Detailed Predictions for: Potato Hill
Launch Altitude (f): 3400
LZ Altitude (f): 1700
Sounding

Station:

 KOAK

Date/Time:

 4 FEB 2012

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)
4 AM Sat 35 35 N 5 2612 3400 0 Blue 0
5 AM Sat 35 35 N 5 2612 3400 0 Blue 0
6 AM Sat 35 35 N 5 2612 3400 0 Blue 0
7 AM Sat 36 36 N 5 2612 3400 0 Blue 0
8 AM Sat 39 39 N 5 2612 3400 0 Blue 0
9 AM Sat 42 42 N 5 2612 3400 0 Blue 0
10 AM Sat 47 48 NE 6 3004 3400 0 Blue 0
11 AM Sat 51 53 NE 6 4808 3756 356 Blue 4
12 Noon Sat 55 57 NE 6 5525 4974 1574 Blue 8
1 PM Sat 58 60 NE 6 6059 5508 2108 Blue 11
2 PM Sat 59 61 NE 6 6254 5686 2286 Blue 12
3 PM Sat 59 60 NE 6 6059 5508 2108 Blue 11
4 PM Sat 57 57 E 6 5525 4974 1574 Blue 8
5 PM Sat 54 54 E 6 4988 4180 780 Blue 5
6 PM Sat 50 50 E 6 3771 3400 0 Blue 1
7 PM Sat 46 46 NE 3 2612 3400 0 Blue 0
8 PM Sat 44 44 NE 3 2612 3400 0 Blue 0
9 PM Sat 43 43 NE 3 2612 3400 0 Blue 0
10 PM Sat 42 42 N 3 2612 3400 0 Blue 0
11 PM Sat 41 41 N 3 2612 3400 0 Blue 0
12 Midnight Sun 40 40 N 3 2612 3400 0 Blue 0
1 AM Sun 39 39 N 3 2612 3400 0 Blue 0
2 AM Sun 38 38 N 3 2612 3400 0 Blue 0
3 AM Sun 37 37 N 3 2612 3400 0 Blue 0
4 AM Sun 37 37 N 5 2612 3400 0 Blue 0
5 AM Sun 36 36 N 5 2612 3400 0 Blue 0
6 AM Sun 36 36 N 5 2612 3400 0 Blue 0
7 AM Sun 37 37 N 5 2612 3400 0 Blue 0
8 AM Sun 40 40 N 5 2612 3400 0 Blue 0
9 AM Sun 43 43 N 5 2612 3400 0 Blue 0
10 AM Sun 48 49 NE 3 3333 3400 0 Blue 0
11 AM Sun 52 53 NE 3 4808 3756 356 Blue 4
12 Noon Sun 56 58 NE 3 5703 5153 1753 Blue 9
1 PM Sun 59 61 E 3 6254 5686 2286 Blue 12
2 PM Sun 61 62 E 3 6476 5863 2463 Blue 13
3 PM Sun 61 62 E 3 6476 5863 2463 Blue 13
4 PM Sun 59 59 E 5 5881 5331 1931 Blue 10
5 PM Sun 56 56 E 5 5346 4796 1396 Blue 7
6 PM Sun 52 52 E 5 4622 3400 0 Blue 3
7 PM Sun 48 48 E 5 3004 3400 0 Blue 0
8 PM Sun 45 45 E 5 2612 3400 0 Blue 0
9 PM Sun 43 43 E 5 2612 3400 0 Blue 0
10 PM Sun 42 42 N 3 2612 3400 0 Blue 0
11 PM Sun 41 41 N 3 2612 3400 0 Blue 0
12 Midnight Mon 40 40 N 3 2612 3400 0 Blue 0
1 AM Mon 40 40 N 3 2612 3400 0 Blue 0
2 AM Mon 39 39 N 3 2612 3400 0 Blue 0
3 AM Mon 39 39 N 3 2612 3400 0 Blue 0
4 AM Mon 39 39 NE 3 2612 3400 0 Blue 0
5 AM Mon 38 38 NE 3 2612 3400 0 Blue 0
6 AM Mon 38 38 NE 3 2612 3400 0 Blue 0
7 AM Mon 39 39 NE 3 2612 3400 0 Blue 0
8 AM Mon 41 41 NE 3 2612 3400 0 Blue 0
9 AM Mon 44 44 NE 3 2612 3400 0 Blue 0
10 AM Mon 47 48 E 6 3004 3400 0 Blue 0
11 AM Mon 51 52 E 6 4622 3400 0 Blue 3
12 Noon Mon 54 55 E 6 5167 4597 1197 Blue 6
1 PM Mon 57 58 E 6 5703 5153 1753 Blue 9
2 PM Mon 58 59 E 6 5881 5331 1931 Blue 10
3 PM Mon 58 58 E 6 5703 5153 1753 Blue 9
4 PM Mon 56 56 E 7 5346 4796 1396 Blue 7
5 PM Mon 54 54 E 7 4988 4180 780 Blue 5
6 PM Mon 51 51 E 7 4200 3400 0 Blue 2
7 PM Mon 48 48 E 7 3004 3400 0 Blue 0
8 PM Mon 46 46 E 7 2612 3400 0 Blue 0
9 PM Mon 45 45 E 7 2612 3400 0 Blue 0
10 PM Mon 44 44 E 5 2612 3400 0 Blue 0
11 PM Mon 43 43 E 5 2612 3400 0 Blue 0
12 Midnight Tue 42 42 E 5 2612 3400 0 Blue 0
1 AM Tue 42 42 E 5 2612 3400 0 Blue 0
2 AM Tue 42 42 E 5 2612 3400 0 Blue 0
3 AM Tue 42 42 E 5 2612 3400 0 Blue 0
4 AM Tue 42 42 E 5 2612 3400 0 Blue 0
5 AM Tue 41 41 E 5 2612 3400 0 Blue 0
6 AM Tue 41 41 E 5 2612 3400 0 Blue 0
7 AM Tue 41 41 E 5 2612 3400 0 Blue 0
8 AM Tue 41 41 E 5 2612 3400 0 Blue 0
9 AM Tue 42 42 E 5 2612 3400 0 Blue 0
10 AM Tue 44 44 E 5 2612 3400 0 Blue 0
11 AM Tue 46 46 E 5 2612 3400 0 Blue 0
12 Noon Tue 48 48 E 5 3004 3400 0 Blue 0
1 PM Tue 50 50 E 5 3771 3400 0 Blue 1
2 PM Tue 50 50 E 5 3771 3400 0 Blue 1
3 PM Tue 50 50 E 5 3771 3400 0 Blue 1
4 PM Tue 49 49 SE 3 3333 3400 0 Blue 0
5 PM Tue 47 47 SE 3 2696 3400 0 Blue 0
6 PM Tue 45 45 SE 3 2612 3400 0 Blue 0
7 PM Tue 44 44 SE 3 2612 3400 0 Blue 0
8 PM Tue 43 43 SE 3 2612 3400 0 Blue 0
9 PM Tue 42 42 SE 3 2612 3400 0 Blue 0
10 PM Tue 42 42 N 2 2612 3400 0 Blue 0
11 PM Tue 41 41 N 2 2612 3400 0 Blue 0
12 Midnight Wed 41 41 N 2 2612 3400 0 Blue 0
1 AM Wed 40 40 N 2 2612 3400 0 Blue 0
2 AM Wed 40 40 N 2 2612 3400 0 Blue 0
3 AM Wed 40 40 N 2 2612 3400 0 Blue 0
4 AM Wed 40 40 N 3 2612 3400 0 Blue 0
5 AM Wed 39 39 N 3 2612 3400 0 Blue 0
6 AM Wed 38 38 N 3 2612 3400 0 Blue 0
7 AM Wed 38 38 N 3 2612 3400 0 Blue 0
8 AM Wed 40 40 N 3 2612 3400 0 Blue 0
9 AM Wed 43 43 N 3 2612 3400 0 Blue 0
10 AM Wed 46 47 N 1 2696 3400 0 Blue 0
11 AM Wed 50 51 N 1 4200 3400 0 Blue 2
12 Noon Wed 53 55 N 1 5167 4597 1197 Blue 6
1 PM Wed 55 57 N 1 5525 4974 1574 Blue 8
2 PM Wed 57 58 N 1 5703 5153 1753 Blue 9
3 PM Wed 57 58 N 1 5703 5153 1753 Blue 9
4 PM Wed 56 56 E 1 5346 4796 1396 Blue 7
5 PM Wed 54 54 E 1 4988 4180 780 Blue 5
6 PM Wed 51 51 E 1 4200 3400 0 Blue 2
7 PM Wed 48 48 E 1 3004 3400 0 Blue 0
8 PM Wed 47 47 E 1 2696 3400 0 Blue 0
9 PM Wed 45 45 E 1 2612 3400 0 Blue 0
10 PM Wed 45 45 N 3 2612 3400 0 Blue 0
11 PM Wed 44 44 N 3 2612 3400 0 Blue 0
12 Midnight Thu 43 43 N 3 2612 3400 0 Blue 0
1 AM Thu 43 43 N 3 2612 3400 0 Blue 0
2 AM Thu 42 42 N 3 2612 3400 0 Blue 0
3 AM Thu 41 41 N 3 2612 3400 0 Blue 0
4 AM Thu 40 40 N 3 2612 3400 0 Blue 0
5 AM Thu 39 39 N 3 2612 3400 0 Blue 0
6 AM Thu 39 39 N 3 2612 3400 0 Blue 0
7 AM Thu 40 40 N 3 2612 3400 0 Blue 0
8 AM Thu 42 42 N 3 2612 3400 0 Blue 0
9 AM Thu 45 45 N 3 2612 3400 0 Blue 0
10 AM Thu 48 49 NE 3 3333 3400 0 Blue 0
11 AM Thu 52 54 NE 3 4988 4180 780 Blue 5
12 Noon Thu 55 57 NE 3 5525 4974 1574 Blue 8
1 PM Thu 57 59 NE 3 5881 5331 1931 Blue 10
2 PM Thu 58 60 NE 3 6059 5508 2108 Blue 11
3 PM Thu 58 59 NE 3 5881 5331 1931 Blue 10
4 PM Thu 57 57 E 2 5525 4974 1574 Blue 8
5 PM Thu 55 55 E 2 5167 4597 1197 Blue 6
6 PM Thu 52 52 E 2 4622 3400 0 Blue 3
7 PM Thu 49 49 E 2 3333 3400 0 Blue 0
8 PM Thu 47 47 E 2 2696 3400 0 Blue 0
9 PM Thu 45 45 E 2 2612 3400 0 Blue 0
10 PM Thu 43 43 S 1 2612 3400 0 Blue 0
11 PM Thu 42 42 S 1 2612 3400 0 Blue 0
12 Midnight Fri 42 42 S 1 2612 3400 0 Blue 0
1 AM Fri 41 41 S 1 2612 3400 0 Blue 0
2 AM Fri 41 41 S 1 2612 3400 0 Blue 0
3 AM Fri 41 41 S 1 2612 3400 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