Ive been a reading a lot about weather and weather reports and I never really took the time to understand the conversion... I know its not very difficult but could some explain how to convert using Pacific Standard Time and Pacific Day Light Savings....

Ive seen the charts but I want to know the math behind it...

Thanks

PST add 8 hours.
DST add 7 hours.
Subtract 24 for any value > 24

That will give you Zulu.

Thanks...... so looking at 12 hour prog charts on weather.gov that is issued or 00, 06, 12, 18 do you do the reverse calculation for local time?

So out west with PST 00z is 8am, 06z is 2pm, 12z is 8pm, and 18 is 2am....

Titus577 wrote:Thanks...... so looking at 12 hour prog charts on weather.gov that is issued or 00, 06, 12, 18 do you do the reverse calculation for local time?

So out west with PST 00z is 8am, 06z is 2pm, 12z is 8pm, and 18 is 2am....

Actually, the other way around. To convert from Zulu to Pacific subtract the numbers above
00z (or 24) - 8 = 1600 = 4pm
06z = 22 = 10pm
12z = 4am
18z = 10am.
(hopefully I didn't screw that up).

Remember, Zulu time is in England and the sun rises there before it rises here so we're always earlier.

The reason Zulu, or Greenwich Mean Time, or UTC, is used is to prevent the need for time zone conversion. When you use Zulu time, everybody is on the same time value. It's 02:00Z in Portland, it's 0:200Z in London. Position of the sun? Daylight savings? No such thing on Zulu time. I believe the prime meridian, or Longitude = zero line coincides with Greenwich, England.

It's great because it would be a real headache for flights that originate in one time zone and land in another to flight plan and coordinate.

Out here in the west we always trail behind relative to the sun, so we subtract our appropriate timezone's differential value depending on daylight savings. Always use the 24 hour clock.

PST = Zulu - 8
PDT = Zulu - 7

and vice versa the opposite direction.

Areas east of the Prime Meridian should add their appropriate differential value to get local time, as they are "ahead" of Zulu time. if travelling east, once you get to the International Date Line, you switch back to being "west" and subtracting the hours for local time.

Good graphic: http://upload.wikimedia.org/wikipedia/commons/7/77/Timezones2008_UTC%2B8.png

I think these guys pretty much summed it up. Its basically a subtraction for you. Convert to military (24hr) time, then subtract 7 or 8. For me I am working overseas right now and we are +6.

I just don't wear a watch......

Gump

I can't calculate all of that in my head..I just dial up the ASOS either in the air or by telephone...it tells me what Zulu time it is..Oh by the way, I got a little air time this evening and I have no clue as to what Zulu I took off and landed..but I do know I took off before sunset and I landed after sunset..nice evening to fly.

GumpAir wrote:I just don't wear a watch......

Gump

Here, I made you a special Zulu watch.

I struggled with this, but no more. I have two big clocks side by side on my office wall, one normal and the other Zulu. When I call for my briefing and they are throwing out these times, I just sit back and watch the clocks.

Zane wrote:

GumpAir wrote:I just don't wear a watch......

Gump

Here, I made you a special Zulu watch.

Ha Thats one of your best yet....................

SO, does anyone have aneasy to remember conversion for celsius to fairenheit?

avi8ter wrote:SO, does anyone have aneasy to remember conversion for celsius to fairenheit?

There is one that I can never remember, unless you are a scientist or a pilot taking a checkride I figure the exact calculation is not needed.
Having said that, -40=-40, 0C=32F, 20C is nice but could be on the cool side depending on shade and wind, 30C is on the warm side of nice, 35C is hot, 38C=100F, 50C is damned hot. That is what I use at UTC+3. In UTC - 9 use the following substitutes; 5C is nice, 15C is warm, 30C is hot, and 40C is unheard of.

avi8ter wrote:SO, does anyone have aneasy to remember conversion for celsius to fairenheit?

F=1.8C+32
C=(F-32)/1.8
F to C is harder since I have to divide by 1.8 or multiply by 1/1.8, which I can never remember.

To get a ballpark, I just use 2 instead of 1.8, which is a lot easier to calculate:

15C ~= 30+32 or 62 which is close to 59.

Conversely 60,which is close to 59 and an even number.
(60-32)/2=28/2=14

close enough for a performance calculation. Maybe not for an FAA written.

http://101science.com/UTCzulu.html

In CDST or CDT

I use "Trees are alive ad 5" or "Trees have Sticks ad 6"

The exact conversion of Celsius to Fahrenheit is easy.

Double it, subtract 10%, add 32

12C, doubled is 24, subtract 10% (2.4) is 22, add 32 is 54.

12C = 54F

It's easy and exact. You can do it in your head. Impress friends and family! (or annoy them)


20, 40, 36, 68. 20c = 68f
15, 30, 27, 59. 15c = 59f
-7, -14, -12, 20. -7c = 20f

100, 200, 180, 212. 100C is 212f
1,000, 2,000, 1,800, 1,832. 1,000c is 1,832f

I put the last two just to show the relationships. Enjoy.

GumpAir wrote:I just don't wear a watch......

Gump

Neither do I..... I have an I-Phone

I have a flight from Kona to Auckland in February.
It's a 10 hour flight.
There is a one hour time zone change.
I will land 33 hours after I take off.

My plane only has a 12 hour range.... I'm confused

porterjet wrote:

avi8ter wrote:SO, does anyone have aneasy to remember conversion for celsius to fairenheit?

There is one that I can never remember, unless you are a scientist or a pilot taking a checkride I figure the exact calculation is not needed.
Having said that, -40=-40, 0C=32F, 20C is nice but could be on the cool side depending on shade and wind, 30C is on the warm side of nice, 35C is hot, 38C=100F, 50C is damned hot. That is what I use at UTC+3. In UTC - 9 use the following substitutes; 5C is nice, 15C is warm, 30C is hot, and 40C is unheard of.

Minus 40C is the same as minus 40F. Pretty close to the melting point of Mercury.

Tim

-40, -80, -72, -40

-40C =-40F