January Pattern and Storm Discussion II

[WilkesboroDude]

 

Image credit and source: Brad Panovich

[beanskip]

Would take it in a heartbeat.

 

 

 

Image credit and source: Brad Panovich

[valkhorn]

 

Image credit and source: Brad Panovich

 

 

Honestly, I think I'm going to wait until this gets within 84 hours to see what the NAM says. Lately, the Euro has been overdoing every single snow in our area. The NAM nailed the last snow for our area, except for NC

[sparkync]

Would take it in a heartbeat.

[BIG FROSTY]

FWIW--- DT posted this

 

 

Wxrisk.com

 

‎*** ALERT *** 12Z EURO ENSEMBLE goes WOOF .. and has has come out... and STRONGLY support the more SOUTHERN track of the JAN 24-25 LOW trough KY and into NC ... In Fact the Euro ensemble mean is a bit snowier than the operational or REGULAR euro model

[eyewall]

I am not buying into this just yet. Especially in a cold air chase scenario. We would need the low to track through SC at least.

[beanskip]

Hmmm --- you think it's a chase? When I looked at Plymouth 850s -- they were well below 0c at Day 4, right before precip arrived -- the 0C line ran NW to SE along the NC/SC line with -4's well down into NC. If that is CAD, you'd think it would hang in longer than shown (usually does). Still, no doubt that a more southerly track would be helpful.

I am not buying into this just yet. Especially in a cold air chase scenario. We would need the low to track through SC at least.

[deltadog03]

he sure does a lot of woofing.....lmao

[eyewall]

Hmmm --- you think it's a chase? When I looked at Plymouth 850s -- they were well below 0c at Day 4, right before precip arrived -- the 0C line ran NW to SE along the NC/SC line with -4's well down into NC. If that is CAD, you'd think it would hang in longer than shown (usually does). Still, no doubt that a more southerly track would be helpful.

 

 

There will be CAD in place for sure but I suppose I meant in getting the column entirely cold enough for something other than ZR or IP. There is a reinforcement of cold air behind the front which is what I meant by the chase. THe GFS is obviously painting more of the FROPA scenario with the 850 line staying NW until the precip exits. I know people are excited because it is the Euro but we don't have a good consensus at this time is what I see.

[BIG FROSTY]

he sure does a lot of woofing.....lmao

 

Yea he like to woof ever chance he gets! lol. I just posted because he was talking about the ensemble's most always wondering what they show..

[superjames1992]

DT did mention that this clipper is most likely going to be an Alberta clipper. He showed a analog date that is similar to what models are projecting. 

 

Here is the date mentioned:

 

 

Wasn't that the infamous 1/2" that brought Raleigh to a standstill? 

 

Anyways, the Euro is certainly interesting.  Verbatim, it looks like a decent shot for those north and west of the I-40/I-85 corridor.  We've seen that one before, eh?

[GaWx]

I am not buying into this just yet. Especially in a cold air chase scenario. We would need the low to track through SC at least.

 

 Further south in the ATL-AHN and the bulk of nonmountainous N GA areas, I'm giving the chance for sig. S/IP out of this as under 5%. The modeled tracks for all runs have been so far off the type of track this area generally needs for the best shot at something significant. That track is a Miller A through the N GOM and then across the N FL pen. or through SE GA/along the coast.

 

 However, I'm a bit more interested in sig. ZR chances based on the climo I mentioned in a post I just did. Whereas I still think these chances are pretty low for the bulk of N GA due to a lack of modeled threats, I don't think it would take nearly as big of an adjustment to get a good tracking Miller B and attendant strong wedging ahead of it as it would a Miller A tracking through the N GOM.. Therefore, I'm currently going with about a 20% chance for sig. ZR for a good portion of the CAD favored areas of N GA from this 1/25ish system.

[JWXnc]

Wasn't that the infamous 1/2" that brought Raleigh to a standstill? :lmao

Nope, I think the infamous 1/2" was January 19, 2005 -- a separate event where the temps were in the mid 20s at lunchtime when it started snowing. The Jan 20th event was a midnight-ish/overnight event.

[eastkywx]

I'm not liking being the "bullseye" from this far out.  Eastern KY is normally jam packed with snow during the winter months but the past 3 years have been a HUGE disappointment.  With the way things have gone, I expect more of a GFS track than the Euro.

[packbacker]

I'm not liking being the "bullseye" from this far out.  Eastern KY is normally jam packed with snow during the winter months but the past 3 years have been a HUGE disappointment.  With the way things have gone, I expect more of a GFS track than the Euro.

 

I thought E-KY had multiple snow events in a 10 day period around Xmas?

[beanskip]

I see -- and agree. Honestly, I don't have too much more faith in the Euro than any of them right now. It's definitely shown some kamikaze solutions the past few weeks -- I fully expect the 0z run to trend back to the north.

There will be CAD in place for sure but I suppose I meant in getting the column entirely cold enough for something other than ZR or IP. There is a reinforcement of cold air behind the front which is what I meant by the chase. THe GFS is obviously painting more of the FROPA scenario with the 850 line staying NW until the precip exits. I know people are excited because it is the Euro but we don't have a good consensus at this time is what I see.

[eastkywx]

I thought E-KY had multiple snow events in a 10 day period around Xmas?

Just the higher terrain along the Virginia border.  Most events that have occured this Winter have all been at elevations above 2000 ft.  Valley locations haven't seen much of anything.  I've had one snow of 1.5" so far this year.  Other than that, not even a dusting.

[packbacker]

The 12z Euro has the low in southern TN at day 4 and the 12z GFS has the low in northern KY....I am guessing that roughly 200 miles.  A good bet though is that  this event will fall somewhere in the middle which probably leaves most of NC out of it, except maybe the mountains.

 

And there respectives Ens agree...

 

12z Euro....

 

 

 

 

12z GFS

 

[mackerel_sky]

The euro solution does have a good CAD signature to it.I guess the timing of the arrival of the precip could make a big difference.what time of day are they showing the precip getting here?

[WilkesboroDude]

The euro solution does have a good CAD signature to it.I guess the timing of the arrival of the precip could make a big difference.what time of day are they showing the precip getting here?

 

NWS Blacksburg

 

 

The next and bigger concern arises at the very end of the short term period...going into the long term period. The 12z European model (ecmwf) has come into line with the 12z GFS/Canadian/UKMET showing a slower arrival of the next upstream and much stronger more phased northern/southern stream system. This will allow temperatures to drop well below freezing in all areas again Thursday night before the thicker clouds start to spread in from the west. Dewpoints will remain very low with a departing Arctic air mass still in place. This will further play in to the potential for a strong wedge to begin to develop early Friday and further enhance the threat for winter precipitation. Expect warm air advection induced precipitation to reach the County Warning Area in the 08z-12z time frame Friday morning. At this point...model soundings suggest that the precipitation will begin as all snow in the western areas...and then begin to transition to a snow/ip/-fzra mixture toward daybreak. The more substantial amounts of precipitation will definitely be after 12z Friday and are dealt with in the long term section. For now...have advertised snow accumulations up to 1/2 inch in the western parts of the County Warning Area...but could easily see the amounts going upward toward 1 to 2 inches with later packages for the western areas. 

[Marion_NC_WX]

The euro solution does have a good CAD signature to it.I guess the timing of the arrival of the precip could make a big difference.what time of day are they showing the precip getting here?

Friday afternoon/evening.

[MillerA]

GSP disco:

 

 

Long term /Friday through Monday/... as of 245 PM Monday...between 0z to 12z Friday...both the GFS and European model (ecmwf) indicate that surface low pressure will advance from the Central Plains to middle KY/TN. As the low approaches...SW low level flow will increase from 15 kts at 0z to 40 kts at 12z...resulting in rapid warm air advection across the southern Appalachians. The GFS indicates a 10 degree rise in 850 mb temperatures...the European model (ecmwf) indicates around 5 degrees rise. Moisture and isentropic lift will gradually increase across the County Warning Area early Friday morning...especially across the mountains and foothills. The arrival of thick clouds and warm air advection should result in a pre midnight low temperatures...followed by steady to slowly rising temperatures. Based on forecast soundings...most areas should receive a cold rain. However...the combination of lingering freezing temperatures north of I-40...with a pronounced warm nose at 850 mb should result in a period of freezing rain. A light accumulation of freezing rain is possible across portions of the northern mountains low level SW flow will likely increase through the daylight hours Friday...with 850 mb temperatures reaching 50 kts between 18z Friday to 0z Sat. 850 mb temperatures continue to warm through the day...ranging from 7c across the upper Savannah River valley to 5c across the Tennessee line middle Friday. The degree of warm air advection should support highs in the u40s mountains to l50s east. Rain will continue along and ahead of the cold front through Friday afternoon. 

[WilkesboroDude]

NWS Blacksburg 2nd Paragraph:

By most models...a wave of low pressure will track over the Ohio

Valley Friday to the northern middle Atlantic Friday night. The

trailing cold front will move from the Ohio Valley Friday morning to

the coastal Piedmont Friday evening. Precipitation associated with

the front will be moving into drier air. Therefore...sleet may fall

as initial p-type Friday morning. Warm air surging in on a 60 knots

southwesterly jet ahead of the front should change sleet over to

rain for at least weather forecast office Blacksburg southern half. To the

north...lingering sub-freezing temperatures poses more of a problem

with p-type. Initial precipitation will likely start out as

snow...then warm air aloft may switch p-type to sleet and/or rain.

Cold pockets in sheltered valleys could very well have freezing rain

Friday morning. If this low tracks as models suggest...p-type issues

will be confined to the morning hours. This was the thinking prior

to the 12z ecm. The 12z ecm tracks the low farther to the south.

This scenario would lead to colder temperatures linger longer into

the day...then followed by even colder temperatures once the front

exits the area. The colder ecm would bring more chances for snow

across the north and p-type issues across the south. Since the ecm

deviated from previous runs/models...will label it as an outlier.

[beanskip]

FWIW  (and based on the last event, not a damned thing) the 18z NAM is way, way, way farther north with all the relevant players on the field.

[mackerel_sky]

Doesn't sound to promising from GSP.

GSP disco:

Long term /Friday through Monday/... 
as of 245 PM Monday...between 0z to 12z Friday...both the GFS and 
European model (ecmwf) indicate that surface low pressure will advance from the Central 
Plains to middle KY/TN. As the low approaches...SW low level flow will 
increase from 15 kts at 0z to 40 kts at 12z...resulting in rapid warm air advection 
across the southern Appalachians. The GFS indicates a 10 degree rise 
in 850 mb temperatures...the European model (ecmwf) indicates around 5 degrees rise. Moisture 
and isentropic lift will gradually increase across the County Warning Area early 
Friday morning...especially across the mountains and foothills. The arrival of 
thick clouds and warm air advection should result in a pre midnight low 
temperatures...followed by steady to slowly rising temperatures. 
Based on forecast soundings...most areas should receive a cold rain. 
However...the combination of lingering freezing temperatures north 
of I-40...with a pronounced warm nose at 850 mb should result in a 
period of freezing rain. A light accumulation of freezing rain is possible across 
portions of the northern mountains low level SW flow will likely increase through 
the daylight hours Friday...with 850 mb temperatures reaching 50 kts between 18z 
Friday to 0z Sat. 850 mb temperatures continue to warm through the day...ranging 
from 7c across the upper Savannah River valley to 5c across the Tennessee 
line middle Friday. The degree of warm air advection should support highs in the u40s 
mountains to l50s east. Rain will continue along and ahead of the cold 
front through Friday afternoon.

[WilkesboroDude]

FWIW  (and based on the last event, not a damned thing) the 18z NAM is way, way, way farther north with all the relevant players on the field.

 

I don't look at the NAM for 5+ day threats. It is better 1-2 days out IMO.

[burgertime]

It's just very hard to get excited about a low coming through TN. Just check the Euro EPS control run and it does shift snow south of I-40....guess we will wait and see. 

[packfan98]

I believe that the euro ensembles are in agreement with the operational run. Could be a southern trend to watch over the next 48 hours. I have a feeling it won't hold. The main thing to watch is that push of arctic air and how far south it gets and it's staying power. One would think any low would track along the boundary of the arctic air instead of plowing straight in to it.

Ok the euro sucked me back in to another week of model watching. Grr!

[burgertime]

I don't look at the NAM for 5+ day threats. It is better 1-2 days out IMO.

 

Uh read what he said. He has been around for a longer than you, he knows when to take the NAM serious. 

[packbacker]

FWIW  (and based on the last event, not a damned thing) the 18z NAM is way, way, way farther north with all the relevant players on the field.

 

Well if we can get a repeat of what happened last week (which isn't likely) with the NAM at this range than everyone will be happy :-).  The NAM had the low tracking to Ohio last week at this range and of course it end up tracking down the border of NC/SC.