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

Station:

KVBG

Date/Time:

27 MAY 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 33 33 N 10 7592 9500 0 Blue 0
6 AM Sun 34 34 N 10 7592 9500 0 Blue 0
7 AM Sun 36 36 N 10 7592 9500 0 Blue 0
8 AM Sun 38 39 N 13 8103 9500 0 Blue 0
9 AM Sun 40 42 N 13 8930 9500 0 Blue 0
10 AM Sun 41 44 N 13 9475 9500 0 Blue 0
11 AM Sun 43 47 N 9 10707 9500 0 Blue 1
12 Noon Sun 44 49 N 9 11106 10010 510 Blue 3
1 PM Sun 46 51 N 9 11505 10898 1398 Blue 5
2 PM Sun 47 52 N 15 11703 11097 1597 Blue 6
3 PM Sun 48 52 N 15 11703 11097 1597 Blue 6
4 PM Sun 49 52 N 15 11703 11097 1597 Blue 6
5 PM Sun 49 51 N 17 11505 10898 1398 Blue 5
6 PM Sun 47 48 N 17 10907 9743 243 Blue 2
7 PM Sun 45 45 N 17 9745 9500 0 Blue 0
8 PM Sun 43 43 N 14 9203 9500 0 Blue 0
9 PM Sun 41 41 N 14 8656 9500 0 Blue 0
10 PM Sun 40 40 N 14 8380 9500 0 Blue 0
11 PM Sun 39 39 N 15 8103 9500 0 Blue 0
12 Midnight Mon 38 38 N 15 7824 9500 0 Blue 0
1 AM Mon 37 37 N 15 7592 9500 0 Blue 0
2 AM Mon 36 36 N 14 7592 9500 0 Blue 0
3 AM Mon 35 35 N 14 7592 9500 0 Blue 0
4 AM Mon 34 34 N 14 7592 9500 0 Blue 0
5 AM Mon 34 34 N 10 7592 9500 0 Blue 0
6 AM Mon 36 36 N 10 7592 9500 0 Blue 0
7 AM Mon 39 39 N 10 8103 9500 0 Blue 0
8 AM Mon 43 44 N 10 9475 9500 0 Blue 0
9 AM Mon 46 49 N 10 11106 10010 510 Blue 3
10 AM Mon 49 54 N 10 12320 11492 1992 Blue 8
11 AM Mon 51 57 N 10 14029 12268 2768 Blue 11
12 Noon Mon 53 60 N 10 16140 13952 4452 Blue 14
1 PM Mon 54 62 N 10 17882 15239 5739 Blue 16
2 PM Mon 55 62 N 12 17882 15239 5739 Blue 16
3 PM Mon 55 61 N 12 16847 14477 4977 Blue 15
4 PM Mon 56 60 N 12 16140 13952 4452 Blue 14
5 PM Mon 56 58 N 15 14571 12849 3349 Blue 12
6 PM Mon 55 56 N 15 13480 11938 2438 Blue 10
7 PM Mon 53 53 N 15 11959 11295 1795 Blue 7
8 PM Mon 51 51 N 15 11505 10898 1398 Blue 5
9 PM Mon 50 50 N 15 11306 10699 1199 Blue 4
10 PM Mon 48 48 N 15 10907 9743 243 Blue 2
11 PM Mon 47 47 NE 9 10707 9500 0 Blue 1
12 Midnight Tue 45 45 NE 9 9745 9500 0 Blue 0
1 AM Tue 44 44 NE 9 9475 9500 0 Blue 0
2 AM Tue 43 43 NE 9 9203 9500 0 Blue 0
3 AM Tue 41 41 NE 9 8656 9500 0 Blue 0
4 AM Tue 40 40 NE 9 8380 9500 0 Blue 0
5 AM Tue 40 40 E 6 8380 9500 0 Blue 0
6 AM Tue 42 42 E 6 8930 9500 0 Blue 0
7 AM Tue 46 46 E 6 10014 9500 0 Blue 0
8 AM Tue 50 51 E 6 11505 10898 1398 Blue 5
9 AM Tue 52 55 E 6 12911 11689 2189 Blue 9
10 AM Tue 54 58 E 6 14571 12849 3349 Blue 12
11 AM Tue 56 60 SW 13 16140 13952 4452 Blue 14
12 Noon Tue 58 63 SW 13 19822 15984 6484 Blue 17
1 PM Tue 60 65 SW 13 22003 17344 7844 Blue 19
2 PM Tue 61 66 SW 13 22216 19151 9651 Blue 20
3 PM Tue 61 65 SW 13 22003 17344 7844 Blue 19
4 PM Tue 60 63 SW 13 19822 15984 6484 Blue 17
5 PM Tue 58 59 W 13 15385 13410 3910 Blue 13
6 PM Tue 57 57 W 13 14029 12268 2768 Blue 11
7 PM Tue 55 55 W 13 12911 11689 2189 Blue 9
8 PM Tue 54 54 W 13 12320 11492 1992 Blue 8
9 PM Tue 52 52 W 13 11703 11097 1597 Blue 6
10 PM Tue 50 50 W 13 11306 10699 1199 Blue 4
11 PM Tue 48 48 SW 9 10907 9743 243 Blue 2
12 Midnight Wed 48 48 SW 9 10907 9743 243 Blue 2
1 AM Wed 47 47 SW 9 10707 9500 0 Blue 1
2 AM Wed 46 46 SW 9 10014 9500 0 Blue 0
3 AM Wed 45 45 SW 9 9745 9500 0 Blue 0
4 AM Wed 43 43 SW 9 9203 9500 0 Blue 0
5 AM Wed 43 43 SW 16 9203 9500 0 Blue 0
6 AM Wed 45 45 SW 16 9745 9500 0 Blue 0
7 AM Wed 48 48 SW 16 10907 9743 243 Blue 2
8 AM Wed 51 52 SW 16 11703 11097 1597 Blue 6
9 AM Wed 53 55 SW 16 12911 11689 2189 Blue 9
10 AM Wed 54 58 SW 16 14571 12849 3349 Blue 12
11 AM Wed 55 59 SW 17 15385 13410 3910 Blue 13
12 Noon Wed 56 61 SW 17 16847 14477 4977 Blue 15
1 PM Wed 56 61 SW 17 16847 14477 4977 Blue 15
2 PM Wed 56 61 SW 17 16847 14477 4977 Blue 15
3 PM Wed 56 60 SW 17 16140 13952 4452 Blue 14
4 PM Wed 55 58 SW 17 14571 12849 3349 Blue 12
5 PM Wed 53 54 SW 21 12320 11492 1992 Blue 8
6 PM Wed 51 51 SW 21 11505 10898 1398 Blue 5
7 PM Wed 49 49 SW 21 11106 10010 510 Blue 3
8 PM Wed 47 47 SW 21 10707 9500 0 Blue 1
9 PM Wed 45 45 SW 21 9745 9500 0 Blue 0
10 PM Wed 44 44 SW 21 9475 9500 0 Blue 0
11 PM Wed 44 44 S 15 9475 9500 0 Blue 0
12 Midnight Thu 43 43 S 15 9203 9500 0 Blue 0
1 AM Thu 42 42 S 15 8930 9500 0 Blue 0
2 AM Thu 41 41 S 15 8656 9500 0 Blue 0
3 AM Thu 39 39 S 15 8103 9500 0 Blue 0
4 AM Thu 38 38 S 15 7824 9500 0 Blue 0
5 AM Thu 38 38 S 13 7824 9500 0 Blue 0
6 AM Thu 40 40 S 13 8380 9500 0 Blue 0
7 AM Thu 43 43 S 13 9203 9500 0 Blue 0
8 AM Thu 45 46 S 13 10014 9500 0 Blue 0
9 AM Thu 47 49 S 13 11106 10010 510 Blue 3
10 AM Thu 47 50 S 13 11306 10699 1199 Blue 4
11 AM Thu 47 51 S 18 11505 10898 1398 Blue 5
12 Noon Thu 48 52 S 18 11703 11097 1597 Blue 6
1 PM Thu 49 54 S 18 12320 11492 1992 Blue 8
2 PM Thu 50 54 S 18 12320 11492 1992 Blue 8
3 PM Thu 49 52 S 18 11703 11097 1597 Blue 6
4 PM Thu 48 50 S 18 11306 10699 1199 Blue 4
5 PM Thu 46 47 SW 21 10707 9500 0 Blue 1
6 PM Thu 44 44 SW 21 9475 9500 0 Blue 0
7 PM Thu 43 43 SW 21 9203 9500 0 Blue 0
8 PM Thu 41 41 SW 21 8656 9500 0 Blue 0
9 PM Thu 39 39 SW 21 8103 9500 0 Blue 0
10 PM Thu 38 38 SW 21 7824 9500 0 Blue 0
11 PM Thu 37 37 W 9 7592 9500 0 Blue 0
12 Midnight Fri 36 36 W 9 7592 9500 0 Blue 0
1 AM Fri 36 36 W 9 7592 9500 0 Blue 0
2 AM Fri 35 35 W 9 7592 9500 0 Blue 0
3 AM Fri 34 34 W 9 7592 9500 0 Blue 0
4 AM Fri 33 33 W 9 7592 9500 0 Blue 0
5 AM Fri 33 33 SW 6 7592 9500 0 Blue 0
6 AM Fri 35 35 SW 6 7592 9500 0 Blue 0
7 AM Fri 38 38 SW 6 7824 9500 0 Blue 0
8 AM Fri 41 42 SW 6 8930 9500 0 Blue 0
9 AM Fri 43 45 SW 6 9745 9500 0 Blue 0
10 AM Fri 44 48 SW 6 10907 9743 243 Blue 2
11 AM Fri 45 50 W 9 11306 10699 1199 Blue 4
12 Noon Fri 47 53 W 9 11959 11295 1795 Blue 7
1 PM Fri 48 54 W 9 12320 11492 1992 Blue 8
2 PM Fri 49 54 W 9 12320 11492 1992 Blue 8
3 PM Fri 50 54 W 9 12320 11492 1992 Blue 8
4 PM Fri 51 54 W 9 12320 11492 1992 Blue 8
5 PM Fri 50 52 W 9 11703 11097 1597 Blue 6
6 PM Fri 48 48 W 9 10907 9743 243 Blue 2
7 PM Fri 45 45 W 9 9745 9500 0 Blue 0
8 PM Fri 43 43 W 9 9203 9500 0 Blue 0
9 PM Fri 42 42 W 9 8930 9500 0 Blue 0
10 PM Fri 42 42 W 9 8930 9500 0 Blue 0
11 PM Fri 41 41 N 7 8656 9500 0 Blue 0
12 Midnight Sat 39 39 N 7 8103 9500 0 Blue 0
1 AM Sat 38 38 N 7 7824 9500 0 Blue 0
2 AM Sat 36 36 N 7 7592 9500 0 Blue 0
3 AM Sat 35 35 N 7 7592 9500 0 Blue 0
4 AM Sat 36 36 N 7 7592 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