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

Station:

KVBG

Date/Time:

16 APR 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 Fri 49 49 E 6 14 6179 5075 0 Blue 1
1 AM Fri 45 45 E 6 13 4826 5075 0 Blue 0
2 AM Fri 41 41 E 6 12 4826 5075 0 Blue 0
3 AM Fri 41 41 E 6 13 4826 5075 0 Blue 0
4 AM Fri 41 41 E 6 13 4826 5075 0 Blue 0
5 AM Fri 41 41 E 6 13 4826 5075 0 Blue 0
6 AM Fri 46 46 SE 4 9 4826 5075 0 Blue 0
7 AM Fri 52 52 S 3 6 6508 6175 1100 Blue 4
8 AM Fri 58 59 SSW 2 2 9059 7344 2269 Blue 11
9 AM Fri 61 63 SW 3 4 11269 9507 4432 Blue 15
10 AM Fri 63 67 WSW 5 6 13745 11788 6713 Blue 19
11 AM Fri 66 72 WSW 7 8 15750 14481 9406 Blue 24
12 Noon Fri 67 74 WSW 7 8 16482 15243 10168 Blue 26
1 PM Fri 69 76 W 6 8 17079 15980 10905 White 28
2 PM Fri 71 78 W 6 8 17481 16696 11621 White 30
3 PM Fri 71 76 W 6 7 17079 15980 10905 White 28
4 PM Fri 71 74 WNW 6 7 16482 15243 10168 Blue 26
5 PM Fri 71 73 WNW 6 6 16119 14865 9790 Blue 25
6 PM Fri 70 70 SW 6 8 14994 13581 8506 Blue 22
7 PM Fri 68 68 SE 5 10 14213 12412 7337 Blue 20
8 PM Fri 67 67 NE 5 12 13745 11788 6713 Blue 19
9 PM Fri 65 65 ENE 6 12 12565 10484 5409 Blue 17
10 PM Fri 62 62 ENE 6 13 10596 8991 3916 Blue 14
11 PM Fri 60 60 E 6 13 9582 7911 2836 Blue 12
12 Midnight Sat 55 55 E 6 13 6933 6503 1428 Blue 7
1 AM Sat 50 50 E 6 13 6288 5088 13 Blue 2
2 AM Sat 45 45 E 6 12 4826 5075 0 Blue 0
3 AM Sat 44 44 E 5 12 4826 5075 0 Blue 0
4 AM Sat 44 44 E 5 11 4826 5075 0 Blue 0
5 AM Sat 43 43 E 5 11 4826 5075 0 Blue 0
6 AM Sat 49 49 SE 4 8 6179 5075 0 Blue 1
7 AM Sat 55 55 SSE 3 6 6933 6503 1428 Blue 7
8 AM Sat 60 61 SSW 3 3 10069 8460 3385 Blue 13
9 AM Sat 63 65 SW 4 5 12565 10484 5409 Blue 17
10 AM Sat 65 69 SW 6 7 14607 13009 7934 Blue 21
11 AM Sat 68 74 WSW 7 8 16482 15243 10168 Blue 26
12 Noon Sat 69 74 WSW 7 8 16482 15243 10168 Blue 26
1 PM Sat 71 74 WSW 6 7 16482 15243 10168 Blue 26
2 PM Sat 73 73 WSW 6 6 16119 14865 9790 Blue 25
3 PM Sat 72 72 S 5 6 15750 14481 9406 Blue 24
4 PM Sat 71 71 SE 5 6 15375 14090 9015 Blue 23
5 PM Sat 70 70 ENE 5 6 14994 13581 8506 Blue 22
6 PM Sat 69 69 ENE 6 9 14607 13009 7934 Blue 21
7 PM Sat 68 68 ENE 6 12 14213 12412 7337 Blue 20
8 PM Sat 67 67 ENE 7 15 13745 11788 6713 Blue 19
9 PM Sat 65 65 ENE 7 16 12565 10484 5409 Blue 17
10 PM Sat 63 63 ENE 8 17 11269 9507 4432 Blue 15
11 PM Sat 61 61 E 8 18 10069 8460 3385 Blue 13
12 Midnight Sun 57 57 E 8 18 7964 6721 1646 Blue 9
1 AM Sun 52 52 E 8 18 6508 6175 1100 Blue 4
2 AM Sun 48 48 E 8 18 5984 5075 0 Blue 0
3 AM Sun 47 47 E 8 17 5089 5075 0 Blue 0
4 AM Sun 47 47 E 8 17 5089 5075 0 Blue 0
5 AM Sun 46 46 E 8 17 4826 5075 0 Blue 0
6 AM Sun 53 53 E 6 12 6618 6284 1209 Blue 5
7 AM Sun 59 59 E 4 7 9059 7344 2269 Blue 11
8 AM Sun 65 66 E 2 3 13167 11131 6056 Blue 18
9 AM Sun 68 70 SSE 4 5 14994 13581 8506 Blue 22
10 AM Sun 71 75 SSW 5 6 16841 15614 10539 Blue 27
11 AM Sun 73 79 W 7 8 17683 17047 11972 White 31
12 Noon Sun 75 82 W 7 8 18295 18295 13220 White 34
1 PM Sun 77 84 W 8 9 18699 18699 13624 White 36
2 PM Sun 78 84 WNW 8 9 18699 18699 13624 White 36
3 PM Sun 78 83 WNW 7 8 18497 18497 13422 White 35
4 PM Sun 78 81 WNW 6 7 18091 18091 13016 White 33
5 PM Sun 78 80 WNW 6 6 17886 17393 12318 White 32
6 PM Sun 77 77 SW 6 9 17280 16341 11266 White 29
7 PM Sun 75 75 SE 6 12 16841 15614 10539 Blue 27
8 PM Sun 73 73 ENE 6 14 16119 14865 9790 Blue 25
9 PM Sun 72 72 ENE 7 15 15750 14481 9406 Blue 24
10 PM Sun 71 71 ENE 7 16 15375 14090 9015 Blue 23
11 PM Sun 69 69 E 8 17 14607 13009 7934 Blue 21

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