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

Station:

KFGZ

Date/Time:

25 APR 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)
6 AM Thu 49 49 NW 6 7292 7255 455 Blue 12
7 AM Thu 51 51 NW 6 7317 7280 480 Blue 14
8 AM Thu 55 57 NW 7 7419 7354 554 Blue 19
9 AM Thu 60 64 N 7 7762 7521 721 Blue 26
10 AM Thu 64 70 N 7 11653 8640 1840 Blue 32
11 AM Thu 67 74 N 7 16061 13165 6365 Blue 36
12 Noon Thu 71 79 NE 7 18532 16876 10076 Blue 41
1 PM Thu 73 79 NE 6 18532 16876 10076 Blue 41
2 PM Thu 76 81 NE 6 19270 17163 10363 Blue 43
3 PM Thu 78 81 NE 5 19270 17163 10363 Blue 43
4 PM Thu 79 80 N 5 18865 17024 10224 Blue 42
5 PM Thu 78 78 W 6 17216 16391 9591 Blue 40
6 PM Thu 76 76 W 6 16937 14880 8080 Blue 38
7 PM Thu 74 74 W 6 16061 13165 6365 Blue 36
8 PM Thu 70 70 SW 5 11653 8640 1840 Blue 32
9 PM Thu 67 67 SW 5 8667 7756 956 Blue 29
10 PM Thu 64 64 SW 7 7762 7521 721 Blue 26
11 PM Thu 63 63 SW 9 7643 7491 691 Blue 25
12 Midnight Fri 62 62 SW 12 7553 7461 661 Blue 24
1 AM Fri 61 61 SW 12 7523 7439 639 Blue 23
2 AM Fri 60 60 W 10 7493 7418 618 Blue 22
3 AM Fri 58 58 W 10 7440 7375 575 Blue 20
4 AM Fri 55 55 W 10 7376 7329 529 Blue 18
5 AM Fri 53 53 W 9 7342 7304 504 Blue 16
6 AM Fri 52 52 W 9 7329 7292 492 Blue 15
7 AM Fri 55 55 W 8 7376 7329 529 Blue 18
8 AM Fri 59 61 SW 7 7523 7439 639 Blue 23
9 AM Fri 64 68 SW 7 9597 7987 1187 Blue 30
10 AM Fri 69 74 SW 7 16061 13165 6365 Blue 36
11 AM Fri 72 79 SW 8 18532 16876 10076 Blue 41
12 Noon Fri 75 82 SW 10 19777 18280 11480 Blue 44
1 PM Fri 76 83 SW 13 20267 18721 11921 Blue 45
2 PM Fri 77 83 SW 16 20267 18721 11921 Blue 45
3 PM Fri 78 82 SW 18 19777 18280 11480 Blue 44
4 PM Fri 78 80 SW 20 18865 17024 10224 Blue 42
5 PM Fri 77 78 SW 21 17216 16391 9591 Blue 40
6 PM Fri 76 76 SW 21 16937 14880 8080 Blue 38
7 PM Fri 73 73 SW 20 15344 11473 4673 Blue 35
8 PM Fri 69 69 SW 17 10560 8315 1515 Blue 31
9 PM Fri 66 66 SW 15 8339 7637 837 Blue 28
10 PM Fri 63 63 SW 15 7643 7491 691 Blue 25
11 PM Fri 61 61 SW 14 7523 7439 639 Blue 23
12 Midnight Sat 60 60 SW 14 7493 7418 618 Blue 22
1 AM Sat 59 59 SW 14 7463 7396 596 Blue 21
2 AM Sat 58 58 W 14 7440 7375 575 Blue 20
3 AM Sat 57 57 W 13 7419 7354 554 Blue 19
4 AM Sat 54 54 W 13 7355 7317 517 Blue 17
5 AM Sat 52 52 W 12 7329 7292 492 Blue 15
6 AM Sat 52 52 W 10 7329 7292 492 Blue 15
7 AM Sat 54 54 W 9 7355 7317 517 Blue 17
8 AM Sat 58 60 W 8 7493 7418 618 Blue 22
9 AM Sat 62 65 W 7 8007 7551 751 Blue 27
10 AM Sat 66 71 W 6 13258 9410 2610 Blue 33
11 AM Sat 69 76 W 5 16937 14880 8080 Blue 38
12 Noon Sat 72 79 W 5 18532 16876 10076 Blue 41
1 PM Sat 74 81 W 6 19270 17163 10363 Blue 43
2 PM Sat 75 80 W 8 18865 17024 10224 Blue 42
3 PM Sat 76 80 W 9 18865 17024 10224 Blue 42
4 PM Sat 77 79 SW 12 18532 16876 10076 Blue 41
5 PM Sat 77 78 SW 13 17216 16391 9591 Blue 40
6 PM Sat 75 75 SW 15 16564 13557 6757 Blue 37
7 PM Sat 73 73 SW 16 15344 11473 4673 Blue 35
8 PM Sat 69 69 SW 16 10560 8315 1515 Blue 31
9 PM Sat 66 66 SW 17 8339 7637 837 Blue 28
10 PM Sat 63 63 SW 18 7643 7491 691 Blue 25
11 PM Sat 62 62 SW 18 7553 7461 661 Blue 24
12 Midnight Sun 61 61 SW 18 7523 7439 639 Blue 23
1 AM Sun 59 59 SW 18 7463 7396 596 Blue 21
2 AM Sun 58 58 SW 17 7440 7375 575 Blue 20
3 AM Sun 56 56 SW 17 7397 7341 541 Blue 19
4 AM Sun 54 54 SW 15 7355 7317 517 Blue 17
5 AM Sun 53 53 SW 14 7342 7304 504 Blue 16
6 AM Sun 52 52 SW 13 7329 7292 492 Blue 15
7 AM Sun 53 53 SW 13 7342 7304 504 Blue 16
8 AM Sun 55 56 SW 15 7397 7341 541 Blue 19
9 AM Sun 59 62 SW 16 7553 7461 661 Blue 24
10 AM Sun 63 68 SW 17 9597 7987 1187 Blue 30
11 AM Sun 67 73 SW 20 15344 11473 4673 Blue 35
12 Noon Sun 70 76 SW 21 16937 14880 8080 Blue 38
1 PM Sun 72 78 SW 21 17216 16391 9591 Blue 40
2 PM Sun 74 79 SW 21 18532 16876 10076 Blue 41
3 PM Sun 75 79 SW 21 18532 16876 10076 Blue 41
4 PM Sun 75 77 SW 21 17076 15891 9091 Blue 39
5 PM Sun 74 75 SW 20 16564 13557 6757 Blue 37
6 PM Sun 73 73 SW 20 15344 11473 4673 Blue 35
7 PM Sun 72 72 SW 20 13654 10483 3683 Blue 34
8 PM Sun 70 70 SW 20 11653 8640 1840 Blue 32
9 PM Sun 67 67 SW 20 8667 7756 956 Blue 29
10 PM Sun 65 65 SW 18 8007 7551 751 Blue 27
11 PM Sun 62 62 SW 17 7553 7461 661 Blue 24
12 Midnight Mon 59 59 SW 15 7463 7396 596 Blue 21
1 AM Mon 57 57 SW 14 7419 7354 554 Blue 19
2 AM Mon 54 54 SW 13 7355 7317 517 Blue 17
3 AM Mon 52 52 SW 12 7329 7292 492 Blue 15
4 AM Mon 51 51 SW 10 7317 7280 480 Blue 14
5 AM Mon 50 50 SW 10 7305 7267 467 Blue 13
6 AM Mon 50 50 SW 9 7305 7267 467 Blue 13
7 AM Mon 52 52 SW 9 7329 7292 492 Blue 15
8 AM Mon 54 55 SW 10 7376 7329 529 Blue 18
9 AM Mon 58 60 SW 10 7493 7418 618 Blue 22
10 AM Mon 61 63 S 12 7643 7491 691 Blue 25
11 AM Mon 64 67 S 13 8667 7756 956 Blue 29
12 Noon Mon 67 70 S 14 11653 8640 1840 Blue 32
1 PM Mon 68 71 S 16 13258 9410 2610 Blue 33
2 PM Mon 69 72 S 17 13654 10483 3683 Blue 34
3 PM Mon 69 71 S 20 13258 9410 2610 Blue 33
4 PM Mon 68 69 S 22 10560 8315 1515 Blue 31
5 PM Mon 67 67 S 24 8667 7756 956 Blue 29
6 PM Mon 66 66 S 25 8339 7637 837 Blue 28
7 PM Mon 64 64 S 25 7762 7521 721 Blue 26
8 PM Mon 61 61 S 25 7523 7439 639 Blue 23
9 PM Mon 59 59 SW 24 7463 7396 596 Blue 21
10 PM Mon 56 56 SW 23 7397 7341 541 Blue 19
11 PM Mon 53 53 SW 22 7342 7304 504 Blue 16
12 Midnight Tue 51 51 SW 20 7317 7280 480 Blue 14
1 AM Tue 49 49 SW 18 7292 7255 455 Blue 12
2 AM Tue 47 47 SW 18 7268 7231 431 Blue 10
3 AM Tue 45 45 SW 20 7243 7206 406 Blue 8
4 AM Tue 44 44 SW 20 7231 7194 394 Blue 7
5 AM Tue 44 44 SW 20 7231 7194 394 Blue 7
6 AM Tue 45 45 SW 20 7243 7206 406 Blue 8
7 AM Tue 46 46 SW 20 7256 7218 418 Blue 9
8 AM Tue 49 50 SW 20 7305 7267 467 Blue 13
9 AM Tue 52 55 SW 20 7376 7329 529 Blue 18
10 AM Tue 55 60 SW 20 7493 7418 618 Blue 22
11 AM Tue 58 64 SW 20 7762 7521 721 Blue 26
12 Noon Tue 60 66 SW 20 8339 7637 837 Blue 28
1 PM Tue 62 68 SW 20 9597 7987 1187 Blue 30
2 PM Tue 64 69 SW 20 10560 8315 1515 Blue 31
3 PM Tue 65 69 SW 21 10560 8315 1515 Blue 31
4 PM Tue 65 67 SW 21 8667 7756 956 Blue 29
5 PM Tue 65 66 SW 21 8339 7637 837 Blue 28
6 PM Tue 64 64 SW 22 7762 7521 721 Blue 26
7 PM Tue 63 63 SW 21 7643 7491 691 Blue 25
8 PM Tue 61 61 SW 21 7523 7439 639 Blue 23
9 PM Tue 59 59 SW 20 7463 7396 596 Blue 21
10 PM Tue 57 57 SW 18 7419 7354 554 Blue 19
11 PM Tue 55 55 SW 18 7376 7329 529 Blue 18
12 Midnight Wed 53 53 SW 17 7342 7304 504 Blue 16
1 AM Wed 50 50 SW 16 7305 7267 467 Blue 13
2 AM Wed 48 48 SW 16 7280 7243 443 Blue 11
3 AM Wed 46 46 SW 15 7256 7218 418 Blue 9
4 AM Wed 45 45 SW 15 7243 7206 406 Blue 8
5 AM Wed 45 45 SW 15 7243 7206 406 Blue 8

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