Detailed Predictions for: Slide Mountain
Launch Lat, Long, Altitude (f): 39.31966654775122, -119.8678295108672, 8200
LZ Altitude (f): 6000
Sounding

Station:

KREV

Date/Time:

16 SEP 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 Thu 62 47 WSW 6 7 7684 8200 0 Blue 0
1 AM Thu 62 47 WSW 6 7 7684 8200 0 Blue 0
2 AM Thu 61 46 WSW 6 6 7684 8200 0 Blue 0
3 AM Thu 60 45 WSW 5 6 7684 8200 0 Blue 0
4 AM Thu 59 44 WSW 5 6 7684 8200 0 Blue 0
5 AM Thu 59 44 WSW 4 5 7684 8200 0 Blue 0
6 AM Thu 58 43 WSW 4 5 7684 8200 0 Blue 0
7 AM Thu 57 42 WSW 4 5 7684 8200 0 Blue 0
8 AM Thu 48 33 WSW 3 6 7684 8200 0 Blue 0
9 AM Thu 54 40 SW 2 5 7684 8200 0 Blue 0
10 AM Thu 57 45 SSW 2 6 7684 8200 0 Blue 0
11 AM Thu 62 51 SSW 3 6 7684 8200 0 Blue 0
12 Noon Thu 64 54 SW 4 8 8049 8200 0 Blue 0
1 PM Thu 72 63 WSW 7 8 12976 11827 3627 Blue 7
2 PM Thu 73 63 WSW 11 13 12976 11827 3627 Blue 7
3 PM Thu 73 62 WSW 13 15 12338 11586 3386 Blue 6
4 PM Thu 72 60 WSW 13 15 11855 9667 1467 Blue 4
5 PM Thu 70 56 WSW 14 18 8425 8200 0 Blue 0
6 PM Thu 78 63 WSW 11 13 12976 11827 3627 Blue 7
7 PM Thu 71 56 W 6 6 8425 8200 0 Blue 0
8 PM Thu 66 51 W 5 6 7684 8200 0 Blue 0
9 PM Thu 63 48 W 4 5 7684 8200 0 Blue 0
10 PM Thu 62 47 WSW 4 5 7684 8200 0 Blue 0
11 PM Thu 62 47 WSW 5 6 7684 8200 0 Blue 0
12 Midnight Fri 61 46 W 5 6 7684 8200 0 Blue 0
1 AM Fri 60 45 WSW 4 6 7684 8200 0 Blue 0
2 AM Fri 60 45 WSW 4 6 7684 8200 0 Blue 0
3 AM Fri 59 44 WSW 4 5 7684 8200 0 Blue 0
4 AM Fri 59 44 WSW 4 5 7684 8200 0 Blue 0
5 AM Fri 59 44 WSW 4 6 7684 8200 0 Blue 0
6 AM Fri 58 43 WSW 4 6 7684 8200 0 Blue 0
7 AM Fri 41 26 WSW 4 9 7684 8200 0 Blue 0
8 AM Fri 48 33 WSW 4 8 7684 8200 0 Blue 0
9 AM Fri 54 40 WSW 3 6 7684 8200 0 Blue 0
10 AM Fri 59 47 SW 2 6 7684 8200 0 Blue 0
11 AM Fri 64 53 SSW 3 5 7861 8200 0 Blue 0
12 Noon Fri 66 56 SSW 4 8 8425 8200 0 Blue 0
1 PM Fri 73 64 SW 6 7 13533 12067 3867 Blue 8
2 PM Fri 75 65 WSW 11 13 13760 12306 4106 Blue 9
3 PM Fri 74 63 WSW 16 19 12976 11827 3627 Blue 7
4 PM Fri 73 61 WSW 18 21 12097 11344 3144 Blue 5
5 PM Fri 70 56 WSW 19 23 8425 8200 0 Blue 0
6 PM Fri 82 67 WSW 15 17 14961 13493 5293 Blue 11
7 PM Fri 76 61 WSW 7 8 12097 11344 3144 Blue 5
8 PM Fri 66 51 WSW 6 7 7684 8200 0 Blue 0
9 PM Fri 64 49 WSW 6 7 7684 8200 0 Blue 0
10 PM Fri 63 48 WSW 6 8 7684 8200 0 Blue 0
11 PM Fri 62 47 WSW 6 7 7684 8200 0 Blue 0
12 Midnight Sat 61 46 WSW 6 7 7684 8200 0 Blue 0
1 AM Sat 61 46 WSW 6 7 7684 8200 0 Blue 0
2 AM Sat 61 46 WSW 6 7 7684 8200 0 Blue 0
3 AM Sat 60 45 WSW 6 7 7684 8200 0 Blue 0
4 AM Sat 60 45 WSW 6 7 7684 8200 0 Blue 0
5 AM Sat 60 45 SW 6 7 7684 8200 0 Blue 0
6 AM Sat 59 44 SW 6 8 7684 8200 0 Blue 0
7 AM Sat 57 42 SW 7 8 7684 8200 0 Blue 0
8 AM Sat 48 33 SW 7 15 7684 8200 0 Blue 0
9 AM Sat 54 40 SW 11 23 7684 8200 0 Blue 0
10 AM Sat 58 46 SW 15 29 7684 8200 0 Blue 0
11 AM Sat 65 54 SW 18 21 8049 8200 0 Blue 0
12 Noon Sat 67 57 SW 21 24 9728 8200 0 Blue 1
1 PM Sat 68 59 SW 23 26 11613 8423 223 Blue 3
2 PM Sat 68 58 SW 23 27 11369 8237 37 Blue 2
3 PM Sat 67 56 SW 24 27 8425 8200 0 Blue 0
4 PM Sat 65 53 SW 24 28 7861 8200 0 Blue 0
5 PM Sat 63 49 WSW 23 26 7684 8200 0 Blue 0
6 PM Sat 70 55 WSW 18 20 8237 8200 0 Blue 0
7 PM Sat 63 48 WSW 9 11 7684 8200 0 Blue 0
8 PM Sat 53 38 WSW 8 12 7684 8200 0 Blue 0
9 PM Sat 57 42 WSW 8 9 7684 8200 0 Blue 0
10 PM Sat 57 42 WSW 8 9 7684 8200 0 Blue 0
11 PM Sat 57 42 WSW 7 8 7684 8200 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 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