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

Station:

KOAK

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 38 38 W 5 2592 4000 0 Blue 0
5 AM Fri 37 37 W 5 2592 4000 0 Blue 0
6 AM Fri 36 36 W 5 2592 4000 0 Blue 0
7 AM Fri 36 36 NW 3 2592 4000 0 Blue 0
8 AM Fri 38 38 NW 3 2592 4000 0 Blue 0
9 AM Fri 41 41 NW 3 2592 4000 0 Blue 0
10 AM Fri 44 45 E 3 3512 4000 0 Blue 3
11 AM Fri 46 48 E 3 4507 4000 0 White 6
12 Noon Fri 48 50 E 3 4955 4332 332 White 8
1 PM Fri 49 51 W 3 5172 4694 694 White 9
2 PM Fri 50 51 W 3 5172 4694 694 White 9
3 PM Fri 50 50 W 3 4955 4332 332 White 8
4 PM Fri 48 48 W 2 4507 4000 0 White 6
5 PM Fri 46 46 W 2 3781 4000 0 Blue 4
6 PM Fri 43 43 W 2 3016 4000 0 Blue 1
7 PM Fri 41 41 NE 3 2592 4000 0 Blue 0
8 PM Fri 40 40 NE 3 2592 4000 0 Blue 0
9 PM Fri 39 39 NE 3 2592 4000 0 Blue 0
10 PM Fri 39 39 NE 5 2592 4000 0 Blue 0
11 PM Fri 39 39 NE 5 2592 4000 0 Blue 0
12 Midnight Sat 38 38 NE 5 2592 4000 0 Blue 0
1 AM Sat 38 38 NE 5 2592 4000 0 Blue 0
2 AM Sat 38 38 NE 5 2592 4000 0 Blue 0
3 AM Sat 37 37 NE 5 2592 4000 0 Blue 0
4 AM Sat 37 37 W 5 2592 4000 0 Blue 0
5 AM Sat 37 37 W 5 2592 4000 0 Blue 0
6 AM Sat 37 37 W 5 2592 4000 0 Blue 0
7 AM Sat 38 38 W 5 2592 4000 0 Blue 0
8 AM Sat 40 40 W 5 2592 4000 0 Blue 0
9 AM Sat 43 43 W 5 3016 4000 0 Blue 1
10 AM Sat 46 47 SW 2 4289 4000 0 White 5
11 AM Sat 50 52 SW 2 5388 5388 1388 White 10
12 Noon Sat 53 55 SW 2 6033 6033 2033 White 13
1 PM Sat 54 56 SW 2 6247 6247 2247 White 14
2 PM Sat 55 56 SW 2 6247 6247 2247 White 14
3 PM Sat 54 54 SW 2 5818 5818 1818 White 12
4 PM Sat 52 52 SW 3 5388 5388 1388 White 10
5 PM Sat 49 49 SW 3 4736 4000 0 White 7
6 PM Sat 45 45 SW 3 3512 4000 0 Blue 3
7 PM Sat 42 42 SW 3 2592 4000 0 Blue 0
8 PM Sat 40 40 SW 3 2592 4000 0 Blue 0
9 PM Sat 40 40 SW 3 2592 4000 0 Blue 0
10 PM Sat 39 39 SE 2 2592 4000 0 Blue 0
11 PM Sat 39 39 SE 2 2592 4000 0 Blue 0
12 Midnight Sun 39 39 SE 2 2592 4000 0 Blue 0
1 AM Sun 38 38 SE 2 2592 4000 0 Blue 0
2 AM Sun 37 37 SE 2 2592 4000 0 Blue 0
3 AM Sun 37 37 SE 2 2592 4000 0 Blue 0
4 AM Sun 36 36 E 2 2592 4000 0 Blue 0
5 AM Sun 35 35 E 2 2592 4000 0 Blue 0
6 AM Sun 35 35 E 2 2592 4000 0 Blue 0
7 AM Sun 36 36 E 2 2592 4000 0 Blue 0
8 AM Sun 38 38 E 2 2592 4000 0 Blue 0
9 AM Sun 41 41 E 2 2592 4000 0 Blue 0
10 AM Sun 44 45 S 3 3512 4000 0 Blue 3
11 AM Sun 48 49 S 3 4736 4000 0 White 7
12 Noon Sun 52 53 S 3 5603 5603 1603 White 11
1 PM Sun 54 55 S 3 6033 6033 2033 White 13
2 PM Sun 54 55 S 3 6033 6033 2033 White 13
3 PM Sun 53 53 S 3 5603 5603 1603 White 11
4 PM Sun 51 51 SW 3 5172 4694 694 White 9
5 PM Sun 49 49 SW 3 4736 4000 0 White 7
6 PM Sun 47 47 SW 3 4289 4000 0 White 5
7 PM Sun 46 46 SW 3 3781 4000 0 Blue 4
8 PM Sun 46 46 SW 3 3781 4000 0 Blue 4
9 PM Sun 47 47 SW 3 4289 4000 0 White 5
10 PM Sun 47 47 S 5 4289 4000 0 White 5
11 PM Sun 47 47 S 5 4289 4000 0 White 5
12 Midnight Mon 47 47 S 5 4289 4000 0 White 5
1 AM Mon 47 47 S 5 4289 4000 0 White 5
2 AM Mon 47 47 S 5 4289 4000 0 White 5
3 AM Mon 48 48 S 5 4507 4000 0 White 6
4 AM Mon 48 48 S 7 4507 4000 0 White 6
5 AM Mon 49 49 S 7 4736 4000 0 White 7
6 AM Mon 49 49 S 7 4736 4000 0 White 7
7 AM Mon 49 49 S 7 4736 4000 0 White 7
8 AM Mon 50 50 S 7 4955 4332 332 White 8
9 AM Mon 50 50 S 7 4955 4332 332 White 8
10 AM Mon 50 50 S 7 4955 4332 332 White 8
11 AM Mon 51 51 S 7 5172 4694 694 White 9
12 Noon Mon 52 52 S 7 5388 5388 1388 White 10
1 PM Mon 53 53 S 7 5603 5603 1603 White 11
2 PM Mon 53 53 S 7 5603 5603 1603 White 11
3 PM Mon 53 53 S 7 5603 5603 1603 White 11
4 PM Mon 53 53 S 6 5603 5603 1603 White 11
5 PM Mon 54 54 S 6 5818 5818 1818 White 12
6 PM Mon 54 54 S 6 5818 5818 1818 White 12
7 PM Mon 54 54 S 6 5818 5818 1818 White 12
8 PM Mon 54 54 S 6 5818 5818 1818 White 12
9 PM Mon 54 54 S 6 5818 5818 1818 White 12
10 PM Mon 54 54 SE 5 5818 5818 1818 White 12
11 PM Mon 54 54 SE 5 5818 5818 1818 White 12
12 Midnight Tue 54 54 SE 5 5818 5818 1818 White 12
1 AM Tue 54 54 SE 5 5818 5818 1818 White 12
2 AM Tue 54 54 SE 5 5818 5818 1818 White 12
3 AM Tue 54 54 SE 5 5818 5818 1818 White 12
4 AM Tue 54 54 SE 6 5818 5818 1818 White 12
5 AM Tue 54 54 SE 6 5818 5818 1818 White 12
6 AM Tue 54 54 SE 6 5818 5818 1818 White 12
7 AM Tue 54 54 SE 6 5818 5818 1818 White 12
8 AM Tue 54 54 SE 6 5818 5818 1818 White 12
9 AM Tue 55 55 SE 6 6033 6033 2033 White 13
10 AM Tue 55 55 SE 9 6033 6033 2033 White 13
11 AM Tue 55 55 SE 9 6033 6033 2033 White 13
12 Noon Tue 55 55 SE 9 6033 6033 2033 White 13
1 PM Tue 55 55 SE 9 6033 6033 2033 White 13
2 PM Tue 55 55 SE 9 6033 6033 2033 White 13
3 PM Tue 55 55 SE 9 6033 6033 2033 White 13
4 PM Tue 55 55 SE 8 6033 6033 2033 White 13
5 PM Tue 55 55 SE 8 6033 6033 2033 White 13
6 PM Tue 55 55 SE 8 6033 6033 2033 White 13
7 PM Tue 55 55 SE 8 6033 6033 2033 White 13
8 PM Tue 55 55 SE 8 6033 6033 2033 White 13
9 PM Tue 55 55 SE 8 6033 6033 2033 White 13
10 PM Tue 55 55 SE 8 6033 6033 2033 White 13
11 PM Tue 55 55 SE 8 6033 6033 2033 White 13
12 Midnight Wed 55 55 SE 8 6033 6033 2033 White 13
1 AM Wed 55 55 SE 8 6033 6033 2033 White 13
2 AM Wed 55 55 SE 8 6033 6033 2033 White 13
3 AM Wed 55 55 SE 8 6033 6033 2033 White 13
4 AM Wed 55 55 SE 9 6033 6033 2033 White 13
5 AM Wed 55 55 SE 9 6033 6033 2033 White 13
6 AM Wed 55 55 SE 9 6033 6033 2033 White 13
7 AM Wed 55 55 SE 9 6033 6033 2033 White 13
8 AM Wed 55 55 SE 9 6033 6033 2033 White 13
9 AM Wed 55 55 SE 9 6033 6033 2033 White 13
10 AM Wed 56 56 SE 8 6247 6247 2247 White 14
11 AM Wed 56 56 SE 8 6247 6247 2247 White 14
12 Noon Wed 56 56 SE 8 6247 6247 2247 White 14
1 PM Wed 56 56 SE 8 6247 6247 2247 White 14
2 PM Wed 56 56 SE 8 6247 6247 2247 White 14
3 PM Wed 56 56 SE 8 6247 6247 2247 White 14
4 PM Wed 56 56 S 6 6247 6247 2247 White 14
5 PM Wed 55 55 S 6 6033 6033 2033 White 13
6 PM Wed 55 55 S 6 6033 6033 2033 White 13
7 PM Wed 54 54 S 6 5818 5818 1818 White 12
8 PM Wed 54 54 S 6 5818 5818 1818 White 12
9 PM Wed 54 54 S 6 5818 5818 1818 White 12
10 PM Wed 54 54 S 6 5818 5818 1818 White 12
11 PM Wed 54 54 S 6 5818 5818 1818 White 12
12 Midnight Thu 54 54 S 6 5818 5818 1818 White 12
1 AM Thu 53 53 S 6 5603 5603 1603 White 11
2 AM Thu 53 53 S 6 5603 5603 1603 White 11
3 AM Thu 54 54 S 6 5818 5818 1818 White 12

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