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

Station:

 KOAK

Date/Time:

 10 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)
7 AM Wed 29 29 E 6 2582 3400 0 Blue 0
8 AM Wed 32 32 E 6 2582 3400 0 Blue 0
9 AM Wed 37 38 E 6 4947 3400 0 Blue 2
10 AM Wed 41 43 E 6 7020 5754 2354 White 7
11 AM Wed 44 47 E 6 7865 7442 4042 White 11
12 Noon Wed 46 49 E 6 8285 7791 4391 White 13
1 PM Wed 47 50 NW 3 8495 7965 4565 White 14
2 PM Wed 47 49 NW 3 8285 7791 4391 White 13
3 PM Wed 47 48 NW 3 8075 7617 4217 White 12
4 PM Wed 45 45 NW 3 7443 6440 3040 White 9
5 PM Wed 43 43 NW 3 7020 5754 2354 White 7
6 PM Wed 41 41 NW 3 6276 4785 1385 Blue 5
7 PM Wed 38 38 W 2 4947 3400 0 Blue 2
8 PM Wed 36 36 W 2 2697 3400 0 Blue 0
9 PM Wed 34 34 W 2 2582 3400 0 Blue 0
10 PM Wed 33 33 NW 3 2582 3400 0 Blue 0
11 PM Wed 33 33 NW 3 2582 3400 0 Blue 0
12 Midnight Thu 32 32 NW 3 2582 3400 0 Blue 0
1 AM Thu 32 32 NW 2 2582 3400 0 Blue 0
2 AM Thu 32 32 NW 2 2582 3400 0 Blue 0
3 AM Thu 31 31 NW 2 2582 3400 0 Blue 0
4 AM Thu 31 31 NW 2 2582 3400 0 Blue 0
5 AM Thu 31 31 NW 2 2582 3400 0 Blue 0
6 AM Thu 31 31 NW 2 2582 3400 0 Blue 0
7 AM Thu 33 33 N 1 2582 3400 0 Blue 0
8 AM Thu 37 37 N 1 3073 3400 0 Blue 1
9 AM Thu 43 44 N 1 7232 6228 2828 White 8
10 AM Thu 48 50 S 4 8495 7965 4565 White 14
11 AM Thu 51 53 S 4 9000 8469 5069 Blue 17
12 Noon Thu 54 57 S 4 9611 9129 5729 Blue 21
1 PM Thu 56 59 S 4 9729 9457 6057 Blue 23
2 PM Thu 56 58 S 4 9670 9293 5893 Blue 22
3 PM Thu 56 57 S 4 9611 9129 5729 Blue 21
4 PM Thu 55 55 SW 4 9331 8799 5399 Blue 19
5 PM Thu 52 52 SW 4 8834 8303 4903 Blue 16
6 PM Thu 49 49 SW 4 8285 7791 4391 White 13
7 PM Thu 46 46 SW 4 7654 6953 3553 White 10
8 PM Thu 44 44 SW 4 7232 6228 2828 White 8
9 PM Thu 43 43 SW 4 7020 5754 2354 White 7
10 PM Thu 42 42 SW 3 6507 5295 1895 Blue 6
11 PM Thu 41 41 SW 3 6276 4785 1385 Blue 5
12 Midnight Fri 41 41 SW 3 6276 4785 1385 Blue 5
1 AM Fri 40 40 SW 3 5802 3400 0 Blue 4
2 AM Fri 40 40 SW 3 5802 3400 0 Blue 4
3 AM Fri 39 39 SW 3 5322 3400 0 Blue 3
4 AM Fri 38 38 S 5 4947 3400 0 Blue 2
5 AM Fri 38 38 S 5 4947 3400 0 Blue 2
6 AM Fri 39 39 S 5 5322 3400 0 Blue 3
7 AM Fri 39 39 S 5 5322 3400 0 Blue 3
8 AM Fri 41 41 S 5 6276 4785 1385 Blue 5
9 AM Fri 43 43 S 5 7020 5754 2354 White 7
10 AM Fri 45 45 S 9 7443 6440 3040 White 9
11 AM Fri 47 47 S 9 7865 7442 4042 White 11
12 Noon Fri 48 48 S 9 8075 7617 4217 White 12
1 PM Fri 49 49 S 9 8285 7791 4391 White 13
2 PM Fri 49 49 S 9 8285 7791 4391 White 13
3 PM Fri 48 48 S 9 8075 7617 4217 White 12
4 PM Fri 47 47 W 8 7865 7442 4042 White 11
5 PM Fri 45 45 W 8 7443 6440 3040 White 9
6 PM Fri 44 44 W 8 7232 6228 2828 White 8
7 PM Fri 42 42 W 8 6507 5295 1895 Blue 6
8 PM Fri 39 39 W 8 5322 3400 0 Blue 3
9 PM Fri 37 37 W 8 3073 3400 0 Blue 1
10 PM Fri 35 35 W 8 2582 3400 0 Blue 0
11 PM Fri 34 34 W 8 2582 3400 0 Blue 0
12 Midnight Sat 33 33 W 8 2582 3400 0 Blue 0
1 AM Sat 33 33 W 8 2582 3400 0 Blue 0
2 AM Sat 33 33 W 8 2582 3400 0 Blue 0
3 AM Sat 32 32 W 8 2582 3400 0 Blue 0
4 AM Sat 32 32 NW 6 2582 3400 0 Blue 0
5 AM Sat 31 31 NW 6 2582 3400 0 Blue 0
6 AM Sat 31 31 NW 6 2582 3400 0 Blue 0
7 AM Sat 32 32 NW 6 2582 3400 0 Blue 0
8 AM Sat 36 36 NW 6 2697 3400 0 Blue 0
9 AM Sat 40 41 NW 6 6276 4785 1385 Blue 5
10 AM Sat 45 47 N 6 7865 7442 4042 White 11
11 AM Sat 48 50 N 6 8495 7965 4565 White 14
12 Noon Sat 50 53 N 6 9000 8469 5069 Blue 17
1 PM Sat 52 55 N 6 9331 8799 5399 Blue 19
2 PM Sat 52 54 N 6 9166 8634 5234 Blue 18
3 PM Sat 52 53 N 6 9000 8469 5069 Blue 17
4 PM Sat 51 51 W 6 8668 8137 4737 Blue 15
5 PM Sat 49 49 W 6 8285 7791 4391 White 13
6 PM Sat 46 46 W 6 7654 6953 3553 White 10
7 PM Sat 43 43 W 6 7020 5754 2354 White 7
8 PM Sat 41 41 W 6 6276 4785 1385 Blue 5
9 PM Sat 40 40 W 6 5802 3400 0 Blue 4
10 PM Sat 39 39 NW 4 5322 3400 0 Blue 3
11 PM Sat 38 38 NW 4 4947 3400 0 Blue 2
12 Midnight Sun 37 37 NW 4 3073 3400 0 Blue 1
1 AM Sun 36 36 NW 4 2697 3400 0 Blue 0
2 AM Sun 36 36 NW 4 2697 3400 0 Blue 0
3 AM Sun 36 36 NW 4 2697 3400 0 Blue 0
4 AM Sun 35 35 NW 3 2582 3400 0 Blue 0
5 AM Sun 34 34 NW 3 2582 3400 0 Blue 0
6 AM Sun 34 34 NW 3 2582 3400 0 Blue 0
7 AM Sun 35 35 NW 3 2582 3400 0 Blue 0
8 AM Sun 40 40 NW 3 5802 3400 0 Blue 4
9 AM Sun 45 46 NW 3 7654 6953 3553 White 10
10 AM Sun 51 53 S 0 9000 8469 5069 Blue 17
11 AM Sun 55 58 S 0 9670 9293 5893 Blue 22
12 Noon Sun 59 63 S 0 9950 9774 6374 Blue 27
1 PM Sun 61 64 S 0 10083 9828 6428 Blue 28
2 PM Sun 61 64 S 0 10083 9828 6428 Blue 28
3 PM Sun 62 64 S 0 10083 9828 6428 Blue 28
4 PM Sun 61 62 S 2 9896 9715 6315 Blue 26
5 PM Sun 57 57 S 2 9611 9129 5729 Blue 21
6 PM Sun 53 53 S 2 9000 8469 5069 Blue 17
7 PM Sun 50 50 S 2 8495 7965 4565 White 14
8 PM Sun 47 47 S 2 7865 7442 4042 White 11
9 PM Sun 46 46 S 2 7654 6953 3553 White 10
10 PM Sun 44 44 N 1 7232 6228 2828 White 8
11 PM Sun 43 43 N 1 7020 5754 2354 White 7
12 Midnight Mon 43 43 N 1 7020 5754 2354 White 7
1 AM Mon 42 42 N 1 6507 5295 1895 Blue 6
2 AM Mon 41 41 N 1 6276 4785 1385 Blue 5
3 AM Mon 41 41 N 1 6276 4785 1385 Blue 5
4 AM Mon 40 40 N 1 5802 3400 0 Blue 4
5 AM Mon 39 39 N 1 5322 3400 0 Blue 3
6 AM Mon 39 39 N 1 5322 3400 0 Blue 3
7 AM Mon 40 40 N 1 5802 3400 0 Blue 4
8 AM Mon 44 44 N 1 7232 6228 2828 White 8
9 AM Mon 49 50 N 1 8495 7965 4565 White 14
10 AM Mon 54 56 E 4 9496 8964 5564 Blue 20
11 AM Mon 57 60 E 4 9788 9597 6197 Blue 24
12 Noon Mon 59 63 E 4 9950 9774 6374 Blue 27
1 PM Mon 60 63 E 4 9950 9774 6374 Blue 27
2 PM Mon 61 64 E 4 10083 9828 6428 Blue 28
3 PM Mon 61 63 E 4 9950 9774 6374 Blue 27
4 PM Mon 60 61 SW 7 9842 9656 6256 Blue 25
5 PM Mon 57 57 SW 7 9611 9129 5729 Blue 21
6 PM Mon 54 54 SW 7 9166 8634 5234 Blue 18
7 PM Mon 51 51 SW 7 8668 8137 4737 Blue 15
8 PM Mon 49 49 SW 7 8285 7791 4391 White 13
9 PM Mon 47 47 SW 7 7865 7442 4042 White 11
10 PM Mon 47 47 W 7 7865 7442 4042 White 11
11 PM Mon 46 46 W 7 7654 6953 3553 White 10
12 Midnight Tue 45 45 W 7 7443 6440 3040 White 9
1 AM Tue 45 45 W 7 7443 6440 3040 White 9
2 AM Tue 44 44 W 7 7232 6228 2828 White 8
3 AM Tue 44 44 W 7 7232 6228 2828 White 8
4 AM Tue 43 43 SW 8 7020 5754 2354 White 7
5 AM Tue 42 42 SW 8 6507 5295 1895 Blue 6
6 AM Tue 42 42 SW 8 6507 5295 1895 Blue 6

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