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

Station:

KVBG

Date/Time:

4 DEC 2020

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)
4 AM Fri 46 46 NE 3 2884 5075 0 Blue 0
5 AM Fri 45 45 E 1 2884 5075 0 Blue 0
6 AM Fri 44 44 E 1 2884 5075 0 Blue 0
7 AM Fri 44 44 SW 0 2884 5075 0 Blue 0
8 AM Fri 50 50 NE 2 2884 5075 0 Blue 0
9 AM Fri 56 56 W 1 3351 5075 0 Blue 0
10 AM Fri 57 58 SW 1 3838 5075 0 Blue 0
11 AM Fri 59 61 W 3 4563 5075 0 Blue 0
12 Noon Fri 60 62 W 5 4803 5075 0 Blue 0
1 PM Fri 61 63 W 5 5042 5075 0 Blue 0
2 PM Fri 60 61 W 5 4563 5075 0 Blue 0
3 PM Fri 60 60 W 3 4323 5075 0 Blue 0
4 PM Fri 55 55 W 2 3105 5075 0 Blue 0
5 PM Fri 49 49 N 2 2884 5075 0 Blue 0
6 PM Fri 48 48 NE 2 2884 5075 0 Blue 0
7 PM Fri 48 48 E 3 2884 5075 0 Blue 0
8 PM Fri 47 47 E 3 2884 5075 0 Blue 0
9 PM Fri 47 47 E 3 2884 5075 0 Blue 0
10 PM Fri 46 46 E 3 2884 5075 0 Blue 0
11 PM Fri 47 47 E 3 2884 5075 0 Blue 0
12 Midnight Sat 46 46 E 3 2884 5075 0 Blue 0
1 AM Sat 47 47 E 5 2884 5075 0 Blue 0
2 AM Sat 48 48 E 5 2884 5075 0 Blue 0
3 AM Sat 48 48 E 5 2884 5075 0 Blue 0
4 AM Sat 47 47 E 5 2884 5075 0 Blue 0
5 AM Sat 47 47 E 5 2884 5075 0 Blue 0
6 AM Sat 46 46 E 5 2884 5075 0 Blue 0
7 AM Sat 47 47 E 5 2884 5075 0 Blue 0
8 AM Sat 52 52 E 3 2884 5075 0 Blue 0
9 AM Sat 57 57 E 2 3595 5075 0 Blue 0
10 AM Sat 59 60 SW 3 4323 5075 0 Blue 0
11 AM Sat 60 61 SW 3 4563 5075 0 Blue 0
12 Noon Sat 61 62 SW 3 4803 5075 0 Blue 0
1 PM Sat 61 62 W 5 4803 5075 0 Blue 0
2 PM Sat 60 61 W 5 4563 5075 0 Blue 0
3 PM Sat 58 58 W 5 3838 5075 0 Blue 0
4 PM Sat 56 56 W 2 3351 5075 0 Blue 0
5 PM Sat 54 54 W 2 2884 5075 0 Blue 0
6 PM Sat 51 51 W 2 2884 5075 0 Blue 0
7 PM Sat 49 49 E 3 2884 5075 0 Blue 0
8 PM Sat 48 48 E 3 2884 5075 0 Blue 0
9 PM Sat 47 47 E 3 2884 5075 0 Blue 0
10 PM Sat 46 46 NE 3 2884 5075 0 Blue 0
11 PM Sat 46 46 NE 3 2884 5075 0 Blue 0
12 Midnight Sun 46 46 NE 3 2884 5075 0 Blue 0
1 AM Sun 46 46 NE 5 2884 5075 0 Blue 0
2 AM Sun 46 46 NE 5 2884 5075 0 Blue 0
3 AM Sun 45 45 NE 5 2884 5075 0 Blue 0
4 AM Sun 45 45 NE 3 2884 5075 0 Blue 0
5 AM Sun 44 44 NE 3 2884 5075 0 Blue 0
6 AM Sun 43 43 NE 3 2884 5075 0 Blue 0
7 AM Sun 43 43 NE 3 2884 5075 0 Blue 0
8 AM Sun 46 46 NE 3 2884 5075 0 Blue 0
9 AM Sun 50 50 NE 3 2884 5075 0 Blue 0
10 AM Sun 53 54 W 5 2884 5075 0 Blue 0
11 AM Sun 55 56 W 5 3351 5075 0 Blue 0
12 Noon Sun 56 57 W 5 3595 5075 0 Blue 0
1 PM Sun 56 57 W 6 3595 5075 0 Blue 0
2 PM Sun 55 56 W 6 3351 5075 0 Blue 0
3 PM Sun 52 52 W 6 2884 5075 0 Blue 0
4 PM Sun 50 50 NW 3 2884 5075 0 Blue 0
5 PM Sun 48 48 NW 3 2884 5075 0 Blue 0
6 PM Sun 46 46 NW 3 2884 5075 0 Blue 0
7 PM Sun 44 44 E 5 2884 5075 0 Blue 0
8 PM Sun 43 43 E 5 2884 5075 0 Blue 0
9 PM Sun 43 43 E 5 2884 5075 0 Blue 0
10 PM Sun 43 43 E 7 2884 5075 0 Blue 0
11 PM Sun 43 43 E 7 2884 5075 0 Blue 0
12 Midnight Mon 44 44 E 7 2884 5075 0 Blue 0
1 AM Mon 44 44 E 10 2884 5075 0 Blue 0
2 AM Mon 44 44 E 10 2884 5075 0 Blue 0
3 AM Mon 44 44 E 10 2884 5075 0 Blue 0
4 AM Mon 44 44 NE 9 2884 5075 0 Blue 0
5 AM Mon 43 43 NE 9 2884 5075 0 Blue 0
6 AM Mon 42 42 NE 9 2884 5075 0 Blue 0
7 AM Mon 43 43 E 6 2884 5075 0 Blue 0
8 AM Mon 46 46 E 6 2884 5075 0 Blue 0
9 AM Mon 50 50 E 6 2884 5075 0 Blue 0
10 AM Mon 54 55 NE 3 3105 5075 0 Blue 0
11 AM Mon 56 57 NE 3 3595 5075 0 Blue 0
12 Noon Mon 58 60 NE 3 4323 5075 0 Blue 0
1 PM Mon 58 59 NE 5 4081 5075 0 Blue 0
2 PM Mon 57 58 NE 5 3838 5075 0 Blue 0
3 PM Mon 55 55 NE 5 3105 5075 0 Blue 0
4 PM Mon 53 53 NE 3 2884 5075 0 Blue 0
5 PM Mon 51 51 NE 3 2884 5075 0 Blue 0
6 PM Mon 49 49 NE 3 2884 5075 0 Blue 0
7 PM Mon 47 47 NE 3 2884 5075 0 Blue 0
8 PM Mon 46 46 NE 3 2884 5075 0 Blue 0
9 PM Mon 46 46 NE 3 2884 5075 0 Blue 0
10 PM Mon 46 46 E 5 2884 5075 0 Blue 0
11 PM Mon 46 46 E 5 2884 5075 0 Blue 0
12 Midnight Tue 46 46 E 5 2884 5075 0 Blue 0
1 AM Tue 46 46 NE 6 2884 5075 0 Blue 0
2 AM Tue 46 46 NE 6 2884 5075 0 Blue 0
3 AM Tue 46 46 NE 6 2884 5075 0 Blue 0
4 AM Tue 46 46 NE 5 2884 5075 0 Blue 0
5 AM Tue 45 45 NE 5 2884 5075 0 Blue 0
6 AM Tue 44 44 NE 5 2884 5075 0 Blue 0
7 AM Tue 45 45 E 5 2884 5075 0 Blue 0
8 AM Tue 49 49 E 5 2884 5075 0 Blue 0
9 AM Tue 54 54 E 5 2884 5075 0 Blue 0
10 AM Tue 58 59 E 2 4081 5075 0 Blue 0
11 AM Tue 61 63 E 2 5042 5075 0 Blue 0
12 Noon Tue 63 65 E 2 6325 5075 0 Blue 2
1 PM Tue 63 64 W 3 5625 5075 0 Blue 1
2 PM Tue 62 63 W 3 5042 5075 0 Blue 0
3 PM Tue 60 60 W 3 4323 5075 0 Blue 0
4 PM Tue 57 57 NE 2 3595 5075 0 Blue 0
5 PM Tue 54 54 NE 2 2884 5075 0 Blue 0
6 PM Tue 52 52 NE 2 2884 5075 0 Blue 0
7 PM Tue 50 50 E 2 2884 5075 0 Blue 0
8 PM Tue 49 49 E 2 2884 5075 0 Blue 0
9 PM Tue 49 49 E 2 2884 5075 0 Blue 0
10 PM Tue 49 49 E 3 2884 5075 0 Blue 0
11 PM Tue 49 49 E 3 2884 5075 0 Blue 0
12 Midnight Wed 48 48 E 3 2884 5075 0 Blue 0
1 AM Wed 48 48 E 5 2884 5075 0 Blue 0
2 AM Wed 48 48 E 5 2884 5075 0 Blue 0
3 AM Wed 48 48 E 5 2884 5075 0 Blue 0
4 AM Wed 48 48 NE 3 2884 5075 0 Blue 0
5 AM Wed 47 47 NE 3 2884 5075 0 Blue 0
6 AM Wed 46 46 NE 3 2884 5075 0 Blue 0
7 AM Wed 47 47 E 3 2884 5075 0 Blue 0
8 AM Wed 50 50 E 3 2884 5075 0 Blue 0
9 AM Wed 55 55 E 3 3105 5075 0 Blue 0
10 AM Wed 59 60 W 2 4323 5075 0 Blue 0
11 AM Wed 61 62 W 2 4803 5075 0 Blue 0
12 Noon Wed 62 64 W 2 5625 5075 0 Blue 1
1 PM Wed 62 63 W 3 5042 5075 0 Blue 0
2 PM Wed 61 62 W 3 4803 5075 0 Blue 0
3 PM Wed 59 59 W 3 4081 5075 0 Blue 0
4 PM Wed 56 56 NW 1 3351 5075 0 Blue 0
5 PM Wed 53 53 NW 1 2884 5075 0 Blue 0
6 PM Wed 50 50 NW 1 2884 5075 0 Blue 0
7 PM Wed 48 48 NE 2 2884 5075 0 Blue 0
8 PM Wed 47 47 NE 2 2884 5075 0 Blue 0
9 PM Wed 46 46 NE 2 2884 5075 0 Blue 0
10 PM Wed 46 46 E 2 2884 5075 0 Blue 0
11 PM Wed 46 46 E 2 2884 5075 0 Blue 0
12 Midnight Thu 45 45 E 2 2884 5075 0 Blue 0
1 AM Thu 45 45 E 3 2884 5075 0 Blue 0
2 AM Thu 45 45 E 3 2884 5075 0 Blue 0
3 AM Thu 45 45 E 3 2884 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