Detailed Predictions for: Walts
Launch Altitude (f): 9085
LZ Altitude (f): 3640
Sounding

Station:

KVBG

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 38 38 NW 15 7172 9085 0 Blue 0
6 AM Sun 39 39 NW 16 7172 9085 0 Blue 0
7 AM Sun 42 42 N 16 7172 9085 0 Blue 0
8 AM Sun 46 47 N 17 7211 9085 0 Blue 0
9 AM Sun 51 53 N 17 8748 9085 0 Blue 4
10 AM Sun 56 59 N 18 10736 9523 438 Blue 10
11 AM Sun 59 64 N 17 11704 11101 2016 Blue 15
12 Noon Sun 61 66 N 16 12287 11486 2401 Blue 17
1 PM Sun 62 66 N 14 12287 11486 2401 Blue 17
2 PM Sun 62 65 N 12 11953 11294 2209 Blue 16
3 PM Sun 61 63 N 10 11511 10908 1823 Blue 14
4 PM Sun 59 60 N 8 10930 9783 698 Blue 11
5 PM Sun 58 58 N 8 10064 9263 178 Blue 9
6 PM Sun 56 56 N 9 9542 9085 0 Blue 7
7 PM Sun 54 54 N 10 9014 9085 0 Blue 5
8 PM Sun 52 52 NW 12 8481 9085 0 Blue 3
9 PM Sun 51 51 NW 13 8213 9085 0 Blue 2
10 PM Sun 49 49 NW 14 7672 9085 0 Blue 0
11 PM Sun 47 47 NW 14 7211 9085 0 Blue 0
12 Midnight Mon 46 46 NW 14 7172 9085 0 Blue 0
1 AM Mon 46 46 NW 14 7172 9085 0 Blue 0
2 AM Mon 45 45 NW 14 7172 9085 0 Blue 0
3 AM Mon 43 43 NW 14 7172 9085 0 Blue 0
4 AM Mon 42 42 NW 13 7172 9085 0 Blue 0
5 AM Mon 42 42 NW 13 7172 9085 0 Blue 0
6 AM Mon 44 44 NW 13 7172 9085 0 Blue 0
7 AM Mon 47 47 N 13 7211 9085 0 Blue 0
8 AM Mon 51 52 N 13 8481 9085 0 Blue 3
9 AM Mon 56 59 N 13 10736 9523 438 Blue 10
10 AM Mon 61 66 N 12 12287 11486 2401 Blue 17
11 AM Mon 65 72 N 12 15923 13826 4741 Blue 23
12 Noon Mon 68 75 NE 12 18876 15723 6638 Blue 26
1 PM Mon 69 76 NE 10 20627 16408 7323 Blue 27
2 PM Mon 69 75 NE 10 18876 15723 6638 Blue 26
3 PM Mon 68 72 NE 9 15923 13826 4741 Blue 23
4 PM Mon 67 70 NE 9 14452 12757 3672 Blue 21
5 PM Mon 66 67 NE 8 12856 11677 2592 Blue 18
6 PM Mon 64 64 NE 7 11704 11101 2016 Blue 15
7 PM Mon 63 63 N 7 11511 10908 1823 Blue 14
8 PM Mon 61 61 N 7 11124 10042 957 Blue 12
9 PM Mon 59 59 N 7 10736 9523 438 Blue 10
10 PM Mon 57 57 N 8 9803 9085 0 Blue 8
11 PM Mon 55 55 NW 9 9279 9085 0 Blue 6
12 Midnight Tue 54 54 NW 10 9014 9085 0 Blue 5
1 AM Tue 52 52 NW 12 8481 9085 0 Blue 3
2 AM Tue 50 50 NW 12 7943 9085 0 Blue 1
3 AM Tue 49 49 NW 10 7672 9085 0 Blue 0
4 AM Tue 47 47 NW 9 7211 9085 0 Blue 0
5 AM Tue 47 47 NW 8 7211 9085 0 Blue 0
6 AM Tue 49 49 NW 7 7672 9085 0 Blue 0
7 AM Tue 52 52 N 7 8481 9085 0 Blue 3
8 AM Tue 56 57 N 7 9803 9085 0 Blue 8
9 AM Tue 61 63 NE 7 11511 10908 1823 Blue 14
10 AM Tue 66 69 NE 7 13937 12196 3111 Blue 20
11 AM Tue 69 73 E 7 16613 14335 5250 Blue 24
12 Noon Tue 71 76 E 7 20627 16408 7323 Blue 27
1 PM Tue 72 77 SE 7 21491 17056 7971 White 28
2 PM Tue 72 76 S 7 20627 16408 7323 Blue 27
3 PM Tue 71 74 S 7 17265 14992 5907 Blue 25
4 PM Tue 70 72 SW 8 15923 13826 4741 Blue 23
5 PM Tue 68 69 W 8 13937 12196 3111 Blue 20
6 PM Tue 66 66 W 8 12287 11486 2401 Blue 17
7 PM Tue 63 63 W 9 11511 10908 1823 Blue 14
8 PM Tue 61 61 W 9 11124 10042 957 Blue 12
9 PM Tue 59 59 W 9 10736 9523 438 Blue 10
10 PM Tue 57 57 W 10 9803 9085 0 Blue 8
11 PM Tue 56 56 W 10 9542 9085 0 Blue 7
12 Midnight Wed 55 55 W 10 9279 9085 0 Blue 6
1 AM Wed 53 53 W 12 8748 9085 0 Blue 4
2 AM Wed 52 52 W 12 8481 9085 0 Blue 3
3 AM Wed 50 50 W 13 7943 9085 0 Blue 1
4 AM Wed 49 49 W 13 7672 9085 0 Blue 0
5 AM Wed 49 49 W 14 7672 9085 0 Blue 0
6 AM Wed 51 51 W 14 8213 9085 0 Blue 2
7 AM Wed 55 55 SW 13 9279 9085 0 Blue 6
8 AM Wed 59 60 SW 13 10930 9783 698 Blue 11
9 AM Wed 63 65 S 12 11953 11294 2209 Blue 16
10 AM Wed 67 71 S 10 15187 13300 4215 Blue 22
11 AM Wed 70 75 SE 10 18876 15723 6638 Blue 26
12 Noon Wed 72 78 S 12 21690 18283 9198 White 29
1 PM Wed 72 78 S 13 21690 18283 9198 White 29
2 PM Wed 71 76 S 15 20627 16408 7323 Blue 27
3 PM Wed 70 74 SW 16 17265 14992 5907 Blue 25
4 PM Wed 68 71 SW 17 15187 13300 4215 Blue 22
5 PM Wed 66 67 W 18 12856 11677 2592 Blue 18
6 PM Wed 63 63 W 18 11511 10908 1823 Blue 14
7 PM Wed 61 61 W 18 11124 10042 957 Blue 12
8 PM Wed 59 59 W 17 10736 9523 438 Blue 10
9 PM Wed 56 56 W 16 9542 9085 0 Blue 7
10 PM Wed 54 54 W 16 9014 9085 0 Blue 5
11 PM Wed 51 51 W 15 8213 9085 0 Blue 2
12 Midnight Thu 49 49 W 15 7672 9085 0 Blue 0
1 AM Thu 47 47 W 15 7211 9085 0 Blue 0
2 AM Thu 45 45 W 15 7172 9085 0 Blue 0
3 AM Thu 44 44 W 15 7172 9085 0 Blue 0
4 AM Thu 44 44 W 14 7172 9085 0 Blue 0
5 AM Thu 45 45 W 14 7172 9085 0 Blue 0
6 AM Thu 47 47 W 13 7211 9085 0 Blue 0
7 AM Thu 50 50 SW 10 7943 9085 0 Blue 1
8 AM Thu 54 55 SW 9 9279 9085 0 Blue 6
9 AM Thu 57 60 SW 8 10930 9783 698 Blue 11
10 AM Thu 60 64 SW 7 11704 11101 2016 Blue 15
11 AM Thu 63 69 S 7 13937 12196 3111 Blue 20
12 Noon Thu 65 72 SW 8 15923 13826 4741 Blue 23
1 PM Thu 65 72 SW 12 15923 13826 4741 Blue 23
2 PM Thu 65 72 SW 14 15923 13826 4741 Blue 23
3 PM Thu 64 69 SW 17 13937 12196 3111 Blue 20
4 PM Thu 62 66 SW 20 12287 11486 2401 Blue 17
5 PM Thu 60 62 W 22 11318 10715 1630 Blue 13
6 PM Thu 58 59 W 23 10736 9523 438 Blue 10
7 PM Thu 55 55 W 24 9279 9085 0 Blue 6
8 PM Thu 52 52 W 24 8481 9085 0 Blue 3
9 PM Thu 50 50 W 23 7943 9085 0 Blue 1
10 PM Thu 47 47 W 23 7211 9085 0 Blue 0
11 PM Thu 45 45 NW 22 7172 9085 0 Blue 0
12 Midnight Fri 43 43 NW 21 7172 9085 0 Blue 0
1 AM Fri 41 41 NW 18 7172 9085 0 Blue 0
2 AM Fri 40 40 NW 17 7172 9085 0 Blue 0
3 AM Fri 40 40 NW 15 7172 9085 0 Blue 0
4 AM Fri 40 40 NW 13 7172 9085 0 Blue 0
5 AM Fri 42 42 NW 12 7172 9085 0 Blue 0
6 AM Fri 44 44 NW 10 7172 9085 0 Blue 0
7 AM Fri 47 47 N 10 7211 9085 0 Blue 0
8 AM Fri 51 52 N 10 8481 9085 0 Blue 3
9 AM Fri 55 58 NE 10 10064 9263 178 Blue 9
10 AM Fri 58 62 E 10 11318 10715 1630 Blue 13
11 AM Fri 61 67 E 10 12856 11677 2592 Blue 18
12 Noon Fri 64 71 E 10 15187 13300 4215 Blue 22
1 PM Fri 65 72 E 12 15923 13826 4741 Blue 23
2 PM Fri 66 72 E 12 15923 13826 4741 Blue 23
3 PM Fri 66 71 E 12 15187 13300 4215 Blue 22
4 PM Fri 66 69 SE 12 13937 12196 3111 Blue 20
5 PM Fri 65 67 SE 12 12856 11677 2592 Blue 18
6 PM Fri 63 64 SE 10 11704 11101 2016 Blue 15
7 PM Fri 61 61 SE 9 11124 10042 957 Blue 12
8 PM Fri 59 59 S 9 10736 9523 438 Blue 10
9 PM Fri 57 57 S 8 9803 9085 0 Blue 8
10 PM Fri 54 54 SW 7 9014 9085 0 Blue 5
11 PM Fri 51 51 SW 6 8213 9085 0 Blue 2
12 Midnight Sat 49 49 SW 6 7672 9085 0 Blue 0
1 AM Sat 46 46 SW 6 7172 9085 0 Blue 0
2 AM Sat 44 44 W 6 7172 9085 0 Blue 0
3 AM Sat 43 43 W 6 7172 9085 0 Blue 0
4 AM Sat 43 43 W 7 7172 9085 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