Spring starts with a cold shot from old man winter...

[Tom23]

Shoot, those time in Z's always throws me for a loop. I still don't know exactly what which one is which. To my understanding, in a regular non-DST time, 0z is at midnight, 6z is at 6 A.M., 12z is 12 noon, and 18z is around 6 in the evening. Is that right??

[mempho]

Z time is zulu time.  Zulu time is UTC (GMT).  During CST, you subtract 6 hours and during CDT, you subtract 5 hours.

Therefore, 18z is currently 1pm (12pm during standard time).

[Tom23]

So, you go by military time, making 18th hour 6:00 p.m., and subtract 6 hours, under standard time???

[Thundersnow]

Just to elaborate, there's a "universal time" that the world goes by which all other time zones are adjusted to.  The time zone goes by names such as "Greenwich Mean Time" (GMT) "Coordinated Universal Time" (UTC) or "Zulu Time" (Z).  So, you may see either GMT, UTC, or Z.  But, they all three refer to the same time zone.

That particular time zone runs from England down through the western edge of Europe and Africa.  It is based on the time in Greenwich, England.  

http://en.wikipedia.org/wiki/Coordinated_Universal_Time

So, when you see 0Z or 0:00 GMT/UTC, it's midnight over in England.  But, the world uses that time as a kind of universal time so that we're all talking about the same time.

The rest of the world merely adjusts that time based on the hours' offset between each time zone and that mean timezone in England.

Central Standard Time is 6 hours behind Greenwich.  So, to figure out what time it is here, subtract 6 hours.  But, Daylight Savings Time forces us ahead an hour, so it ends up being 5 hours.

If you're in Eastern Time, then you're 5 hours behind GMT/Z/UTC during Standard time and 4 hours behind during Daylight Savings Time.

[Thundersnow]

So, you go by military time, making 18th hour 6:00 p.m., and subtract 6 hours, under standard time???

Well, but, see you're in Eastern Time, so you actually subtract 5 hours to figure out what time it is... 4 hours during DST.

So, 18Z for you is actually 18-4 for EDT or 14:00 (2:00 PM)!

[Curt]

I'm gonna say this, and I'm gonna be quiet until this thing materializes, if it ever does. Remember that event in early March that had major snowstorm potentials written all over it??? Remember what actually happened??? Missed us to the South, except for a few snow showers that accumulated an inch or two, and that melted in an hour.

What I'm saying is, this is still early to follow this one closely. PERFECT setup is what we'll need to see in order to get any kind of snow, let alone accumulations. Sun angle is waay to high now for any of a light snow to stick, and ground temps are warm.
So I'm staying out of this one for now. Think storms.

Sun angle is higher, but heavy snowfall rates can and do offset the radiational effect this late in the season. Snow in these situations WILL not only stick but is usually heavy and wet and can easily bring down power lines and trees. Both of the heaviest snowstorms in Memphis occurred in the third week of March WITH major accums according to news reports from the 1892 event, and from factual account (my dad) in 1968.

With that said, I am not all that bullish on snow for anyone atm. Y'days models showed a hit for Kansas City, today for other parts, namely St. Louis with about 6 inches. Strange things can happen this time of year.

[jmundie]

I've been watching with some caution. I certainly wasn't gonna be the first to mention the possibility of snow.

And if it happens... will be a good surprise end to the season.

[dwagner88]

I'm seeing lots of general model agreement with the principal issues being details of timing and surface low placement but I'm seeing lots of 90* and negative tilt on the models and precip lagging behind the baroclinic transition zone...even the GFS ensemble members.  Here's the 12z NOGAPS at 96, for instance (I don't have 2m temps for this one, but you get the general picture):

This just looks wrong. We can't get snow in the middle of winter with the LPC so far north, no way it happens in March.

[jmundie]

This just looks wrong. We can't get snow in the middle of winter with the LPC so far north, no way it happens in March.

If you'd read prior posts, this is a weird situation called an anafront, where most of the precipitation associated with the system is post frontal.

Weird, but I wouldn't say impossible.

[dwagner88]

If you'd read prior posts, this is a weird situation called an anafront, where most of the precipitation associated with the system is post frontal.

Weird, but I wouldn't say impossible.

Allright, I'll bite. I searched every page of this thread and couldn't find where anybody had mentioned the term "anafront" until you did just now. Googled it and found this:
http://amsglossary.allenpress.com/glossary/search?id=anafront1

Warm air ascending to high altitudes is not really what's being shown on the models and also doesn't sound like it would be supportive of snow. Needless to say, precip occuring behind a cold front is something to be wary of in January. Remember the super clipper? That was supposed to have precip occuring behind the baroclinic zone after the cold air came, but, as is usually the case, the cold air chased out the moisture. I doubt that anybody outside the mountains get the from this one.

[Eric]

Allright, I'll bite. I searched every page of this thread and couldn't find where anybody had mentioned the term "anafront" until you did just now. Googled it and found this:
http://amsglossary.allenpress.com/glossary/search?id=anafront1

Warm air ascending to high altitudes is not really what's being shown on the models and also doesn't sound like it would be supportive of snow. Needless to say, precip occuring behind a cold front is something to be wary of in January. Remember the super clipper? That was supposed to have precip occuring behind the baroclinic zone after the cold air came, but, as is usually the case, the cold air chased out the moisture. I doubt that anybody outside the mountains get the from this one.

It's in the severe weather thread. 

http://tennesseewx.com/index.php/topic,2462.msg80755.html#msg80755

[dwagner88]

It's in the severe weather thread. 

http://tennesseewx.com/index.php/topic,2462.msg80755.html#msg80755

Ha, and we both posted the same definition! What are the chances? Learn something new every day on here.

[shooting70]

Eric,the 0zgfs looks funny to me.The ULL is right over us and just meanders around.Im thinking just a fluke run.Would be nice to see at least some flurries or light snow.Im just confused by this run.

[toastido]

[ams30721us]

hmmmmm I found this interesting this morning.......
From HSV this morning:

RAIN CHANCES REALLY PICK UP SATURDAY NIGHT...AND WILL LINGER INTO
SUNDAY MORNING. AM NOT PARTICULARLY IMPRESSED WITH THE TSTM CHANCES
BUT SOME TSTMS DO APPEAR POSSIBLE ALONG AND PERHAPS JUST AHEAD OF
THE FRONT. MAIN THREAT WITH THE STORMS LOOKS LIKE GUSTY WINDS BUT
HAIL IS ALSO A THREAT GIVEN LOW PROGGED WBZ HEIGHTS. MODELS ARE NOW
CLOSING OFF THE UPPER LOW WITH THE NEXT SYSTEM...AND DRAGGING A
RATHER STRONG AND SLOW-MOVING UPPER LOW RIGHT ACROSS THE AREA SUNDAY
AND SUNDAY NIGHT. THIS COMBO REQUIRES SIGNIFICANTLY INCREASING PCPN
CHANCES SUNDAY AND SUNDAY NIGHT...AS WELL AS LOWERING TEMPERATURES
THROUGHOUT THE PERIOD. YES...MORE COLD AND RAW WEATHER.

IN FACT...I DOUBT WE REACH 50 DEGREES ON SUNDAY WITH OFF-AND-ON
SHOWERS. THEN SUNDAY NIGHT...MORE LIGHT SHOWERS ARE POSSIBLE...AND
IF THERE WERE TO BE ANY HEAVIER SHOWERS...THEY MIGHT FALL AS A
RAIN/SNOW MIX OR EVEN ALL SNOW GIVEN THE THERMAL PROFILES. WAY TOO
FAR OUT AND TOO UNCERTAIN TO MENTION SNOW...BUT MID 30S LOWS AND A
CHANCE POP ARE ENOUGH TO GET SOME ATTENTION. A LIGHT FREEZE IS
POSSIBLE IN THE TYPICALLY COLD SPOTS MONDAY AND/OR TUESDAY MORNINGS.

From Nashville:

THE LOW OVER THE LOWER PLAINS RACES NEWD FRI NGT/SAT AM AND THEN SLOWS
DOWN OVER THE OHIO VALLEY EVENTUALLY WINDING UP OVER HUNTINGDON
WVA ON SUN EVE. THE ASSOCD COLD FRONT SWEEPS ACROSS THE MIDSTATE
LATE SAT NGT AND EXITS THE AREA SUN AM. A GOOD BIT OF MOISTURE AND
COLD AIR BEHIND THE FRONT. THERE HAS BEEN SOME DISCUSSION ABOUT
THE POSSIBILITY OF SNOW SUN NGT. WHILE THE MID/UPPER LEVEL ARE CERTAINLY
COLD ENOUGH...THE LOWER LEVELS ARE MARGINAL. FORECAST SOUNDINGS
FOR KBNA SHOW THE FREEZING LEVEL NEVER GETS BELOW 1543` ASL(944` MSL).
THUS WILL NOT INCLUDE MENTION OF ANY SNOW ATTM BECAUSE IT APPEARS
TO BE A MARGINAL EVENT AND IT IS STILL 3 DAYS AWAY. LATER MODEL
RUNS WILL REVEAL A BETTER PICTURE.

From Memphis:

AS THE SYSTEM OCCLUDES WITH THE FRONT EAST OF THE AREA...A POCKET
OF VERY COLD AIR ALOFT WILL ROTATE AROUND THE SOUTH SIDE OF THE LOW
WITH 925 MB TEMPERATURES AROUND -3C AND FREEZING LEVELS AROUND 1
KFT. USING THE TOP-DOWN METHOD...A 1 KFT FREEZING LEVEL YIELDS
ABOUT A 50 PERCENT CHANCE OF SNOW REACHING THE SURFACE. THUS...WRAP
AROUND RAIN AND SNOW SHOWERS LATE SATURDAY NIGHT AND SUNDAY
MORNING ARE PROBABLE. SUNDAY LOOKS LIKE A VERY UNPLEASANT DAY WITH
HIGHS REMAINING IN THE LOW TO MID 40S...THOSE SCATTERED RAIN AND
POSSIBLY SNOW SHOWERS THROUGH THE DAY...AND GUSTY WINDS UNDER
CYCLONIC FLOW.

hmmm sounds a little interesting. Havent really been following this so far.