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

Station:

KOAK

Date/Time:

25 NOV 2020

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 39 39 N 13 2431 4000 0 Blue 0
5 AM Wed 39 39 N 13 2431 4000 0 Blue 0
6 AM Wed 41 41 N 13 2431 4000 0 Blue 0
7 AM Wed 42 42 N 13 2431 4000 0 Blue 0
8 AM Wed 43 43 N 13 2431 4000 0 Blue 0
9 AM Wed 43 43 N 13 2431 4000 0 Blue 0
10 AM Wed 44 45 N 13 2431 4000 0 Blue 0
11 AM Wed 46 48 N 13 3488 4000 0 Blue 2
12 Noon Wed 47 49 N 13 3614 4000 0 Blue 3
1 PM Wed 48 50 N 12 3740 4000 0 Blue 4
2 PM Wed 48 49 N 12 3614 4000 0 Blue 3
3 PM Wed 48 48 N 12 3488 4000 0 Blue 2
4 PM Wed 47 47 N 10 3362 4000 0 Blue 1
5 PM Wed 46 46 N 10 2765 4000 0 Blue 0
6 PM Wed 44 44 N 10 2431 4000 0 Blue 0
7 PM Wed 42 42 N 10 2431 4000 0 Blue 0
8 PM Wed 40 40 N 10 2431 4000 0 Blue 0
9 PM Wed 38 38 N 10 2431 4000 0 Blue 0
10 PM Wed 37 37 N 15 2431 4000 0 Blue 0
11 PM Wed 36 36 N 15 2431 4000 0 Blue 0
12 Midnight Thu 36 36 N 15 2431 4000 0 Blue 0
1 AM Thu 36 36 N 16 2431 4000 0 Blue 0
2 AM Thu 37 37 N 16 2431 4000 0 Blue 0
3 AM Thu 37 37 N 16 2431 4000 0 Blue 0
4 AM Thu 38 38 N 21 2431 4000 0 Blue 0
5 AM Thu 39 39 N 21 2431 4000 0 Blue 0
6 AM Thu 41 41 N 21 2431 4000 0 Blue 0
7 AM Thu 42 42 N 17 2431 4000 0 Blue 0
8 AM Thu 43 43 N 17 2431 4000 0 Blue 0
9 AM Thu 45 45 N 17 2431 4000 0 Blue 0
10 AM Thu 46 47 NE 7 3362 4000 0 Blue 1
11 AM Thu 48 50 NE 7 3740 4000 0 Blue 4
12 Noon Thu 50 52 NE 7 3992 4000 0 Blue 6
1 PM Thu 51 53 NE 7 4118 4000 0 Blue 7
2 PM Thu 52 53 NE 7 4118 4000 0 Blue 7
3 PM Thu 53 53 NE 7 4118 4000 0 Blue 7
4 PM Thu 53 53 N 9 4118 4000 0 Blue 7
5 PM Thu 52 52 N 9 3992 4000 0 Blue 6
6 PM Thu 51 51 N 9 3866 4000 0 Blue 5
7 PM Thu 50 50 NE 8 3740 4000 0 Blue 4
8 PM Thu 48 48 NE 8 3488 4000 0 Blue 2
9 PM Thu 46 46 NE 8 2765 4000 0 Blue 0
10 PM Thu 44 44 NE 10 2431 4000 0 Blue 0
11 PM Thu 43 43 NE 10 2431 4000 0 Blue 0
12 Midnight Fri 42 42 NE 10 2431 4000 0 Blue 0
1 AM Fri 42 42 NE 8 2431 4000 0 Blue 0
2 AM Fri 42 42 NE 8 2431 4000 0 Blue 0
3 AM Fri 42 42 NE 8 2431 4000 0 Blue 0
4 AM Fri 43 43 NE 5 2431 4000 0 Blue 0
5 AM Fri 44 44 NE 5 2431 4000 0 Blue 0
6 AM Fri 46 46 NE 5 2765 4000 0 Blue 0
7 AM Fri 47 47 NE 5 3362 4000 0 Blue 1
8 AM Fri 49 49 NE 5 3614 4000 0 Blue 3
9 AM Fri 51 51 NE 5 3866 4000 0 Blue 5
10 AM Fri 52 53 NE 3 4118 4000 0 Blue 7
11 AM Fri 54 55 NE 3 4803 4000 0 Blue 9
12 Noon Fri 55 57 NE 3 5118 4237 237 Blue 11
1 PM Fri 56 58 SE 2 5342 4761 761 Blue 12
2 PM Fri 57 58 SE 2 5342 4761 761 Blue 12
3 PM Fri 57 57 SE 2 5118 4237 237 Blue 11
4 PM Fri 56 56 S 1 4950 4111 111 Blue 10
5 PM Fri 55 55 S 1 4803 4000 0 Blue 9
6 PM Fri 54 54 S 1 4243 4000 0 Blue 8
7 PM Fri 52 52 NE 2 3992 4000 0 Blue 6
8 PM Fri 50 50 NE 2 3740 4000 0 Blue 4
9 PM Fri 48 48 NE 2 3488 4000 0 Blue 2
10 PM Fri 46 46 NE 2 2765 4000 0 Blue 0
11 PM Fri 44 44 NE 2 2431 4000 0 Blue 0
12 Midnight Sat 43 43 NE 2 2431 4000 0 Blue 0
1 AM Sat 42 42 NE 2 2431 4000 0 Blue 0
2 AM Sat 42 42 NE 2 2431 4000 0 Blue 0
3 AM Sat 42 42 NE 2 2431 4000 0 Blue 0
4 AM Sat 43 43 NE 3 2431 4000 0 Blue 0
5 AM Sat 44 44 NE 3 2431 4000 0 Blue 0
6 AM Sat 46 46 NE 3 2765 4000 0 Blue 0
7 AM Sat 48 48 NE 2 3488 4000 0 Blue 2
8 AM Sat 50 50 NE 2 3740 4000 0 Blue 4
9 AM Sat 52 52 NE 2 3992 4000 0 Blue 6
10 AM Sat 54 55 NE 2 4803 4000 0 Blue 9
11 AM Sat 56 58 NE 2 5342 4761 761 Blue 12
12 Noon Sat 58 60 NE 2 5675 5104 1104 Blue 14
1 PM Sat 59 61 SW 2 5793 5322 1322 Blue 15
2 PM Sat 59 60 SW 2 5675 5104 1104 Blue 14
3 PM Sat 59 59 SW 2 5541 4940 940 Blue 13
4 PM Sat 58 58 SW 2 5342 4761 761 Blue 12
5 PM Sat 57 57 SW 2 5118 4237 237 Blue 11
6 PM Sat 55 55 SW 2 4803 4000 0 Blue 9
7 PM Sat 53 53 NE 2 4118 4000 0 Blue 7
8 PM Sat 51 51 NE 2 3866 4000 0 Blue 5
9 PM Sat 49 49 NE 2 3614 4000 0 Blue 3
10 PM Sat 47 47 NE 2 3362 4000 0 Blue 1
11 PM Sat 45 45 NE 2 2431 4000 0 Blue 0
12 Midnight Sun 44 44 NE 2 2431 4000 0 Blue 0
1 AM Sun 43 43 NE 2 2431 4000 0 Blue 0
2 AM Sun 43 43 NE 2 2431 4000 0 Blue 0
3 AM Sun 43 43 NE 2 2431 4000 0 Blue 0
4 AM Sun 44 44 NE 2 2431 4000 0 Blue 0
5 AM Sun 45 45 NE 2 2431 4000 0 Blue 0
6 AM Sun 47 47 NE 2 3362 4000 0 Blue 1
7 AM Sun 49 49 NE 2 3614 4000 0 Blue 3
8 AM Sun 51 51 NE 2 3866 4000 0 Blue 5
9 AM Sun 52 52 NE 2 3992 4000 0 Blue 6
10 AM Sun 54 55 NE 3 4803 4000 0 Blue 9
11 AM Sun 55 56 NE 3 4950 4111 111 Blue 10
12 Noon Sun 56 57 NE 3 5118 4237 237 Blue 11
1 PM Sun 57 58 SW 3 5342 4761 761 Blue 12
2 PM Sun 57 58 SW 3 5342 4761 761 Blue 12
3 PM Sun 57 57 SW 3 5118 4237 237 Blue 11
4 PM Sun 56 56 SW 2 4950 4111 111 Blue 10
5 PM Sun 55 55 SW 2 4803 4000 0 Blue 9
6 PM Sun 54 54 SW 2 4243 4000 0 Blue 8
7 PM Sun 52 52 N 2 3992 4000 0 Blue 6
8 PM Sun 51 51 N 2 3866 4000 0 Blue 5
9 PM Sun 49 49 N 2 3614 4000 0 Blue 3
10 PM Sun 48 48 NE 2 3488 4000 0 Blue 2
11 PM Sun 47 47 NE 2 3362 4000 0 Blue 1
12 Midnight Mon 45 45 NE 2 2431 4000 0 Blue 0
1 AM Mon 45 45 NE 2 2431 4000 0 Blue 0
2 AM Mon 44 44 NE 2 2431 4000 0 Blue 0
3 AM Mon 43 43 NE 2 2431 4000 0 Blue 0
4 AM Mon 43 43 N 2 2431 4000 0 Blue 0
5 AM Mon 43 43 N 2 2431 4000 0 Blue 0
6 AM Mon 43 43 N 2 2431 4000 0 Blue 0
7 AM Mon 44 44 N 3 2431 4000 0 Blue 0
8 AM Mon 44 44 N 3 2431 4000 0 Blue 0
9 AM Mon 45 45 N 3 2431 4000 0 Blue 0
10 AM Mon 46 46 NW 3 2765 4000 0 Blue 0
11 AM Mon 48 48 NW 3 3488 4000 0 Blue 2
12 Noon Mon 49 49 NW 3 3614 4000 0 Blue 3
1 PM Mon 51 51 W 5 3866 4000 0 Blue 5
2 PM Mon 52 52 W 5 3992 4000 0 Blue 6
3 PM Mon 53 53 W 5 4118 4000 0 Blue 7
4 PM Mon 53 53 W 3 4118 4000 0 Blue 7
5 PM Mon 53 53 W 3 4118 4000 0 Blue 7
6 PM Mon 52 52 W 3 3992 4000 0 Blue 6
7 PM Mon 50 50 NW 3 3740 4000 0 Blue 4
8 PM Mon 49 49 NW 3 3614 4000 0 Blue 3
9 PM Mon 47 47 NW 3 3362 4000 0 Blue 1
10 PM Mon 45 45 N 3 2431 4000 0 Blue 0
11 PM Mon 44 44 N 3 2431 4000 0 Blue 0
12 Midnight Tue 42 42 N 3 2431 4000 0 Blue 0
1 AM Tue 41 41 N 3 2431 4000 0 Blue 0
2 AM Tue 41 41 N 3 2431 4000 0 Blue 0
3 AM Tue 41 41 N 3 2431 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