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Pattern Microwave March

Webberweather53 said:
If there's one area on the globe where models will preferentially struggle w/ the MJO, it's would be the entrance into the Maritime Continent (transition between phases 3-4). Traditionally, models have a dry bias over the Maritime Continent that's due in part to the disruption of the wind-induced surface heat exchange (WISHE), (one of the primary processes that drives the MJO over the Pacific/W Hem & Indian Ocean)), and the model's misrepresentation of the regional-scale, diurnally excited circulation, and quasi-stationary potential vorticity generation downstream of the topography in Sumatra, Borneo, and Papua/New Guinea that feedbacks onto the eastward propagating MJO wave. I also suspect lower frequency interference from ENSO is also contributing to these massive errors in the models' MJO forecast in the past several days.
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This dry bias in the Maritime Continent may not seem important to the average individual, however errors here teleconnect to North Pacific & North America. Look no further than the recent ECMWF run wherein the model was correctly initialized w/ considerably more intense convection/precipitation northeast of the Maritime Continent. This increase in convection during the 12z initialization of the ECMWF resulted in a stronger/more amplified ridge in the far North Pacific that augmented the northern stream disturbance over SE Canada & forced it further SE, and ultimately led to a snowstorm in the Carolinas by day 6-7 by squashing the disturbance sliding to the south of the vortex. If you really breakdown tropical telconnections w/ our sensible weather into its most basic components, enhanced convectively-induced heating anomalies over the tropics generate rossby wave trains that modify the waveguide (jet stream) & pre-existing mid-latitude disturbances, which can thereby also feedback and further excite attendant tropical convection by preferentially "breaking" at different regions of the tropics
 
H/t to Paul Roundy for pointing out this discrepancy... Pretty huge increase in convection on this ECMWF run northeast of Papua/New Guinea...

Hopefully this clears up any confusion on what I was referring to in my last few posts & the implications of tropical convection on extratropical rossby wave trains.
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The CMC Model have also trend South, this could be a Mid Atlantic Special, I think for us here in South Carolina it would take a lot of work for this to work out for us here in KCAE!!!
 
0Z Euro, not surprisingly, is further NW with no snow at least on the frontside for NC and the heavy snow centered about 200 miles north of the 12Z's location giving Richmond and DC a big snow (6-9"). Let's see what the 0Z EPS shows.

Edit: After the storm and a warmer day 1-6., it is colder day 7-10 vs the 12Z Euro.
 
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Well, what do you know?! The 0Z EPS mean is actually just as cold as the 12Z EPS mean, if not a tad colder, in NC during the potential storm. The 0Z snow mean is actually higher than what the 12Z EPS mean showed in NC. This just got more interesting for at least the time being. Also, the 0Z EPS is signficantly colder than the 12Z EPS over the SE 3/13-4 behind this storm. Keep in mind that the 12Z was significantly colder than yesterday's 0Z EPS.
 
After looking at the runs this morning, maybe we have a legit threat this time for North Carolina. Sadly, I don't see this coming further south unless I see a low go further south or another part of the weather pattern do something unexpected. Yes, the Euro went north a bit, but if it comes back south, I would think snow is a possibility in NC. The GFS and CMC show it, but we all know how we have been deceived before. However, since it is in a shorter range, and the Euro picked up on it initially, the models may be onto something. Aren't we near the range of the UKMET also?
GaWx said:
Well, what do you know?! The 0Z EPS mean is actually just as cold as the 12Z EPS mean, if not a tad colder, in NC during the potential storm. The 0Z snow mean is actually higher than what the 12Z EPS mean showed in NC. This just got more interesting for at least the time being. Also, the 0Z EPS is signficantly colder than the 12Z EPS over the SE 3/13-4 behind this storm. Keep in mind that the 12Z was significantly colder than yesterday's 0Z EPS.
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Yep, the EPS is colder, but actually if you look at the 162 frame, it is far colder and the 0C 850 line is down to NC in that run rather than the 12Z where it was way north by hundreds of miles.

Also, doesn't the GFS look like a Miller B system? Maybe we are progressing toward one at least.
 
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>50% of ensemble members have snow. I feel like I've seen this song and dance before...given track of the system, RDU will thread the needle here and it may end up being a central VA type system much like the 00z Euro. We'll see, but at least trends in the GFS and EPS means are nice.

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Jon said:
>50% of ensemble members have snow. I feel like I've seen this song and dance before...given track of the system, RDU will thread the needle here and it may end up being a central VA type system much like the 00z Euro. We'll see, but at least trends in the GFS and EPS means are nice.




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Holy chit I didnt expect to see that
 
NWMSGuy said:
I see SPC has a new Day 6 threat area highlighted. Any thoughts?
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I'm interested in it with the surface low passing just to our NW no doubt we will have better dynamics


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Storm5 said:
I'm interested either surface low passing just to our NW no doubt we will have better dynamics


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South of whatever stalled front there is the warm sector should be in the 65-80 degree range with dew points well into the 60s. Pretty good setup for severe IMO
 
The southward shifts continue on the GFS. Definitely headed in the right direction for the Carolinas... Need a lot more where this came from.
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Webberweather53 said:
The southward shifts continue on the GFS. Definitely headed in the right direction for the Carolinas... Need a lot more where this came from.
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Let's hope it keeps going south. Maybe if it does, the MA won't get any :D. If we see this trend continue for about another 100 - 200 miles, it very well may become a Miller B in my opinion. Given that the MJO did what the models didn't expect it to, maybe it will. Hopefully someone can get something out of it, assuming it occurs.
 
0z EPS certainly has piqued my interest but we really need this thing to shift much further south to over compensate for the inevitable 11th hour NW shift....

Love Webbs post above about the W. Pac convection, Rossby wave train forcing the Canadian vortex SE, good stuff right there! Can March pull a rabbit out of the hat?????
 
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