Detailed Predictions for: Slick Rock
Launch Altitude (f): 5075
LZ Altitude (f): 1140
Sounding

Station:

 KVBG

Date/Time:

 3 SEP 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
5 AM Fri 63 63 N 7 3340 5075 0 Blue 0
6 AM Fri 61 61 N 7 3340 5075 0 Blue 0
7 AM Fri 61 61 N 7 3340 5075 0 Blue 0
8 AM Fri 62 62 E 5 3340 5075 0 Blue 0
9 AM Fri 68 70 E 5 3340 5075 0 Blue 0
10 AM Fri 76 80 E 5 3340 5075 0 Blue 0
11 AM Fri 82 87 S 6 8932 6264 1189 Blue 4
12 Noon Fri 85 92 S 6 11363 9997 4922 Blue 9
1 PM Fri 87 94 S 6 11991 10970 5895 Blue 11
2 PM Fri 88 95 SW 10 12302 11286 6211 Blue 12
3 PM Fri 89 94 SW 10 11991 10970 5895 Blue 11
4 PM Fri 91 95 SW 10 12302 11286 6211 Blue 12
5 PM Fri 90 92 W 8 11363 9997 4922 Blue 9
6 PM Fri 85 85 W 8 7300 5075 0 Blue 2
7 PM Fri 79 79 W 8 3340 5075 0 Blue 0
8 PM Fri 73 73 N 5 3340 5075 0 Blue 0
9 PM Fri 70 70 N 5 3340 5075 0 Blue 0
10 PM Fri 69 69 N 5 3340 5075 0 Blue 0
11 PM Fri 68 68 N 7 3340 5075 0 Blue 0
12 Midnight Sat 67 67 N 7 3340 5075 0 Blue 0
1 AM Sat 65 65 N 7 3340 5075 0 Blue 0
2 AM Sat 64 64 N 5 3340 5075 0 Blue 0
3 AM Sat 63 63 N 5 3340 5075 0 Blue 0
4 AM Sat 62 62 N 5 3340 5075 0 Blue 0
5 AM Sat 62 62 N 6 3340 5075 0 Blue 0
6 AM Sat 61 61 N 6 3340 5075 0 Blue 0
7 AM Sat 60 60 N 6 3340 5075 0 Blue 0
8 AM Sat 62 62 E 5 3340 5075 0 Blue 0
9 AM Sat 68 70 E 5 3340 5075 0 Blue 0
10 AM Sat 75 79 E 5 3340 5075 0 Blue 0
11 AM Sat 82 87 S 7 8932 6264 1189 Blue 4
12 Noon Sat 86 93 S 7 11678 10651 5576 Blue 10
1 PM Sat 88 95 S 7 12302 11286 6211 Blue 12
2 PM Sat 89 96 SW 10 12609 11600 6525 Blue 13
3 PM Sat 90 95 SW 10 12302 11286 6211 Blue 12
4 PM Sat 90 94 SW 10 11991 10970 5895 Blue 11
5 PM Sat 88 90 SW 10 10722 8834 3759 Blue 7
6 PM Sat 84 84 SW 10 6342 5075 0 Blue 1
7 PM Sat 79 79 SW 10 3340 5075 0 Blue 0
8 PM Sat 74 74 NW 10 3340 5075 0 Blue 0
9 PM Sat 71 71 NW 10 3340 5075 0 Blue 0
10 PM Sat 68 68 NW 10 3340 5075 0 Blue 0
11 PM Sat 67 67 NE 6 3340 5075 0 Blue 0
12 Midnight Sun 65 65 NE 6 3340 5075 0 Blue 0
1 AM Sun 65 65 NE 6 3340 5075 0 Blue 0
2 AM Sun 64 64 N 6 3340 5075 0 Blue 0
3 AM Sun 64 64 N 6 3340 5075 0 Blue 0
4 AM Sun 64 64 N 6 3340 5075 0 Blue 0
5 AM Sun 64 64 NE 5 3340 5075 0 Blue 0
6 AM Sun 62 62 NE 5 3340 5075 0 Blue 0
7 AM Sun 60 60 NE 5 3340 5075 0 Blue 0
8 AM Sun 60 60 NE 5 3340 5075 0 Blue 0
9 AM Sun 65 67 NE 5 3340 5075 0 Blue 0
10 AM Sun 71 75 NE 5 3340 5075 0 Blue 0
11 AM Sun 77 82 SW 9 4490 5075 0 Blue 0
12 Noon Sun 80 87 SW 9 8932 6264 1189 Blue 4
1 PM Sun 82 89 SW 9 10110 8059 2984 Blue 6
2 PM Sun 83 90 SW 9 10722 8834 3759 Blue 7
3 PM Sun 84 89 SW 9 10110 8059 2984 Blue 6
4 PM Sun 84 88 SW 9 9531 7202 2127 Blue 5
5 PM Sun 83 85 NW 12 7300 5075 0 Blue 2
6 PM Sun 79 79 NW 12 3340 5075 0 Blue 0
7 PM Sun 74 74 NW 12 3340 5075 0 Blue 0
8 PM Sun 69 69 NW 12 3340 5075 0 Blue 0
9 PM Sun 65 65 NW 12 3340 5075 0 Blue 0
10 PM Sun 62 62 NW 12 3340 5075 0 Blue 0
11 PM Sun 60 60 NE 7 3340 5075 0 Blue 0
12 Midnight Mon 59 59 NE 7 3340 5075 0 Blue 0
1 AM Mon 58 58 NE 7 3340 5075 0 Blue 0
2 AM Mon 58 58 NE 7 3340 5075 0 Blue 0
3 AM Mon 56 56 NE 7 3340 5075 0 Blue 0
4 AM Mon 55 55 NE 7 3340 5075 0 Blue 0
5 AM Mon 54 54 NE 6 3340 5075 0 Blue 0
6 AM Mon 52 52 NE 6 3340 5075 0 Blue 0
7 AM Mon 52 52 NE 6 3340 5075 0 Blue 0
8 AM Mon 54 54 NE 6 3340 5075 0 Blue 0
9 AM Mon 59 61 NE 6 3340 5075 0 Blue 0
10 AM Mon 66 70 NE 6 3340 5075 0 Blue 0
11 AM Mon 73 78 SW 7 3340 5075 0 Blue 0
12 Noon Mon 77 84 SW 7 6342 5075 0 Blue 1
1 PM Mon 79 86 SW 7 8171 5213 138 Blue 3
2 PM Mon 80 87 SW 7 8932 6264 1189 Blue 4
3 PM Mon 82 87 SW 7 8932 6264 1189 Blue 4
4 PM Mon 82 86 SW 7 8171 5213 138 Blue 3
5 PM Mon 81 83 W 7 5264 5075 0 Blue 0
6 PM Mon 77 77 W 7 3340 5075 0 Blue 0
7 PM Mon 72 72 W 7 3340 5075 0 Blue 0
8 PM Mon 67 67 W 7 3340 5075 0 Blue 0
9 PM Mon 63 63 W 7 3340 5075 0 Blue 0
10 PM Mon 60 60 W 7 3340 5075 0 Blue 0
11 PM Mon 58 58 E 3 3340 5075 0 Blue 0
12 Midnight Tue 57 57 E 3 3340 5075 0 Blue 0
1 AM Tue 56 56 E 3 3340 5075 0 Blue 0
2 AM Tue 56 56 E 3 3340 5075 0 Blue 0
3 AM Tue 55 55 E 3 3340 5075 0 Blue 0
4 AM Tue 55 55 E 3 3340 5075 0 Blue 0
5 AM Tue 55 55 E 7 3340 5075 0 Blue 0
6 AM Tue 53 53 E 7 3340 5075 0 Blue 0
7 AM Tue 52 52 E 7 3340 5075 0 Blue 0
8 AM Tue 53 53 E 7 3340 5075 0 Blue 0
9 AM Tue 59 61 E 7 3340 5075 0 Blue 0
10 AM Tue 66 70 E 7 3340 5075 0 Blue 0
11 AM Tue 72 77 W 9 3340 5075 0 Blue 0
12 Noon Tue 75 82 W 9 4490 5075 0 Blue 0
1 PM Tue 77 84 W 9 6342 5075 0 Blue 1
2 PM Tue 78 85 W 9 7300 5075 0 Blue 2
3 PM Tue 78 83 W 9 5264 5075 0 Blue 0
4 PM Tue 78 82 W 9 4490 5075 0 Blue 0
5 PM Tue 76 78 W 12 3340 5075 0 Blue 0
6 PM Tue 74 74 W 12 3340 5075 0 Blue 0
7 PM Tue 70 70 W 12 3340 5075 0 Blue 0
8 PM Tue 67 67 W 12 3340 5075 0 Blue 0
9 PM Tue 64 64 W 12 3340 5075 0 Blue 0
10 PM Tue 61 61 W 12 3340 5075 0 Blue 0
11 PM Tue 58 58 E 2 3340 5075 0 Blue 0
12 Midnight Wed 57 57 E 2 3340 5075 0 Blue 0
1 AM Wed 56 56 E 2 3340 5075 0 Blue 0
2 AM Wed 56 56 E 2 3340 5075 0 Blue 0
3 AM Wed 55 55 E 2 3340 5075 0 Blue 0
4 AM Wed 55 55 E 2 3340 5075 0 Blue 0
5 AM Wed 54 54 SE 1 3340 5075 0 Blue 0
6 AM Wed 53 53 SE 1 3340 5075 0 Blue 0
7 AM Wed 51 51 SE 1 3340 5075 0 Blue 0
8 AM Wed 52 52 SE 1 3340 5075 0 Blue 0
9 AM Wed 55 57 SE 1 3340 5075 0 Blue 0
10 AM Wed 60 64 SE 1 3340 5075 0 Blue 0
11 AM Wed 64 69 W 9 3340 5075 0 Blue 0
12 Noon Wed 67 74 W 9 3340 5075 0 Blue 0
1 PM Wed 70 77 W 9 3340 5075 0 Blue 0
2 PM Wed 71 78 W 9 3340 5075 0 Blue 0
3 PM Wed 72 77 W 9 3340 5075 0 Blue 0
4 PM Wed 71 75 W 9 3340 5075 0 Blue 0
5 PM Wed 70 72 W 12 3340 5075 0 Blue 0
6 PM Wed 68 68 W 12 3340 5075 0 Blue 0
7 PM Wed 66 66 W 12 3340 5075 0 Blue 0
8 PM Wed 64 64 W 12 3340 5075 0 Blue 0
9 PM Wed 61 61 W 12 3340 5075 0 Blue 0
10 PM Wed 59 59 W 12 3340 5075 0 Blue 0
11 PM Wed 58 58 N 3 3340 5075 0 Blue 0
12 Midnight Thu 57 57 N 3 3340 5075 0 Blue 0
1 AM Thu 56 56 N 3 3340 5075 0 Blue 0
2 AM Thu 55 55 N 3 3340 5075 0 Blue 0
3 AM Thu 55 55 N 3 3340 5075 0 Blue 0
4 AM Thu 54 54 N 3 3340 5075 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