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

Station:

KVBG

Date/Time:

20 AUG 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 67 67 NE 3 4063 5075 0 Blue 0
6 AM Tue 65 65 NE 3 3881 5075 0 Blue 0
7 AM Tue 65 65 E 2 3881 5075 0 Blue 0
8 AM Tue 73 73 NW 2 4611 5075 0 Blue 0
9 AM Tue 77 79 W 2 5905 5075 0 Blue 3
10 AM Tue 78 82 W 5 6982 5881 806 Blue 6
11 AM Tue 80 86 W 6 8365 7295 2220 Blue 10
12 Noon Tue 83 90 W 6 9694 8650 3575 Blue 14
1 PM Tue 85 93 W 7 11435 9633 4558 Blue 16
2 PM Tue 86 93 W 7 11435 9633 4558 Blue 16
3 PM Tue 87 93 W 6 11435 9633 4558 Blue 16
4 PM Tue 87 91 W 6 10019 8981 3906 Blue 15
5 PM Tue 86 88 W 6 9036 7979 2904 Blue 12
6 PM Tue 83 84 W 5 7681 6596 1521 Blue 8
7 PM Tue 77 77 W 3 5166 5075 0 Blue 1
8 PM Tue 70 70 NW 2 4337 5075 0 Blue 0
9 PM Tue 69 69 N 2 4246 5075 0 Blue 0
10 PM Tue 69 69 N 3 4246 5075 0 Blue 0
11 PM Tue 68 68 N 3 4154 5075 0 Blue 0
12 Midnight Wed 69 69 N 3 4246 5075 0 Blue 0
1 AM Wed 69 69 N 2 4246 5075 0 Blue 0
2 AM Wed 68 68 N 3 4154 5075 0 Blue 0
3 AM Wed 68 68 N 3 4154 5075 0 Blue 0
4 AM Wed 68 68 NE 3 4154 5075 0 Blue 0
5 AM Wed 67 67 NE 3 4063 5075 0 Blue 0
6 AM Wed 65 65 NE 3 3881 5075 0 Blue 0
7 AM Wed 65 65 E 3 3881 5075 0 Blue 0
8 AM Wed 73 73 NW 2 4611 5075 0 Blue 0
9 AM Wed 76 78 W 2 5538 5075 0 Blue 2
10 AM Wed 79 83 W 6 7334 6241 1166 Blue 7
11 AM Wed 81 87 W 6 8702 7639 2564 Blue 11
12 Noon Wed 83 90 W 6 9694 8650 3575 Blue 14
1 PM Wed 85 93 W 6 11435 9633 4558 Blue 16
2 PM Wed 86 93 W 6 11435 9633 4558 Blue 16
3 PM Wed 87 93 W 6 11435 9633 4558 Blue 16
4 PM Wed 87 91 W 6 10019 8981 3906 Blue 15
5 PM Wed 86 88 W 6 9036 7979 2904 Blue 12
6 PM Wed 81 82 W 6 6982 5881 806 Blue 6
7 PM Wed 76 76 W 6 4885 5075 0 Blue 0
8 PM Wed 71 71 NW 2 4428 5075 0 Blue 0
9 PM Wed 69 69 NW 2 4246 5075 0 Blue 0
10 PM Wed 69 69 NW 2 4246 5075 0 Blue 0
11 PM Wed 69 69 NE 3 4246 5075 0 Blue 0
12 Midnight Thu 69 69 NE 3 4246 5075 0 Blue 0
1 AM Thu 70 70 NE 3 4337 5075 0 Blue 0
2 AM Thu 70 70 NE 3 4337 5075 0 Blue 0
3 AM Thu 69 69 NE 3 4246 5075 0 Blue 0
4 AM Thu 69 69 NE 3 4246 5075 0 Blue 0
5 AM Thu 69 69 E 3 4246 5075 0 Blue 0
6 AM Thu 70 70 E 3 4337 5075 0 Blue 0
7 AM Thu 72 72 E 3 4519 5075 0 Blue 0
8 AM Thu 75 75 SW 2 4793 5075 0 Blue 0
9 AM Thu 78 80 SW 2 6269 5150 75 Blue 4
10 AM Thu 80 84 SW 2 7681 6596 1521 Blue 8
11 AM Thu 83 88 SW 6 9036 7979 2904 Blue 12
12 Noon Thu 85 91 SW 6 10019 8981 3906 Blue 15
1 PM Thu 87 94 SW 6 12403 9955 4880 Blue 17
2 PM Thu 88 92 W 6 10340 9309 4234 Blue 15
3 PM Thu 89 92 W 6 10340 9309 4234 Blue 15
4 PM Thu 89 91 W 6 10019 8981 3906 Blue 15
5 PM Thu 88 90 W 5 9694 8650 3575 Blue 14
6 PM Thu 83 83 W 5 7334 6241 1166 Blue 7
7 PM Thu 77 77 W 5 5166 5075 0 Blue 1
8 PM Thu 72 72 W 2 4519 5075 0 Blue 0
9 PM Thu 70 70 W 2 4337 5075 0 Blue 0
10 PM Thu 70 70 W 2 4337 5075 0 Blue 0
11 PM Thu 71 71 E 2 4428 5075 0 Blue 0
12 Midnight Fri 71 71 E 2 4428 5075 0 Blue 0
1 AM Fri 72 72 E 2 4519 5075 0 Blue 0
2 AM Fri 72 72 NE 3 4519 5075 0 Blue 0
3 AM Fri 71 71 NE 3 4428 5075 0 Blue 0
4 AM Fri 71 71 NE 3 4428 5075 0 Blue 0
5 AM Fri 71 71 E 5 4428 5075 0 Blue 0
6 AM Fri 73 73 E 5 4611 5075 0 Blue 0
7 AM Fri 75 75 E 5 4793 5075 0 Blue 0
8 AM Fri 78 78 S 2 5538 5075 0 Blue 2
9 AM Fri 81 83 S 2 7334 6241 1166 Blue 7
10 AM Fri 84 88 S 2 9036 7979 2904 Blue 12
11 AM Fri 86 92 SW 6 10340 9309 4234 Blue 15
12 Noon Fri 88 95 SW 6 13271 10274 5199 Blue 18
1 PM Fri 90 97 SW 6 14803 12151 7076 Blue 20
2 PM Fri 91 98 W 6 15494 13018 7943 Blue 21
3 PM Fri 92 98 W 6 15494 13018 7943 Blue 21
4 PM Fri 92 96 W 6 14065 11185 6110 Blue 19
5 PM Fri 90 92 W 5 10340 9309 4234 Blue 15
6 PM Fri 85 86 W 5 8365 7295 2220 Blue 10
7 PM Fri 79 79 W 5 5905 5075 0 Blue 3
8 PM Fri 74 74 W 2 4702 5075 0 Blue 0
9 PM Fri 72 72 W 2 4519 5075 0 Blue 0
10 PM Fri 72 72 W 2 4519 5075 0 Blue 0
11 PM Fri 73 73 E 2 4611 5075 0 Blue 0
12 Midnight Sat 73 73 E 2 4611 5075 0 Blue 0
1 AM Sat 73 73 E 2 4611 5075 0 Blue 0
2 AM Sat 73 73 E 2 4611 5075 0 Blue 0
3 AM Sat 72 72 E 2 4519 5075 0 Blue 0
4 AM Sat 72 72 E 2 4519 5075 0 Blue 0
5 AM Sat 72 72 NE 3 4519 5075 0 Blue 0
6 AM Sat 74 74 NE 3 4702 5075 0 Blue 0
7 AM Sat 76 76 NE 3 4885 5075 0 Blue 0
8 AM Sat 79 79 E 2 5905 5075 0 Blue 3
9 AM Sat 81 83 E 2 7334 6241 1166 Blue 7
10 AM Sat 84 88 E 2 9036 7979 2904 Blue 12
11 AM Sat 86 92 SW 6 10340 9309 4234 Blue 15
12 Noon Sat 88 95 SW 6 13271 10274 5199 Blue 18
1 PM Sat 91 98 SW 6 15494 13018 7943 Blue 21
2 PM Sat 92 99 W 6 16147 13810 8735 Blue 22
3 PM Sat 93 99 W 6 16147 13810 8735 Blue 22
4 PM Sat 93 97 W 6 14803 12151 7076 Blue 20
5 PM Sat 92 94 W 5 12403 9955 4880 Blue 17
6 PM Sat 87 88 W 5 9036 7979 2904 Blue 12
7 PM Sat 81 81 W 5 6627 5518 443 Blue 5
8 PM Sat 76 76 N 2 4885 5075 0 Blue 0
9 PM Sat 74 74 N 2 4702 5075 0 Blue 0
10 PM Sat 74 74 N 2 4702 5075 0 Blue 0
11 PM Sat 74 74 E 2 4702 5075 0 Blue 0
12 Midnight Sun 74 74 E 2 4702 5075 0 Blue 0
1 AM Sun 73 73 E 2 4611 5075 0 Blue 0
2 AM Sun 73 73 N 3 4611 5075 0 Blue 0
3 AM Sun 73 73 N 3 4611 5075 0 Blue 0
4 AM Sun 72 72 N 3 4519 5075 0 Blue 0
5 AM Sun 73 73 E 3 4611 5075 0 Blue 0
6 AM Sun 74 74 E 3 4702 5075 0 Blue 0
7 AM Sun 77 77 E 3 5166 5075 0 Blue 1
8 AM Sun 79 79 S 2 5905 5075 0 Blue 3
9 AM Sun 82 84 S 2 7681 6596 1521 Blue 8
10 AM Sun 84 88 S 2 9036 7979 2904 Blue 12
11 AM Sun 87 93 W 6 11435 9633 4558 Blue 16
12 Noon Sun 89 96 W 6 14065 11185 6110 Blue 19
1 PM Sun 91 98 W 6 15494 13018 7943 Blue 21
2 PM Sun 92 99 W 6 16147 13810 8735 Blue 22
3 PM Sun 93 99 W 6 16147 13810 8735 Blue 22
4 PM Sun 93 97 W 6 14803 12151 7076 Blue 20
5 PM Sun 92 94 W 6 12403 9955 4880 Blue 17
6 PM Sun 87 88 W 6 9036 7979 2904 Blue 12
7 PM Sun 82 82 W 6 6982 5881 806 Blue 6
8 PM Sun 77 77 W 2 5166 5075 0 Blue 1
9 PM Sun 75 75 W 2 4793 5075 0 Blue 0
10 PM Sun 75 75 W 2 4793 5075 0 Blue 0
11 PM Sun 75 75 NW 2 4793 5075 0 Blue 0
12 Midnight Mon 75 75 NW 2 4793 5075 0 Blue 0
1 AM Mon 74 74 NW 2 4702 5075 0 Blue 0
2 AM Mon 74 74 E 2 4702 5075 0 Blue 0
3 AM Mon 74 74 E 2 4702 5075 0 Blue 0
4 AM Mon 73 73 E 2 4611 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