1/17/16 Winter Weather Threat

[Amos83]

a month ago during the blowtorch people would have given their right arm for token flakes flying around. Now everyone is boohooing the potential of a few flakes in the air. I'll take a couple of flakes in the air any day of winter.

[frazdaddy]

As long as you're on board, I'm riding shotgun. Shortwave sampling can't be any more crucial than it is for this storm.

Me as well, for the reasons burger stated. It's not like we have anything else to watch.

[packfan98]

Can Jon or someone tell me how a better sample could be beneficial?  It seems to me, in this instance, it's the PV placement that's by far the most important in squashing whatever energy comes on shore.  I guess maybe some phase interaction is possible as Burger said, but it looks to be too far south and late to make much difference. 

[Solak]

We've has our flurry storm here already... I'm good with the rest of the winter.

[Shawn]

Can Jon or someone tell me how a better sample could be beneficial?  It seems to me, in this instance, it's the PV placement that's by far the most important in squashing whatever energy comes on shore.  I guess maybe some phase interaction is possible as Burger said, but it looks to be too far south and late to make much difference. 

 

After 00z tonight if there isn't more of a phase and the energy in the South doesn't speed up a bit, then you'll be forced to stick with the northern stream generating some flurries over N. GA, NC.

 

Guess we want to sample the energy onshore to get an idea of it's strength and orientation, etc.

[tarheelwx]

In years past when everyone talks about the better sampling, it is a sign of the ship slowly sinking.  Hopefully someone added this to our catch phrase thread. 

 

Seems like the Euro is holding firm.  Some northern stream energy, but the southern stream energy goes way south and dies out.

 

TW

[fountainguy97]

Something to realize is that this storm never really was modeled as a massive snowstorm for anyone.  We are inside 84 hrs and have many models giving many people a dusting to an inch. Shoot we have watched and watched and watched the models for sign of winter to come to life and the facts say ITS ALIVE!

 

Also if I remember correctly I have watched many storms do this. The models agree on the storm then when it is sampled our dreaded NW shift ensues slowly until abt 48 hrs out.  This storm is FAR from dead and hey the GFS actually beat the EURO this time around as the much more consistent model. 

[DopplerWx]

In years past when everyone talks about the better sampling, it is a sign of the ship slowly sinking.  Hopefully someone added this to our catch phrase thread. 

 

Seems like the Euro is holding firm.  Some northern stream energy, but the southern stream energy goes way south and dies out.

 

TW

you do realize we arent just pulling this out of thin air right?  rah mentioned it in their morning disco.  

[fountainguy97]

In years past when everyone talks about the better sampling, it is a sign of the ship slowly sinking.  Hopefully someone added this to our catch phrase thread. 

 

Seems like the Euro is holding firm.  Some northern stream energy, but the southern stream energy goes way south and dies out.

 

TW

 

you realize the EURO is actually pretty close to a phase right?  3 hrs faster with the northern stream and its a different ball game

 

And euro is north abt 30-50 Miles.  2 more shifts and again its game on.  And the sampling could easily provide that or could go the other wa

[MichaelJ]

Disappointing but hey, looks like we will have an active Hurricane season. Any body got a list of the names picked out for this season? 

[Cold Rain]

We often see storms show up in the LR and then go away and then come back.  This can be due to several factors, but the strength of the shortwave that causes the storm to spin up is one of the most important.  Many times, the reason storms show up, then vanish, then show up again is because the energy in question travels through data void areas.  Models underestimate the strength of the wave.  No storm.  The wave emerges, gets sampled better, and viola, you have a storm again.

 

This isn't a new phenomenon.  It happens a lot.  We just don't care most of the time because we usually don't track rain events.

 

Of course, other things like PV placement, strength, orientiation, direction of the flow, speed of the flow etc. matter as well.

 

If our shortwave is stronger than the current "thinking" by the models, changes can absolutely occur.  We should start to see those by tomorrow, I would guess, if they are to happen.

 

I'm not wishcasting with this post either, because I think my area will be mostly rain, if we end up with a decent system.  We want to see the shortwave appear stronger after it's better sampled, as it will have a better time holding together.  We'll see.

[Shawn]

For my Columbia, SC area people.  This is 100% spot on. 

Latest KCAE Discussion:

 

 

 

THE MODELS SHOW LOW PRESSURE MOVING QUICKLY FROM THE GULF OF  
MEXICO SATURDAY NIGHT TO OFF THE FLORIDA AND GEORGIA COASTS  
SUNDAY. THE GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT  
SHOWING LIMITED MOISTURE AND THE BULK OF UPPER-LEVEL LIFT SOUTH  
AND EAST OF THE FORECAST AREA SATURDAY NIGHT. THE MODELS INDICATE  
LITTLE OR NO ISENTROPIC LIFT WITH H85 WESTERLY FLOW. LIFT AHEAD OF  
THE ASSOCIATED MID-LEVEL SHORTWAVE TROUGH IS DEPICTED MAINLY  
SOUTH OF THE FORECAST AREA. THE NAM...GFS...AND ECMWF HAVE QPF  
LESS THAN 0.1 OF AN INCH EXCEPT THE NAM HAS AMOUNTS AROUND 0.1 OF  
AN INCH IN THE SOUTHEAST PART OF THE FORECAST AREA. THE NAM AND  
GFS MOS HAVE POPS OF 20 TO 50 PERCENT WITH THE HIGHER POPS IN THE  
SOUTHEAST. MODEL TIME-HEIGHT DISPLAYS MAINTAIN TEMPERATURES ABOVE  
FREEZING IN THE LOWEST LAYERS. EXPECT LIGHT AMOUNTS WHICH SHOULD  
LIMIT COOLING FROM ALOFT. THE TOP-DOWN METHOD USING BOTH THE NAM  
AND GFS INDICATED LIQUID PRECIPITATION FOR ALL THE FORECAST AREA.  

[packfan98]

We often see storms show up in the LR and then go away and then come back.  This can be due to several factors, but the strength of the shortwave that causes the storm to spin up is one of the most important.  Many times, the reason storms show up, then vanish, then show up again is because the energy in question travels through data void areas.  Models underestimate the strength of the wave.  No storm.  The wave emerges, gets sampled better, and viola, you have a storm again.

 

This isn't a new phenomenon.  It happens a lot.  We just don't care most of the time because we usually don't track rain events.

 

Of course, other things like PV placement, strength, orientiation, direction of the flow, speed of the flow etc. matter as well.

 

If our shortwave is stronger than the current "thinking" by the models, changes can absolutely occur.  We should start to see those by tomorrow, I would guess, if they are to happen.

 

I'm not wishcasting with this post either, because I think my area will be mostly rain, if we end up with a decent system.  We want to see the shortwave appear stronger after it's better sampled, as it will have a better time holding together.  We'll see.

 

Great post CR!

[tarheelwx]

you do realize we arent just pulling this out of thin air right?  rah mentioned it in their morning disco.  

Of course.  I've heard it for years.  I'm just saying that you mostly hear it when something starts fading, and we're hoping for a reversal.  Usually the new sampling data comes in and there is little significant change to the models.  There have been a few exceptions and hopefully this one is different from the norm.   

TW

[toxictwister00]

We often see storms show up in the LR and then go away and then come back.  This can be due to several factors, but the strength of the shortwave that causes the storm to spin up is one of the most important.  Many times, the reason storms show up, then vanish, then show up again is because the energy in question travels through data void areas.  Models underestimate the strength of the wave.  No storm.  The wave emerges, gets sampled better, and viola, you have a storm again.

 

This isn't a new phenomenon.  It happens a lot.  We just don't care most of the time because we usually don't track rain events.

 

Of course, other things like PV placement, strength, orientiation, direction of the flow, speed of the flow etc. matter as well.

 

If our shortwave is stronger than the current "thinking" by the models, changes can absolutely occur.  We should start to see those by tomorrow, I would guess, if they are to happen.

 

I'm not wishcasting with this post either, because I think my area will be mostly rain, if we end up with a decent system.  We want to see the shortwave appear stronger after it's better sampled, as it will have a better time holding together.  We'll see.

 

I wish I could like this post because I agree 100%. I know the phrase about models haven't properly sampled the data where the pieces of energy is gets cliche and overused a lot, but in some small cases that can be true. We'll certainly know by the 00z suite tomorrow night at the latest. (I hope) lol

[fountainguy97]

Btw check out the 500mb charts the rgem just spit out. Tons of northern stream phasing and almost neg tilt over texas

[Shawn]

Btw check out the 500mb charts the rgem just spit out. Tons of northern stream phasing and almost neg tilt over texas

 

Hm.  From weatherbell.

 

[Jonathan]

CMC is VERY interesting with the northern stream interaction in VA/NC..

[DopplerWx]

also, the euro has gone from DOA in havana yesterday to the central gulf at 12z.  still suppressed but small changes from run to run.

[Brick Tamland]

Need deltadog to chime in here. He's also saying it's trending north.

[superjames1992]

RGEM is VERY interesting with the northern stream interaction in VA/NC..

I_nw_EST_2016011412_072.png

 

I think that's the regular Canadian which did show some NC/VA snow (and was a big shift since yesterday along with the Euro and one reason I don't see any reason to give up), but the 12z RGEM at hr 48 was interesting at h5.

 

I'd also add that the JMA (LOL) has shifted north towards the other modeling some, as well.

[DopplerWx]

Need deltadog to chime in here. He's also saying it's trending north.

yea his 500mb vort map was very telling. 

[Jonathan]

I think that's the regular Canadian which did show some NC/VA snow (and was a big shift since yesterday along with the Euro and one reason I don't see any reason to give up), but the 12z RGEM at hr 48 was interesting at h5.

Crap, you're right. Just a different website. My bad!

Does the RGEM go past 48hr on any site?

[ozmaea]

I see the gfs has a little energy for the nc/sc area anyone else seeing that or should we ignore it because its the gfs

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[superjames1992]

Crap, you're right. Just a different website. My bad!

Does the RGEM go past 48hr on any site?

 

The RGEM only goes out to hr 48 for the 00z and 12z runs while the 06z and 18z runs go out to hr 54.  Unlike the NAM, they only run the model when it's in its wheelhouse and don't run it out to hr 84 when things start getting nuts, haha.

[packfan98]

Crap, you're right. Just a different website. My bad!

Does the RGEM go past 48hr on any site?

The 6z and 18z goes to hr54.  The next run should be telling!

[SnowGoose69]

FYI the RGEM is typically amped at 42-54 hours...inside 36 it becomes more reliable, inside 24 very good.

[packfan98]

FYI the RGEM is typically amped at 42-54 hours...inside 36 it becomes more reliable, inside 24 very good.

 

Thanks for the heads up. 

[burgertime]

Something to keep in mind is that the NAM is going to best product to use in the short range in the US due to how much data it can sample. If it shows the vort slowing down once it's sampled then I'll be ready to throw in the towell. 

[PackGrad05]

This thing keeps reeeeeling everyone in.