Detailed Predictions for: Slick Rock
Launch Lat, Long, Altitude (f): 36.184800, -118.727000, 5075
LZ Altitude (f): 1140
Sounding

Station:

KVBG

Date/Time:

12 MAY 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 69 69 E 7 16 8275 5906 831 Blue 1
1 AM Wed 63 63 E 7 15 4895 5075 0 Blue 0
2 AM Wed 57 57 E 7 15 4895 5075 0 Blue 0
3 AM Wed 57 57 E 7 15 4895 5075 0 Blue 0
4 AM Wed 56 56 E 7 14 4895 5075 0 Blue 0
5 AM Wed 55 55 E 6 14 4895 5075 0 Blue 0
6 AM Wed 62 62 SE 5 11 4895 5075 0 Blue 0
7 AM Wed 69 69 S 4 7 8275 5906 831 Blue 1
8 AM Wed 76 77 SSW 3 3 12948 10249 5174 Blue 9
9 AM Wed 79 82 SW 4 5 14839 13756 8681 Blue 13
10 AM Wed 82 87 WSW 5 6 18195 15410 10335 Blue 18
11 AM Wed 85 92 WSW 7 8 19867 19439 14364 White 23
12 Noon Wed 87 95 WSW 7 8 20448 20448 15373 White 26
1 PM Wed 89 97 W 7 8 20833 20833 15758 White 28
2 PM Wed 91 99 W 7 8 21218 21218 16143 White 30
3 PM Wed 91 97 W 6 8 20833 20833 15758 White 28
4 PM Wed 91 95 WNW 6 7 20448 20448 15373 White 26
5 PM Wed 91 93 WNW 6 7 20061 20061 14986 White 24
6 PM Wed 89 90 SSW 5 7 19479 17323 12248 White 21
7 PM Wed 87 87 SE 4 7 18195 15410 10335 Blue 18
8 PM Wed 84 84 NE 3 7 15528 14378 9303 Blue 15
9 PM Wed 82 82 ENE 4 10 14839 13756 8681 Blue 13
10 PM Wed 81 81 ENE 6 12 14488 13501 8426 Blue 12
11 PM Wed 79 79 E 7 15 13830 11981 6906 Blue 11
12 Midnight Thu 72 72 E 7 14 8814 8257 3182 Blue 4
1 AM Thu 65 65 E 6 14 4895 5075 0 Blue 0
2 AM Thu 58 58 E 6 13 4895 5075 0 Blue 0
3 AM Thu 57 57 E 6 13 4895 5075 0 Blue 0
4 AM Thu 57 57 E 6 13 4895 5075 0 Blue 0
5 AM Thu 56 56 E 6 12 4895 5075 0 Blue 0
6 AM Thu 63 63 SE 5 9 4895 5075 0 Blue 0
7 AM Thu 69 69 S 4 6 8275 5906 831 Blue 1
8 AM Thu 76 77 SW 3 4 12948 10249 5174 Blue 9
9 AM Thu 79 82 SW 4 5 14839 13756 8681 Blue 13
10 AM Thu 81 86 WSW 6 6 16570 15070 9995 Blue 17
11 AM Thu 84 91 WSW 7 8 19673 19035 13960 White 22
12 Noon Thu 86 94 WSW 7 8 20255 20255 15180 White 25
1 PM Thu 88 96 W 7 8 20641 20641 15566 White 27
2 PM Thu 90 98 W 7 8 21026 21026 15951 White 29
3 PM Thu 90 96 W 7 8 20641 20641 15566 White 27
4 PM Thu 90 94 WNW 7 8 20255 20255 15180 White 25
5 PM Thu 91 93 WNW 7 8 20061 20061 14986 White 24
6 PM Thu 90 91 SSW 6 9 19673 19035 13960 White 22
7 PM Thu 88 88 SE 6 10 19085 15854 10779 White 19
8 PM Thu 87 87 NE 5 11 18195 15410 10335 Blue 18
9 PM Thu 86 86 ENE 5 12 16570 15070 9995 Blue 17
10 PM Thu 85 85 E 6 12 16048 14726 9651 Blue 16
11 PM Thu 84 84 E 6 13 15528 14378 9303 Blue 15
12 Midnight Fri 75 75 E 6 13 11328 8793 3718 Blue 7
1 AM Fri 66 66 E 6 12 5935 5075 0 Blue 0
2 AM Fri 57 57 E 5 12 4895 5075 0 Blue 0
3 AM Fri 56 56 E 5 12 4895 5075 0 Blue 0
4 AM Fri 56 56 E 5 11 4895 5075 0 Blue 0
5 AM Fri 55 55 E 5 11 4895 5075 0 Blue 0
6 AM Fri 61 61 SE 4 9 4895 5075 0 Blue 0
7 AM Fri 68 68 S 4 6 7911 5075 0 Blue 0
8 AM Fri 74 75 SW 3 4 11328 8793 3718 Blue 7
9 AM Fri 77 80 SW 4 5 14132 12745 7670 Blue 11
10 AM Fri 80 85 WSW 5 6 16048 14726 9651 Blue 16
11 AM Fri 82 89 WSW 6 7 19282 16373 11298 White 20
12 Noon Fri 85 93 W 7 8 20061 20061 14986 White 24
1 PM Fri 87 95 W 7 8 20448 20448 15373 White 26
2 PM Fri 89 97 W 7 8 20833 20833 15758 White 28
3 PM Fri 89 95 WNW 8 9 20448 20448 15373 White 26
4 PM Fri 89 93 WNW 9 11 20061 20061 14986 White 24
5 PM Fri 90 92 WNW 10 11 19867 19439 14364 White 23
6 PM Fri 88 89 SW 7 9 19282 16373 11298 White 20
7 PM Fri 86 86 S 4 6 16570 15070 9995 Blue 17
8 PM Fri 84 84 ESE 1 3 15528 14378 9303 Blue 15
9 PM Fri 82 82 ESE 3 6 14839 13756 8681 Blue 13
10 PM Fri 79 79 ESE 4 8 13830 11981 6906 Blue 11
11 PM Fri 77 77 E 5 11 12948 10249 5174 Blue 9

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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