Detailed Predictions for: Jean Ridge
Launch Lat, Long, Altitude (f): 35.8093, -115.2139, 3304
LZ Altitude (f): 2844
Sounding

Station:

KREV

Date/Time:

21 APR 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 68 68 SW 16 31 11740 9508 6204 White 11
1 AM Wed 63 63 SW 15 31 9183 6778 3474 Blue 6
2 AM Wed 58 58 SW 15 31 5421 4974 1670 Blue 2
3 AM Wed 57 57 SW 15 31 5118 4974 1670 Blue 1
4 AM Wed 56 56 SW 15 30 0 3304 0 Blue 0
5 AM Wed 55 55 SSW 15 30 0 3304 0 Blue 0
6 AM Wed 56 56 SW 15 25 0 3304 0 Blue 0
7 AM Wed 57 57 SW 13 20 5118 4974 1670 Blue 1
8 AM Wed 58 59 SW 13 15 5773 4974 1670 Blue 3
9 AM Wed 61 64 WSW 14 16 9399 8406 5102 Blue 7
10 AM Wed 63 68 WSW 15 18 11740 9508 6204 White 11
11 AM Wed 66 72 W 17 20 12563 12563 9259 White 15
12 Noon Wed 68 75 W 17 20 13169 13169 9865 White 18
1 PM Wed 70 77 W 18 21 13569 13569 10265 White 20
2 PM Wed 73 80 W 19 21 14164 14164 10860 White 23
3 PM Wed 73 78 W 18 21 13768 13768 10464 White 21
4 PM Wed 72 75 W 18 21 13169 13169 9865 White 18
5 PM Wed 72 73 W 18 20 12768 12768 9464 White 16
6 PM Wed 70 70 W 14 17 12152 11635 8331 White 13
7 PM Wed 67 67 WSW 10 14 11533 9371 6067 White 10
8 PM Wed 64 64 WSW 6 11 9399 8406 5102 Blue 7
9 PM Wed 62 62 WSW 6 12 8828 5745 2441 Blue 5
10 PM Wed 59 59 SW 6 13 5773 4974 1670 Blue 3
11 PM Wed 56 56 SW 7 13 0 3304 0 Blue 0
12 Midnight Thu 55 55 SW 6 12 0 3304 0 Blue 0
1 AM Thu 53 53 SSW 5 11 0 3304 0 Blue 0
2 AM Thu 52 52 SSW 5 10 0 3304 0 Blue 0
3 AM Thu 51 51 SSW 4 9 0 3304 0 Blue 0
4 AM Thu 50 50 SSW 4 8 0 3304 0 Blue 0
5 AM Thu 50 50 SSW 3 6 0 3304 0 Blue 0
6 AM Thu 53 53 SE 2 5 0 3304 0 Blue 0
7 AM Thu 56 56 ENE 2 3 0 3304 0 Blue 0
8 AM Thu 59 60 N 1 2 7324 5103 1799 Blue 4
9 AM Thu 62 65 NNE 2 2 9537 8762 5458 Blue 8
10 AM Thu 64 69 NE 3 4 11946 10445 7141 White 12
11 AM Thu 67 73 NE 4 4 12768 12768 9464 White 16
12 Noon Thu 68 75 SE 4 4 13169 13169 9865 White 18
1 PM Thu 70 77 SW 3 4 13569 13569 10265 White 20
2 PM Thu 72 78 NW 3 3 13768 13768 10464 White 21
3 PM Thu 72 75 WNW 3 3 13169 13169 9865 White 18
4 PM Thu 72 73 WNW 2 3 12768 12768 9464 White 16
5 PM Thu 72 72 W 2 2 12563 12563 9259 White 15
6 PM Thu 70 70 WSW 4 7 12152 11635 8331 White 13
7 PM Thu 68 68 SSW 6 11 11740 9508 6204 White 11
8 PM Thu 66 66 S 8 16 11326 9114 5810 White 9
9 PM Thu 63 63 SSW 8 15 9183 6778 3474 Blue 6
10 PM Thu 61 61 SSW 7 15 8468 5396 2092 Blue 5
11 PM Thu 57 57 SW 7 15 5118 4974 1670 Blue 1
12 Midnight Fri 56 56 SW 7 15 0 3304 0 Blue 0
1 AM Fri 55 55 SW 7 16 0 3304 0 Blue 0
2 AM Fri 54 54 SW 8 17 0 3304 0 Blue 0
3 AM Fri 53 53 SW 8 17 0 3304 0 Blue 0
4 AM Fri 52 52 SW 8 17 0 3304 0 Blue 0
5 AM Fri 51 51 SW 8 17 0 3304 0 Blue 0
6 AM Fri 54 54 SW 7 14 0 3304 0 Blue 0
7 AM Fri 58 58 SW 7 11 5421 4974 1670 Blue 2
8 AM Fri 61 62 SW 6 7 8828 5745 2441 Blue 5
9 AM Fri 65 68 WSW 6 8 11740 9508 6204 White 11
10 AM Fri 69 74 WSW 7 8 12968 12968 9664 White 17
11 AM Fri 73 79 WSW 7 8 13966 13966 10662 White 22
12 Noon Fri 75 82 WSW 10 11 14559 14559 11255 White 25
1 PM Fri 77 84 WSW 13 15 14953 14953 11649 White 27
2 PM Fri 79 86 WSW 16 18 15345 15345 12041 White 29
3 PM Fri 79 84 WSW 16 19 14953 14953 11649 White 27
4 PM Fri 79 82 WSW 17 19 14559 14559 11255 White 25
5 PM Fri 78 79 WSW 17 20 13966 13966 10662 White 22
6 PM Fri 76 76 WSW 17 23 13370 13370 10066 White 19
7 PM Fri 75 75 WSW 16 27 13169 13169 9865 White 18
8 PM Fri 73 73 WSW 15 30 12768 12768 9464 White 16
9 PM Fri 70 70 SW 13 27 12152 11635 8331 White 13
10 PM Fri 68 68 SW 11 23 11740 9508 6204 White 11
11 PM Fri 66 66 SW 10 20 11326 9114 5810 White 9

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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