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

Station:

KOAK

Date/Time:

27 MAY 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 44 44 E 5 2749 4590 0 Blue 0
6 AM Sun 45 45 E 5 2749 4590 0 Blue 0
7 AM Sun 48 48 E 5 2749 4590 0 Blue 0
8 AM Sun 51 52 NE 6 2879 4590 0 Blue 0
9 AM Sun 55 58 NE 6 5285 4590 0 Blue 3
10 AM Sun 59 63 NE 6 7689 6730 2140 Blue 8
11 AM Sun 63 69 NE 8 8450 7912 3322 Blue 14
12 Noon Sun 65 72 NE 8 9409 8404 3814 Blue 17
1 PM Sun 68 75 NE 8 10558 9354 4764 Blue 20
2 PM Sun 70 77 N 12 11093 10265 5675 Blue 22
3 PM Sun 72 78 N 12 11410 10509 5919 Blue 23
4 PM Sun 74 78 N 12 11410 10509 5919 Blue 23
5 PM Sun 74 77 N 9 11093 10265 5675 Blue 22
6 PM Sun 73 74 N 9 10326 9040 4450 Blue 19
7 PM Sun 70 70 N 9 8772 7989 3399 Blue 15
8 PM Sun 67 67 N 6 7999 7757 3167 Blue 12
9 PM Sun 64 64 N 6 7767 7526 2936 Blue 9
10 PM Sun 61 61 N 6 7535 5262 672 Blue 6
11 PM Sun 58 58 NE 3 5285 4590 0 Blue 3
12 Midnight Mon 56 56 NE 3 4595 4590 0 Blue 1
1 AM Mon 55 55 NE 3 4363 4590 0 Blue 0
2 AM Mon 53 53 E 5 3435 4590 0 Blue 0
3 AM Mon 52 52 E 5 2879 4590 0 Blue 0
4 AM Mon 50 50 E 5 2749 4590 0 Blue 0
5 AM Mon 50 50 E 5 2749 4590 0 Blue 0
6 AM Mon 51 51 E 5 2749 4590 0 Blue 0
7 AM Mon 54 54 E 5 3975 4590 0 Blue 0
8 AM Mon 57 58 E 5 5285 4590 0 Blue 3
9 AM Mon 61 64 E 5 7767 7526 2936 Blue 9
10 AM Mon 65 69 E 5 8450 7912 3322 Blue 14
11 AM Mon 69 75 NE 7 10558 9354 4764 Blue 20
12 Noon Mon 72 79 NE 7 11895 10739 6149 Blue 24
1 PM Mon 75 83 NE 7 12809 12142 7552 White 28
2 PM Mon 77 84 N 8 13018 12472 7882 White 29
3 PM Mon 79 85 N 8 13225 12661 8071 White 30
4 PM Mon 80 84 N 8 13018 12472 7882 White 29
5 PM Mon 80 83 N 7 12809 12142 7552 White 28
6 PM Mon 78 79 N 7 11895 10739 6149 Blue 24
7 PM Mon 75 75 N 7 10558 9354 4764 Blue 20
8 PM Mon 72 72 N 7 9409 8404 3814 Blue 17
9 PM Mon 68 68 N 7 8124 7834 3244 Blue 13
10 PM Mon 64 64 N 7 7767 7526 2936 Blue 9
11 PM Mon 61 61 E 6 7535 5262 672 Blue 6
12 Midnight Tue 59 59 E 6 5884 4591 1 Blue 4
1 AM Tue 58 58 E 6 5285 4590 0 Blue 3
2 AM Tue 56 56 E 6 4595 4590 0 Blue 1
3 AM Tue 55 55 E 6 4363 4590 0 Blue 0
4 AM Tue 54 54 E 6 3975 4590 0 Blue 0
5 AM Tue 53 53 E 6 3435 4590 0 Blue 0
6 AM Tue 54 54 E 6 3975 4590 0 Blue 0
7 AM Tue 56 56 E 6 4595 4590 0 Blue 1
8 AM Tue 60 61 E 6 7535 5262 672 Blue 6
9 AM Tue 65 67 E 6 7999 7757 3167 Blue 12
10 AM Tue 70 73 E 6 9854 8724 4134 Blue 18
11 AM Tue 75 80 W 13 12183 11020 6430 White 25
12 Noon Tue 78 84 W 13 13018 12472 7882 White 29
1 PM Tue 80 86 W 13 13431 12831 8241 White 31
2 PM Tue 81 87 W 13 13636 13001 8411 White 32
3 PM Tue 81 86 W 13 13431 12831 8241 White 31
4 PM Tue 81 84 W 13 13018 12472 7882 White 29
5 PM Tue 79 81 W 13 12392 11334 6744 White 26
6 PM Tue 77 78 W 13 11410 10509 5919 Blue 23
7 PM Tue 73 73 W 13 9854 8724 4134 Blue 18
8 PM Tue 70 70 W 13 8772 7989 3399 Blue 15
9 PM Tue 66 66 W 13 7921 7680 3090 Blue 11
10 PM Tue 62 62 W 13 7612 5851 1261 Blue 7
11 PM Tue 59 59 NE 5 5884 4591 1 Blue 4
12 Midnight Wed 56 56 NE 5 4595 4590 0 Blue 1
1 AM Wed 54 54 NE 5 3975 4590 0 Blue 0
2 AM Wed 53 53 NE 5 3435 4590 0 Blue 0
3 AM Wed 51 51 NE 5 2749 4590 0 Blue 0
4 AM Wed 50 50 NE 5 2749 4590 0 Blue 0
5 AM Wed 49 49 NE 3 2749 4590 0 Blue 0
6 AM Wed 49 49 NE 3 2749 4590 0 Blue 0
7 AM Wed 51 51 NE 3 2749 4590 0 Blue 0
8 AM Wed 53 54 NE 3 3975 4590 0 Blue 0
9 AM Wed 56 58 NE 3 5285 4590 0 Blue 3
10 AM Wed 60 63 NE 3 7689 6730 2140 Blue 8
11 AM Wed 64 67 N 6 7999 7757 3167 Blue 12
12 Noon Wed 67 71 N 6 9092 8081 3491 Blue 16
1 PM Wed 69 73 N 6 9854 8724 4134 Blue 18
2 PM Wed 71 75 N 6 10558 9354 4764 Blue 20
3 PM Wed 71 74 N 6 10326 9040 4450 Blue 19
4 PM Wed 71 73 N 6 9854 8724 4134 Blue 18
5 PM Wed 69 70 W 8 8772 7989 3399 Blue 15
6 PM Wed 67 67 W 8 7999 7757 3167 Blue 12
7 PM Wed 65 65 W 8 7844 7603 3013 Blue 10
8 PM Wed 62 62 W 8 7612 5851 1261 Blue 7
9 PM Wed 59 59 W 8 5884 4591 1 Blue 4
10 PM Wed 56 56 W 8 4595 4590 0 Blue 1
11 PM Wed 54 54 S 5 3975 4590 0 Blue 0
12 Midnight Thu 52 52 S 5 2879 4590 0 Blue 0
1 AM Thu 50 50 S 5 2749 4590 0 Blue 0
2 AM Thu 49 49 S 5 2749 4590 0 Blue 0
3 AM Thu 47 47 S 5 2749 4590 0 Blue 0
4 AM Thu 46 46 S 5 2749 4590 0 Blue 0
5 AM Thu 45 45 S 3 2749 4590 0 Blue 0
6 AM Thu 45 45 S 3 2749 4590 0 Blue 0
7 AM Thu 47 47 S 3 2749 4590 0 Blue 0
8 AM Thu 49 49 S 3 2749 4590 0 Blue 0
9 AM Thu 52 53 S 3 3435 4590 0 Blue 0
10 AM Thu 55 57 S 3 4826 4590 0 Blue 2
11 AM Thu 58 61 SW 7 7535 5262 672 Blue 6
12 Noon Thu 60 63 SW 7 7689 6730 2140 Blue 8
1 PM Thu 61 65 SW 7 7844 7603 3013 Blue 10
2 PM Thu 61 64 SW 7 7767 7526 2936 Blue 9
3 PM Thu 62 65 SW 7 7844 7603 3013 Blue 10
4 PM Thu 62 64 SW 7 7767 7526 2936 Blue 9
5 PM Thu 62 63 SW 12 7689 6730 2140 Blue 8
6 PM Thu 60 60 SW 12 6840 4820 230 Blue 5
7 PM Thu 59 59 SW 12 5884 4591 1 Blue 4
8 PM Thu 56 56 SW 12 4595 4590 0 Blue 1
9 PM Thu 54 54 SW 12 3975 4590 0 Blue 0
10 PM Thu 51 51 SW 12 2749 4590 0 Blue 0
11 PM Thu 49 49 SW 6 2749 4590 0 Blue 0
12 Midnight Fri 48 48 SW 6 2749 4590 0 Blue 0
1 AM Fri 47 47 SW 6 2749 4590 0 Blue 0
2 AM Fri 46 46 SW 6 2749 4590 0 Blue 0
3 AM Fri 45 45 SW 6 2749 4590 0 Blue 0
4 AM Fri 43 43 SW 6 2749 4590 0 Blue 0
5 AM Fri 43 43 W 5 2749 4590 0 Blue 0
6 AM Fri 44 44 W 5 2749 4590 0 Blue 0
7 AM Fri 46 46 W 5 2749 4590 0 Blue 0
8 AM Fri 49 49 W 5 2749 4590 0 Blue 0
9 AM Fri 52 53 W 5 3435 4590 0 Blue 0
10 AM Fri 56 58 W 5 5285 4590 0 Blue 3
11 AM Fri 59 64 W 7 7767 7526 2936 Blue 9
12 Noon Fri 61 67 W 7 7999 7757 3167 Blue 12
1 PM Fri 63 69 W 7 8450 7912 3322 Blue 14
2 PM Fri 65 71 W 7 9092 8081 3491 Blue 16
3 PM Fri 66 71 W 7 9092 8081 3491 Blue 16
4 PM Fri 66 69 W 7 8450 7912 3322 Blue 14
5 PM Fri 66 68 W 9 8124 7834 3244 Blue 13
6 PM Fri 65 66 W 9 7921 7680 3090 Blue 11
7 PM Fri 63 63 W 9 7689 6730 2140 Blue 8
8 PM Fri 61 61 W 9 7535 5262 672 Blue 6
9 PM Fri 58 58 W 9 5285 4590 0 Blue 3
10 PM Fri 54 54 W 9 3975 4590 0 Blue 0
11 PM Fri 51 51 S 3 2749 4590 0 Blue 0
12 Midnight Sat 49 49 S 3 2749 4590 0 Blue 0
1 AM Sat 48 48 S 3 2749 4590 0 Blue 0
2 AM Sat 47 47 S 3 2749 4590 0 Blue 0
3 AM Sat 45 45 S 3 2749 4590 0 Blue 0
4 AM Sat 43 43 S 3 2749 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