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

Station:

KFGZ

Date/Time:

19 AUG 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)
6 AM Sun 64 64 NW 7 7306 7270 470 Blue 11
7 AM Sun 66 66 N 7 7330 7294 494 Blue 13
8 AM Sun 70 71 N 8 7391 7354 554 Blue 18
9 AM Sun 74 77 N 8 7772 7487 687 Blue 24
10 AM Sun 79 84 N 8 15801 9637 2837 Blue 31
11 AM Sun 83 90 N 8 16027 15864 9064 Blue 37
12 Noon Sun 86 94 N 9 17343 16080 9280 Blue 41
1 PM Sun 87 95 N 10 17819 16179 9379 Blue 42
2 PM Sun 88 95 N 13 17819 16179 9379 Blue 42
3 PM Sun 89 94 N 14 17343 16080 9280 Blue 41
4 PM Sun 91 94 N 14 17343 16080 9280 Blue 41
5 PM Sun 91 92 N 13 16350 15923 9123 Blue 39
6 PM Sun 90 90 N 12 16027 15864 9064 Blue 37
7 PM Sun 87 87 N 9 15871 15793 8993 Blue 34
8 PM Sun 83 83 NW 7 15736 8539 1739 Blue 30
9 PM Sun 78 78 NW 5 8002 7522 722 Blue 25
10 PM Sun 74 74 NW 5 7488 7390 590 Blue 21
11 PM Sun 72 72 W 5 7417 7366 566 Blue 19
12 Midnight Mon 70 70 W 5 7379 7342 542 Blue 17
1 AM Mon 68 68 SW 5 7354 7318 518 Blue 15
2 AM Mon 67 67 S 3 7342 7306 506 Blue 14
3 AM Mon 66 66 S 3 7330 7294 494 Blue 13
4 AM Mon 64 64 S 3 7306 7270 470 Blue 11
5 AM Mon 62 62 SE 2 7282 7243 443 Blue 9
6 AM Mon 63 63 SE 2 7294 7258 458 Blue 10
7 AM Mon 66 66 SE 2 7330 7294 494 Blue 13
8 AM Mon 71 72 SE 2 7417 7366 566 Blue 19
9 AM Mon 77 80 SE 3 8560 7764 964 Blue 27
10 AM Mon 82 86 SE 5 15848 15683 8883 Blue 33
11 AM Mon 86 91 SE 7 16106 15891 9091 Blue 38
12 Noon Mon 89 94 S 8 17343 16080 9280 Blue 41
1 PM Mon 90 95 S 8 17819 16179 9379 Blue 42
2 PM Mon 91 95 S 8 17819 16179 9379 Blue 42
3 PM Mon 91 94 S 8 17343 16080 9280 Blue 41
4 PM Mon 91 93 S 8 16854 16001 9201 Blue 40
5 PM Mon 91 92 SW 9 16350 15923 9123 Blue 39
6 PM Mon 89 89 SW 9 15948 15840 9040 Blue 36
7 PM Mon 85 85 SW 9 15824 12314 5514 Blue 32
8 PM Mon 80 80 SW 8 8560 7764 964 Blue 27
9 PM Mon 76 76 SW 8 7624 7451 651 Blue 23
10 PM Mon 73 73 SW 8 7453 7378 578 Blue 20
11 PM Mon 71 71 SW 9 7391 7354 554 Blue 18
12 Midnight Tue 70 70 W 9 7379 7342 542 Blue 17
1 AM Tue 69 69 W 9 7366 7330 530 Blue 16
2 AM Tue 68 68 W 8 7354 7318 518 Blue 15
3 AM Tue 66 66 W 7 7330 7294 494 Blue 13
4 AM Tue 64 64 W 6 7306 7270 470 Blue 11
5 AM Tue 63 63 W 5 7294 7258 458 Blue 10
6 AM Tue 63 63 W 3 7294 7258 458 Blue 10
7 AM Tue 65 65 W 3 7318 7282 482 Blue 12
8 AM Tue 69 69 SW 5 7366 7330 530 Blue 16
9 AM Tue 74 75 S 6 7524 7416 616 Blue 22
10 AM Tue 79 81 S 7 9779 7986 1186 Blue 28
11 AM Tue 83 86 S 7 15848 15683 8883 Blue 33
12 Noon Tue 86 89 S 8 15948 15840 9040 Blue 36
1 PM Tue 88 91 S 8 16106 15891 9091 Blue 38
2 PM Tue 88 90 SW 9 16027 15864 9064 Blue 37
3 PM Tue 88 90 SW 9 16027 15864 9064 Blue 37
4 PM Tue 88 89 SW 10 15948 15840 9040 Blue 36
5 PM Tue 87 87 W 10 15871 15793 8993 Blue 34
6 PM Tue 85 85 W 10 15824 12314 5514 Blue 32
7 PM Tue 82 82 W 9 13021 8263 1463 Blue 29
8 PM Tue 78 78 W 8 8002 7522 722 Blue 25
9 PM Tue 75 75 W 7 7524 7416 616 Blue 22
10 PM Tue 73 73 W 7 7453 7378 578 Blue 20
11 PM Tue 71 71 SW 7 7391 7354 554 Blue 18
12 Midnight Wed 71 71 SW 7 7391 7354 554 Blue 18
1 AM Wed 70 70 SW 7 7379 7342 542 Blue 17
2 AM Wed 69 69 SW 6 7366 7330 530 Blue 16
3 AM Wed 68 68 SW 6 7354 7318 518 Blue 15
4 AM Wed 66 66 SW 5 7330 7294 494 Blue 13
5 AM Wed 65 65 SW 5 7318 7282 482 Blue 12
6 AM Wed 64 64 SW 3 7306 7270 470 Blue 11
7 AM Wed 66 66 SW 3 7330 7294 494 Blue 13
8 AM Wed 70 70 SW 3 7379 7342 542 Blue 17
9 AM Wed 74 75 SW 5 7524 7416 616 Blue 22
10 AM Wed 79 81 SW 6 9779 7986 1186 Blue 28
11 AM Wed 82 85 S 7 15824 12314 5514 Blue 32
12 Noon Wed 85 88 S 8 15901 15817 9017 Blue 35
1 PM Wed 87 90 SW 10 16027 15864 9064 Blue 37
2 PM Wed 87 90 W 12 16027 15864 9064 Blue 37
3 PM Wed 87 89 W 12 15948 15840 9040 Blue 36
4 PM Wed 86 87 W 12 15871 15793 8993 Blue 34
5 PM Wed 85 85 W 12 15824 12314 5514 Blue 32
6 PM Wed 83 83 W 10 15736 8539 1739 Blue 30
7 PM Wed 80 80 W 10 8560 7764 964 Blue 27
8 PM Wed 77 77 W 9 7772 7487 687 Blue 24
9 PM Wed 74 74 W 8 7488 7390 590 Blue 21
10 PM Wed 71 71 W 8 7391 7354 554 Blue 18
11 PM Wed 70 70 W 7 7379 7342 542 Blue 17
12 Midnight Thu 69 69 W 7 7366 7330 530 Blue 16
1 AM Thu 68 68 W 7 7354 7318 518 Blue 15
2 AM Thu 67 67 SW 6 7342 7306 506 Blue 14
3 AM Thu 65 65 SW 6 7318 7282 482 Blue 12
4 AM Thu 64 64 SW 6 7306 7270 470 Blue 11
5 AM Thu 62 62 SW 6 7282 7243 443 Blue 9
6 AM Thu 62 62 SW 6 7282 7243 443 Blue 9
7 AM Thu 64 64 SW 6 7306 7270 470 Blue 11
8 AM Thu 66 66 SW 6 7330 7294 494 Blue 13
9 AM Thu 70 71 W 6 7391 7354 554 Blue 18
10 AM Thu 74 76 W 7 7624 7451 651 Blue 23
11 AM Thu 78 81 W 8 9779 7986 1186 Blue 28
12 Noon Thu 81 85 W 9 15824 12314 5514 Blue 32
1 PM Thu 82 86 W 12 15848 15683 8883 Blue 33
2 PM Thu 83 86 W 14 15848 15683 8883 Blue 33
3 PM Thu 84 87 W 15 15871 15793 8993 Blue 34
4 PM Thu 84 85 W 15 15824 12314 5514 Blue 32
5 PM Thu 84 85 W 14 15824 12314 5514 Blue 32
6 PM Thu 82 82 W 13 13021 8263 1463 Blue 29
7 PM Thu 79 79 W 12 8282 7617 817 Blue 26
8 PM Thu 75 75 W 12 7524 7416 616 Blue 22
9 PM Thu 72 72 W 10 7417 7366 566 Blue 19
10 PM Thu 70 70 W 9 7379 7342 542 Blue 17
11 PM Thu 69 69 W 9 7366 7330 530 Blue 16
12 Midnight Fri 69 69 W 8 7366 7330 530 Blue 16
1 AM Fri 68 68 W 8 7354 7318 518 Blue 15
2 AM Fri 66 66 W 7 7330 7294 494 Blue 13
3 AM Fri 65 65 W 7 7318 7282 482 Blue 12
4 AM Fri 63 63 W 7 7294 7258 458 Blue 10
5 AM Fri 62 62 W 7 7282 7243 443 Blue 9
6 AM Fri 62 62 W 7 7282 7243 443 Blue 9
7 AM Fri 63 63 W 7 7294 7258 458 Blue 10
8 AM Fri 67 68 W 7 7354 7318 518 Blue 15
9 AM Fri 71 73 W 7 7453 7378 578 Blue 20
10 AM Fri 75 78 NW 8 8002 7522 722 Blue 25
11 AM Fri 79 83 NW 8 15736 8539 1739 Blue 30
12 Noon Fri 82 86 NW 9 15848 15683 8883 Blue 33
1 PM Fri 83 87 W 10 15871 15793 8993 Blue 34
2 PM Fri 84 87 W 12 15871 15793 8993 Blue 34
3 PM Fri 85 88 W 12 15901 15817 9017 Blue 35
4 PM Fri 85 86 W 12 15848 15683 8883 Blue 33
5 PM Fri 85 85 W 12 15824 12314 5514 Blue 32
6 PM Fri 83 83 W 10 15736 8539 1739 Blue 30
7 PM Fri 80 80 W 10 8560 7764 964 Blue 27
8 PM Fri 76 76 W 10 7624 7451 651 Blue 23
9 PM Fri 73 73 W 9 7453 7378 578 Blue 20
10 PM Fri 70 70 W 9 7379 7342 542 Blue 17
11 PM Fri 68 68 W 9 7354 7318 518 Blue 15
12 Midnight Sat 67 67 W 9 7342 7306 506 Blue 14
1 AM Sat 67 67 W 9 7342 7306 506 Blue 14
2 AM Sat 66 66 W 9 7330 7294 494 Blue 13
3 AM Sat 65 65 W 9 7318 7282 482 Blue 12
4 AM Sat 63 63 W 8 7294 7258 458 Blue 10
5 AM Sat 62 62 W 8 7282 7243 443 Blue 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 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