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

Station:

KVBG

Date/Time:

25 SEP 2017

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 Mon 56 56 E 8 2497 5075 0 Blue 0
6 AM Mon 56 56 E 8 2497 5075 0 Blue 0
7 AM Mon 57 57 E 8 2497 5075 0 Blue 0
8 AM Mon 59 59 E 7 2497 5075 0 Blue 0
9 AM Mon 63 64 E 7 6189 5075 0 Blue 2
10 AM Mon 67 70 E 7 8366 8003 2928 Blue 8
11 AM Mon 70 74 W 6 8828 8464 3389 Blue 12
12 Noon Mon 72 77 W 6 9436 8809 3734 Blue 15
1 PM Mon 73 78 W 6 9717 8924 3849 Blue 16
2 PM Mon 74 79 W 7 10013 9125 4050 Blue 17
3 PM Mon 75 79 W 7 10013 9125 4050 Blue 17
4 PM Mon 75 77 W 7 9436 8809 3734 Blue 15
5 PM Mon 74 75 W 6 8943 8579 3504 Blue 13
6 PM Mon 71 71 W 6 8481 8118 3043 Blue 9
7 PM Mon 68 68 W 6 8134 6854 1779 Blue 6
8 PM Mon 64 64 E 5 6189 5075 0 Blue 2
9 PM Mon 62 62 E 5 4708 5075 0 Blue 0
10 PM Mon 62 62 E 5 4708 5075 0 Blue 0
11 PM Mon 61 61 E 7 3968 5075 0 Blue 0
12 Midnight Tue 60 60 E 7 3182 5075 0 Blue 0
1 AM Tue 59 59 E 7 2497 5075 0 Blue 0
2 AM Tue 58 58 E 8 2497 5075 0 Blue 0
3 AM Tue 58 58 E 8 2497 5075 0 Blue 0
4 AM Tue 58 58 E 8 2497 5075 0 Blue 0
5 AM Tue 57 57 NE 8 2497 5075 0 Blue 0
6 AM Tue 57 57 NE 8 2497 5075 0 Blue 0
7 AM Tue 57 57 NE 8 2497 5075 0 Blue 0
8 AM Tue 59 59 NE 8 2497 5075 0 Blue 0
9 AM Tue 63 64 NE 8 6189 5075 0 Blue 2
10 AM Tue 68 71 NE 8 8481 8118 3043 Blue 9
11 AM Tue 73 77 W 6 9436 8809 3734 Blue 15
12 Noon Tue 75 80 W 6 10307 9388 4313 Blue 18
1 PM Tue 76 82 W 6 10886 9954 4879 Blue 20
2 PM Tue 77 82 W 7 10886 9954 4879 Blue 20
3 PM Tue 78 82 W 7 10886 9954 4879 Blue 20
4 PM Tue 78 80 W 7 10307 9388 4313 Blue 18
5 PM Tue 77 78 S 5 9717 8924 3849 Blue 16
6 PM Tue 74 74 S 5 8828 8464 3389 Blue 12
7 PM Tue 70 70 S 5 8366 8003 2928 Blue 8
8 PM Tue 66 66 S 5 7620 5362 287 Blue 4
9 PM Tue 64 64 S 5 6189 5075 0 Blue 2
10 PM Tue 62 62 S 5 4708 5075 0 Blue 0
11 PM Tue 62 62 E 8 4708 5075 0 Blue 0
12 Midnight Wed 61 61 E 8 3968 5075 0 Blue 0
1 AM Wed 61 61 E 8 3968 5075 0 Blue 0
2 AM Wed 61 61 E 8 3968 5075 0 Blue 0
3 AM Wed 60 60 E 8 3182 5075 0 Blue 0
4 AM Wed 60 60 E 8 3182 5075 0 Blue 0
5 AM Wed 59 59 NE 8 2497 5075 0 Blue 0
6 AM Wed 59 59 NE 8 2497 5075 0 Blue 0
7 AM Wed 59 59 NE 8 2497 5075 0 Blue 0
8 AM Wed 61 61 NE 8 3968 5075 0 Blue 0
9 AM Wed 65 66 NE 8 7620 5362 287 Blue 4
10 AM Wed 70 73 NE 8 8712 8348 3273 Blue 11
11 AM Wed 74 78 W 3 9717 8924 3849 Blue 16
12 Noon Wed 76 81 W 3 10597 9659 4584 Blue 19
1 PM Wed 78 84 W 3 11456 10533 5458 Blue 22
2 PM Wed 79 84 W 3 11456 10533 5458 Blue 22
3 PM Wed 79 83 W 3 11172 10245 5170 Blue 21
4 PM Wed 79 81 W 3 10597 9659 4584 Blue 19
5 PM Wed 78 79 S 3 10013 9125 4050 Blue 17
6 PM Wed 75 75 S 3 8943 8579 3504 Blue 13
7 PM Wed 72 72 S 3 8597 8233 3158 Blue 10
8 PM Wed 69 69 S 3 8250 7537 2462 Blue 7
9 PM Wed 66 66 S 3 7620 5362 287 Blue 4
10 PM Wed 65 65 S 3 6925 5075 0 Blue 3
11 PM Wed 64 64 E 6 6189 5075 0 Blue 2
12 Midnight Thu 63 63 E 6 5403 5075 0 Blue 1
1 AM Thu 62 62 E 6 4708 5075 0 Blue 0
2 AM Thu 62 62 E 6 4708 5075 0 Blue 0
3 AM Thu 61 61 E 6 3968 5075 0 Blue 0
4 AM Thu 61 61 E 6 3968 5075 0 Blue 0
5 AM Thu 61 61 NE 7 3968 5075 0 Blue 0
6 AM Thu 60 60 NE 7 3182 5075 0 Blue 0
7 AM Thu 60 60 NE 7 3182 5075 0 Blue 0
8 AM Thu 61 61 NE 7 3968 5075 0 Blue 0
9 AM Thu 65 66 NE 7 7620 5362 287 Blue 4
10 AM Thu 69 72 NE 7 8597 8233 3158 Blue 10
11 AM Thu 73 77 SW 5 9436 8809 3734 Blue 15
12 Noon Thu 76 81 SW 5 10597 9659 4584 Blue 19
1 PM Thu 77 83 SW 5 11172 10245 5170 Blue 21
2 PM Thu 78 83 SW 5 11172 10245 5170 Blue 21
3 PM Thu 79 83 SW 5 11172 10245 5170 Blue 21
4 PM Thu 79 81 SW 5 10597 9659 4584 Blue 19
5 PM Thu 78 79 W 5 10013 9125 4050 Blue 17
6 PM Thu 75 75 W 5 8943 8579 3504 Blue 13
7 PM Thu 71 71 W 5 8481 8118 3043 Blue 9
8 PM Thu 68 68 W 5 8134 6854 1779 Blue 6
9 PM Thu 66 66 W 5 7620 5362 287 Blue 4
10 PM Thu 65 65 W 5 6925 5075 0 Blue 3
11 PM Thu 65 65 NE 5 6925 5075 0 Blue 3
12 Midnight Fri 64 64 NE 5 6189 5075 0 Blue 2
1 AM Fri 63 63 NE 5 5403 5075 0 Blue 1
2 AM Fri 62 62 NE 5 4708 5075 0 Blue 0
3 AM Fri 61 61 NE 5 3968 5075 0 Blue 0
4 AM Fri 60 60 NE 5 3182 5075 0 Blue 0
5 AM Fri 59 59 N 7 2497 5075 0 Blue 0
6 AM Fri 59 59 N 7 2497 5075 0 Blue 0
7 AM Fri 60 60 N 7 3182 5075 0 Blue 0
8 AM Fri 62 62 N 7 4708 5075 0 Blue 0
9 AM Fri 65 66 N 7 7620 5362 287 Blue 4
10 AM Fri 70 73 N 7 8712 8348 3273 Blue 11
11 AM Fri 74 78 SW 5 9717 8924 3849 Blue 16
12 Noon Fri 77 82 SW 5 10886 9954 4879 Blue 20
1 PM Fri 79 84 SW 5 11456 10533 5458 Blue 22
2 PM Fri 80 85 SW 5 11738 10819 5744 Blue 23
3 PM Fri 81 85 SW 5 11738 10819 5744 Blue 23
4 PM Fri 81 83 SW 5 11172 10245 5170 Blue 21
5 PM Fri 80 81 W 5 10597 9659 4584 Blue 19
6 PM Fri 77 77 W 5 9436 8809 3734 Blue 15
7 PM Fri 73 73 W 5 8712 8348 3273 Blue 11
8 PM Fri 69 69 W 5 8250 7537 2462 Blue 7
9 PM Fri 67 67 W 5 8019 6131 1056 Blue 5
10 PM Fri 65 65 W 5 6925 5075 0 Blue 3
11 PM Fri 65 65 NE 5 6925 5075 0 Blue 3
12 Midnight Sat 64 64 NE 5 6189 5075 0 Blue 2
1 AM Sat 63 63 NE 5 5403 5075 0 Blue 1
2 AM Sat 62 62 NE 5 4708 5075 0 Blue 0
3 AM Sat 62 62 NE 5 4708 5075 0 Blue 0
4 AM Sat 61 61 NE 5 3968 5075 0 Blue 0
5 AM Sat 60 60 N 6 3182 5075 0 Blue 0
6 AM Sat 60 60 N 6 3182 5075 0 Blue 0
7 AM Sat 61 61 N 6 3968 5075 0 Blue 0
8 AM Sat 62 62 N 6 4708 5075 0 Blue 0
9 AM Sat 66 67 N 6 8019 6131 1056 Blue 5
10 AM Sat 70 72 N 6 8597 8233 3158 Blue 10
11 AM Sat 74 78 SW 5 9717 8924 3849 Blue 16
12 Noon Sat 77 82 SW 5 10886 9954 4879 Blue 20
1 PM Sat 79 84 SW 5 11456 10533 5458 Blue 22
2 PM Sat 80 85 SW 5 11738 10819 5744 Blue 23
3 PM Sat 81 85 SW 5 11738 10819 5744 Blue 23
4 PM Sat 81 83 SW 5 11172 10245 5170 Blue 21
5 PM Sat 79 80 W 6 10307 9388 4313 Blue 18
6 PM Sat 76 76 W 6 9171 8694 3619 Blue 14
7 PM Sat 73 73 W 6 8712 8348 3273 Blue 11
8 PM Sat 69 69 W 6 8250 7537 2462 Blue 7
9 PM Sat 67 67 W 6 8019 6131 1056 Blue 5
10 PM Sat 66 66 W 6 7620 5362 287 Blue 4
11 PM Sat 65 65 E 5 6925 5075 0 Blue 3
12 Midnight Sun 64 64 E 5 6189 5075 0 Blue 2
1 AM Sun 63 63 E 5 5403 5075 0 Blue 1
2 AM Sun 63 63 E 5 5403 5075 0 Blue 1
3 AM Sun 62 62 E 5 4708 5075 0 Blue 0
4 AM Sun 62 62 E 5 4708 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