun 46 46 W 17 8589 9500 0 Blue 0
9 PM Sun 44 44 W 17 8589 9500 0 Blue 0
10 PM Sun 44 44 W 17 8589 9500 0 Blue 0
11 PM Sun 43 43 W 9 8589 9500 0 Blue 0
12 Midnight Mon 41 41 W 9 8589 9500 0 Blue 0
1 AM Mon 38 38 W 9 8589 9500 0 Blue 0
2 AM Mon 36 36 W 9 8589 9500 0 Blue 0
3 AM Mon 36 36 W 9 8589 9500 0 Blue 0
4 AM Mon 36 36 W 9 8589 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