February Pattern and Storm Discussion

[Brick Tamland]

Blocking that is being shown as strong as it is on the modeling won't break down that easily SnowNiner. At least past occurrences say that it won't.  Besides, it's an off hour run in the long range. I would pay more attention to the suddenly rock solid weeklies when judging the block out past day 7.

 

I was getting ready to write the same.....

 

The long range is in mid-March, though. It takes quite a storm to generate anything the later we go. 

 

I would focus more on the upcoming systems this weekend and then next week. This may be where we finally "cash in."

 

My cashing in comment was based on that graph, too. Looks like we at least have through next week to look for opportunities, though.

[SnowNiner]

Is this a good look from the GFS Ensembles in the 10 day range (for what they're worth I know)?  Trying to understand patterns better.  There seems to be a double block, Greenland and Alaska and a split flow? in the south and the SE is in negative height anomolies (barely). 

 

On the other side there's hardly any ridge and it looks almost zonal.  Thoughts? 

 

[GreensboroWx]

Is this a good look from the GFS Ensembles in the 10 day range (for what they're worth I know)?  Trying to understand patterns better.  There seems to be a double block, Greenland and Alaska and a split flow? in the south and the SE is in negative height anomolies (barely). 

 

On the other side there's hardly any ridge and it looks almost zonal.  Thoughts? 

 

 

Not bad....Shows VERY strong block over Canada, with a weak ridge just off of the W coast....low pressure undercutting the ridge, and could send pieces of energy along the STJ. Another low sitting over the Aleutian Is....sometimes vorts will spin out of this and crush the ridge and sometimes they will ride up and over helping to dig the trough in the east. 

[MotoWeatherman]

12z NAM at 84hr has our weekend shortwave diving due south through Kansas.   For us to get anthing good out of this I want to see that low up in the NE to exit stage right so our system can amplify more as the shortwave rounds the base of the trough.

[franklin NCwx]

12z NAM at 84hr

 

 

[MotoWeatherman]

LOL...yep...posting any NAM map past 24hr qualifies for that for sure. 

[franklin NCwx]

LOL...yep...posting any NAM map past 24hr qualifies for that for sure. 

Sorry I could not resist. Question tho, was is causing the gfs to show so much qpf over the sw mtns? It actually has .25 qpf on sat sw of Asheville. Is it because it closes off at h5 and tracks over us?

[franklin NCwx]

Looks like we better cash in this weekend if we want to see something.

ensembles!

 

 

 

 

 

 

 

[MotoWeatherman]

Sorry I could not resist. Question tho, was is causing the gfs to show so much qpf over the sw mtns? It actually has .25 qpf on sat sw of Asheville. Is it because it closes off at h5 and tracks over us?

 

I think is because of the track of the 500mb low and the fact that it is strengthening and generates a vertical velocity max at 700mb right over the SW mtns.  The divergence aloft at 500mb looks good in that spot also.  It's like the system is just so close to being so much more you get these pockets of localized QPF maximums.

[franklin NCwx]

I think is because of the track of the 500mb low and the fact that it is strengthening and generates a vertical velocity max at 700mb right over the SW mtns.  The divergence aloft at 500mb looks good in that spot also.  It's like the system is just so close to being so much more you get these pockets of localized QPF maximums.

Thanks, It would be nice to see this trend a little stronger. As of now I would take the 2-3 inches it's printing out and call it a win.

[Brick Tamland]

WxSouth    

If there's going to be a deep south Cutoff this weekend, Northeast vortex will have to get out of the way. Gonna be close

[Shack]

Sorry I could not resist. Question tho, was is causing the gfs to show so much qpf over the sw mtns? It actually has .25 qpf on sat sw of Asheville. Is it because it closes off at h5 and tracks over us?

I was contemplating the same question.  Upslope doesn't account for this does it?

Franklin, how does your part of Macon county do in the upslope events?

[DaculaWeather]

http://www.daculaweather.com/4_hpc_extended_disco.php

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD

949 AM EST TUE FEB 26 2013

 

VALID 12Z FRI MAR 01 2013 - 12Z TUE MAR 05 2013

 

 

THE EUROPEAN CENTRE PRODUCT SUITE HAS PROVEN STABLE ENOUGH OVER THE PAST SEVERAL DAYS TO RELY PRIMARILY UPON ITS DETERMINISTIC MODEL, WITH MODEST INCORPORATION OF THE ENSEMBLE MEAN. IN THE CASE OF THE CURRENT FORECAST, THERE IS LITTLE WITH WHICH TO QUIBBLE THROUGH DAY 5 AMONG ALL THE GLOBAL NUMERICAL MODELS, WITH THE NATION DOMINATED BY A BROAD, POSITIVE-TILT LONGWAVE. BY DAY 6, THE GUIDANCE INDICATES THAT ENERGY WILL BE POOLING OVER THE HIGH PLAINS--THE REFLECTION OF A PATTERN CHANGE BEGINNING WITH THE FLATTENING OF THE WESTERN RIDGE. 

 

BY DAY 7, A NEW CLOSED LOW IS ANTICIPATED OFF THE WEST COAST, WITH A WINTRY WAVE PUSHING ACROSS THE MISSISSIPPI AND TENNESSEE VALLEYS. THE BLOCKY PATTERN THERETOFORE WILL INSURE DEEP-LAYER COLD AIR IN SITU, WITH AN INFLUX OF GULF MOISTURE FUELING WHAT WILL PERHAPS BE ONE OF THE LAST GASPS OF WINTER FOR THE LOWER ELEVATIONS OF THE EAST.

[franklin NCwx]

I was contemplating the same question.  Upslope doesn't account for this does it?

Franklin, how does your part of Macon county do in the upslope events?

No, this does not account for upslope, this is all from the Sat system.

Most of the time not very well compared to the favored areas along the NC/Tenn line. Usually it's off and on snow showers with around 1/2 inch to an inch of accumulations. Sometimes if the flow is more west or southwest we can pick up a few inches. Being downwind of the Smokies in a true NW flow event, those high peaks just eat up most of the moisture. Are you looking for a good upslope spot?

[SnowNiner]

http://www.daculaweather.com/4_hpc_extended_disco.php

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD

949 AM EST TUE FEB 26 2013

 

VALID 12Z FRI MAR 01 2013 - 12Z TUE MAR 05 2013

 

 

THE EUROPEAN CENTRE PRODUCT SUITE HAS PROVEN STABLE ENOUGH OVER THE PAST SEVERAL DAYS TO RELY PRIMARILY UPON ITS DETERMINISTIC MODEL, WITH MODEST INCORPORATION OF THE ENSEMBLE MEAN. IN THE CASE OF THE CURRENT FORECAST, THERE IS LITTLE WITH WHICH TO QUIBBLE THROUGH DAY 5 AMONG ALL THE GLOBAL NUMERICAL MODELS, WITH THE NATION DOMINATED BY A BROAD, POSITIVE-TILT LONGWAVE. BY DAY 6, THE GUIDANCE INDICATES THAT ENERGY WILL BE POOLING OVER THE HIGH PLAINS--THE REFLECTION OF A PATTERN CHANGE BEGINNING WITH THE FLATTENING OF THE WESTERN RIDGE. 

 

BY DAY 7, A NEW CLOSED LOW IS ANTICIPATED OFF THE WEST COAST, WITH A WINTRY WAVE PUSHING ACROSS THE MISSISSIPPI AND TENNESSEE VALLEYS. THE BLOCKY PATTERN THERETOFORE WILL INSURE DEEP-LAYER COLD AIR IN SITU, WITH AN INFLUX OF GULF MOISTURE FUELING WHAT WILL PERHAPS BE ONE OF THE LAST GASPS OF WINTER FOR THE LOWER ELEVATIONS OF THE EAST.

 

 

Aw, that sounds sad.  Seems like that system mentioned next week is probably our last and best shot at seeing something.  It's been said, we'll see if the blocking starting to relax at that time can bring the goods.    Concerned it's a closed low.  We know how those go.  But they bring alot of moisture with them usually so we'll see. 

[Tacoma]

Aw, that sounds sad.  Seems like that system mentioned next week is probably our last and best shot at seeing something.  It's been said, we'll see if the blocking starting to relax at that time can bring the goods.    Concerned it's a closed low.  We know how those go.  But they bring alot of moisture with them usually so we'll see. 

if next week brings us a decent system I'll take it as a grand finale,  I'd love to have a 4 inch snow fall and anything else would be icing on the cake.

[Cold Rain]

Somebody needs to pick up the PBP with the GFS and tell us how the ridge is more west and the trough closes off stronger and the QPF is better!

[franklin NCwx]

Closed off.

 

 

 

[franklin NCwx]

Here she comes, still positive tilt so this run won't be what we want.

 

 

 

 

[franklin NCwx]

opens up at 108.

 

 

 

 

 

[Cold Rain]

QPF Max over Asheville at 114.

[Cold Rain]

More QPF at 120. Trough is all discombobulated. Strong vort, though.

[burgertime]

CLT and 74/85 corridor in NC look like the winners on this run.  Although the QPF max is probably going to end up over GSO.

[calculus1]

opens up at 108.

 

Surface maps reflect much more precip actually reaching the ground in the ensuing frames.  WNC does decent on this event.  I would estimate 2-4 inches for a large part of central NC back to the mountains.  Not much makes it to the ground in N GA or SC.

[tnweathernut]

This looks to me to be a pretty potent vort (and trending a lil stronger each model run).  I would think that if trends continue, the qpf will beef up a little along and to the north of its track.  Not talking about a huge event, but more widespread 2-4 with pockets of lolipops of 5 to 6 could happen with this type of setup.

[packbacker]

CLT and 74/85 corridor in NC look like the winners on this run. Although the QPF max is probably going to end up over GSO.

Looks great for you guys, the snow hole continues for RDU.

[Brick Tamland]

Looks great for you guys, the snow hole continues for RDU.

 

 

Not worried. I bet the precip will be more or trend more to central NC like usual.

[packfan98]

Triad special on this run.  Obviously the sweet spot will jump around from run to run.  Be looking for that low to stay a little closer to the coast for a longer period of time.  

 

[tnweathernut]

I would also add that this event has more potential the further east you go..........maybe maxing out it's potential near the coast in the Carolinas.  At the very least, we have something legit to follow.

[SnowNiner]

Where is the precipitation coming from on this run?  Is it because the low closed off tapping gulf moisture or is it from the lee trough forming after the surface low forms in the Atlantic?