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

Station:

KVBG

Date/Time:

18 JAN 2018

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 Thu 54 54 E 3 2982 5075 0 Blue 0
5 AM Thu 54 54 E 3 2982 5075 0 Blue 0
6 AM Thu 54 54 E 3 2982 5075 0 Blue 0
7 AM Thu 54 54 E 5 2982 5075 0 Blue 0
8 AM Thu 56 56 E 5 2982 5075 0 Blue 0
9 AM Thu 58 58 E 5 2982 5075 0 Blue 0
10 AM Thu 60 61 W 3 3355 5075 0 Blue 0
11 AM Thu 62 63 W 3 3907 5075 0 Blue 0
12 Noon Thu 63 64 W 3 4265 5075 0 Blue 1
1 PM Thu 63 64 W 6 4265 5075 0 Blue 1
2 PM Thu 63 64 W 6 4265 5075 0 Blue 1
3 PM Thu 62 62 W 6 3632 5075 0 Blue 0
4 PM Thu 61 61 NW 3 3355 5075 0 Blue 0
5 PM Thu 59 59 NW 3 2982 5075 0 Blue 0
6 PM Thu 56 56 NW 3 2982 5075 0 Blue 0
7 PM Thu 54 54 N 3 2982 5075 0 Blue 0
8 PM Thu 53 53 N 3 2982 5075 0 Blue 0
9 PM Thu 52 52 N 3 2982 5075 0 Blue 0
10 PM Thu 51 51 NE 3 2982 5075 0 Blue 0
11 PM Thu 51 51 NE 3 2982 5075 0 Blue 0
12 Midnight Fri 50 50 NE 3 2982 5075 0 Blue 0
1 AM Fri 50 50 W 2 2982 5075 0 Blue 0
2 AM Fri 49 49 W 2 2982 5075 0 Blue 0
3 AM Fri 49 49 W 2 2982 5075 0 Blue 0
4 AM Fri 49 49 W 5 2982 5075 0 Blue 0
5 AM Fri 48 48 W 5 2982 5075 0 Blue 0
6 AM Fri 48 48 W 5 2982 5075 0 Blue 0
7 AM Fri 47 47 W 5 2982 5075 0 Blue 0
8 AM Fri 47 47 W 5 2982 5075 0 Blue 0
9 AM Fri 46 46 W 5 2982 5075 0 Blue 0
10 AM Fri 46 46 W 8 2982 5075 0 Blue 0
11 AM Fri 46 46 W 8 2982 5075 0 Blue 0
12 Noon Fri 45 45 W 8 2982 5075 0 Blue 0
1 PM Fri 45 45 W 8 2982 5075 0 Blue 0
2 PM Fri 44 44 W 8 2982 5075 0 Blue 0
3 PM Fri 43 43 W 8 2982 5075 0 Blue 0
4 PM Fri 42 42 NW 9 2982 5075 0 Blue 0
5 PM Fri 41 41 NW 9 2982 5075 0 Blue 0
6 PM Fri 40 40 NW 9 2982 5075 0 Blue 0
7 PM Fri 39 39 NW 9 2982 5075 0 Blue 0
8 PM Fri 38 38 NW 9 2982 5075 0 Blue 0
9 PM Fri 37 37 NW 9 2982 5075 0 Blue 0
10 PM Fri 37 37 NW 7 2982 5075 0 Blue 0
11 PM Fri 36 36 NW 7 2982 5075 0 Blue 0
12 Midnight Sat 35 35 NW 7 2982 5075 0 Blue 0
1 AM Sat 34 34 NW 7 2982 5075 0 Blue 0
2 AM Sat 34 34 NW 7 2982 5075 0 Blue 0
3 AM Sat 34 34 NW 7 2982 5075 0 Blue 0
4 AM Sat 33 33 NW 6 2982 5075 0 Blue 0
5 AM Sat 32 32 NW 6 2982 5075 0 Blue 0
6 AM Sat 31 31 NW 6 2982 5075 0 Blue 0
7 AM Sat 31 31 NW 6 2982 5075 0 Blue 0
8 AM Sat 32 32 NW 6 2982 5075 0 Blue 0
9 AM Sat 34 34 NW 6 2982 5075 0 Blue 0
10 AM Sat 36 36 W 7 2982 5075 0 Blue 0
11 AM Sat 37 38 W 7 2982 5075 0 Blue 0
12 Noon Sat 38 39 W 7 2982 5075 0 Blue 0
1 PM Sat 38 39 W 7 2982 5075 0 Blue 0
2 PM Sat 38 38 W 7 2982 5075 0 Blue 0
3 PM Sat 38 38 W 7 2982 5075 0 Blue 0
4 PM Sat 37 37 NW 9 2982 5075 0 Blue 0
5 PM Sat 36 36 NW 9 2982 5075 0 Blue 0
6 PM Sat 35 35 NW 9 2982 5075 0 Blue 0
7 PM Sat 34 34 NW 9 2982 5075 0 Blue 0
8 PM Sat 34 34 NW 9 2982 5075 0 Blue 0
9 PM Sat 34 34 NW 9 2982 5075 0 Blue 0
10 PM Sat 34 34 NE 3 2982 5075 0 Blue 0
11 PM Sat 34 34 NE 3 2982 5075 0 Blue 0
12 Midnight Sun 34 34 NE 3 2982 5075 0 Blue 0
1 AM Sun 34 34 NE 3 2982 5075 0 Blue 0
2 AM Sun 33 33 NE 3 2982 5075 0 Blue 0
3 AM Sun 33 33 NE 3 2982 5075 0 Blue 0
4 AM Sun 33 33 NE 2 2982 5075 0 Blue 0
5 AM Sun 32 32 NE 2 2982 5075 0 Blue 0
6 AM Sun 32 32 NE 2 2982 5075 0 Blue 0
7 AM Sun 33 33 NE 2 2982 5075 0 Blue 0
8 AM Sun 35 35 NE 2 2982 5075 0 Blue 0
9 AM Sun 37 37 NE 2 2982 5075 0 Blue 0
10 AM Sun 40 40 W 3 2982 5075 0 Blue 0
11 AM Sun 42 43 W 3 2982 5075 0 Blue 0
12 Noon Sun 43 44 W 3 2982 5075 0 Blue 0
1 PM Sun 43 44 W 3 2982 5075 0 Blue 0
2 PM Sun 44 45 W 3 2982 5075 0 Blue 0
3 PM Sun 44 44 W 3 2982 5075 0 Blue 0
4 PM Sun 44 44 N 3 2982 5075 0 Blue 0
5 PM Sun 43 43 N 3 2982 5075 0 Blue 0
6 PM Sun 42 42 N 3 2982 5075 0 Blue 0
7 PM Sun 41 41 N 3 2982 5075 0 Blue 0
8 PM Sun 41 41 N 3 2982 5075 0 Blue 0
9 PM Sun 41 41 N 3 2982 5075 0 Blue 0
10 PM Sun 41 41 N 3 2982 5075 0 Blue 0
11 PM Sun 41 41 N 3 2982 5075 0 Blue 0
12 Midnight Mon 40 40 N 3 2982 5075 0 Blue 0
1 AM Mon 40 40 N 3 2982 5075 0 Blue 0
2 AM Mon 40 40 N 3 2982 5075 0 Blue 0
3 AM Mon 40 40 N 3 2982 5075 0 Blue 0
4 AM Mon 40 40 NE 5 2982 5075 0 Blue 0
5 AM Mon 40 40 NE 5 2982 5075 0 Blue 0
6 AM Mon 40 40 NE 5 2982 5075 0 Blue 0
7 AM Mon 40 40 NE 5 2982 5075 0 Blue 0
8 AM Mon 42 42 NE 5 2982 5075 0 Blue 0
9 AM Mon 44 44 NE 5 2982 5075 0 Blue 0
10 AM Mon 46 46 W 5 2982 5075 0 Blue 0
11 AM Mon 47 47 W 5 2982 5075 0 Blue 0
12 Noon Mon 48 48 W 5 2982 5075 0 Blue 0
1 PM Mon 49 49 W 5 2982 5075 0 Blue 0
2 PM Mon 49 49 W 5 2982 5075 0 Blue 0
3 PM Mon 49 49 W 5 2982 5075 0 Blue 0
4 PM Mon 48 48 NW 3 2982 5075 0 Blue 0
5 PM Mon 47 47 NW 3 2982 5075 0 Blue 0
6 PM Mon 46 46 NW 3 2982 5075 0 Blue 0
7 PM Mon 46 46 NW 3 2982 5075 0 Blue 0
8 PM Mon 45 45 NW 3 2982 5075 0 Blue 0
9 PM Mon 45 45 NW 3 2982 5075 0 Blue 0
10 PM Mon 45 45 N 3 2982 5075 0 Blue 0
11 PM Mon 45 45 N 3 2982 5075 0 Blue 0
12 Midnight Tue 44 44 N 3 2982 5075 0 Blue 0
1 AM Tue 44 44 N 3 2982 5075 0 Blue 0
2 AM Tue 44 44 N 3 2982 5075 0 Blue 0
3 AM Tue 43 43 N 3 2982 5075 0 Blue 0
4 AM Tue 43 43 NE 5 2982 5075 0 Blue 0
5 AM Tue 43 43 NE 5 2982 5075 0 Blue 0
6 AM Tue 43 43 NE 5 2982 5075 0 Blue 0
7 AM Tue 44 44 NE 5 2982 5075 0 Blue 0
8 AM Tue 45 45 NE 5 2982 5075 0 Blue 0
9 AM Tue 47 47 NE 5 2982 5075 0 Blue 0
10 AM Tue 49 50 W 5 2982 5075 0 Blue 0
11 AM Tue 51 52 W 5 2982 5075 0 Blue 0
12 Noon Tue 52 53 W 5 2982 5075 0 Blue 0
1 PM Tue 53 54 W 5 2982 5075 0 Blue 0
2 PM Tue 54 55 W 5 2982 5075 0 Blue 0
3 PM Tue 54 54 W 5 2982 5075 0 Blue 0
4 PM Tue 54 54 N 3 2982 5075 0 Blue 0
5 PM Tue 52 52 N 3 2982 5075 0 Blue 0
6 PM Tue 50 50 N 3 2982 5075 0 Blue 0
7 PM Tue 49 49 N 3 2982 5075 0 Blue 0
8 PM Tue 49 49 N 3 2982 5075 0 Blue 0
9 PM Tue 50 50 N 3 2982 5075 0 Blue 0
10 PM Tue 50 50 NE 3 2982 5075 0 Blue 0
11 PM Tue 50 50 NE 3 2982 5075 0 Blue 0
12 Midnight Wed 49 49 NE 3 2982 5075 0 Blue 0
1 AM Wed 48 48 NE 3 2982 5075 0 Blue 0
2 AM Wed 48 48 NE 3 2982 5075 0 Blue 0
3 AM Wed 48 48 NE 3 2982 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