Detailed Predictions for: Merriam Crater
Launch Altitude (f): 6800
LZ Altitude (f): 6000
Sounding

Station:

KFGZ

Date/Time:

16 FEB 2019

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 Sat 34 34 SW 16 6122 6800 0 White 0
6 AM Sat 32 32 SW 16 6122 6800 0 White 0
7 AM Sat 31 31 W 15 0 6800 0 Blue 0
8 AM Sat 31 31 W 15 0 6800 0 Blue 0
9 AM Sat 33 33 W 14 6122 6800 0 White 0
10 AM Sat 35 36 W 13 6251 6800 0 White 0
11 AM Sat 37 39 W 13 6921 6921 121 White 0
12 Noon Sat 39 41 W 12 7366 7366 566 White 6
1 PM Sat 40 42 W 12 7586 7586 786 White 7
2 PM Sat 41 43 W 12 7806 7806 1006 White 8
3 PM Sat 40 41 W 13 7366 7366 566 White 6
4 PM Sat 40 40 W 14 7143 7143 343 White 0
5 PM Sat 39 39 W 15 6921 6921 121 White 0
6 PM Sat 35 35 W 14 6122 6800 0 White 0
7 PM Sat 32 32 W 13 6122 6800 0 White 0
8 PM Sat 31 31 W 12 0 6800 0 Blue 0
9 PM Sat 29 29 W 12 0 6800 0 Blue 0
10 PM Sat 28 28 W 10 0 6800 0 Blue 0
11 PM Sat 27 27 SW 10 0 6800 0 Blue 0
12 Midnight Sun 27 27 SW 9 0 6800 0 Blue 0
1 AM Sun 27 27 SW 8 0 6800 0 Blue 0
2 AM Sun 27 27 SW 8 0 6800 0 Blue 0
3 AM Sun 26 26 SW 8 0 6800 0 Blue 0
4 AM Sun 25 25 SW 9 0 6800 0 Blue 0
5 AM Sun 24 24 SW 10 0 6800 0 Blue 0
6 AM Sun 23 23 SW 10 0 6800 0 Blue 0
7 AM Sun 23 23 SW 10 0 6800 0 Blue 0
8 AM Sun 24 24 SW 10 0 6800 0 Blue 0
9 AM Sun 26 26 SW 12 0 6800 0 Blue 0
10 AM Sun 29 30 SW 12 0 6800 0 Blue 0
11 AM Sun 32 33 SW 13 6122 6800 0 White 0
12 Noon Sun 34 36 SW 13 6251 6800 0 White 0
1 PM Sun 36 38 SW 14 6698 6800 0 White 0
2 PM Sun 36 37 SW 14 6475 6800 0 White 0
3 PM Sun 35 36 SW 15 6251 6800 0 White 0
4 PM Sun 34 34 SW 16 6122 6800 0 White 0
5 PM Sun 33 33 SW 16 6122 6800 0 White 0
6 PM Sun 31 31 SW 15 0 6800 0 Blue 0
7 PM Sun 29 29 SW 13 0 6800 0 Blue 0
8 PM Sun 27 27 SW 10 0 6800 0 Blue 0
9 PM Sun 27 27 SW 9 0 6800 0 Blue 0
10 PM Sun 26 26 SW 8 0 6800 0 Blue 0
11 PM Sun 26 26 SW 7 0 6800 0 Blue 0
12 Midnight Mon 27 27 SW 7 0 6800 0 Blue 0
1 AM Mon 27 27 S 8 0 6800 0 Blue 0
2 AM Mon 26 26 S 9 0 6800 0 Blue 0
3 AM Mon 26 26 S 9 0 6800 0 Blue 0
4 AM Mon 25 25 SW 9 0 6800 0 Blue 0
5 AM Mon 24 24 SW 9 0 6800 0 Blue 0
6 AM Mon 23 23 SW 8 0 6800 0 Blue 0
7 AM Mon 23 23 SW 7 0 6800 0 Blue 0
8 AM Mon 23 23 W 7 0 6800 0 Blue 0
9 AM Mon 25 25 W 7 0 6800 0 Blue 0
10 AM Mon 27 27 W 8 0 6800 0 Blue 0
11 AM Mon 29 30 W 9 0 6800 0 Blue 0
12 Noon Mon 31 32 W 9 6122 6800 0 White 0
1 PM Mon 32 33 W 10 6122 6800 0 White 0
2 PM Mon 32 32 W 10 6122 6800 0 White 0
3 PM Mon 32 32 NW 10 6122 6800 0 White 0
4 PM Mon 31 31 NW 10 0 6800 0 Blue 0
5 PM Mon 30 30 NW 10 0 6800 0 Blue 0
6 PM Mon 28 28 NW 10 0 6800 0 Blue 0
7 PM Mon 25 25 NW 9 0 6800 0 Blue 0
8 PM Mon 23 23 NW 9 0 6800 0 Blue 0
9 PM Mon 22 22 NW 8 0 6800 0 Blue 0
10 PM Mon 21 21 NW 8 0 6800 0 Blue 0
11 PM Mon 21 21 NW 7 0 6800 0 Blue 0
12 Midnight Tue 21 21 NW 7 0 6800 0 Blue 0
1 AM Tue 21 21 NW 7 0 6800 0 Blue 0
2 AM Tue 20 20 NW 7 0 6800 0 Blue 0
3 AM Tue 19 19 NW 7 0 6800 0 Blue 0
4 AM Tue 18 18 NW 7 0 6800 0 Blue 0
5 AM Tue 17 17 NW 7 0 6800 0 Blue 0
6 AM Tue 16 16 N 7 0 6800 0 Blue 0
7 AM Tue 17 17 N 7 0 6800 0 Blue 0
8 AM Tue 18 18 N 7 0 6800 0 Blue 0
9 AM Tue 21 21 N 7 0 6800 0 Blue 0
10 AM Tue 24 25 N 7 0 6800 0 Blue 0
11 AM Tue 27 28 N 8 0 6800 0 Blue 0
12 Noon Tue 29 31 N 8 0 6800 0 Blue 0
1 PM Tue 31 33 N 8 6122 6800 0 White 0
2 PM Tue 32 33 N 8 6122 6800 0 White 0
3 PM Tue 32 33 NW 8 6122 6800 0 White 0
4 PM Tue 32 32 NW 8 6122 6800 0 White 0
5 PM Tue 31 31 NW 8 0 6800 0 Blue 0
6 PM Tue 28 28 NW 7 0 6800 0 Blue 0
7 PM Tue 25 25 NW 7 0 6800 0 Blue 0
8 PM Tue 23 23 NW 7 0 6800 0 Blue 0
9 PM Tue 21 21 NW 7 0 6800 0 Blue 0
10 PM Tue 20 20 NW 7 0 6800 0 Blue 0
11 PM Tue 20 20 NW 7 0 6800 0 Blue 0
12 Midnight Wed 19 19 NW 7 0 6800 0 Blue 0
1 AM Wed 18 18 NW 7 0 6800 0 Blue 0
2 AM Wed 17 17 NW 6 0 6800 0 Blue 0
3 AM Wed 17 17 W 6 0 6800 0 Blue 0
4 AM Wed 16 16 W 6 0 6800 0 Blue 0
5 AM Wed 15 15 W 6 0 6800 0 Blue 0
6 AM Wed 14 14 W 6 0 6800 0 Blue 0
7 AM Wed 15 15 W 6 0 6800 0 Blue 0
8 AM Wed 16 16 W 6 0 6800 0 Blue 0
9 AM Wed 20 20 SW 6 0 6800 0 Blue 0
10 AM Wed 25 26 SW 6 0 6800 0 Blue 0
11 AM Wed 30 32 SW 7 6122 6800 0 White 0
12 Noon Wed 33 35 SW 7 6122 6800 0 White 0
1 PM Wed 35 37 SW 8 6475 6800 0 White 0
2 PM Wed 36 38 SW 8 6698 6800 0 White 0
3 PM Wed 36 37 SW 9 6475 6800 0 White 0
4 PM Wed 36 36 SW 9 6251 6800 0 White 0
5 PM Wed 34 34 SW 10 6122 6800 0 White 0
6 PM Wed 32 32 SW 10 6122 6800 0 White 0
7 PM Wed 28 28 SW 10 0 6800 0 Blue 0
8 PM Wed 26 26 SW 10 0 6800 0 Blue 0
9 PM Wed 24 24 SW 10 0 6800 0 Blue 0
10 PM Wed 23 23 SW 10 0 6800 0 Blue 0
11 PM Wed 23 23 SW 10 0 6800 0 Blue 0
12 Midnight Thu 23 23 S 10 0 6800 0 Blue 0
1 AM Thu 23 23 S 10 0 6800 0 Blue 0
2 AM Thu 23 23 S 10 0 6800 0 Blue 0
3 AM Thu 23 23 S 10 0 6800 0 Blue 0
4 AM Thu 22 22 S 10 0 6800 0 Blue 0
5 AM Thu 22 22 S 12 0 6800 0 Blue 0
6 AM Thu 21 21 S 12 0 6800 0 Blue 0
7 AM Thu 20 20 S 13 0 6800 0 Blue 0
8 AM Thu 22 22 S 13 0 6800 0 Blue 0
9 AM Thu 25 25 S 14 0 6800 0 Blue 0
10 AM Thu 29 29 SW 15 0 6800 0 Blue 0
11 AM Thu 33 34 SW 15 6122 6800 0 White 0
12 Noon Thu 35 36 SW 16 6251 6800 0 White 0
1 PM Thu 37 38 SW 16 6698 6800 0 White 0
2 PM Thu 37 38 SW 16 6698 6800 0 White 0
3 PM Thu 37 37 SW 16 6475 6800 0 White 0
4 PM Thu 37 37 SW 16 6475 6800 0 White 0
5 PM Thu 36 36 SW 16 6251 6800 0 White 0
6 PM Thu 34 34 SW 16 6122 6800 0 White 0
7 PM Thu 33 33 SW 15 6122 6800 0 White 0
8 PM Thu 31 31 SW 15 0 6800 0 Blue 0
9 PM Thu 30 30 SW 14 0 6800 0 Blue 0
10 PM Thu 30 30 SW 14 0 6800 0 Blue 0
11 PM Thu 30 30 SW 14 0 6800 0 Blue 0
12 Midnight Fri 30 30 SW 14 0 6800 0 Blue 0
1 AM Fri 30 30 SW 14 0 6800 0 Blue 0
2 AM Fri 29 29 SW 13 0 6800 0 Blue 0
3 AM Fri 28 28 SW 13 0 6800 0 Blue 0
4 AM Fri 27 27 SW 13 0 6800 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