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

Station:

KVBG

Date/Time:

19 AUG 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 72 72 NE 6 3100 5075 0 Blue 0
6 AM Sun 72 72 NE 6 3100 5075 0 Blue 0
7 AM Sun 72 72 NE 6 3100 5075 0 Blue 0
8 AM Sun 77 77 S 2 3100 5075 0 Blue 0
9 AM Sun 79 81 S 2 3774 5075 0 Blue 0
10 AM Sun 80 84 S 2 7327 5075 0 Blue 2
11 AM Sun 82 88 SW 8 9149 7887 2812 Blue 6
12 Noon Sun 84 91 SW 8 10118 9094 4019 Blue 9
1 PM Sun 87 95 SW 8 11564 10514 5439 Blue 13
2 PM Sun 88 95 SW 9 11564 10514 5439 Blue 13
3 PM Sun 91 97 SW 9 12227 11164 6089 Blue 15
4 PM Sun 91 95 SW 9 11564 10514 5439 Blue 13
5 PM Sun 90 92 SW 3 10585 9417 4342 Blue 10
6 PM Sun 88 89 SW 3 9475 8439 3364 Blue 7
7 PM Sun 83 83 SW 3 6303 5075 0 Blue 1
8 PM Sun 77 77 E 2 3100 5075 0 Blue 0
9 PM Sun 76 76 E 2 3100 5075 0 Blue 0
10 PM Sun 75 75 E 2 3100 5075 0 Blue 0
11 PM Sun 74 74 E 5 3100 5075 0 Blue 0
12 Midnight Mon 74 74 E 5 3100 5075 0 Blue 0
1 AM Mon 74 74 E 5 3100 5075 0 Blue 0
2 AM Mon 73 73 E 5 3100 5075 0 Blue 0
3 AM Mon 74 74 E 5 3100 5075 0 Blue 0
4 AM Mon 73 73 E 5 3100 5075 0 Blue 0
5 AM Mon 73 73 E 3 3100 5075 0 Blue 0
6 AM Mon 72 72 E 3 3100 5075 0 Blue 0
7 AM Mon 72 72 E 3 3100 5075 0 Blue 0
8 AM Mon 77 77 S 1 3100 5075 0 Blue 0
9 AM Mon 79 81 S 1 3774 5075 0 Blue 0
10 AM Mon 80 84 S 1 7327 5075 0 Blue 2
11 AM Mon 82 88 W 7 9149 7887 2812 Blue 6
12 Noon Mon 84 91 W 7 10118 9094 4019 Blue 9
1 PM Mon 87 95 W 7 11564 10514 5439 Blue 13
2 PM Mon 88 95 W 8 11564 10514 5439 Blue 13
3 PM Mon 91 97 W 8 12227 11164 6089 Blue 15
4 PM Mon 91 95 W 8 11564 10514 5439 Blue 13
5 PM Mon 90 92 W 6 10585 9417 4342 Blue 10
6 PM Mon 88 89 W 6 9475 8439 3364 Blue 7
7 PM Mon 83 83 W 6 6303 5075 0 Blue 1
8 PM Mon 76 76 NW 2 3100 5075 0 Blue 0
9 PM Mon 75 75 NW 2 3100 5075 0 Blue 0
10 PM Mon 75 75 NW 2 3100 5075 0 Blue 0
11 PM Mon 74 74 N 3 3100 5075 0 Blue 0
12 Midnight Tue 73 73 N 3 3100 5075 0 Blue 0
1 AM Tue 73 73 N 3 3100 5075 0 Blue 0
2 AM Tue 72 72 E 3 3100 5075 0 Blue 0
3 AM Tue 73 73 E 3 3100 5075 0 Blue 0
4 AM Tue 72 72 E 3 3100 5075 0 Blue 0
5 AM Tue 72 72 S 2 3100 5075 0 Blue 0
6 AM Tue 71 71 S 2 3100 5075 0 Blue 0
7 AM Tue 71 71 S 2 3100 5075 0 Blue 0
8 AM Tue 76 76 S 2 3100 5075 0 Blue 0
9 AM Tue 78 80 S 2 3100 5075 0 Blue 0
10 AM Tue 78 82 S 2 4881 5075 0 Blue 0
11 AM Tue 80 85 W 8 7967 5075 0 Blue 3
12 Noon Tue 81 88 W 8 9149 7887 2812 Blue 6
1 PM Tue 85 92 W 8 10585 9417 4342 Blue 10
2 PM Tue 86 93 W 8 10915 9737 4662 Blue 11
3 PM Tue 88 94 W 8 11241 10054 4979 Blue 12
4 PM Tue 88 92 W 8 10585 9417 4342 Blue 10
5 PM Tue 87 89 W 3 9475 8439 3364 Blue 7
6 PM Tue 85 86 W 3 8488 6203 1128 Blue 4
7 PM Tue 81 81 W 3 3774 5075 0 Blue 0
8 PM Tue 75 75 W 3 3100 5075 0 Blue 0
9 PM Tue 74 74 W 3 3100 5075 0 Blue 0
10 PM Tue 73 73 W 3 3100 5075 0 Blue 0
11 PM Tue 72 72 E 3 3100 5075 0 Blue 0
12 Midnight Wed 72 72 E 3 3100 5075 0 Blue 0
1 AM Wed 72 72 E 3 3100 5075 0 Blue 0
2 AM Wed 71 71 E 3 3100 5075 0 Blue 0
3 AM Wed 71 71 E 3 3100 5075 0 Blue 0
4 AM Wed 71 71 E 3 3100 5075 0 Blue 0
5 AM Wed 71 71 E 2 3100 5075 0 Blue 0
6 AM Wed 70 70 E 2 3100 5075 0 Blue 0
7 AM Wed 70 70 E 2 3100 5075 0 Blue 0
8 AM Wed 75 75 E 2 3100 5075 0 Blue 0
9 AM Wed 77 79 E 2 3100 5075 0 Blue 0
10 AM Wed 78 82 E 2 4881 5075 0 Blue 0
11 AM Wed 80 86 W 7 8488 6203 1128 Blue 4
12 Noon Wed 81 88 W 7 9149 7887 2812 Blue 6
1 PM Wed 85 93 W 7 10915 9737 4662 Blue 11
2 PM Wed 86 93 W 7 10915 9737 4662 Blue 11
3 PM Wed 88 94 W 7 11241 10054 4979 Blue 12
4 PM Wed 88 92 W 7 10585 9417 4342 Blue 10
5 PM Wed 87 89 NW 3 9475 8439 3364 Blue 7
6 PM Wed 85 86 NW 3 8488 6203 1128 Blue 4
7 PM Wed 81 81 NW 3 3774 5075 0 Blue 0
8 PM Wed 75 75 NW 3 3100 5075 0 Blue 0
9 PM Wed 74 74 NW 3 3100 5075 0 Blue 0
10 PM Wed 73 73 NW 3 3100 5075 0 Blue 0
11 PM Wed 72 72 NE 5 3100 5075 0 Blue 0
12 Midnight Thu 72 72 NE 5 3100 5075 0 Blue 0
1 AM Thu 72 72 NE 5 3100 5075 0 Blue 0
2 AM Thu 71 71 NE 5 3100 5075 0 Blue 0
3 AM Thu 71 71 NE 5 3100 5075 0 Blue 0
4 AM Thu 71 71 NE 5 3100 5075 0 Blue 0
5 AM Thu 71 71 N 2 3100 5075 0 Blue 0
6 AM Thu 70 70 N 2 3100 5075 0 Blue 0
7 AM Thu 70 70 N 2 3100 5075 0 Blue 0
8 AM Thu 75 75 N 2 3100 5075 0 Blue 0
9 AM Thu 77 79 N 2 3100 5075 0 Blue 0
10 AM Thu 78 82 N 2 4881 5075 0 Blue 0
11 AM Thu 80 86 W 7 8488 6203 1128 Blue 4
12 Noon Thu 81 88 W 7 9149 7887 2812 Blue 6
1 PM Thu 85 93 W 7 10915 9737 4662 Blue 11
2 PM Thu 86 93 W 7 10915 9737 4662 Blue 11
3 PM Thu 88 94 W 7 11241 10054 4979 Blue 12
4 PM Thu 88 92 W 7 10585 9417 4342 Blue 10
5 PM Thu 87 89 NW 2 9475 8439 3364 Blue 7
6 PM Thu 85 86 NW 2 8488 6203 1128 Blue 4
7 PM Thu 80 80 NW 2 3100 5075 0 Blue 0
8 PM Thu 74 74 NW 2 3100 5075 0 Blue 0
9 PM Thu 73 73 NW 2 3100 5075 0 Blue 0
10 PM Thu 72 72 NW 2 3100 5075 0 Blue 0
11 PM Thu 71 71 NE 5 3100 5075 0 Blue 0
12 Midnight Fri 71 71 NE 5 3100 5075 0 Blue 0
1 AM Fri 71 71 NE 5 3100 5075 0 Blue 0
2 AM Fri 70 70 NE 5 3100 5075 0 Blue 0
3 AM Fri 71 71 NE 5 3100 5075 0 Blue 0
4 AM Fri 70 70 NE 5 3100 5075 0 Blue 0
5 AM Fri 70 70 N 2 3100 5075 0 Blue 0
6 AM Fri 69 69 N 2 3100 5075 0 Blue 0
7 AM Fri 69 69 N 2 3100 5075 0 Blue 0
8 AM Fri 74 74 N 2 3100 5075 0 Blue 0
9 AM Fri 76 78 N 2 3100 5075 0 Blue 0
10 AM Fri 77 81 N 2 3774 5075 0 Blue 0
11 AM Fri 79 85 W 8 7967 5075 0 Blue 3
12 Noon Fri 81 88 W 8 9149 7887 2812 Blue 6
1 PM Fri 84 92 W 8 10585 9417 4342 Blue 10
2 PM Fri 85 92 W 8 10585 9417 4342 Blue 10
3 PM Fri 88 94 W 8 11241 10054 4979 Blue 12
4 PM Fri 88 92 W 8 10585 9417 4342 Blue 10
5 PM Fri 87 89 NW 3 9475 8439 3364 Blue 7
6 PM Fri 85 86 NW 3 8488 6203 1128 Blue 4
7 PM Fri 80 80 NW 3 3100 5075 0 Blue 0
8 PM Fri 74 74 NW 3 3100 5075 0 Blue 0
9 PM Fri 73 73 NW 3 3100 5075 0 Blue 0
10 PM Fri 72 72 NW 3 3100 5075 0 Blue 0
11 PM Fri 71 71 NE 5 3100 5075 0 Blue 0
12 Midnight Sat 71 71 NE 5 3100 5075 0 Blue 0
1 AM Sat 71 71 NE 5 3100 5075 0 Blue 0
2 AM Sat 70 70 NE 5 3100 5075 0 Blue 0
3 AM Sat 71 71 NE 5 3100 5075 0 Blue 0
4 AM Sat 70 70 NE 5 3100 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