February Pattern and Storm Discussion

[Snowless in Carrollton]

Well, unfortunately, I don't see any legitimate winter threats over the next 10 days. Am I wrong on that?

Edit: What a complete load of crap the next two weeks look like.

Don't worry. GaWx says March could be a blockbuster month with much better than normal chances for snow.

[SnowNiner]

I hope it would, although the MJO pulse rocketing around into phase 5 and kinda hanging out favors an Ohio Valley storm track I believe, which is what the models are showing.

I also think the proximity these storms are to each other keeps anything from really digging in and giving us a Miller A type scenario. Somebody can weigh in if I'm incorrect.

 

I think the lake cutters on the models are being caused because of the -PNA, the troughs are in the wrong spot.  If we get a +PNA and we get a nice tall ridge in California/Rockies we won't get the cutters.  I don't think MJO plays that significant of a role....if we truly get a -NAO / +PNA period.  Eastern trough with good blockiness wins out IMO. 

 

But yeah, the next 10 days look pretty bad.  First week of March is our probably last hope.  I've got my fix though with the quick 3 inches.  I could get picky and say it didn't stick to the roads (pet peeve) and still haven't gotten over 4 inches in CLT for 9 years but, Sat will hold me off till next year if need be.  It would be nice to get one widespread storm this year to get everybody in on the action.

[GaWx]

I hope it would, although the MJO pulse rocketing around into phase 5 and kinda hanging out favors an Ohio Valley storm track I believe, which is what the models are showing.

I also think the proximity these storms are to each other keeps anything from really digging in and giving us a Miller A type scenario. Somebody can weigh in if I'm incorrect.

 

 I'd say you're not correct about the MJO. I don't know whether or not you read and recall my MJO posts from about five days ago that debunk the myth that the MJO has predictive power regarding major SE US winter storms. I analyzed the 21 major S/IP at KATL and/or KRDU since 1974 and pretty much proved that there is very little, if any, correlation (negative correlation) of the MJO "favorable" ("unfavorable") phases with major SE S/IP. A good number of posters, including at least one red tagger, agreed with my conclusion after seeing the data and my analysis of it. Furthermore, check out these major storms that were in phase 5, alone:

 

 

- 1/9-10/2011: started in 6 and went to 5

- 12/25-6/2010: 5

- 2/26-7/2004: 5

 

 These three were real doozies for some folks and there was obviously nothing Ohio Valley about them. Now, I'm not trying to say that phase 5 is favorable for major SE winter storms. I'm just saying that there is absolutely no indication that it is unfavorable in any way. The hard data totally supports that idea. The PNA, NAO, and AO are one thing. However, you might as well ignore the MJO phase when it comes to making winter storm predictions.

[Cold Rain]

I'd say you're not correct about the MJO. I don't know whether or not you read and recall my MJO posts from about five days ago that debunk the myth that the MJO has predictive power regarding major SE US winter storms. I analyzed the 21 major S/IP at KATL and/or KRDU since 1974 and pretty much proved that there is very little, if any, correlation (negative correlation) of the MJO "favorable" ("unfavorable") phases with major SE S/IP. A good number of posters, including at least one red tagger, agreed with my conclusion after seeing the data and my analysis of it. Furthermore, check out these major storms that were in phase 5, alone:

- 1/9-10/2011: started in 6 and went to 5

- 12/25-6/2010: 5

- 2/26-7/2004: 5

These three were real doozies for some folks and there was obviously nothing Ohio Valley about them. Now, I'm not tying to say that phase 5 is favorable for major SE winter storms. I'm just saying that there is absolutely no indication that it is unfavorable in any way. The hard data totally supports that idea. The PNA, NAO, and AO are one thing. However, you might as well ignore the MJO phase when it comes to making winter storm predictions.

Larry, you still confident about the end of Feb/early March? Good points, as usual, about the MJO stuff. I think there's quite a bit we don't yet know about it's influence, especially taking into account other background features that may be concurrently present.

[Southern Track]

I'd say you're not correct about the MJO. I don't know whether or not you read and recall my MJO posts from about five days ago that debunk the myth that the MJO has predictive power regarding major SE US winter storms. I analyzed the 21 major S/IP at KATL and/or KRDU since 1974 and pretty much proved that there is very little, if any, correlation (negative correlation) of the MJO "favorable" ("unfavorable") phases with major SE S/IP. A good number of posters, including at least one red tagger, agreed with my conclusion after seeing the data and my analysis of it. Furthermore, check out these major storms that were in phase 5, alone:

- 1/9-10/2011: started in 6 and went to 5

- 12/25-6/2010: 5

- 2/26-7/2004: 5

These three were real doozies for some folks and there was obviously nothing Ohio Valley about them. Now, I'm not trying to say that phase 5 is favorable for major SE winter storms. I'm just saying that there is absolutely no indication that it is unfavorable in any way. The hard data totally supports that idea. The PNA, NAO, and AO are one thing. However, you might as well ignore the MJO phase when it comes to making winter storm predictions.

Good input. Thank you.

[metalicwx366]

That is going to be miserable. I'd rather it just warm up and have some sunny and mild days now if all we're going to get the rest of winter is 40s and rain. I don't remember the last time we had a week of sunny days here.

That is going to be amazing. I don't remember the last time we had a week of wet weather along with mild temps. It's been the complete opposite here. Weeks of sunshine.

[GaWx]

Larry, you still confident about the end of Feb/early March? Good points, as usual, about the MJO stuff. I think there's quite a bit we don't yet know about it's influence, especially taking into account other background features that may be concurrently present.

 

 Thanks CR. Yeah, if over 30 years of actual hard SE winter storm data can't convince folks that there is very little correlation between them and MJO phases, then I'd think that nothing would ever be able to do that. So, I put the data out there. Fortunately, it got favorable responses as opposed to people still defending the MJO for this purpose. 

 By the way, in case you missed my post, the 2/16/13 snow, though not major for most, was significant for a good number in the Carolinas and it was in MJO phase 4, one of the supposed "unfavorable" phases.

 

 Regarding the end of Feb to mid March, it is just about time to sit back and see what happens. Climo for the type of winter we've had said to watch this period for a good bit better than normal potential for a ~1-2 week period of the coldest of the winter, overall, and/or 1-2 wintry wx events affecting a good number in the SE US sometime between the end of Feb. and mid March. Of course, even if that were to occur, you know as well as I do that there's no telling that there would be a widespread major SE winter storm included in the mix. We both know that that kind of thing is not predictable this far out in time since so many things have to be just right to make it happen. I don't think a major storm would be needed to make climo the winner here. However, at least there'd seemingly be some chance for even that based on climo. Here's the link to the thread about this that I started on 1/1:

 

http://www.americanwx.com/bb/index.php/topic/38633-rest-of-se-winter-best-by-far-yet-to-come-per-warm-decjan-analogs/

 

 

 Based on the current medium range modeling (I know it has sucked in general), I see zero reason to be discouraged at all at this still early stage. I know they're far from reliable, but the GEFS prediction for the PNA is +, the NAO is -, and the AO is - for late this month into early March. Furthermore, look at how cold the GFS and Euro ensemble mean is for 3/1-5. They are solidly below normal! Look at how warm they are for Canada, especially eastern Canada, which is indicative of excellent higher latitude blocking. So, whereas the medium range models are far from trustworthy, the upcoming indices and SE US temperature anomalies are just about as favorable looking as one would want to see at this early stage. It frankly doesn't get much better looking than that and I'm certainly enjoying seeing this. Keep in mind that the Euro ensemble, which generally doesn't have a cold bias and is about the best performing model guidance, currently looks solidly cold for 3/1-5.

[jmundie]

I'm with GAwx on this one. I have not seen modeling like what we're seeing in quite some time. That block in eastern canada means business, and it seems to strengthen with each run. The System for the end of the week looked to be a severe maker a few days ago, and now is much further south. There is potential for a monster if that block verifies. And damn it if I don't hate being hopeful in late february.

[Lookout]

There is no shortage of Rainfall on the GFS the next 15 days. If you prefer to chase cold rain then you'll love the next several weeks. Heres the 10 day. Next weekend looks wet on both ends.

 

The 0z and 06z gfs rainfall totals are insane here in ga. 0z shows over 10 inches through 192 and 06z shows over a foot of rainfall.  For all the talk of snow and winter weather...this is really a bigger deal with regards to flooding here...and in the upstate if this comes to pass. It is a long ways off and probably over done but the euro agrees with a lot of rainfall here.

 

The below images does not count the 1 to 2 inches in the first 96 hours

 

Even if it's  over done, we are looking at a lot of rain it would appear. New 12z gfs is showing 3 to  4 inches just through hour 126

 

0z gfs

 

06z gfs

 

 

[WXinCanton]

to this point, Lake Lanier is looking so much better as of late.   This comes to fruition and Lanier could be getting very close to full.

[Cold Rain]

Thanks CR. Yeah, if over 30 years of actual hard SE winter storm data can't convince folks that there is very little correlation between them and MJO phases, then I'd think that nothing would ever be able to do that. So, I put the data out there. Fortunately, it got favorable responses as opposed to people still defending the MJO for this purpose.

By the way, in case you missed my post, the 2/16/13 snow, though not major for most, was significant for a good number in the Carolinas and it was in MJO phase 4, one of the supposed "unfavorable" phases.

Regarding the end of Feb to mid March, it is just about time to sit back and see what happens. Climo for the type of winter we've had said to watch this period for a good bit better than normal potential for a ~1-2 week period of the coldest of the winter, overall, and/or 1-2 wintry wx events affecting a good number in the SE US sometime between the end of Feb. and mid March. Of course, even if that were to occur, you know as well as I do that there's no telling that there would be a widespread major SE winter storm included in the mix. We both know that that kind of thing is not predictable this far out in time since so many things have to be just right to make it happen. I don't think a major storm would be needed to make climo the winner here. However, at least there'd seemingly be some chance for even that based on climo. Here's the link to the thread about this that I started on 1/1:

http://www.americanwx.com/bb/index.php/topic/38633-rest-of-se-winter-best-by-far-yet-to-come-per-warm-decjan-analogs/

Based on the current medium range modeling (I know it has sucked in general), I see zero reason to be discouraged at all at this still early stage. I know they're far from reliable, but the GEFS prediction for the PNA is +, the NAO is -, and the AO is - for late this month into early March. Furthermore, look at how cold the GFS and Euro ensemble mean is for 3/1-5. They are solidly below normal! Look at how warm they are for Canada, especially eastern Canada, which is indicative of excellent higher latitude blocking. So, whereas the medium range models are far from trustworthy, the upcoming indices and SE US temperature anomalies are just about as favorable looking as one would want to see at this early stage. It frankly doesn't get much better looking than that and I'm certainly enjoying seeing this. Keep in mind that the Euro ensemble, which generally doesn't have a cold bias and is about the best performing model guidance, currently looks solidly cold for 3/1-5.

Thank you sir! I saw the MJO stuff you posted wrt this last system and I agree with your assessment of it. Looking at the broader index regime, it seems to align favorably, but I'm not seeing a lot of evidence of that leading to anything over the next week or two (which I'd really like to see, as snow seems to have an easier time hanging around in March these days). But as you said, models have been inconsistent at best in the LR. It will be interesting to see if we can get a good March, as your research indicates. If we don't, I feel like it'll will be because we're in a different climate now...where analogues might diminish in value as a predictor (I kinda feel like this is what we'll see). But as always, you do great work, and I hope your assessment turns out right!

[Tacoma]

The 0z and 06z gfs rainfall totals are insane here in ga. 0z shows over 10 inches through 192 and 06z shows over a foot of rainfall.  For all the talk of snow and winter weather...this is really a bigger deal with regards to flooding here...and in the upstate if this comes to pass. It is a long ways off and probably over done but the euro agrees with a lot of rainfall here.

 

The below images does not count the 1 to 2 inches in the first 96 hours

 

Even if it's  over done, we are looking at a lot of rain it would appear. New 12z gfs is showing 3 to  4 inches just through hour 126

 

0z gfs

 

06z gfs

 

 

can we get this to trend colder so it will be all or mostly snow.  same old thing we get great moisture and the temps warm

[GaWx]

can we get this to trend colder so it will be all or mostly snow.  same old thing we get great moisture and the temps warm

 

 Not that they mean much at all since they're for so far out in time and we're talking about the op. GFS, but fwiw, the day 10-16 12Z GFS clown maps are filled with snow in a good portion of the SE US and nearby areas. (I didn't give them the name "clown" in case you're wondering and haven't seen them called that.)

[burgertime]

The 12z GFS I think at least has a "cold" look to it in the LR. To me that is always step number one. Let's face it, indices have just been so-so for us. MJO really didn't do anything.  A -NAO hasn't helped us, a +PNA didn't help us early in the year. Now -NAO and +PNA together should help but we shall see. Personally I'm going to be on the look out for some ULL's that take the right track. I just don't really see a big Miller A hitting us given how overdone the GFS always is on the cold.  Just my two cents.

[DaculaWeather]

to this point, Lake Lanier is looking so much better as of late.   This comes to fruition and Lanier could be getting very close to full.

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

[griteater]

 Thanks CR. Yeah, if over 30 years of actual hard SE winter storm data can't convince folks that there is very little correlation between them and MJO phases, then I'd think that nothing would ever be able to do that. So, I put the data out there. Fortunately, it got favorable responses as opposed to people still defending the MJO for this purpose. 

 By the way, in case you missed my post, the 2/16/13 snow, though not major for most, was significant for a good number in the Carolinas and it was in MJO phase 4, one of the supposed "unfavorable" phases.

 

GA - one thing about the MJO though that I think has to be factored in is the speed at which the MJO is progressing and the time lag of its downstream effects.  Here's a map showing the location of the tropical convection associated with each phase of the MJO

 

 

So, when there is tropical convection firing in the central Pacific in phases 8 and 1, the favored atmospheric response is a downstream +PNA ridge in W North America (source: http://blog.timesunion.com/weather/how-el-nino-influences-our-weather/1247/)

 

Looking at the current MJO phase plot, we were in phases 8 to 1 from Jan 31 thru Feb 11, then we rocketed from phases 2 to 4 from Feb12 thru Feb 17

This loop http://www.atmos.albany.edu/student/kgriffin/maps/500hght_stdanom/500hght_stdanom_npac_loop.html shows the 500mb heights in the Pacific from Feb 4 to current, then 8 days in the future to Feb 26.  The period from Feb 5-15 featured ridging in the E Pacific and W North America...with the ridging during Feb 14-15 being key in the recent storm on the 16th...and as you move the loop forward, you can see a stable central Pacific ridge pattern developing for the period Feb 17-26, more consistent with MJO phases 4-6.

 

Would be interested in other feedback on this, but it's quite possible that the MJO's run through phases 8-1 was instrumental in building the E Pacific / W North America ridge that keyed our recent storm.

[Shawn]

By the end of the week, I think Euro may have something for us to watch.

 

The rain maps that have been posted are insane!  8-9 inches in areas of the South.  Almost look like tropical storm maps! Hopefully we can fix our water tables before Summer!

 

The 12z gfs still pulls most the CAD out before moisture for NC, but still worth the watch as it was a tad more pronounced from my glimpse.

 

I personally haven't been around long enough, but it does seem +PNA, West Based NAO are more important than MJO for snow down here.  Still learning though.

 

Does anyone have any info on this summer's weather trend? aka la nina/nino etc?  Not sure how far those forecasts go besides the possible cfsv2?

[superjames1992]

The GFS has been doing some funky stuff post-truncation lately.

[superjames1992]

It is interesting that four of Raleigh's 10 biggest snowstorms occurred in March or April and only six occurred in January/February.  None occurred in December.

http://raleighwx.ame...opRDUSnows.html

[calculus1]

It is interesting that four of Raleigh's 10 biggest snowstorms occurred in March or April and only three occurred in January and February.  None occurred in December.

http://raleighwx.ame...opRDUSnows.html

 

I'm just trying to do the math here without clicking on the link. 

 

Based on your words, I have 7 of the top 10 biggest Raleigh snowstorms in December - April.  Thus, I must conclude that the other 3 storms in the top 10 came somewhere during the months of May - November?  Really?

[FallsLake]

RAH afternoon mentions a chance of some freezing rain Thursday night:

 

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 235 PM MONDAY...

DAMP/GRAY/CLOUDY/CHILLY WEATHER LIKELY HEADING INTO THE WEEKEND...
ALTHOUGH UNCERTAINTY REMAINS HIGH BEYOND SATURDAY.

FOR THURSDAY NIGHT: MODELS ALL CLOSE OFF A WEAK SURFACE HIGH OVER
THE EASTERN CAROLINAS THURSDAY AFTERNOON WHICH HELPS ASSURE THAT THE
COLD DRY SURFACE AIR REMAINS IN PLACE WITHOUT ANY WARM/MOIST AIR
ADVECTION TO DISLODGE IT PRIOR TO THE RAPID ARRIVAL OF DEEP MOISTURE
AND FORCING FOR ASCENT THURSDAY EVENING. DESPITE ITS FAR-NORTH
CENTER AND MODEST PRESSURES IN THE 35N-45N CORRIDOR... THE LARGE
SCALE SURFACE RIDGE EXTENDING FROM NRN ONTARIO THROUGH THE NORTHEAST
AND MIDATLANTIC WILL BE VERY SLOW TO DEPART... ANCHORED BY A
SHORT-LIVED OMEGA BLOCK SITUATED BETWEEN THE VORTICES OVER THE UPPER
MIDWEST AND CANADIAN MARITIMES. DURING THE EVENING... WHILE THE
(ROUGHLY ISOTHERMAL) TEMPS THROUGHOUT THE LOWEST ~7000 FT SIT
PRECARIOUSLY CLOSE TO THE 0C LINE OR JUST A COUPLE OF DEGREES ABOVE
IT WHILE REMAINING RATHER DRY... THE INCREASE IN BOTH MOISTURE AND
FORCING FOR ASCENT OCCURS HIGHER UP... FROM 700-300 MB... IN
ASSOCIATION WITH INCREASING MID LEVEL DPVA ON THE WEST EDGE OF THE
RIDGE AXIS AS WELL AS UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION
OF THE WSW JETLET OFF THE MIDATLANTIC COAST. WITH THE LIFT ROOTED
HIGH AND LACK OF LOW LEVEL MOISTURE... EXPECT MINIMAL PRECIP THROUGH
MUCH OF THE EVENING. BY THE TIME THE LOWER LEVEL MOISTURE
OVERSPREADS THE AREA FROM THE SW MAINLY AFTER MIDNIGHT... HENCE
BRINGING ABOUT A CONCERN FOR FREEZING PRECIP AS PREDICTED SURFACE
WET BULBS HOVER AROUND 0C... THE UPPER LEVELS (ABOVE -10C) QUICKLY
DRY OUT AS BOTH THE GFS AND ECMWF BRING A SWATH OF DRY AIR BENEATH
THE OMEGA HIGH ACROSS THE REGION. WHILE THIS WILL GREATLY LIMIT
PRECIP AMOUNTS... AS THE DEEPEST MOISTURE WILL HOLD TO OUR SOUTH
WITH LIFT AUGMENTED BY INSTABILITY OVER THE GULF COAST INTO GA/SC...
THE MODEL-INDICATED SURFACE WET BULB TEMPS AND PARTIAL THICKNESSES
BOTH SUGGEST LIGHT FREEZING RAIN AT THE ONSET NORTH OF HIGHWAY 64...
TRENDING QUICKLY TO LIGHT FREEZING DRIZZLE AS THE ICE NUCLEATION
REGION ALOFT DRIES OUT OVERNIGHT. IN SHORT... EXPECT HIGH POPS BUT
WITH MODEST QPF. PRECIP SHOULD NOT BE HEAVY ENOUGH FOR ANYTHING MORE
THAN A THIN GLAZE AT MOST... ALTHOUGH MUCH WILL DEPEND ON SURFACE
CONDITIONS AND PRECEDING TEMPS... IMPOSSIBLE TO SPECIFY AT THIS TIME
RANGE. BUT WE DO ANTICIPATE ESTABLISHMENT OF A STRONG DAMMING WEDGE
THROUGH THE PIEDMONT OVERNIGHT AS THE DRY AIR RIDGE IS REINFORCED
AND STABILIZED FURTHER BY NEAR-SURFACE WEAK COOL AIR ADVECTION
BENEATH INCREASING 850-800 MB WARM AIR ADVECTION. EXPECT TEMPS TO
DROP QUICKLY IN THE EVENING WITH EVAPORATIVE COOLING THEN HOLD IN
THE LOW-MID 30S OVERNIGHT.

FOR FRIDAY THROUGH SATURDAY NIGHT: UNSETTLED WEATHER WILL PERSIST
WITH STRONG FLOW ALOFT (INCLUDING A 140-150 KT JET CORE FROM THE
CENTRAL CONUS INTO THE OH VALLEY/LOWER GREAT LAKES AT 325K-330K
FRIDAY INTO EARLY SATURDAY) AND A STEADY SSWRLY GULF-SOURCE 850 MB
FLOW OVERRUNNING THE COOL STABLE WEDGE AT THE SURFACE. SIGNIFICANT
DIFFERENCES PERSIST BETWEEN THE GFS/ECMWF SOLUTIONS WITH THE GFS
SHOWING A RELATIVE LULL IN PRECIP LATE FRIDAY WHEN THE ECMWF IS
SHOWING HEAVIER PRECIP JUST MOVING IN. GIVEN THAT THESE FEATURES
WILL BE DRIVEN IN A VERY SWIFT AND LONG-FETCH SW FLOW FROM OFF CA
AND BAJA... DIFFERENCES IN TIMING AND MAGNITUDE OF EVEN SUBTLE
FEATURES ARE INEVITABLE. THE ECMWF INDICATION OF A SHARPENING
FRONTAL ZONE FROM THE GULF COAST UP THROUGH SRN/ERN SC AND SE NC IS
REASONABLE AS SURFACE FRONTOGENESIS WOULD BE EXPECTED ON THE
EQUATORWARD SIDE OF SUCH A PRONOUNCED UPPER LEVEL JET WITH WEAK MID
LEVEL PERTURBATIONS RIDING WITHIN THE FAST FLOW TOWARD THE
CAROLINAS. WILL RETAIN AT LEAST GOOD RAIN CHANCES DURING THIS
PERIOD... FOCUSING HIGHER AMOUNTS IN THE SOUTHERN TIER OF THE
FORECAST AREA AND LOWER AMOUNTS NORTH... AND BRINGING THE BETTER
RAIN CHANCES IN FRIDAY NIGHT INTO EARLY SATURDAY TO CORRESPOND TO
THE ECMWF. MODELS TAKE A MID LEVEL TROUGH OUT OF TX FRIDAY EVENING
AND MOVE IT QUICKLY ACROSS THE OH VALLEY AND NORTHEAST BY SATURDAY
NIGHT... SO EXPECT THIS TO INDUCE SUBSIDENCE AND DRYING BY LATE
SATURDAY NIGHT. EXPECT MUCH BELOW NORMAL TEMPS BOTH DAYS WITH HIGHS
IN THE 40S FRIDAY (EXCEPT LOW 50S SOUTHEAST) AND MID 40S TO MID 50S
SATURDAY UNDER THICK CLOUD COVER.

FOR SUNDAY/MONDAY: BRIEFLY CALMER WEATHER WITH MORE TYPICAL
LATE-FEBRUARY TEMPS ARE EXPECTED SUNDAY BETWEEN THE DEPARTING WAVE
AND THE NEXT STORM SYSTEM OVER THE ROCKIES. MODELS SUGGEST A DRY AND
STABLE COLUMN UNDER LONGWAVE RIDGING. EXPECT HIGHS NEAR NORMAL...
MID 50S TO NEAR 60. WE SHOULD SEE INCREASING CLOUDS AGAIN MONDAY AS
THE AFOREMENTIONED SYSTEM TRACKS INTO THE PLAINS AND MIDWEST WITH A
TRAILING TROUGH SHIFTING INTO THE MISS VALLEY. GFS/ECMWF TRY TO
BRING SOME PRECIP INTO SW NC MONDAY AFTERNOON BUT WILL KEEP IT DRY
FOR NOW GIVEN THE UNCERTAINTY REGARDING TIMING. HIGHS A BIT BELOW
NORMAL AS MARGINALLY MILD THICKNESSES ARE OFFSET BY THE INCREASING
CLOUDS. -GIH

&&

 

[jburns]

The GFS has been doing some funky stuff post-truncation lately.

Just like a model.  You trunc them once and then they don't want anything to do with you.

[Snowless in Carrollton]

I'm just trying to do the math here without clicking on the link. 

 

Based on your words, I have 7 of the top 10 biggest Raleigh snowstorms in December - April.  Thus, I must conclude that the other 3 storms in the top 10 came somewhere during the months of May - November?  Really?

I think he meant 3 occurred in both January and February for a total of 6 in those months.

[FallsLake]

18z NAM looking really CADish at 84 hours. Not getting excited at this time but my interest is building.

 

[superjames1992]

I'm just trying to do the math here without clicking on the link. 

 

Based on your words, I have 7 of the top 10 biggest Raleigh snowstorms in December - April.  Thus, I must conclude that the other 3 storms in the top 10 came somewhere during the months of May - November?  Really?

 

 

I think he meant 3 occurred in both January and February for a total of 6 in those months.

 

Yeah, that's what I was trying to say.  I need to reword that.

[calculus1]

Yeah, that's what I was trying to say.  I need to reword that.

 

Yes, I totally had my nerd face on for that one.  No biggie!

[GaWx]

GA - one thing about the MJO though that I think has to be factored in is the speed at which the MJO is progressing and the time lag of its downstream effects.  Here's a map showing the location of the tropical convection associated with each phase of the MJO

 

 

So, when there is tropical convection firing in the central Pacific in phases 8 and 1, the favored atmospheric response is a downstream +PNA ridge in W North America (source: http://blog.timesunion.com/weather/how-el-nino-influences-our-weather/1247/)

 

Looking at the current MJO phase plot, we were in phases 8 to 1 from Jan 31 thru Feb 11, then we rocketed from phases 2 to 4 from Feb12 thru Feb 17

This loop http://www.atmos.albany.edu/student/kgriffin/maps/500hght_stdanom/500hght_stdanom_npac_loop.html shows the 500mb heights in the Pacific from Feb 4 to current, then 8 days in the future to Feb 26.  The period from Feb 5-15 featured ridging in the E Pacific and W North America...with the ridging during Feb 14-15 being key in the recent storm on the 16th...and as you move the loop forward, you can see a stable central Pacific ridge pattern developing for the period Feb 17-26, more consistent with MJO phases 4-6.

 

Would be interested in other feedback on this, but it's quite possible that the MJO's run through phases 8-1 was instrumental in building the E Pacific / W North America ridge that keyed our recent storm.

 

Griteater,

 Thanks for your detailed post about a possible way to utilize the MJO. Here's my problem with it: once we realize that we have to take into account the speed of at which the MJO is progressing and the time lag of its downstream effects, the usefulness of the current MJO is pretty much gone. So, now what are the favorable and unfavorable phases? You're pretty much implying that the current MJO, which I often here correlating to so and so, is no longer anything close to a concrete indicator like is often implied on this BB. I'm sure you know to what I'm referring, especially those maps of avg. temperature anomalies for each current MJO phase. This is getting beyond complicated imo. Anyway, the major winter storms for the SE US are all over the MJO maps. I recommend that people look at the NAO, AO, PNA, etc., but don't waste time thinking about the current and forecasted MJO (besides forecasts aren't even that reliable) since it is of little help imo.

[Cold Rain]

Ok, so Larry and Burger, I have to ask the obligatory, "How are the Weeklies and how does the EPS control run look?"

[WilkesboroDude]

Wide reaching snow cover expansion with this storm coming up over the heartland of the US...Nebraska to Ohio back down to Arkansas. Maybe this can set up the storm track further south?

[downeastnc]

It is interesting that four of Raleigh's 10 biggest snowstorms occurred in March or April and only six occurred in January/February.  None occurred in December.

http://raleighwx.ame...opRDUSnows.html

All the biggest snows here in Greenville have been Dec, Feb and March, I cant think of any Jan snow exceeding 6".here