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

Station:

KVBG

Date/Time:

17 NOV 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)
4 AM Fri 50 50 SW 10 3502 5075 0 Blue 0
5 AM Fri 49 49 SW 10 3086 5075 0 Blue 0
6 AM Fri 50 50 SW 10 3502 5075 0 Blue 0
7 AM Fri 49 49 SW 7 3086 5075 0 Blue 0
8 AM Fri 49 49 SW 7 3086 5075 0 Blue 0
9 AM Fri 50 50 SW 7 3502 5075 0 Blue 0
10 AM Fri 54 55 S 2 5285 5075 0 White 2
11 AM Fri 56 57 S 2 5727 5075 0 White 3
12 Noon Fri 57 58 S 2 5946 5424 349 White 4
1 PM Fri 57 58 S 5 5946 5424 349 White 4
2 PM Fri 58 59 S 5 6166 5770 695 White 5
3 PM Fri 57 57 S 5 5727 5075 0 White 3
4 PM Fri 54 54 S 2 5064 5075 0 White 1
5 PM Fri 51 51 S 2 3912 5075 0 Blue 0
6 PM Fri 48 48 S 2 2663 5075 0 Blue 0
7 PM Fri 47 47 E 1 2589 5075 0 Blue 0
8 PM Fri 46 46 E 1 2589 5075 0 Blue 0
9 PM Fri 47 47 E 1 2589 5075 0 Blue 0
10 PM Fri 46 46 E 1 2589 5075 0 Blue 0
11 PM Fri 46 46 E 1 2589 5075 0 Blue 0
12 Midnight Sat 44 44 E 1 2589 5075 0 Blue 0
1 AM Sat 44 44 E 2 2589 5075 0 Blue 0
2 AM Sat 44 44 E 2 2589 5075 0 Blue 0
3 AM Sat 44 44 E 2 2589 5075 0 Blue 0
4 AM Sat 45 45 E 2 2589 5075 0 Blue 0
5 AM Sat 44 44 E 2 2589 5075 0 Blue 0
6 AM Sat 45 45 E 2 2589 5075 0 Blue 0
7 AM Sat 44 44 NE 1 2589 5075 0 Blue 0
8 AM Sat 44 44 NE 1 2589 5075 0 Blue 0
9 AM Sat 47 48 NE 1 2663 5075 0 Blue 0
10 AM Sat 54 56 W 3 5506 5075 0 White 2
11 AM Sat 59 61 W 3 6605 6451 1376 White 7
12 Noon Sat 61 63 W 3 7043 7043 1968 White 9
1 PM Sat 61 63 W 5 7043 7043 1968 White 9
2 PM Sat 63 64 W 5 7261 7261 2186 White 10
3 PM Sat 61 61 W 5 6605 6451 1376 White 7
4 PM Sat 57 57 NW 2 5727 5075 0 White 3
5 PM Sat 54 54 NW 2 5064 5075 0 White 1
6 PM Sat 51 51 NW 2 3912 5075 0 Blue 0
7 PM Sat 49 49 NE 5 3086 5075 0 Blue 0
8 PM Sat 47 47 NE 5 2589 5075 0 Blue 0
9 PM Sat 48 48 NE 5 2663 5075 0 Blue 0
10 PM Sat 48 48 NE 5 2663 5075 0 Blue 0
11 PM Sat 47 47 NE 5 2589 5075 0 Blue 0
12 Midnight Sun 45 45 NE 5 2589 5075 0 Blue 0
1 AM Sun 45 45 NE 5 2589 5075 0 Blue 0
2 AM Sun 45 45 NE 5 2589 5075 0 Blue 0
3 AM Sun 45 45 NE 5 2589 5075 0 Blue 0
4 AM Sun 46 46 NE 3 2589 5075 0 Blue 0
5 AM Sun 45 45 NE 3 2589 5075 0 Blue 0
6 AM Sun 46 46 NE 3 2589 5075 0 Blue 0
7 AM Sun 45 45 NE 3 2589 5075 0 Blue 0
8 AM Sun 45 45 NE 3 2589 5075 0 Blue 0
9 AM Sun 48 49 NE 3 3086 5075 0 Blue 0
10 AM Sun 55 56 W 3 5506 5075 0 White 2
11 AM Sun 59 61 W 3 6605 6451 1376 White 7
12 Noon Sun 61 63 W 3 7043 7043 1968 White 9
1 PM Sun 61 62 W 3 6824 6787 1712 White 8
2 PM Sun 63 64 W 3 7261 7261 2186 White 10
3 PM Sun 62 62 W 3 6824 6787 1712 White 8
4 PM Sun 58 58 N 3 5946 5424 349 White 4
5 PM Sun 55 55 N 3 5285 5075 0 White 2
6 PM Sun 52 52 N 3 4316 5075 0 Blue 0
7 PM Sun 51 51 N 3 3912 5075 0 Blue 0
8 PM Sun 49 49 N 3 3086 5075 0 Blue 0
9 PM Sun 50 50 N 3 3502 5075 0 Blue 0
10 PM Sun 49 49 NE 3 3086 5075 0 Blue 0
11 PM Sun 49 49 NE 3 3086 5075 0 Blue 0
12 Midnight Mon 47 47 NE 3 2589 5075 0 Blue 0
1 AM Mon 47 47 NE 3 2589 5075 0 Blue 0
2 AM Mon 47 47 NE 3 2589 5075 0 Blue 0
3 AM Mon 47 47 NE 3 2589 5075 0 Blue 0
4 AM Mon 48 48 N 3 2663 5075 0 Blue 0
5 AM Mon 47 47 N 3 2589 5075 0 Blue 0
6 AM Mon 48 48 N 3 2663 5075 0 Blue 0
7 AM Mon 47 47 N 3 2589 5075 0 Blue 0
8 AM Mon 47 47 N 3 2589 5075 0 Blue 0
9 AM Mon 49 49 N 3 3086 5075 0 Blue 0
10 AM Mon 55 55 NW 5 5285 5075 0 White 2
11 AM Mon 59 60 NW 5 6386 6113 1038 White 6
12 Noon Mon 60 61 NW 5 6605 6451 1376 White 7
1 PM Mon 61 62 NW 5 6824 6787 1712 White 8
2 PM Mon 62 62 NW 5 6824 6787 1712 White 8
3 PM Mon 61 61 NW 5 6605 6451 1376 White 7
4 PM Mon 58 58 NW 5 5946 5424 349 White 4
5 PM Mon 56 56 NW 5 5506 5075 0 White 2
6 PM Mon 53 53 NW 5 4714 5075 0 Blue 0
7 PM Mon 52 52 NW 5 4316 5075 0 Blue 0
8 PM Mon 51 51 NW 5 3912 5075 0 Blue 0
9 PM Mon 51 51 NW 5 3912 5075 0 Blue 0
10 PM Mon 51 51 N 3 3912 5075 0 Blue 0
11 PM Mon 50 50 N 3 3502 5075 0 Blue 0
12 Midnight Tue 49 49 N 3 3086 5075 0 Blue 0
1 AM Tue 49 49 N 3 3086 5075 0 Blue 0
2 AM Tue 49 49 N 3 3086 5075 0 Blue 0
3 AM Tue 49 49 N 3 3086 5075 0 Blue 0
4 AM Tue 50 50 N 3 3502 5075 0 Blue 0
5 AM Tue 49 49 N 3 3086 5075 0 Blue 0
6 AM Tue 50 50 N 3 3502 5075 0 Blue 0
7 AM Tue 49 49 N 3 3086 5075 0 Blue 0
8 AM Tue 49 49 N 3 3086 5075 0 Blue 0
9 AM Tue 52 52 N 3 4316 5075 0 Blue 0
10 AM Tue 59 60 NW 3 6386 6113 1038 White 6
11 AM Tue 64 65 NW 3 7477 7477 2402 White 11
12 Noon Tue 66 68 NW 3 8126 8126 3051 White 14
1 PM Tue 66 67 NW 3 7911 7911 2836 White 13
2 PM Tue 68 69 NW 3 8342 8342 3267 White 15
3 PM Tue 67 67 NW 3 7911 7911 2836 White 13
4 PM Tue 63 63 N 3 7043 7043 1968 White 9
5 PM Tue 60 60 N 3 6386 6113 1038 White 6
6 PM Tue 57 57 N 3 5727 5075 0 White 3
7 PM Tue 56 56 N 3 5506 5075 0 White 2
8 PM Tue 54 54 N 3 5064 5075 0 White 1
9 PM Tue 55 55 N 3 5285 5075 0 White 2
10 PM Tue 54 54 NE 3 5064 5075 0 White 1
11 PM Tue 54 54 NE 3 5064 5075 0 White 1
12 Midnight Wed 52 52 NE 3 4316 5075 0 Blue 0
1 AM Wed 52 52 NE 3 4316 5075 0 Blue 0
2 AM Wed 52 52 NE 3 4316 5075 0 Blue 0
3 AM Wed 52 52 NE 3 4316 5075 0 Blue 0
4 AM Wed 53 53 NW 3 4714 5075 0 Blue 0
5 AM Wed 52 52 NW 3 4316 5075 0 Blue 0
6 AM Wed 53 53 NW 3 4714 5075 0 Blue 0
7 AM Wed 52 52 NW 3 4316 5075 0 Blue 0
8 AM Wed 52 52 NW 3 4316 5075 0 Blue 0
9 AM Wed 55 56 NW 3 5506 5075 0 White 2
10 AM Wed 63 64 W 3 7261 7261 2186 White 10
11 AM Wed 67 69 W 3 8342 8342 3267 White 15
12 Noon Wed 69 71 W 3 8773 8773 3698 White 17
1 PM Wed 70 72 W 3 8987 8987 3912 White 18
2 PM Wed 72 73 W 3 9202 9202 4127 White 19
3 PM Wed 70 70 W 3 8558 8558 3483 White 16
4 PM Wed 66 66 N 3 7694 7694 2619 White 12
5 PM Wed 62 62 N 3 6824 6787 1712 White 8
6 PM Wed 58 58 N 3 5946 5424 349 White 4
7 PM Wed 56 56 N 3 5506 5075 0 White 2
8 PM Wed 55 55 N 3 5285 5075 0 White 2
9 PM Wed 56 56 N 3 5506 5075 0 White 2
10 PM Wed 55 55 NE 3 5285 5075 0 White 2
11 PM Wed 54 54 NE 3 5064 5075 0 White 1
12 Midnight Thu 52 52 NE 3 4316 5075 0 Blue 0
1 AM Thu 52 52 NE 3 4316 5075 0 Blue 0
2 AM Thu 53 53 NE 3 4714 5075 0 Blue 0
3 AM Thu 52 52 NE 3 4316 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