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

Station:

KOAK

Date/Time:

17 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 Wed 46 46 S 3 2224 4000 0 Blue 0
5 AM Wed 45 45 S 3 2224 4000 0 Blue 0
6 AM Wed 45 45 S 3 2224 4000 0 Blue 0
7 AM Wed 46 46 SE 3 2224 4000 0 Blue 0
8 AM Wed 47 47 SE 3 2224 4000 0 Blue 0
9 AM Wed 50 50 SE 3 2224 4000 0 Blue 0
10 AM Wed 52 52 S 5 2224 4000 0 Blue 0
11 AM Wed 54 54 S 5 3179 4000 0 Blue 1
12 Noon Wed 56 57 S 5 3553 4000 0 Blue 4
1 PM Wed 58 59 S 6 3728 4000 0 Blue 6
2 PM Wed 58 58 S 6 3631 4000 0 Blue 5
3 PM Wed 58 58 S 6 3631 4000 0 Blue 5
4 PM Wed 57 57 SW 6 3553 4000 0 Blue 4
5 PM Wed 55 55 SW 6 3396 4000 0 Blue 2
6 PM Wed 54 54 SW 6 3179 4000 0 Blue 1
7 PM Wed 52 52 SW 5 2224 4000 0 Blue 0
8 PM Wed 51 51 SW 5 2224 4000 0 Blue 0
9 PM Wed 51 51 SW 5 2224 4000 0 Blue 0
10 PM Wed 50 50 SW 7 2224 4000 0 Blue 0
11 PM Wed 50 50 SW 7 2224 4000 0 Blue 0
12 Midnight Thu 50 50 SW 7 2224 4000 0 Blue 0
1 AM Thu 50 50 S 8 2224 4000 0 Blue 0
2 AM Thu 50 50 S 8 2224 4000 0 Blue 0
3 AM Thu 50 50 S 8 2224 4000 0 Blue 0
4 AM Thu 50 50 S 9 2224 4000 0 Blue 0
5 AM Thu 50 50 S 9 2224 4000 0 Blue 0
6 AM Thu 50 50 S 9 2224 4000 0 Blue 0
7 AM Thu 51 51 SW 9 2224 4000 0 Blue 0
8 AM Thu 48 48 SW 9 2224 4000 0 Blue 0
9 AM Thu 48 48 SW 9 2224 4000 0 Blue 0
10 AM Thu 47 47 SW 9 2224 4000 0 Blue 0
11 AM Thu 47 47 SW 9 2224 4000 0 Blue 0
12 Noon Thu 48 48 SW 9 2224 4000 0 Blue 0
1 PM Thu 48 48 SW 10 2224 4000 0 Blue 0
2 PM Thu 48 48 SW 10 2224 4000 0 Blue 0
3 PM Thu 47 47 SW 10 2224 4000 0 Blue 0
4 PM Thu 45 45 W 13 2224 4000 0 Blue 0
5 PM Thu 44 44 W 13 2224 4000 0 Blue 0
6 PM Thu 43 43 W 13 2224 4000 0 Blue 0
7 PM Thu 43 43 W 13 2224 4000 0 Blue 0
8 PM Thu 42 42 W 13 2224 4000 0 Blue 0
9 PM Thu 42 42 W 13 2224 4000 0 Blue 0
10 PM Thu 42 42 SW 9 2224 4000 0 Blue 0
11 PM Thu 41 41 SW 9 2224 4000 0 Blue 0
12 Midnight Fri 40 40 SW 9 2224 4000 0 Blue 0
1 AM Fri 40 40 SW 9 2224 4000 0 Blue 0
2 AM Fri 39 39 SW 9 2224 4000 0 Blue 0
3 AM Fri 39 39 SW 9 2224 4000 0 Blue 0
4 AM Fri 39 39 W 7 2224 4000 0 Blue 0
5 AM Fri 38 38 W 7 2224 4000 0 Blue 0
6 AM Fri 38 38 W 7 2224 4000 0 Blue 0
7 AM Fri 38 38 W 7 2224 4000 0 Blue 0
8 AM Fri 38 38 W 7 2224 4000 0 Blue 0
9 AM Fri 39 39 W 7 2224 4000 0 Blue 0
10 AM Fri 40 40 W 5 2224 4000 0 Blue 0
11 AM Fri 41 41 W 5 2224 4000 0 Blue 0
12 Noon Fri 42 42 W 5 2224 4000 0 Blue 0
1 PM Fri 43 43 W 5 2224 4000 0 Blue 0
2 PM Fri 43 43 W 5 2224 4000 0 Blue 0
3 PM Fri 43 43 W 5 2224 4000 0 Blue 0
4 PM Fri 42 42 W 7 2224 4000 0 Blue 0
5 PM Fri 41 41 W 7 2224 4000 0 Blue 0
6 PM Fri 40 40 W 7 2224 4000 0 Blue 0
7 PM Fri 38 38 W 7 2224 4000 0 Blue 0
8 PM Fri 38 38 W 7 2224 4000 0 Blue 0
9 PM Fri 37 37 W 7 2224 4000 0 Blue 0
10 PM Fri 37 37 NW 7 2224 4000 0 Blue 0
11 PM Fri 37 37 NW 7 2224 4000 0 Blue 0
12 Midnight Sat 36 36 NW 7 2224 4000 0 Blue 0
1 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
2 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
3 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
4 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
5 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
6 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
7 AM Sat 36 36 NW 7 2224 4000 0 Blue 0
8 AM Sat 38 38 NW 7 2224 4000 0 Blue 0
9 AM Sat 40 40 NW 7 2224 4000 0 Blue 0
10 AM Sat 43 43 NW 8 2224 4000 0 Blue 0
11 AM Sat 45 45 NW 8 2224 4000 0 Blue 0
12 Noon Sat 47 47 NW 8 2224 4000 0 Blue 0
1 PM Sat 49 49 NW 8 2224 4000 0 Blue 0
2 PM Sat 49 49 NW 8 2224 4000 0 Blue 0
3 PM Sat 48 48 NW 8 2224 4000 0 Blue 0
4 PM Sat 47 47 W 8 2224 4000 0 Blue 0
5 PM Sat 45 45 W 8 2224 4000 0 Blue 0
6 PM Sat 43 43 W 8 2224 4000 0 Blue 0
7 PM Sat 42 42 W 8 2224 4000 0 Blue 0
8 PM Sat 41 41 W 8 2224 4000 0 Blue 0
9 PM Sat 40 40 W 8 2224 4000 0 Blue 0
10 PM Sat 40 40 NW 6 2224 4000 0 Blue 0
11 PM Sat 40 40 NW 6 2224 4000 0 Blue 0
12 Midnight Sun 40 40 NW 6 2224 4000 0 Blue 0
1 AM Sun 40 40 NW 6 2224 4000 0 Blue 0
2 AM Sun 40 40 NW 6 2224 4000 0 Blue 0
3 AM Sun 41 41 NW 6 2224 4000 0 Blue 0
4 AM Sun 41 41 S 9 2224 4000 0 Blue 0
5 AM Sun 41 41 S 9 2224 4000 0 Blue 0
6 AM Sun 42 42 S 9 2224 4000 0 Blue 0
7 AM Sun 42 42 S 9 2224 4000 0 Blue 0
8 AM Sun 43 43 S 9 2224 4000 0 Blue 0
9 AM Sun 43 43 S 9 2224 4000 0 Blue 0
10 AM Sun 44 44 SE 9 2224 4000 0 Blue 0
11 AM Sun 44 44 SE 9 2224 4000 0 Blue 0
12 Noon Sun 45 45 SE 9 2224 4000 0 Blue 0
1 PM Sun 45 45 SE 9 2224 4000 0 Blue 0
2 PM Sun 45 45 SE 9 2224 4000 0 Blue 0
3 PM Sun 45 45 SE 9 2224 4000 0 Blue 0
4 PM Sun 45 45 S 9 2224 4000 0 Blue 0
5 PM Sun 45 45 S 9 2224 4000 0 Blue 0
6 PM Sun 45 45 S 9 2224 4000 0 Blue 0
7 PM Sun 45 45 S 9 2224 4000 0 Blue 0
8 PM Sun 45 45 S 9 2224 4000 0 Blue 0
9 PM Sun 44 44 S 9 2224 4000 0 Blue 0
10 PM Sun 44 44 SW 8 2224 4000 0 Blue 0
11 PM Sun 44 44 SW 8 2224 4000 0 Blue 0
12 Midnight Mon 43 43 SW 8 2224 4000 0 Blue 0
1 AM Mon 43 43 SW 8 2224 4000 0 Blue 0
2 AM Mon 43 43 SW 8 2224 4000 0 Blue 0
3 AM Mon 43 43 SW 8 2224 4000 0 Blue 0
4 AM Mon 43 43 NW 3 2224 4000 0 Blue 0
5 AM Mon 43 43 NW 3 2224 4000 0 Blue 0
6 AM Mon 43 43 NW 3 2224 4000 0 Blue 0
7 AM Mon 43 43 NW 3 2224 4000 0 Blue 0
8 AM Mon 43 43 NW 3 2224 4000 0 Blue 0
9 AM Mon 44 44 NW 3 2224 4000 0 Blue 0
10 AM Mon 45 45 N 5 2224 4000 0 Blue 0
11 AM Mon 46 46 N 5 2224 4000 0 Blue 0
12 Noon Mon 48 48 N 5 2224 4000 0 Blue 0
1 PM Mon 49 49 N 5 2224 4000 0 Blue 0
2 PM Mon 49 49 N 5 2224 4000 0 Blue 0
3 PM Mon 49 49 N 5 2224 4000 0 Blue 0
4 PM Mon 48 48 E 5 2224 4000 0 Blue 0
5 PM Mon 46 46 E 5 2224 4000 0 Blue 0
6 PM Mon 45 45 E 5 2224 4000 0 Blue 0
7 PM Mon 43 43 E 5 2224 4000 0 Blue 0
8 PM Mon 43 43 E 5 2224 4000 0 Blue 0
9 PM Mon 42 42 E 5 2224 4000 0 Blue 0
10 PM Mon 42 42 NE 5 2224 4000 0 Blue 0
11 PM Mon 42 42 NE 5 2224 4000 0 Blue 0
12 Midnight Tue 42 42 NE 5 2224 4000 0 Blue 0
1 AM Tue 42 42 NE 5 2224 4000 0 Blue 0
2 AM Tue 42 42 NE 5 2224 4000 0 Blue 0
3 AM Tue 42 42 NE 5 2224 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