Detailed Predictions for: Blossom Valley
Launch Altitude (f): 1500
LZ Altitude (f): 700
Sounding

Station:

KNKX

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 53 53 E 2 633 1500 0 Blue 0
6 AM Sun 54 54 NE 2 633 1500 0 Blue 0
7 AM Sun 56 56 NE 2 1882 1500 0 Blue 0
8 AM Sun 58 58 NW 2 2444 1500 0 White 2
9 AM Sun 61 62 W 3 3315 3012 1512 White 6
10 AM Sun 64 66 W 5 4175 4175 2675 White 10
11 AM Sun 66 72 W 7 5373 4997 3497 Blue 16
12 Noon Sun 69 76 W 7 5925 5475 3975 Blue 20
1 PM Sun 71 78 W 8 6139 5759 4259 Blue 22
2 PM Sun 72 78 W 10 6139 5759 4259 Blue 22
3 PM Sun 71 76 W 10 5925 5475 3975 Blue 20
4 PM Sun 71 74 W 10 5639 5236 3736 Blue 18
5 PM Sun 69 70 W 9 5044 4794 3294 White 14
6 PM Sun 67 67 W 8 4389 4389 2889 White 11
7 PM Sun 64 64 W 8 3745 3745 2245 White 8
8 PM Sun 61 61 W 6 3098 2618 1118 White 5
9 PM Sun 58 58 W 5 2444 1500 0 White 2
10 PM Sun 57 57 W 3 2216 1500 0 White 1
11 PM Sun 56 56 W 1 1882 1500 0 Blue 0
12 Midnight Mon 56 56 W 1 1882 1500 0 Blue 0
1 AM Mon 55 55 W 1 717 1500 0 Blue 0
2 AM Mon 55 55 SW 0 717 1500 0 Blue 0
3 AM Mon 55 55 SW 0 717 1500 0 Blue 0
4 AM Mon 54 54 SW 0 633 1500 0 Blue 0
5 AM Mon 54 54 N 0 633 1500 0 Blue 0
6 AM Mon 54 54 NW 0 633 1500 0 Blue 0
7 AM Mon 55 55 S 1 717 1500 0 Blue 0
8 AM Mon 58 58 W 2 2444 1500 0 White 2
9 AM Mon 61 61 W 3 3098 2618 1118 White 5
10 AM Mon 66 66 W 5 4175 4175 2675 White 10
11 AM Mon 70 76 W 7 5925 5475 3975 Blue 20
12 Noon Mon 73 80 W 8 6280 6043 4543 Blue 24
1 PM Mon 74 81 W 8 6350 6127 4627 Blue 25
2 PM Mon 75 81 W 9 6350 6127 4627 Blue 25
3 PM Mon 74 79 W 9 6209 5901 4401 Blue 23
4 PM Mon 74 77 W 9 6067 5617 4117 Blue 21
5 PM Mon 73 75 W 8 5782 5356 3856 Blue 19
6 PM Mon 70 70 W 8 5044 4794 3294 White 14
7 PM Mon 67 67 W 7 4389 4389 2889 White 11
8 PM Mon 64 64 W 5 3745 3745 2245 White 8
9 PM Mon 62 62 W 3 3315 3012 1512 White 6
10 PM Mon 60 60 SW 2 2883 2243 743 White 4
11 PM Mon 59 59 W 1 2666 1870 370 White 3
12 Midnight Tue 58 58 W 1 2444 1500 0 White 2
1 AM Tue 57 57 W 1 2216 1500 0 White 1
2 AM Tue 56 56 SW 1 1882 1500 0 Blue 0
3 AM Tue 56 56 W 1 1882 1500 0 Blue 0
4 AM Tue 55 55 W 1 717 1500 0 Blue 0
5 AM Tue 55 55 W 0 717 1500 0 Blue 0
6 AM Tue 55 55 NW 1 717 1500 0 Blue 0
7 AM Tue 56 56 W 1 1882 1500 0 Blue 0
8 AM Tue 58 58 W 3 2444 1500 0 White 2
9 AM Tue 62 62 W 5 3315 3012 1512 White 6
10 AM Tue 67 67 W 6 4389 4389 2889 White 11
11 AM Tue 72 79 W 7 6209 5901 4401 Blue 23
12 Noon Tue 76 84 W 8 6561 6337 4837 Blue 28
1 PM Tue 78 86 W 9 6703 6478 4978 Blue 30
2 PM Tue 78 85 W 10 6632 6408 4908 Blue 29
3 PM Tue 78 84 W 10 6561 6337 4837 Blue 28
4 PM Tue 76 80 SW 9 6280 6043 4543 Blue 24
5 PM Tue 74 76 SW 9 5925 5475 3975 Blue 20
6 PM Tue 72 72 SW 8 5373 4997 3497 Blue 16
7 PM Tue 70 70 SW 7 5044 4794 3294 White 14
8 PM Tue 67 67 SW 6 4389 4389 2889 White 11
9 PM Tue 65 65 SW 5 3960 3960 2460 White 9
10 PM Tue 62 62 SW 5 3315 3012 1512 White 6
11 PM Tue 60 60 SW 3 2883 2243 743 White 4
12 Midnight Wed 59 59 SW 3 2666 1870 370 White 3
1 AM Wed 58 58 SW 2 2444 1500 0 White 2
2 AM Wed 57 57 SW 2 2216 1500 0 White 1
3 AM Wed 56 56 S 2 1882 1500 0 Blue 0
4 AM Wed 56 56 S 1 1882 1500 0 Blue 0
5 AM Wed 56 56 SE 1 1882 1500 0 Blue 0
6 AM Wed 56 56 SE 1 1882 1500 0 Blue 0
7 AM Wed 57 57 SE 1 2216 1500 0 White 1
8 AM Wed 60 60 S 6 2883 2243 743 White 4
9 AM Wed 63 63 S 6 3530 3401 1901 White 7
10 AM Wed 67 67 S 6 4389 4389 2889 White 11
11 AM Wed 70 77 SW 9 6067 5617 4117 Blue 21
12 Noon Wed 73 81 SW 9 6350 6127 4627 Blue 25
1 PM Wed 74 82 SW 9 6420 6197 4697 Blue 26
2 PM Wed 74 81 SW 10 6350 6127 4627 Blue 25
3 PM Wed 74 80 SW 10 6280 6043 4543 Blue 24
4 PM Wed 73 77 SW 10 6067 5617 4117 Blue 21
5 PM Wed 72 74 SW 9 5639 5236 3736 Blue 18
6 PM Wed 70 70 SW 9 5044 4794 3294 White 14
7 PM Wed 67 67 SW 9 4389 4389 2889 White 11
8 PM Wed 64 64 SW 7 3745 3745 2245 White 8
9 PM Wed 61 61 SW 7 3098 2618 1118 White 5
10 PM Wed 59 59 SW 7 2666 1870 370 White 3
11 PM Wed 57 57 S 5 2216 1500 0 White 1
12 Midnight Thu 56 56 S 5 1882 1500 0 Blue 0
1 AM Thu 56 56 S 5 1882 1500 0 Blue 0
2 AM Thu 56 56 S 3 1882 1500 0 Blue 0
3 AM Thu 56 56 S 3 1882 1500 0 Blue 0
4 AM Thu 56 56 S 3 1882 1500 0 Blue 0
5 AM Thu 56 56 SW 5 1882 1500 0 Blue 0
6 AM Thu 56 56 SW 5 1882 1500 0 Blue 0
7 AM Thu 57 57 SW 5 2216 1500 0 White 1
8 AM Thu 58 58 SW 6 2444 1500 0 White 2
9 AM Thu 60 60 SW 6 2883 2243 743 White 4
10 AM Thu 63 63 SW 6 3530 3401 1901 White 7
11 AM Thu 65 71 SW 8 5253 4884 3384 Blue 15
12 Noon Thu 67 74 SW 8 5639 5236 3736 Blue 18
1 PM Thu 68 75 SW 8 5782 5356 3856 Blue 19
2 PM Thu 69 75 SW 12 5782 5356 3856 Blue 19
3 PM Thu 69 74 SW 12 5639 5236 3736 Blue 18
4 PM Thu 68 71 SW 12 5253 4884 3384 Blue 15
5 PM Thu 67 69 W 10 4831 4698 3198 White 13
6 PM Thu 65 65 W 10 3960 3960 2460 White 9
7 PM Thu 63 63 W 10 3530 3401 1901 White 7
8 PM Thu 60 60 W 7 2883 2243 743 White 4
9 PM Thu 59 59 W 7 2666 1870 370 White 3
10 PM Thu 58 58 W 7 2444 1500 0 White 2
11 PM Thu 57 57 W 3 2216 1500 0 White 1
12 Midnight Fri 56 56 W 3 1882 1500 0 Blue 0
1 AM Fri 55 55 W 3 717 1500 0 Blue 0
2 AM Fri 54 54 NW 2 633 1500 0 Blue 0
3 AM Fri 53 53 NW 2 633 1500 0 Blue 0
4 AM Fri 53 53 NW 2 633 1500 0 Blue 0
5 AM Fri 53 53 NW 1 633 1500 0 Blue 0
6 AM Fri 54 54 NW 1 633 1500 0 Blue 0
7 AM Fri 55 55 NW 1 717 1500 0 Blue 0
8 AM Fri 57 57 W 3 2216 1500 0 White 1
9 AM Fri 60 60 W 3 2883 2243 743 White 4
10 AM Fri 63 64 W 3 3745 3745 2245 White 8
11 AM Fri 66 73 W 6 5496 5117 3617 Blue 17
12 Noon Fri 69 77 W 6 6067 5617 4117 Blue 21
1 PM Fri 71 79 W 6 6209 5901 4401 Blue 23
2 PM Fri 72 79 W 8 6209 5901 4401 Blue 23
3 PM Fri 72 78 W 8 6139 5759 4259 Blue 22
4 PM Fri 71 75 W 8 5782 5356 3856 Blue 19
5 PM Fri 70 72 W 9 5373 4997 3497 Blue 16
6 PM Fri 69 69 W 9 4831 4698 3198 White 13
7 PM Fri 67 67 W 9 4389 4389 2889 White 11
8 PM Fri 65 65 NW 6 3960 3960 2460 White 9
9 PM Fri 63 63 NW 6 3530 3401 1901 White 7
10 PM Fri 60 60 NW 6 2883 2243 743 White 4
11 PM Fri 58 58 N 2 2444 1500 0 White 2
12 Midnight Sat 57 57 N 2 2216 1500 0 White 1
1 AM Sat 56 56 N 2 1882 1500 0 Blue 0
2 AM Sat 56 56 N 1 1882 1500 0 Blue 0
3 AM Sat 55 55 N 1 717 1500 0 Blue 0
4 AM Sat 54 54 N 1 633 1500 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