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

Station:

 KOAK

Date/Time:

 3 SEP 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
5 AM Fri 70 70 W 1 2605 4000 0 Blue 0
6 AM Fri 71 71 W 1 2605 4000 0 Blue 0
7 AM Fri 72 72 W 1 2605 4000 0 Blue 0
8 AM Fri 74 74 E 1 2605 4000 0 Blue 0
9 AM Fri 76 77 E 1 2605 4000 0 Blue 0
10 AM Fri 78 81 E 1 3651 4000 0 Blue 2
11 AM Fri 81 86 SE 5 4899 4274 274 Blue 7
12 Noon Fri 83 89 SE 5 6203 4888 888 Blue 10
1 PM Fri 85 92 SE 5 7493 6156 2156 Blue 13
2 PM Fri 86 92 SE 8 7493 6156 2156 Blue 13
3 PM Fri 88 93 SE 8 8256 6576 2576 Blue 14
4 PM Fri 89 93 SE 8 8256 6576 2576 Blue 14
5 PM Fri 88 90 SW 8 6627 5296 1296 Blue 11
6 PM Fri 83 84 SW 8 4594 4000 0 Blue 5
7 PM Fri 77 77 SW 8 2605 4000 0 Blue 0
8 PM Fri 72 72 NW 7 2605 4000 0 Blue 0
9 PM Fri 69 69 NW 7 2605 4000 0 Blue 0
10 PM Fri 68 68 NW 7 2605 4000 0 Blue 0
11 PM Fri 68 68 NW 2 2605 4000 0 Blue 0
12 Midnight Sat 67 67 NW 2 2605 4000 0 Blue 0
1 AM Sat 67 67 NW 2 2605 4000 0 Blue 0
2 AM Sat 67 67 NW 1 2605 4000 0 Blue 0
3 AM Sat 66 66 NW 1 2605 4000 0 Blue 0
4 AM Sat 65 65 NW 1 2605 4000 0 Blue 0
5 AM Sat 64 64 N 5 2605 4000 0 Blue 0
6 AM Sat 64 64 N 5 2605 4000 0 Blue 0
7 AM Sat 65 65 N 5 2605 4000 0 Blue 0
8 AM Sat 67 67 E 3 2605 4000 0 Blue 0
9 AM Sat 70 71 E 3 2605 4000 0 Blue 0
10 AM Sat 75 78 E 3 2780 4000 0 Blue 0
11 AM Sat 79 83 W 5 4290 4000 0 Blue 4
12 Noon Sat 82 88 W 5 5771 4737 737 Blue 9
1 PM Sat 83 89 W 5 6203 4888 888 Blue 10
2 PM Sat 84 90 W 6 6627 5296 1296 Blue 11
3 PM Sat 83 88 W 6 5771 4737 737 Blue 9
4 PM Sat 82 86 W 6 4899 4274 274 Blue 7
5 PM Sat 80 82 NW 8 3972 4000 0 Blue 3
6 PM Sat 76 77 NW 8 2605 4000 0 Blue 0
7 PM Sat 72 72 NW 8 2605 4000 0 Blue 0
8 PM Sat 68 68 NW 8 2605 4000 0 Blue 0
9 PM Sat 65 65 NW 8 2605 4000 0 Blue 0
10 PM Sat 63 63 NW 8 2605 4000 0 Blue 0
11 PM Sat 62 62 N 8 2605 4000 0 Blue 0
12 Midnight Sun 62 62 N 8 2605 4000 0 Blue 0
1 AM Sun 62 62 N 8 2605 4000 0 Blue 0
2 AM Sun 62 62 N 8 2605 4000 0 Blue 0
3 AM Sun 62 62 N 8 2605 4000 0 Blue 0
4 AM Sun 61 61 N 8 2605 4000 0 Blue 0
5 AM Sun 61 61 NE 3 2605 4000 0 Blue 0
6 AM Sun 60 60 NE 3 2605 4000 0 Blue 0
7 AM Sun 60 60 NE 3 2605 4000 0 Blue 0
8 AM Sun 61 61 NE 3 2605 4000 0 Blue 0
9 AM Sun 64 65 NE 3 2605 4000 0 Blue 0
10 AM Sun 68 71 NE 3 2605 4000 0 Blue 0
11 AM Sun 71 75 E 3 2605 4000 0 Blue 0
12 Noon Sun 74 80 E 3 3327 4000 0 Blue 1
1 PM Sun 75 81 E 3 3651 4000 0 Blue 2
2 PM Sun 75 81 E 3 3651 4000 0 Blue 2
3 PM Sun 75 80 E 3 3327 4000 0 Blue 1
4 PM Sun 75 79 E 3 3001 4000 0 Blue 0
5 PM Sun 74 76 NW 12 2605 4000 0 Blue 0
6 PM Sun 72 73 NW 12 2605 4000 0 Blue 0
7 PM Sun 70 70 NW 12 2605 4000 0 Blue 0
8 PM Sun 67 67 NW 12 2605 4000 0 Blue 0
9 PM Sun 64 64 NW 12 2605 4000 0 Blue 0
10 PM Sun 60 60 NW 12 2605 4000 0 Blue 0
11 PM Sun 58 58 NE 7 2605 4000 0 Blue 0
12 Midnight Mon 56 56 NE 7 2605 4000 0 Blue 0
1 AM Mon 55 55 NE 7 2605 4000 0 Blue 0
2 AM Mon 55 55 NE 7 2605 4000 0 Blue 0
3 AM Mon 55 55 NE 7 2605 4000 0 Blue 0
4 AM Mon 56 56 NE 7 2605 4000 0 Blue 0
5 AM Mon 57 57 NE 7 2605 4000 0 Blue 0
6 AM Mon 57 57 NE 7 2605 4000 0 Blue 0
7 AM Mon 58 58 NE 7 2605 4000 0 Blue 0
8 AM Mon 59 59 NE 7 2605 4000 0 Blue 0
9 AM Mon 62 63 NE 7 2605 4000 0 Blue 0
10 AM Mon 66 69 NE 7 2605 4000 0 Blue 0
11 AM Mon 70 74 W 2 2605 4000 0 Blue 0
12 Noon Mon 73 79 W 2 3001 4000 0 Blue 0
1 PM Mon 75 81 W 2 3651 4000 0 Blue 2
2 PM Mon 76 82 W 2 3972 4000 0 Blue 3
3 PM Mon 77 82 W 2 3972 4000 0 Blue 3
4 PM Mon 77 81 W 2 3651 4000 0 Blue 2
5 PM Mon 76 78 W 8 2780 4000 0 Blue 0
6 PM Mon 74 75 W 8 2605 4000 0 Blue 0
7 PM Mon 71 71 W 8 2605 4000 0 Blue 0
8 PM Mon 67 67 W 8 2605 4000 0 Blue 0
9 PM Mon 63 63 W 8 2605 4000 0 Blue 0
10 PM Mon 60 60 W 8 2605 4000 0 Blue 0
11 PM Mon 57 57 E 2 2605 4000 0 Blue 0
12 Midnight Tue 56 56 E 2 2605 4000 0 Blue 0
1 AM Tue 55 55 E 2 2605 4000 0 Blue 0
2 AM Tue 55 55 E 2 2605 4000 0 Blue 0
3 AM Tue 55 55 E 2 2605 4000 0 Blue 0
4 AM Tue 55 55 E 2 2605 4000 0 Blue 0
5 AM Tue 56 56 E 2 2605 4000 0 Blue 0
6 AM Tue 58 58 E 2 2605 4000 0 Blue 0
7 AM Tue 60 60 E 2 2605 4000 0 Blue 0
8 AM Tue 63 63 E 2 2605 4000 0 Blue 0
9 AM Tue 65 66 E 2 2605 4000 0 Blue 0
10 AM Tue 67 69 E 2 2605 4000 0 Blue 0
11 AM Tue 69 72 SW 5 2605 4000 0 Blue 0
12 Noon Tue 70 73 SW 5 2605 4000 0 Blue 0
1 PM Tue 71 75 SW 5 2605 4000 0 Blue 0
2 PM Tue 71 75 SW 5 2605 4000 0 Blue 0
3 PM Tue 70 73 SW 5 2605 4000 0 Blue 0
4 PM Tue 70 72 SW 5 2605 4000 0 Blue 0
5 PM Tue 68 69 W 13 2605 4000 0 Blue 0
6 PM Tue 67 67 W 13 2605 4000 0 Blue 0
7 PM Tue 64 64 W 13 2605 4000 0 Blue 0
8 PM Tue 62 62 W 13 2605 4000 0 Blue 0
9 PM Tue 60 60 W 13 2605 4000 0 Blue 0
10 PM Tue 57 57 W 13 2605 4000 0 Blue 0
11 PM Tue 56 56 NW 5 2605 4000 0 Blue 0
12 Midnight Wed 54 54 NW 5 2605 4000 0 Blue 0
1 AM Wed 53 53 NW 5 2605 4000 0 Blue 0
2 AM Wed 52 52 NW 5 2605 4000 0 Blue 0
3 AM Wed 52 52 NW 5 2605 4000 0 Blue 0
4 AM Wed 52 52 NW 5 2605 4000 0 Blue 0
5 AM Wed 52 52 NW 3 2605 4000 0 Blue 0
6 AM Wed 53 53 NW 3 2605 4000 0 Blue 0
7 AM Wed 55 55 NW 3 2605 4000 0 Blue 0
8 AM Wed 57 57 NW 3 2605 4000 0 Blue 0
9 AM Wed 59 60 NW 3 2605 4000 0 Blue 0
10 AM Wed 61 63 NW 3 2605 4000 0 Blue 0
11 AM Wed 63 66 W 7 2605 4000 0 Blue 0
12 Noon Wed 64 68 W 7 2605 4000 0 Blue 0
1 PM Wed 65 69 W 7 2605 4000 0 Blue 0
2 PM Wed 66 70 W 7 2605 4000 0 Blue 0
3 PM Wed 66 69 W 7 2605 4000 0 Blue 0
4 PM Wed 66 68 W 7 2605 4000 0 Blue 0
5 PM Wed 66 67 W 10 2605 4000 0 Blue 0
6 PM Wed 65 65 W 10 2605 4000 0 Blue 0
7 PM Wed 63 63 W 10 2605 4000 0 Blue 0
8 PM Wed 62 62 W 10 2605 4000 0 Blue 0
9 PM Wed 60 60 W 10 2605 4000 0 Blue 0
10 PM Wed 59 59 W 10 2605 4000 0 Blue 0
11 PM Wed 57 57 W 3 2605 4000 0 Blue 0
12 Midnight Thu 56 56 W 3 2605 4000 0 Blue 0
1 AM Thu 55 55 W 3 2605 4000 0 Blue 0
2 AM Thu 54 54 W 3 2605 4000 0 Blue 0
3 AM Thu 54 54 W 3 2605 4000 0 Blue 0
4 AM Thu 54 54 W 3 2605 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