Detailed Predictions for: Hat Creek Rim
Launch Altitude (f): 4590
LZ Altitude (f): 3575
Sounding

Station:

 KOAK

Date/Time:

 18 MAY 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)
5 AM Fri 36 36 E 6 3848 4590 0 Blue 0
6 AM Fri 39 39 E 6 3848 4590 0 Blue 0
7 AM Fri 44 44 E 6 3848 4590 0 Blue 0
8 AM Fri 49 50 E 3 3848 4590 0 Blue 0
9 AM Fri 53 56 E 3 3895 4590 0 Blue 0
10 AM Fri 56 60 E 3 7830 4861 271 Blue 3
11 AM Fri 60 64 N 8 8596 7903 3313 Blue 7
12 Noon Fri 63 68 N 8 10275 8865 4275 Blue 11
1 PM Fri 66 71 N 8 11933 10231 5641 Blue 14
2 PM Fri 68 73 N 8 12912 11183 6593 Blue 16
3 PM Fri 69 73 N 8 12912 11183 6593 Blue 16
4 PM Fri 69 72 N 8 12511 10559 5969 Blue 15
5 PM Fri 68 70 NW 9 11330 10019 5429 Blue 13
6 PM Fri 65 66 NW 9 9869 8244 3654 Blue 9
7 PM Fri 62 62 NW 9 8029 7698 3108 Blue 5
8 PM Fri 58 58 NW 6 7357 4590 0 Blue 1
9 PM Fri 54 54 NW 6 3848 4590 0 Blue 0
10 PM Fri 50 50 NW 6 3848 4590 0 Blue 0
11 PM Fri 46 46 N 3 3848 4590 0 Blue 0
12 Midnight Sat 44 44 N 3 3848 4590 0 Blue 0
1 AM Sat 43 43 N 3 3848 4590 0 Blue 0
2 AM Sat 42 42 E 6 3848 4590 0 Blue 0
3 AM Sat 40 40 E 6 3848 4590 0 Blue 0
4 AM Sat 39 39 E 6 3848 4590 0 Blue 0
5 AM Sat 40 40 E 5 3848 4590 0 Blue 0
6 AM Sat 43 43 E 5 3848 4590 0 Blue 0
7 AM Sat 47 47 E 5 3848 4590 0 Blue 0
8 AM Sat 52 53 E 3 3848 4590 0 Blue 0
9 AM Sat 57 59 E 3 7742 4590 0 Blue 2
10 AM Sat 63 67 E 3 10056 8550 3960 Blue 10
11 AM Sat 67 72 N 6 12511 10559 5969 Blue 15
12 Noon Sat 70 76 N 6 13603 12843 8253 Blue 19
1 PM Sat 72 78 N 6 14059 13302 8712 Blue 21
2 PM Sat 74 80 W 9 15456 13756 9166 White 23
3 PM Sat 75 80 W 9 15456 13756 9166 White 23
4 PM Sat 76 80 W 9 15456 13756 9166 White 23
5 PM Sat 75 77 W 10 13832 13073 8483 Blue 20
6 PM Sat 73 74 W 10 13143 11780 7190 Blue 17
7 PM Sat 69 69 W 10 10699 9833 5243 Blue 12
8 PM Sat 64 64 W 10 8596 7903 3313 Blue 7
9 PM Sat 61 61 W 10 7913 7273 2683 Blue 4
10 PM Sat 57 57 W 10 4892 4590 0 Blue 0
11 PM Sat 54 54 S 5 3848 4590 0 Blue 0
12 Midnight Sun 51 51 S 5 3848 4590 0 Blue 0
1 AM Sun 50 50 S 5 3848 4590 0 Blue 0
2 AM Sun 49 49 S 5 3848 4590 0 Blue 0
3 AM Sun 47 47 S 5 3848 4590 0 Blue 0
4 AM Sun 46 46 S 5 3848 4590 0 Blue 0
5 AM Sun 47 47 SE 6 3848 4590 0 Blue 0
6 AM Sun 49 49 SE 6 3848 4590 0 Blue 0
7 AM Sun 54 54 SE 6 3848 4590 0 Blue 0
8 AM Sun 59 60 SE 6 7830 4861 271 Blue 3
9 AM Sun 64 66 SE 6 9869 8244 3654 Blue 9
10 AM Sun 69 73 SE 6 12912 11183 6593 Blue 16
11 AM Sun 74 79 N 6 14736 13529 8939 Blue 22
12 Noon Sun 77 83 N 6 16055 15185 10595 White 26
1 PM Sun 80 86 N 6 16650 16371 11781 White 29
2 PM Sun 81 87 N 6 16848 16689 12099 White 30
3 PM Sun 83 88 N 6 17045 17004 12414 White 31
4 PM Sun 83 86 N 6 16650 16371 11781 White 29
5 PM Sun 82 84 W 13 16254 15723 11133 White 27
6 PM Sun 79 80 W 13 15456 13756 9166 White 23
7 PM Sun 75 75 W 13 13374 12352 7762 Blue 18
8 PM Sun 70 70 W 13 11330 10019 5429 Blue 13
9 PM Sun 65 65 W 13 9105 8014 3424 Blue 8
10 PM Sun 60 60 W 13 7830 4861 271 Blue 3
11 PM Sun 56 56 SW 1 3895 4590 0 Blue 0
12 Midnight Mon 54 54 SW 1 3848 4590 0 Blue 0
1 AM Mon 53 53 SW 1 3848 4590 0 Blue 0
2 AM Mon 52 52 SW 1 3848 4590 0 Blue 0
3 AM Mon 50 50 SW 1 3848 4590 0 Blue 0
4 AM Mon 48 48 SW 1 3848 4590 0 Blue 0
5 AM Mon 48 48 SE 3 3848 4590 0 Blue 0
6 AM Mon 50 50 SE 3 3848 4590 0 Blue 0
7 AM Mon 53 53 SE 3 3848 4590 0 Blue 0
8 AM Mon 57 57 SE 3 4892 4590 0 Blue 0
9 AM Mon 60 61 SE 3 7913 7273 2683 Blue 4
10 AM Mon 63 65 SE 3 9105 8014 3424 Blue 8
11 AM Mon 66 69 W 9 10699 9833 5243 Blue 12
12 Noon Mon 68 71 W 9 11933 10231 5641 Blue 14
1 PM Mon 69 72 W 9 12511 10559 5969 Blue 15
2 PM Mon 69 72 W 9 12511 10559 5969 Blue 15
3 PM Mon 69 72 W 9 12511 10559 5969 Blue 15
4 PM Mon 69 71 W 9 11933 10231 5641 Blue 14
5 PM Mon 68 69 W 14 10699 9833 5243 Blue 12
6 PM Mon 66 66 W 14 9869 8244 3654 Blue 9
7 PM Mon 63 63 W 14 8286 7820 3230 Blue 6
8 PM Mon 60 60 W 14 7830 4861 271 Blue 3
9 PM Mon 56 56 W 14 3895 4590 0 Blue 0
10 PM Mon 53 53 W 14 3848 4590 0 Blue 0
11 PM Mon 50 50 W 7 3848 4590 0 Blue 0
12 Midnight Tue 48 48 W 7 3848 4590 0 Blue 0
1 AM Tue 46 46 W 7 3848 4590 0 Blue 0
2 AM Tue 45 45 W 7 3848 4590 0 Blue 0
3 AM Tue 44 44 W 7 3848 4590 0 Blue 0
4 AM Tue 43 43 W 7 3848 4590 0 Blue 0
5 AM Tue 43 43 SW 5 3848 4590 0 Blue 0
6 AM Tue 45 45 SW 5 3848 4590 0 Blue 0
7 AM Tue 48 48 SW 5 3848 4590 0 Blue 0
8 AM Tue 51 51 SW 5 3848 4590 0 Blue 0
9 AM Tue 54 55 SW 5 3848 4590 0 Blue 0
10 AM Tue 57 59 SW 5 7742 4590 0 Blue 2
11 AM Tue 59 63 W 10 8286 7820 3230 Blue 6
12 Noon Tue 62 67 W 10 10056 8550 3960 Blue 10
1 PM Tue 63 68 W 10 10275 8865 4275 Blue 11
2 PM Tue 65 70 W 10 11330 10019 5429 Blue 13
3 PM Tue 66 70 W 10 11330 10019 5429 Blue 13
4 PM Tue 66 69 W 10 10699 9833 5243 Blue 12
5 PM Tue 65 66 NW 10 9869 8244 3654 Blue 9
6 PM Tue 64 64 NW 10 8596 7903 3313 Blue 7
7 PM Tue 61 61 NW 10 7913 7273 2683 Blue 4
8 PM Tue 58 58 NW 10 7357 4590 0 Blue 1
9 PM Tue 55 55 NW 10 3848 4590 0 Blue 0
10 PM Tue 51 51 NW 10 3848 4590 0 Blue 0
11 PM Tue 47 47 N 2 3848 4590 0 Blue 0
12 Midnight Wed 45 45 N 2 3848 4590 0 Blue 0
1 AM Wed 44 44 N 2 3848 4590 0 Blue 0
2 AM Wed 43 43 N 2 3848 4590 0 Blue 0
3 AM Wed 42 42 N 2 3848 4590 0 Blue 0
4 AM Wed 41 41 N 2 3848 4590 0 Blue 0
5 AM Wed 42 42 N 8 3848 4590 0 Blue 0
6 AM Wed 44 44 N 8 3848 4590 0 Blue 0
7 AM Wed 47 47 N 8 3848 4590 0 Blue 0
8 AM Wed 51 51 N 8 3848 4590 0 Blue 0
9 AM Wed 55 56 N 8 3895 4590 0 Blue 0
10 AM Wed 59 62 N 8 8029 7698 3108 Blue 5
11 AM Wed 63 67 W 8 10056 8550 3960 Blue 10
12 Noon Wed 66 71 W 8 11933 10231 5641 Blue 14
1 PM Wed 69 74 W 8 13143 11780 7190 Blue 17
2 PM Wed 70 75 W 8 13374 12352 7762 Blue 18
3 PM Wed 71 75 W 8 13374 12352 7762 Blue 18
4 PM Wed 71 74 W 8 13143 11780 7190 Blue 17
5 PM Wed 69 71 NW 9 11933 10231 5641 Blue 14
6 PM Wed 68 69 NW 9 10699 9833 5243 Blue 12
7 PM Wed 65 65 NW 9 9105 8014 3424 Blue 8
8 PM Wed 62 62 NW 9 8029 7698 3108 Blue 5
9 PM Wed 59 59 NW 9 7742 4590 0 Blue 2
10 PM Wed 56 56 NW 9 3895 4590 0 Blue 0
11 PM Wed 53 53 NE 6 3848 4590 0 Blue 0
12 Midnight Thu 50 50 NE 6 3848 4590 0 Blue 0
1 AM Thu 48 48 NE 6 3848 4590 0 Blue 0
2 AM Thu 47 47 NE 6 3848 4590 0 Blue 0
3 AM Thu 45 45 NE 6 3848 4590 0 Blue 0
4 AM Thu 44 44 NE 6 3848 4590 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