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

Station:

 KOAK

Date/Time:

 18 MAR 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 Thu 44 44 NE 4 2605 4000 0 Blue 0
6 AM Thu 48 48 NE 4 2605 4000 0 Blue 0
7 AM Thu 48 48 NE 4 2605 4000 0 Blue 0
8 AM Thu 49 49 NE 6 2605 4000 0 Blue 0
9 AM Thu 51 52 NE 6 2605 4000 0 Blue 0
10 AM Thu 55 57 NE 6 2605 4000 0 Blue 0
11 AM Thu 57 60 NE 12 2605 4000 0 Blue 0
12 Noon Thu 61 66 NE 12 4598 4000 0 Blue 3
1 PM Thu 64 69 NE 12 7122 4586 586 Blue 6
2 PM Thu 66 71 NE 12 7411 6970 2970 Blue 8
3 PM Thu 67 71 NE 12 7411 6970 2970 Blue 8
4 PM Thu 67 70 NE 12 7266 4765 765 Blue 7
5 PM Thu 65 66 NE 11 4598 4000 0 Blue 3
6 PM Thu 62 62 NE 11 2784 4000 0 Blue 0
7 PM Thu 57 57 NE 11 2605 4000 0 Blue 0
8 PM Thu 50 50 NE 10 2605 4000 0 Blue 0
9 PM Thu 47 47 NE 10 2605 4000 0 Blue 0
10 PM Thu 47 47 NE 10 2605 4000 0 Blue 0
11 PM Thu 47 47 NE 13 2605 4000 0 Blue 0
12 Midnight Fri 46 46 NE 13 2605 4000 0 Blue 0
1 AM Fri 46 46 NE 13 2605 4000 0 Blue 0
2 AM Fri 44 44 NE 12 2605 4000 0 Blue 0
3 AM Fri 44 44 NE 12 2605 4000 0 Blue 0
4 AM Fri 44 44 NE 12 2605 4000 0 Blue 0
5 AM Fri 45 45 NE 10 2605 4000 0 Blue 0
6 AM Fri 49 49 NE 10 2605 4000 0 Blue 0
7 AM Fri 50 50 NE 10 2605 4000 0 Blue 0
8 AM Fri 50 50 NE 7 2605 4000 0 Blue 0
9 AM Fri 52 53 NE 7 2605 4000 0 Blue 0
10 AM Fri 56 58 NE 7 2605 4000 0 Blue 0
11 AM Fri 59 62 W 3 2784 4000 0 Blue 0
12 Noon Fri 63 68 W 3 6988 4273 273 Blue 5
1 PM Fri 66 71 W 3 7411 6970 2970 Blue 8
2 PM Fri 68 73 W 3 7701 7245 3245 Blue 10
3 PM Fri 69 73 W 3 7701 7245 3245 Blue 10
4 PM Fri 69 72 W 3 7556 7101 3101 Blue 9
5 PM Fri 66 67 W 3 4796 4000 0 Blue 4
6 PM Fri 63 63 W 3 2938 4000 0 Blue 0
7 PM Fri 57 57 W 3 2605 4000 0 Blue 0
8 PM Fri 50 50 W 3 2605 4000 0 Blue 0
9 PM Fri 47 47 W 3 2605 4000 0 Blue 0
10 PM Fri 46 46 W 3 2605 4000 0 Blue 0
11 PM Fri 46 46 E 3 2605 4000 0 Blue 0
12 Midnight Sat 46 46 E 3 2605 4000 0 Blue 0
1 AM Sat 45 45 E 3 2605 4000 0 Blue 0
2 AM Sat 44 44 E 3 2605 4000 0 Blue 0
3 AM Sat 44 44 E 3 2605 4000 0 Blue 0
4 AM Sat 43 43 E 3 2605 4000 0 Blue 0
5 AM Sat 44 44 NE 3 2605 4000 0 Blue 0
6 AM Sat 47 47 NE 3 2605 4000 0 Blue 0
7 AM Sat 48 48 NE 3 2605 4000 0 Blue 0
8 AM Sat 48 48 NE 3 2605 4000 0 Blue 0
9 AM Sat 50 51 NE 3 2605 4000 0 Blue 0
10 AM Sat 53 55 NE 3 2605 4000 0 Blue 0
11 AM Sat 56 59 S 6 2605 4000 0 Blue 0
12 Noon Sat 59 64 S 6 3588 4000 0 Blue 1
1 PM Sat 62 67 S 6 4796 4000 0 Blue 4
2 PM Sat 63 68 S 6 6988 4273 273 Blue 5
3 PM Sat 64 68 S 6 6988 4273 273 Blue 5
4 PM Sat 64 67 S 6 4796 4000 0 Blue 4
5 PM Sat 62 63 W 5 2938 4000 0 Blue 0
6 PM Sat 59 59 W 5 2605 4000 0 Blue 0
7 PM Sat 54 54 W 5 2605 4000 0 Blue 0
8 PM Sat 47 47 W 5 2605 4000 0 Blue 0
9 PM Sat 44 44 W 5 2605 4000 0 Blue 0
10 PM Sat 44 44 W 5 2605 4000 0 Blue 0
11 PM Sat 44 44 NW 4 2605 4000 0 Blue 0
12 Midnight Sun 43 43 NW 4 2605 4000 0 Blue 0
1 AM Sun 43 43 NW 4 2605 4000 0 Blue 0
2 AM Sun 41 41 NW 4 2605 4000 0 Blue 0
3 AM Sun 41 41 NW 4 2605 4000 0 Blue 0
4 AM Sun 41 41 NW 4 2605 4000 0 Blue 0
5 AM Sun 42 42 NW 6 2605 4000 0 Blue 0
6 AM Sun 45 45 NW 6 2605 4000 0 Blue 0
7 AM Sun 46 46 NW 6 2605 4000 0 Blue 0
8 AM Sun 46 46 NW 6 2605 4000 0 Blue 0
9 AM Sun 48 48 NW 6 2605 4000 0 Blue 0
10 AM Sun 51 52 NW 6 2605 4000 0 Blue 0
11 AM Sun 54 57 NW 7 2605 4000 0 Blue 0
12 Noon Sun 57 60 NW 7 2605 4000 0 Blue 0
1 PM Sun 60 64 NW 7 3588 4000 0 Blue 1
2 PM Sun 61 65 NW 7 4310 4000 0 Blue 2
3 PM Sun 62 65 NW 7 4310 4000 0 Blue 2
4 PM Sun 62 64 NW 7 3588 4000 0 Blue 1
5 PM Sun 60 60 S 7 2605 4000 0 Blue 0
6 PM Sun 57 57 S 7 2605 4000 0 Blue 0
7 PM Sun 52 52 S 7 2605 4000 0 Blue 0
8 PM Sun 46 46 S 7 2605 4000 0 Blue 0
9 PM Sun 43 43 S 7 2605 4000 0 Blue 0
10 PM Sun 43 43 S 7 2605 4000 0 Blue 0
11 PM Sun 43 43 N 2 2605 4000 0 Blue 0
12 Midnight Mon 42 42 N 2 2605 4000 0 Blue 0
1 AM Mon 42 42 N 2 2605 4000 0 Blue 0
2 AM Mon 40 40 N 2 2605 4000 0 Blue 0
3 AM Mon 40 40 N 2 2605 4000 0 Blue 0
4 AM Mon 40 40 N 2 2605 4000 0 Blue 0
5 AM Mon 41 41 E 3 2605 4000 0 Blue 0
6 AM Mon 44 44 E 3 2605 4000 0 Blue 0
7 AM Mon 45 45 E 3 2605 4000 0 Blue 0
8 AM Mon 45 45 E 3 2605 4000 0 Blue 0
9 AM Mon 47 47 E 3 2605 4000 0 Blue 0
10 AM Mon 50 51 E 3 2605 4000 0 Blue 0
11 AM Mon 53 55 W 6 2605 4000 0 Blue 0
12 Noon Mon 56 59 W 6 2605 4000 0 Blue 0
1 PM Mon 59 62 W 6 2784 4000 0 Blue 0
2 PM Mon 60 63 W 6 2938 4000 0 Blue 0
3 PM Mon 61 63 W 6 2938 4000 0 Blue 0
4 PM Mon 61 63 W 6 2938 4000 0 Blue 0
5 PM Mon 59 59 W 6 2605 4000 0 Blue 0
6 PM Mon 57 57 W 6 2605 4000 0 Blue 0
7 PM Mon 53 53 W 6 2605 4000 0 Blue 0
8 PM Mon 47 47 W 6 2605 4000 0 Blue 0
9 PM Mon 45 45 W 6 2605 4000 0 Blue 0
10 PM Mon 44 44 W 6 2605 4000 0 Blue 0
11 PM Mon 44 44 NW 2 2605 4000 0 Blue 0
12 Midnight Tue 44 44 NW 2 2605 4000 0 Blue 0
1 AM Tue 44 44 NW 2 2605 4000 0 Blue 0
2 AM Tue 42 42 NW 2 2605 4000 0 Blue 0
3 AM Tue 42 42 NW 2 2605 4000 0 Blue 0
4 AM Tue 42 42 NW 2 2605 4000 0 Blue 0
5 AM Tue 43 43 NW 4 2605 4000 0 Blue 0
6 AM Tue 46 46 NW 4 2605 4000 0 Blue 0
7 AM Tue 46 46 NW 4 2605 4000 0 Blue 0
8 AM Tue 46 46 NW 4 2605 4000 0 Blue 0
9 AM Tue 48 48 NW 4 2605 4000 0 Blue 0
10 AM Tue 50 51 NW 4 2605 4000 0 Blue 0
11 AM Tue 52 54 NW 4 2605 4000 0 Blue 0
12 Noon Tue 55 58 NW 4 2605 4000 0 Blue 0
1 PM Tue 57 60 NW 4 2605 4000 0 Blue 0
2 PM Tue 58 61 NW 4 2629 4000 0 Blue 0
3 PM Tue 59 62 NW 4 2784 4000 0 Blue 0
4 PM Tue 59 61 NW 4 2629 4000 0 Blue 0
5 PM Tue 57 58 NW 11 2605 4000 0 Blue 0
6 PM Tue 54 54 NW 11 2605 4000 0 Blue 0
7 PM Tue 50 50 NW 11 2605 4000 0 Blue 0
8 PM Tue 44 44 NW 11 2605 4000 0 Blue 0
9 PM Tue 41 41 NW 11 2605 4000 0 Blue 0
10 PM Tue 41 41 NW 11 2605 4000 0 Blue 0
11 PM Tue 41 41 NW 4 2605 4000 0 Blue 0
12 Midnight Wed 40 40 NW 4 2605 4000 0 Blue 0
1 AM Wed 40 40 NW 4 2605 4000 0 Blue 0
2 AM Wed 38 38 NW 4 2605 4000 0 Blue 0
3 AM Wed 38 38 NW 4 2605 4000 0 Blue 0
4 AM Wed 38 38 NW 4 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