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

Station:

KVBG

Date/Time:

16 SEP 2018

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 Sun 34 34 SW 13 9478 9500 0 Blue 0
6 AM Sun 35 35 SW 13 9478 9500 0 Blue 0
7 AM Sun 37 37 SW 13 9478 9500 0 Blue 0
8 AM Sun 40 40 S 12 9478 9500 0 Blue 0
9 AM Sun 44 45 S 12 9478 9500 0 Blue 0
10 AM Sun 48 51 S 12 10104 9500 0 Blue 0
11 AM Sun 52 56 S 13 11787 10555 1055 Blue 5
12 Noon Sun 55 60 S 13 13866 12283 2783 Blue 9
1 PM Sun 57 63 S 13 15289 13799 4299 Blue 12
2 PM Sun 58 63 SW 12 15289 13799 4299 Blue 12
3 PM Sun 58 62 SW 12 14826 13307 3807 Blue 11
4 PM Sun 58 61 SW 12 14352 12802 3302 Blue 10
5 PM Sun 57 58 SW 10 12856 11197 1697 Blue 7
6 PM Sun 55 55 SW 10 11226 10324 824 Blue 4
7 PM Sun 53 53 SW 10 10562 9886 386 Blue 2
8 PM Sun 50 50 NE 9 9888 9500 0 Blue 0
9 PM Sun 46 46 NE 9 9478 9500 0 Blue 0
10 PM Sun 43 43 NE 9 9478 9500 0 Blue 0
11 PM Sun 41 41 SE 9 9478 9500 0 Blue 0
12 Midnight Mon 40 40 SE 9 9478 9500 0 Blue 0
1 AM Mon 40 40 SE 9 9478 9500 0 Blue 0
2 AM Mon 39 39 S 8 9478 9500 0 Blue 0
3 AM Mon 38 38 S 8 9478 9500 0 Blue 0
4 AM Mon 36 36 S 8 9478 9500 0 Blue 0
5 AM Mon 35 35 S 10 9478 9500 0 Blue 0
6 AM Mon 36 36 S 10 9478 9500 0 Blue 0
7 AM Mon 38 38 S 10 9478 9500 0 Blue 0
8 AM Mon 41 41 S 10 9478 9500 0 Blue 0
9 AM Mon 45 46 S 10 9478 9500 0 Blue 0
10 AM Mon 49 52 S 10 10330 9671 171 Blue 1
11 AM Mon 53 57 S 10 12330 10784 1284 Blue 6
12 Noon Mon 56 61 S 10 14352 12802 3302 Blue 10
1 PM Mon 58 64 S 10 15732 14278 4778 Blue 13
2 PM Mon 59 64 SW 13 15732 14278 4778 Blue 13
3 PM Mon 59 63 SW 13 15289 13799 4299 Blue 12
4 PM Mon 59 62 SW 13 14826 13307 3807 Blue 11
5 PM Mon 58 59 W 10 13368 11749 2249 Blue 8
6 PM Mon 56 56 W 10 11787 10555 1055 Blue 5
7 PM Mon 53 53 W 10 10562 9886 386 Blue 2
8 PM Mon 50 50 W 10 9888 9500 0 Blue 0
9 PM Mon 47 47 W 10 9478 9500 0 Blue 0
10 PM Mon 44 44 W 10 9478 9500 0 Blue 0
11 PM Mon 42 42 S 8 9478 9500 0 Blue 0
12 Midnight Tue 41 41 S 8 9478 9500 0 Blue 0
1 AM Tue 40 40 S 8 9478 9500 0 Blue 0
2 AM Tue 39 39 S 8 9478 9500 0 Blue 0
3 AM Tue 38 38 S 8 9478 9500 0 Blue 0
4 AM Tue 37 37 S 8 9478 9500 0 Blue 0
5 AM Tue 36 36 SW 8 9478 9500 0 Blue 0
6 AM Tue 37 37 SW 8 9478 9500 0 Blue 0
7 AM Tue 38 38 SW 8 9478 9500 0 Blue 0
8 AM Tue 41 41 SW 8 9478 9500 0 Blue 0
9 AM Tue 45 46 SW 8 9478 9500 0 Blue 0
10 AM Tue 49 52 SW 8 10330 9671 171 Blue 1
11 AM Tue 53 57 SW 14 12330 10784 1284 Blue 6
12 Noon Tue 56 61 SW 14 14352 12802 3302 Blue 10
1 PM Tue 57 63 SW 14 15289 13799 4299 Blue 12
2 PM Tue 58 63 SW 14 15289 13799 4299 Blue 12
3 PM Tue 58 62 SW 14 14826 13307 3807 Blue 11
4 PM Tue 57 60 SW 14 13866 12283 2783 Blue 9
5 PM Tue 55 56 W 13 11787 10555 1055 Blue 5
6 PM Tue 53 53 W 13 10562 9886 386 Blue 2
7 PM Tue 50 50 W 13 9888 9500 0 Blue 0
8 PM Tue 48 48 W 13 9478 9500 0 Blue 0
9 PM Tue 45 45 W 13 9478 9500 0 Blue 0
10 PM Tue 43 43 W 13 9478 9500 0 Blue 0
11 PM Tue 41 41 SW 7 9478 9500 0 Blue 0
12 Midnight Wed 40 40 SW 7 9478 9500 0 Blue 0
1 AM Wed 39 39 SW 7 9478 9500 0 Blue 0
2 AM Wed 38 38 SW 7 9478 9500 0 Blue 0
3 AM Wed 37 37 SW 7 9478 9500 0 Blue 0
4 AM Wed 36 36 SW 7 9478 9500 0 Blue 0
5 AM Wed 35 35 SW 10 9478 9500 0 Blue 0
6 AM Wed 35 35 SW 10 9478 9500 0 Blue 0
7 AM Wed 35 35 SW 10 9478 9500 0 Blue 0
8 AM Wed 37 37 SW 10 9478 9500 0 Blue 0
9 AM Wed 41 42 SW 10 9478 9500 0 Blue 0
10 AM Wed 45 48 SW 10 9478 9500 0 Blue 0
11 AM Wed 49 53 W 8 10562 9886 386 Blue 2
12 Noon Wed 51 56 W 8 11787 10555 1055 Blue 5
1 PM Wed 53 59 W 8 13368 11749 2249 Blue 8
2 PM Wed 55 60 W 8 13866 12283 2783 Blue 9
3 PM Wed 56 60 W 8 13866 12283 2783 Blue 9
4 PM Wed 57 60 W 8 13866 12283 2783 Blue 9
5 PM Wed 55 56 N 9 11787 10555 1055 Blue 5
6 PM Wed 51 51 N 9 10104 9500 0 Blue 0
7 PM Wed 45 45 N 9 9478 9500 0 Blue 0
8 PM Wed 42 42 N 9 9478 9500 0 Blue 0
9 PM Wed 41 41 N 9 9478 9500 0 Blue 0
10 PM Wed 42 42 N 9 9478 9500 0 Blue 0
11 PM Wed 42 42 E 7 9478 9500 0 Blue 0
12 Midnight Thu 39 39 E 7 9478 9500 0 Blue 0
1 AM Thu 36 36 E 7 9478 9500 0 Blue 0
2 AM Thu 34 34 E 7 9478 9500 0 Blue 0
3 AM Thu 34 34 E 7 9478 9500 0 Blue 0
4 AM Thu 35 35 E 7 9478 9500 0 Blue 0
5 AM Thu 37 37 S 8 9478 9500 0 Blue 0
6 AM Thu 37 37 S 8 9478 9500 0 Blue 0
7 AM Thu 38 38 S 8 9478 9500 0 Blue 0
8 AM Thu 40 40 S 8 9478 9500 0 Blue 0
9 AM Thu 43 44 S 8 9478 9500 0 Blue 0
10 AM Thu 48 51 S 8 10104 9500 0 Blue 0
11 AM Thu 53 57 SW 9 12330 10784 1284 Blue 6
12 Noon Thu 55 60 SW 9 13866 12283 2783 Blue 9
1 PM Thu 57 63 SW 9 15289 13799 4299 Blue 12
2 PM Thu 58 63 SW 9 15289 13799 4299 Blue 12
3 PM Thu 59 63 SW 9 15289 13799 4299 Blue 12
4 PM Thu 58 61 SW 9 14352 12802 3302 Blue 10
5 PM Thu 56 57 W 9 12330 10784 1284 Blue 6
6 PM Thu 52 52 W 9 10330 9671 171 Blue 1
7 PM Thu 47 47 W 9 9478 9500 0 Blue 0
8 PM Thu 43 43 W 9 9478 9500 0 Blue 0
9 PM Thu 42 42 W 9 9478 9500 0 Blue 0
10 PM Thu 42 42 W 9 9478 9500 0 Blue 0
11 PM Thu 42 42 SW 9 9478 9500 0 Blue 0
12 Midnight Fri 40 40 SW 9 9478 9500 0 Blue 0
1 AM Fri 36 36 SW 9 9478 9500 0 Blue 0
2 AM Fri 34 34 SW 9 9478 9500 0 Blue 0
3 AM Fri 34 34 SW 9 9478 9500 0 Blue 0
4 AM Fri 36 36 SW 9 9478 9500 0 Blue 0
5 AM Fri 37 37 SW 14 9478 9500 0 Blue 0
6 AM Fri 37 37 SW 14 9478 9500 0 Blue 0
7 AM Fri 37 37 SW 14 9478 9500 0 Blue 0
8 AM Fri 39 39 SW 14 9478 9500 0 Blue 0
9 AM Fri 42 43 SW 14 9478 9500 0 Blue 0
10 AM Fri 47 50 SW 14 9888 9500 0 Blue 0
11 AM Fri 51 55 SW 15 11226 10324 824 Blue 4
12 Noon Fri 54 59 SW 15 13368 11749 2249 Blue 8
1 PM Fri 55 61 SW 15 14352 12802 3302 Blue 10
2 PM Fri 56 61 SW 15 14352 12802 3302 Blue 10
3 PM Fri 57 61 SW 15 14352 12802 3302 Blue 10
4 PM Fri 56 59 SW 15 13368 11749 2249 Blue 8
5 PM Fri 54 55 SW 16 11226 10324 824 Blue 4
6 PM Fri 50 50 SW 16 9888 9500 0 Blue 0
7 PM Fri 46 46 SW 16 9478 9500 0 Blue 0
8 PM Fri 43 43 SW 16 9478 9500 0 Blue 0
9 PM Fri 42 42 SW 16 9478 9500 0 Blue 0
10 PM Fri 42 42 SW 16 9478 9500 0 Blue 0
11 PM Fri 43 43 S 16 9478 9500 0 Blue 0
12 Midnight Sat 41 41 S 16 9478 9500 0 Blue 0
1 AM Sat 38 38 S 16 9478 9500 0 Blue 0
2 AM Sat 36 36 S 16 9478 9500 0 Blue 0
3 AM Sat 36 36 S 16 9478 9500 0 Blue 0
4 AM Sat 37 37 S 16 9478 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