January Pattern and Storm Discussion II

[valkhorn]

Text extraction says all rain for hickory and charlotte. well that excitement was fun while it lasted.  

Knoxville gets shafted on that run with no precip but cold air. Join the club.

[BullCityWx]

One thing the GFS had tonight was about 48 continuous hours of below freezing air across the Western Piedmont and Foothills.

[BullCityWx]

Hey y'all, I started a thread regarding the next event seeing as it looks like it could be a decent sized event somewhere in the south. If we could keep the posts about that event in that thread and talk about the arctic blast in this thread, I'd appreciate it   

[Marion_NC_WX]

Hey y'all, I started a thread regarding the next event seeing as it looks like it could be a decent sized event somewhere in the south. If we could keep the posts about that event in that thread and talk about the arctic blast in this thread, I'd appreciate it 

 

 

You usually bring good mojo for us, glad you officially started the thread.

 

 

BTW, -18 850's IMBY @ 192 is going to be a kick in the pants after what little cold weather we have seen so far.

[griteater]

CMC has -20C 850mb temps in Atlanta at hr204

[BullCityWx]

CMC has -20C 850mb temps in Atlanta at hr204

 

I dont know whats more impressive...the cold that builds or the clipper that digs to central mississippi.

[griteater]

From the Jan 14 weekly MJO update from CPC/NCEP...

• The MJO remained active over the past week with rapid propagation from the Maritime continent into the western Pacific.

• Dynamical and statistical model MJO index forecasts are only in fair agreement this week, with some dynamical forecasts, namely the GFS and Canadian ensemble means, limiting eastward propagation during the period. The statistical tools and other dynamical model forecasts maintain eastward propagation into the western Hemisphere.

•Based on the latest observations and MJO index forecasts, the MJO is forecast to remain active and propagate across the western Pacific over the next two weeks.

•The MJO is expected to contribute to enhanced (suppressed) convection across the western and central equatorial Pacific (Indian Ocean and western Maritime Continent) during the period. Tropical cyclogenesis remains favored for portions of the southwest Pacific.

•The MJO favors an increased likelihood for below-normal temperatures for parts of the central and eastern U.S. during the last 7-10 days of January into early February. Drier-than-average conditions are also favored for portions of the western U.S.

[DaculaWeather]

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

 

 

EXTENDED FORECAST DISCUSSIONNWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD1247 AM EST TUE JAN 15 2013VALID 12Z FRI JAN 18 2013 - 12Z TUE JAN 22 2013OVERVIEW...AN AMPLIFIED RIDGE/TROUGH PATTERN ACROSS THE CONUS SHOULD HOLDTHROUGH THE MEDIUM RANGE PERIOD. THE MODELS/ENSEMBLES HAVE WAVEREDON HOW MUCH AND WHEN THE ARCTIC AIR ASSOCIATED WITH THE CANADIANVORTEX /OR ENERGY ROTATING AROUND IT/ WILL INVADE AT LEAST THENORTHERN TIER BUT THE THEME HAS BEEN CONSISTENT. THE COLD/DRYAIRMASS WILL GENERALLY INHIBIT PRECIPITATION COAST-TO-COAST EXCEPTFOR NEAR THE GREAT LAKES AND SOUTHEAST.

 

SENSIBLE WEATHER...THE TEMPERATURE TREND EAST OF THE DIVIDE WILL BE DOWN NEARLYEVERYWHERE... WITH FLORIDA AND SOUTH TEXAS THE LAST HOLDOUTS ASTHE ARCTIC FRONT PUSHES SOUTH AND EAST INTO EARLY NEXT WEEK. MOSTLOCATIONS NORTH OF 30N SHOULD DIP BELOW FREEZING BY TUE/D7 WHILESUBZERO TEMPERATURES SHOULD BE CONFINED TO THEDAKOTAS/MINNESOTA/WISCONSIN/MONTANA... AS WELL AS NORTHERN MAINE.THE WEST SHOULD BE NEAR TO ABOVE NORMAL EXCEPT IN THE MOUNTAINLOCATIONS TRAPPED UNDER AN INVERSION.

[DaculaWeather]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
416 AM CST TUE JAN 15 2013

.SYNOPSIS...
A VERY COMPLEX FORECAST IS UPON US WITH AN OMEGA BLOCK PATTERN SETUP
OVER THE WESTERN HEMISPHERE. ACROSS NORTH AMERICA, A STALLED
AMPLIFIED LONGWAVE TROUGH AXIS SITS FROM THE SOUTHERN PLAINS TO
CANADA WITH A STRONG SW JET ATOP MUCH OF EASTERN NORTH AMERICA. IN
ADDITION, AN ARCTIC FRONT IS CURRENTLY STALLED JUST TO THE SOUTHEAST
OF THE TN VALLEY. THE PROGRESSION OF THIS TROUGH AXIS OVERRUNNING AN
ARCTIC AIRMASS WILL DICTATE THE WEATHER (FROZEN AND/OR LIQUID)
THROUGH THURSDAY. WINTER WEATHER AND FLOODING WILL BE THE MAIN
IMPACTS FOR THIS FORECAST WITH RIVER FLOODING ALREADY DEVELOPING AND
EXPECTED TO LAST INTO THE WEEKEND (WITH THE LIKELIHOOD OF MORE
RIVERS RESPONDING TO THE HIGH AMOUNT OF RUNOFF FROM RAINFALL OVER THE
PAST 5-6 DAYS).

[JJJAckson]

Dallas reporting snow and WWA have gone up for the DFW metroplex in the last hour. 

[metalicwx366]

Dallas reporting snow and WWA have gone up for the DFW metroplex in the last hour.

That's the 4th winter event they have seen this winter.

[toxictwister00]

I love the observation coming from Dallas Love Field.

 

 

04:53 Light Small Hail/Snow Pellets Snow 35 19 52 N 8 30.20

[Srain]

Just a heads up for you folks. Conditions are deteriorating quickly across N Central and E Texas this morning. Once again the models have under estimated the short wave progressing E across Northern Mexico and there are some indications that a negative tilted 5H low will develop that was not modeled. Just something to keep an eye on today. College Station in Northern SE Texas is reporting freezing rain at this hour as well.

[EmersonGA]

Funny things always happen under these lows, it seems. I can remember a low a few years ago in a similar situation that produced a heavy wet snow in SE GA.

I think that storm was in November if I recall correctly.  It also produced some sleet down in Orlando.

[buckeyefan1]

Just a heads up for you folks. Conditions are deteriorating quickly across N Central and E Texas this morning. Once again the models have under estimated the short wave progressing E across Northern Mexico and there are some indications that a negative tilted 5H low will develop that was not modeled. Just something to keep an eye on today. College Station in Northern SE Texas is reporting freezing rain at this hour as well.

I'm hearing reports of thundersnow  Congrats to those getting in on the surprise this morning!  Nice little short wave showing up in the link below   

 

http://www.goes.noaa.gov/GSSLOOPS/ecwv.html

[burgertime]

I'm hearing reports of thundersnow  Congrats to those getting in on the surprise this morning!  Nice little short wave showing up in the link below  

 

http://www.goes.noaa.gov/GSSLOOPS/ecwv.html

 

Pretty amazing on that WV loop you can see the driving energy behind that system. 

[tnweathernut]

Pretty amazing on that WV loop you can see the driving energy behind that system. 

What you can also see is the lack of a push of the front as little ripples ride up the stalled boundry through east TN.  It's forecasted to finally push east of our area, but looking at that water vapor you can already see the building plume of clouds in response to the energy coming through the southwest. 

 

I am going to go out on a limb and say this system will indeed be more NAM like, then suppressed as shown on much of the modeling of the last few days.  12z should be fun today.

[Stormsfury]

I think that storm was in November if I recall correctly.  It also produced some sleet down in Orlando.

It was November 21, 2006 which also produced the first ever report of thundersnow at KCHS.   

I'd link the map of it, but the KCHS website is in the process of integrating to their new site.  

[GreensboroWx]

Strong vorts like this one are nearly ALWAYS trouble for models to resolve. If you look at the current wx in the Dallas area versus what the NAM has currently, it is WAY off. 

 

I think this bowling ball low will produce great for some.

[DaculaWeather]

Almost every MJO graph has it rapidly moving it into Phase 8 very soon. 

 

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

 

[GreensboroWx]

Almost every MJO graph has it rapidly moving it into Phase 8 very soon. 

 

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

 

 

We'll we have nearly everything we need now.....+PNA, -NAO, -AO, and a favorable MJO. Hopefully, all of this hurry up and wait will pay off soon!!

[Cold Rain]

We'll we have nearly everything we need now.....+PNA, -NAO, -AO, and a favorable MJO. Hopefully, all of this hurry up and wait will pay off soon!!

I'd like to see a wetter pattern to go along with it. Not seeing a lot of evidence of it in the modeling, but that's not to say something won't show up on the next cycle. I'm feeling good about the cold, though, which is something that I haven't been able to say in a long, long time.

[buckeyefan1]

Has anyone shared this yet from WxSouth/Foothills? I really hope this trend continues this time around.

 

 

 

 
Here's a look at the Arctic Oscillation. Last Winter was almost totally positive, above zero. But since Sandy, it's been strongly negative. This makes a negative October, November, December and almost positive that January will be negative as well. In my study on the correlation between Southeast Winter Storms and the Negative AO, I concluded that in the end, having 3 consecutive months of negative AO will end up producing ABOVE average snow and ice across a good chunk of the upper South/Mid South and lower MidAtlantic regions. Now it looks like models are catching on to this, as some serious Arctic air will going to come down next week, then likely the week after that, meanwhile the storm track could be from the Northwest, across the lower Plains and into the Southeast. So my area of above normal snowfall would be northern sections of Mississippi, Alabama, Georgia and SC. And much of NC, and Virginia. If you believe in statistics, it's hard to ignore these facts. I stand by this study and if it fails, it would be the only time that I can see where the negative AO didn't produce. Guess we will see by season's end.

He made a thread about this already 

 

http://www.americanwx.com/bb/index.php/topic/38742-negative-ao-winters-almost-always-end-up-snowy-in-southeast/

[Brick Tamland]

Oops, sorry. Not sure what happened to my post. But I really hope that trend that WxSouth talked about continues this winter.

[DaculaWeather]

SSW Update

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

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

 

All of the upper levels are now cooling, but all of the lower levels are warming, which would say that the SSW is doing a good job at disrupting the stratosphere. 

 

From this table, you can see winds are east to west from 20 hPa to the top and very slow, they are west to east from 30 hPa down with a little more speed.

 

 

We still have positive pressure anomalies and expect to see those ebb and flow as the strat tries to return to some stability after being torn apart. 

 

[GaStorm]

Oops, sorry. Not sure what happened to my post. But I really hope that trend that WxSouth talked about continues this winter.

I saw your post before it got removed. Some really good info about the -AO and winter storms in the SE. Hope it works in our favor soon.

 

Edit: Look at buckeyefan1's response above.

[Brick Tamland]

I saw your post before it got removed. Some really good info about the -AO and winter storms in the SE. Hope it works in our favor soon.

 

Edit: Look at buckeyefan1's response above.

 

I'll try again for others. It's really good stuff, and WxSouth just posted this on his facebook page recently.

 

 

Here's a look at the Arctic Oscillation. Last Winter was almost totally positive, above zero. But since Sandy, it's been strongly negative. This makes a negative October, November, December and almost positive that January will be negative... as well. In my study on the correlation between Southeast Winter Storms and the Negative AO, I concluded that in the end, having 3 consecutive months of negative AO will end up producing ABOVE average snow and ice across a good chunk of the upper South/Mid South and lower MidAtlantic regions. Now it looks like models are catching on to this, as some serious Arctic air will going to come down next week, then likely the week after that, meanwhile the storm track could be from the Northwest, across the lower Plains and into the Southeast. So my area of above normal snowfall would be northern sections of Mississippi, Alabama, Georgia and SC. And much of NC, and Virginia. If you believe in statistics, it's hard to ignore these facts....I stand by this study and if it fails, it would be the only time that I can see where the negative AO didn't produce. Guess we will see by season's end.

[Marion_NC_WX]

this is going to be a shock to the system next week...

 

[tnweathernut]

There are a lot of impulses in the flow to the northwest in Canada, but we are losing our PNA toward truncation on the 12z GFS. It will be interesting to see if we can score a clipper here in the midsouth to NC in the coming 10 days.

[ncwinterwxman]

Yeah...I was just looking at that...if you look at the 00Z Canadian, it was trying to hold a piece together toward the end of its run for the mid-south region but then lost it toward the end of the run.  I really like the CMC's representation of the pattern for next week as I think it has a much better handle on the cold pattern that is coming vs. the ECMWF and GFS.  It will be interesting to see which model verifies. 

There are a lot of impulses in the flow to the northwest in Canada, but we are losing our PNA toward truncation on the 12z GFS. It will be interesting to see if we can score a clipper here in the midsouth to NC in the coming 10 days.