Detailed Predictions for: Elk Mountain
Launch Altitude (f): 4000
LZ Altitude (f): 1600
Sounding

Station:

KOAK

Date/Time:

11 DEC 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 Tue 40 40 N 7 2438 4000 0 Blue 0
5 AM Tue 40 40 N 7 2438 4000 0 Blue 0
6 AM Tue 40 40 N 7 2438 4000 0 Blue 0
7 AM Tue 41 41 N 7 2438 4000 0 Blue 0
8 AM Tue 43 43 N 7 2438 4000 0 Blue 0
9 AM Tue 45 45 N 7 2438 4000 0 Blue 0
10 AM Tue 48 48 N 8 2804 4000 0 Blue 0
11 AM Tue 50 50 N 8 3828 4000 0 Blue 2
12 Noon Tue 52 52 N 8 5013 4000 0 Blue 4
1 PM Tue 54 54 NW 9 5287 4294 294 Blue 6
2 PM Tue 54 54 NW 9 5287 4294 294 Blue 6
3 PM Tue 54 54 NW 9 5287 4294 294 Blue 6
4 PM Tue 53 53 NW 8 5225 4000 0 Blue 5
5 PM Tue 52 52 NW 8 5013 4000 0 Blue 4
6 PM Tue 50 50 NW 8 3828 4000 0 Blue 2
7 PM Tue 49 49 NW 9 3323 4000 0 Blue 1
8 PM Tue 49 49 NW 9 3323 4000 0 Blue 1
9 PM Tue 48 48 NW 9 2804 4000 0 Blue 0
10 PM Tue 48 48 NW 10 2804 4000 0 Blue 0
11 PM Tue 47 47 NW 10 2438 4000 0 Blue 0
12 Midnight Wed 47 47 NW 10 2438 4000 0 Blue 0
1 AM Wed 47 47 NW 9 2438 4000 0 Blue 0
2 AM Wed 46 46 NW 9 2438 4000 0 Blue 0
3 AM Wed 46 46 NW 9 2438 4000 0 Blue 0
4 AM Wed 45 45 N 9 2438 4000 0 Blue 0
5 AM Wed 44 44 N 9 2438 4000 0 Blue 0
6 AM Wed 43 43 N 9 2438 4000 0 Blue 0
7 AM Wed 43 43 NE 7 2438 4000 0 Blue 0
8 AM Wed 44 44 NE 7 2438 4000 0 Blue 0
9 AM Wed 46 46 NE 7 2438 4000 0 Blue 0
10 AM Wed 49 50 NE 6 3828 4000 0 Blue 2
11 AM Wed 51 52 NE 6 5013 4000 0 Blue 4
12 Noon Wed 53 54 NE 6 5287 4294 294 Blue 6
1 PM Wed 54 55 N 5 5350 4959 959 Blue 7
2 PM Wed 55 56 N 5 5413 5219 1219 Blue 8
3 PM Wed 55 55 N 5 5350 4959 959 Blue 7
4 PM Wed 54 54 N 5 5287 4294 294 Blue 6
5 PM Wed 52 52 N 5 5013 4000 0 Blue 4
6 PM Wed 49 49 N 5 3323 4000 0 Blue 1
7 PM Wed 47 47 N 5 2438 4000 0 Blue 0
8 PM Wed 46 46 N 5 2438 4000 0 Blue 0
9 PM Wed 45 45 N 5 2438 4000 0 Blue 0
10 PM Wed 45 45 N 5 2438 4000 0 Blue 0
11 PM Wed 44 44 N 5 2438 4000 0 Blue 0
12 Midnight Thu 44 44 N 5 2438 4000 0 Blue 0
1 AM Thu 43 43 N 5 2438 4000 0 Blue 0
2 AM Thu 43 43 N 5 2438 4000 0 Blue 0
3 AM Thu 43 43 N 5 2438 4000 0 Blue 0
4 AM Thu 42 42 E 3 2438 4000 0 Blue 0
5 AM Thu 42 42 E 3 2438 4000 0 Blue 0
6 AM Thu 42 42 E 3 2438 4000 0 Blue 0
7 AM Thu 43 43 E 3 2438 4000 0 Blue 0
8 AM Thu 44 44 E 3 2438 4000 0 Blue 0
9 AM Thu 46 46 E 3 2438 4000 0 Blue 0
10 AM Thu 49 49 SE 5 3323 4000 0 Blue 1
11 AM Thu 51 52 SE 5 5013 4000 0 Blue 4
12 Noon Thu 54 55 SE 5 5350 4959 959 Blue 7
1 PM Thu 56 57 SE 5 5486 5282 1282 Blue 9
2 PM Thu 57 58 SE 5 5584 5344 1344 Blue 10
3 PM Thu 57 57 SE 5 5486 5282 1282 Blue 9
4 PM Thu 56 56 SE 7 5413 5219 1219 Blue 8
5 PM Thu 53 53 SE 7 5225 4000 0 Blue 5
6 PM Thu 49 49 SE 7 3323 4000 0 Blue 1
7 PM Thu 46 46 SE 7 2438 4000 0 Blue 0
8 PM Thu 44 44 SE 7 2438 4000 0 Blue 0
9 PM Thu 44 44 SE 7 2438 4000 0 Blue 0
10 PM Thu 43 43 S 9 2438 4000 0 Blue 0
11 PM Thu 43 43 S 9 2438 4000 0 Blue 0
12 Midnight Fri 42 42 S 9 2438 4000 0 Blue 0
1 AM Fri 42 42 S 9 2438 4000 0 Blue 0
2 AM Fri 42 42 S 9 2438 4000 0 Blue 0
3 AM Fri 42 42 S 9 2438 4000 0 Blue 0
4 AM Fri 42 42 S 10 2438 4000 0 Blue 0
5 AM Fri 42 42 S 10 2438 4000 0 Blue 0
6 AM Fri 43 43 S 10 2438 4000 0 Blue 0
7 AM Fri 43 43 S 10 2438 4000 0 Blue 0
8 AM Fri 44 44 S 10 2438 4000 0 Blue 0
9 AM Fri 45 45 S 10 2438 4000 0 Blue 0
10 AM Fri 46 46 S 15 2438 4000 0 Blue 0
11 AM Fri 46 46 S 15 2438 4000 0 Blue 0
12 Noon Fri 47 47 S 15 2438 4000 0 Blue 0
1 PM Fri 48 48 S 15 2804 4000 0 Blue 0
2 PM Fri 48 48 S 15 2804 4000 0 Blue 0
3 PM Fri 48 48 S 15 2804 4000 0 Blue 0
4 PM Fri 47 47 W 10 2438 4000 0 Blue 0
5 PM Fri 45 45 W 10 2438 4000 0 Blue 0
6 PM Fri 43 43 W 10 2438 4000 0 Blue 0
7 PM Fri 42 42 W 10 2438 4000 0 Blue 0
8 PM Fri 41 41 W 10 2438 4000 0 Blue 0
9 PM Fri 41 41 W 10 2438 4000 0 Blue 0
10 PM Fri 40 40 NE 5 2438 4000 0 Blue 0
11 PM Fri 40 40 NE 5 2438 4000 0 Blue 0
12 Midnight Sat 40 40 NE 5 2438 4000 0 Blue 0
1 AM Sat 39 39 NE 5 2438 4000 0 Blue 0
2 AM Sat 39 39 NE 5 2438 4000 0 Blue 0
3 AM Sat 39 39 NE 5 2438 4000 0 Blue 0
4 AM Sat 39 39 S 6 2438 4000 0 Blue 0
5 AM Sat 39 39 S 6 2438 4000 0 Blue 0
6 AM Sat 39 39 S 6 2438 4000 0 Blue 0
7 AM Sat 40 40 S 6 2438 4000 0 Blue 0
8 AM Sat 41 41 S 6 2438 4000 0 Blue 0
9 AM Sat 44 44 S 6 2438 4000 0 Blue 0
10 AM Sat 46 46 SE 6 2438 4000 0 Blue 0
11 AM Sat 49 49 SE 6 3323 4000 0 Blue 1
12 Noon Sat 51 51 SE 6 4320 4000 0 Blue 3
1 PM Sat 52 52 SE 6 5013 4000 0 Blue 4
2 PM Sat 53 53 SE 6 5225 4000 0 Blue 5
3 PM Sat 53 53 SE 6 5225 4000 0 Blue 5
4 PM Sat 52 52 S 8 5013 4000 0 Blue 4
5 PM Sat 50 50 S 8 3828 4000 0 Blue 2
6 PM Sat 48 48 S 8 2804 4000 0 Blue 0
7 PM Sat 46 46 S 8 2438 4000 0 Blue 0
8 PM Sat 45 45 S 8 2438 4000 0 Blue 0
9 PM Sat 45 45 S 8 2438 4000 0 Blue 0
10 PM Sat 45 45 S 14 2438 4000 0 Blue 0
11 PM Sat 46 46 S 14 2438 4000 0 Blue 0
12 Midnight Sun 46 46 S 14 2438 4000 0 Blue 0
1 AM Sun 45 45 S 14 2438 4000 0 Blue 0
2 AM Sun 45 45 S 14 2438 4000 0 Blue 0
3 AM Sun 45 45 S 14 2438 4000 0 Blue 0
4 AM Sun 45 45 S 17 2438 4000 0 Blue 0
5 AM Sun 45 45 S 17 2438 4000 0 Blue 0
6 AM Sun 45 45 S 17 2438 4000 0 Blue 0
7 AM Sun 45 45 S 17 2438 4000 0 Blue 0
8 AM Sun 46 46 S 17 2438 4000 0 Blue 0
9 AM Sun 47 47 S 17 2438 4000 0 Blue 0
10 AM Sun 47 47 S 15 2438 4000 0 Blue 0
11 AM Sun 48 48 S 15 2804 4000 0 Blue 0
12 Noon Sun 48 48 S 15 2804 4000 0 Blue 0
1 PM Sun 48 48 S 15 2804 4000 0 Blue 0
2 PM Sun 48 48 S 15 2804 4000 0 Blue 0
3 PM Sun 48 48 S 15 2804 4000 0 Blue 0
4 PM Sun 47 47 SW 10 2438 4000 0 Blue 0
5 PM Sun 46 46 SW 10 2438 4000 0 Blue 0
6 PM Sun 45 45 SW 10 2438 4000 0 Blue 0
7 PM Sun 44 44 SW 10 2438 4000 0 Blue 0
8 PM Sun 43 43 SW 10 2438 4000 0 Blue 0
9 PM Sun 43 43 SW 10 2438 4000 0 Blue 0
10 PM Sun 42 42 W 8 2438 4000 0 Blue 0
11 PM Sun 42 42 W 8 2438 4000 0 Blue 0
12 Midnight Mon 42 42 W 8 2438 4000 0 Blue 0
1 AM Mon 42 42 W 8 2438 4000 0 Blue 0
2 AM Mon 42 42 W 8 2438 4000 0 Blue 0
3 AM Mon 42 42 W 8 2438 4000 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