January 2019 Medium/Long Range Pattern Discussion

[John1122]

Regionally in February 1998 Jackson Kentucky had a 12 inch snow depth with 18.6 inches falling on around 2 inches of liquid. Somerset Kentucky had a 14 inch snow depth, no report on what fell with around 2.1 inches of liquid. I had a 17 inch snow depth with 2.5 inches of liquid.  West of me there were 20 inch depths in Scott Co and Fentress Co.  Crossville had a 10 inch depth with 13 inches falling on around 2.5 inches of liquid but there was some rain in Crossville.  Allardt had a 17 inch snow depth with 2.7 inches of liquid. Jamestown had a 20 inch snow depth on 2.4 inches of liquid.  Cookeville is listed with 3 inches of liquid but no snow depth. Though that is likely missing data as we have eye witness reports of 12+ inches there. Elevations above 3000 feet in my area had 30+ inches.

More snow volume fell in this storm than any other in my lifetime. But it was much wetter than the blizzard so the depth wasn't as great. Widespread power outages. So odd that there were two monsters like that in East Tennessee in a short period. My cousin was about to graduate from ETSU during the first event there, I was pretty jealous of the snowfall he experienced, not knowing I'd get the same soon after.

[Carvers Gap]

Anyone have a snow map for the TRI region for that storm?  I am just wondering what Kingsport actually received by that storm.  I drove over a few days later and was astonished at how much JC received.  I don't remember seeing much on the ground until Boone's Creek, and then it ramped up quickly.  I think it was one of those deals where the rates kept JC as snow and KPT was mix/snow.

[EastKnox]

You know it's a slow day when we reminisce about past snowstorms.  On a positive note, yesterday's look at 360H moved to 336H, so at least it's not getting stuck in perpetuity at day 15.

[Kentucky]

1 hour ago, John1122 said:

Regionally in February 1998 Jackson Kentucky had a 12 inch snow depth with 18.6 inches falling on around 2 inches of liquid. Somerset Kentucky had a 14 inch snow depth, no report on what fell with around 2.1 inches of liquid. I had a 17 inch snow depth with 2.5 inches of liquid.  West of me there were 20 inch depths in Scott Co and Fentress Co.  Crossville had a 10 inch depth with 13 inches falling on around 2.5 inches of liquid but there was some rain in Crossville.  Allardt had a 17 inch snow depth with 2.7 inches of liquid. Jamestown had a 20 inch snow depth on 2.4 inches of liquid.  Cookeville is listed with 3 inches of liquid but no snow depth. Though that is likely missing data as we have eye witness reports of 12+ inches there. Elevations above 3000 feet in my area had 30+ inches.

More snow volume fell in this storm than any other in my lifetime. But it was much wetter than the blizzard so the depth wasn't as great. Widespread power outages. So odd that there were two monsters like that in East Tennessee in a short period. My cousin was about to graduate from ETSU during the first event there, I was pretty jealous of the snowfall he experienced, not knowing I'd get the same soon after.

Friend of mine in Corbin has lengthy vhs of all those 90's storms. At the time I had no idea how rare those storms would be. 

[Holston_River_Rambler]

Weeklies 500 mb:

 

 

[Holston_River_Rambler]

Looking at the 45 days snowfall maps for each of the 51 members, my take away is that this run trended overall better for snow chances since it seems like only slight changes (member perturbations) could lead to epic results. 

 

or

 

Some solutions favored the Midwest/ OH Valley and had us on the outside looking in. 

 

Hopefully the trend is our friend here. 

Under no circumstances should Flash look at member 48. 

EPS 45 day

[Icy Hot]

5 hours ago, Math/Met said:

The 98 snowstorm in NE TN was probably my favorite weather event of all time. I didn’t realize that Kingsport missed it. I know Greene County, Washington County, and other spots along the mountains got hammered.  Incredible snowfall rates with that system and by far the biggest snowflakes I’ve ever seen (in person or video). I really wish someone had video from that event. I’ve looked several times but never found any footage.

I think I still do. Flakes looked like chicken feathers.

[John1122]

Can't find a map but the 1-28-98 event saw 21 inches fall at Wise with a max depth of 16 inches. Missing data at Mountain City with 9 inches on the ground 2 days after the event.  Erwin has 9 inches falling with 3.05 inches of QPF. No idea if that snow amount is accurate. It also shows 9 inches on the ground the day that 9 inches fell, 6 inches on the ground the next day. Missing data in Abingdon with 10 inches of snow falling recorded.  Tri recorded 2.3 inches of precip but doesn't have snowfall listed/missing data. Elizabethton recorded 18 inches.  5 inches at Gatlinburg. 26 inches at Mt LeConte.

Lots of missing data for NE Tn sites is common for the 90s. Elizabethton looks like it has the least missing data with 18 inches of snow recorded on around 1.9 inches of qpf.

[1234snow]

0z RGEM still giving some in East TN hope with about an inch on the front end Saturday morning.

[Math/Met]

1 hour ago, John1122 said:

Can't find a map but the 1-28-98 event saw 21 inches fall at Wise with a max depth of 16 inches. Missing data at Mountain City with 9 inches on the ground 2 days after the event.  Erwin has 9 inches falling with 3.05 inches of QPF. No idea if that snow amount is accurate. It also shows 9 inches on the ground the day that 9 inches fell, 6 inches on the ground the next day. Missing data in Abingdon with 10 inches of snow falling recorded.  Tri recorded 2.3 inches of precip but doesn't have snowfall listed/missing data. Elizabethton recorded 18 inches.  5 inches at Gatlinburg. 26 inches at Mt LeConte.

Lots of missing data for NE Tn sites is common for the 90s. Elizabethton looks like it has the least missing data with 18 inches of snow recorded on around 1.9 inches of qpf.

I've noticed that too. It's hard to find reliable weather data for this area. 

The MRX weather calendar lists the following for that date. The mountain totals seem realistic, but the valley is underestimated. 

Quote

Snowstorm hit the area in 1998. 24-48" fell in the mountains, 5-10" in the valley. 1 died.

The UT experiment station in Greene County had archived weather data available online a few years ago. I remember seeing a hand written record from that location with 18 inches listed as the snow depth for the day after the storm. I’m sure there was some melting and compaction, so I feel really confident that many areas had around 20 inches.

[Carvers Gap]

Very good looks on the ensembles this morning.  The next ten days will should be a transition to an eastern trough(as Jeff mentioned...could being in the mid-section of the country and work east).  The trough has now moved within ten days.  While the GEFS/GEPS ensembles are colder, the EPS made (IMHO) a moved towards a colder look overnight as its 2m temps had not been in sync with its 500 pattern.  And sometimes 2m temps don't match 500 patterns.  When that happens, the EPS is actually very accurate at depicting that.  That is usually an issue with source regions.  In this case though, with plenty of cold available in Canada(if the 500 patterns verify)...then the last 10 days or so of January should see increasing cold and potential for winter events.

[Holston_River_Rambler]

6z RGEM still trying for SW VA, NE TN, and SE KY.  6z 3k NAM too, but doing something new with a few burst bands of snow moving right at Blunderstorm. Looks like little tiny pieces of vorticity are causing, but honestly not sure what is causing it. 

 

[Holston_River_Rambler]

Isotherm update:

https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?page=29&tab=comments#comment-118187 

He may do one here, but looks like he posted at 33 and Rain first.

[Blue Ridge]

14 hours ago, John1122 said:

Can't find a map but the 1-28-98 event saw 21 inches fall at Wise with a max depth of 16 inches. Missing data at Mountain City with 9 inches on the ground 2 days after the event.  Erwin has 9 inches falling with 3.05 inches of QPF. No idea if that snow amount is accurate. It also shows 9 inches on the ground the day that 9 inches fell, 6 inches on the ground the next day. Missing data in Abingdon with 10 inches of snow falling recorded.  Tri recorded 2.3 inches of precip but doesn't have snowfall listed/missing data. Elizabethton recorded 18 inches.  5 inches at Gatlinburg. 26 inches at Mt LeConte.

Lots of missing data for NE Tn sites is common for the 90s. Elizabethton looks like it has the least missing data with 18 inches of snow recorded on around 1.9 inches of qpf.

I lived in Erwin at the time. Though I was young, I remember the storm vividly. My dad is 6'3" and snow depth topped his knees. I recall him measuring "over two feet" with a yardstick in the aftermath; IIRC, this was several hours after snow had ended. Bear in mind, my parents' home is at ~2000' but in a favored area just west of Unaka Mtn. That location is often the beneficiary of the "squeezing" that occurs during events with a proper trajectory. NW flow events were always fun as a kid.

Some in Limestone Cove and Flag Pond (~3500'+) claim to this day they saw four feet from this storm. Just conjecture on my part, but they likely aren't exaggerating much, if any.

[nrgjeff]

Asia and the Pacific continue to cooperate as the Euro and CFC weeklies drop the winter hammer in tandem.

New storm systems off Asia are being absorbed into the Bering Sea/Aleutians low, rather than moving east into the GOA. Promotes ridge over northwest NA. MJO is still a little muddled, but other drivers are trending toward a cold Southeast US. 

It may take a couple weeks for the storm track to settle. Next weekend looks like another I-70 special; yes, I'm calling it 8 days ahead. Following one might even be north. However we still have February, which has been good to Chattanooga and many others in this Region who have to wait and wait.

If the cold really does verify strong, it may come in faster and harder than initially forecast. We'll see.

[Carvers Gap]

The 12z EPS again moved even colder after d8.  Quite a dramatic change from d8 to d9.5.

[EastKnox]

13 minutes ago, Carvers Gap said:

The 12z EPS again moved even colder after d8.  Quite a dramatic chance from d8 to d9.5.

The trend is our friend?

[Carvers Gap]

On 1/11/2019 at 3:33 PM, EastKnox said:

The trend is our friend?

Good share.  Just seemed like several runs prior to yesterday that the 2m temp EPS depiction did not match the significant trough over eastern NA.  When a ridge goes into AK (EPS/PNA), that is likely tapping cold off the pole and pulling some of that very cold air from Eurasia.  The problem was the pattern at the surface did not match the 500 pattern.  There have been years where that actually happened....great 500 pattern but no cold air underneath.  However, those years usually had features that cut cold off from heading south(from the pole) or Canada was devoid of cold.  However, the recent EPS runs are almost textbook in terms of signaling Arctic air entering the Lower 48.  So, it has been nice to see the EPS 2m mean trend towards colder temps during the past 2-3 runs.  I think Jeff noted in his write-up earlier that the cold could potentially be stronger and a bit earlier than modeled if the idea(cold finally arriving) was actually correct.  It is good to see modeling confirm that idea.  For once(fingers crossed) there are multiple indicators showing cold for the eastern half of NA.  Remember when the Weeklies jumped the gun but had no support?  Now, the GEFS, EPS, GEPS, sometimes the CFSv2(spits out something different every run....a broken clock is right twice a day deal), JMA Weeklies(just flipped cold...nice), and just some good old-fashioned(meaning non-computer) work from the Jeff and other mets on the forum point towards cold arriving in NA.  I know for myself...I am little bit on edge simply because I think we have all seen flips..flip back the other way.  In this case, the upcoming pattern just fits several colder analogs that had warm Decembers and warm early Januarys.  It fits John's work on cold that arrives during January in relation to the November pattern.  I fits climatology.  It fits SSW induced blocking arriving 2-3 weeks after the split.  The only headache is I do think the MJO is a fly in the ointment(I think Jeff mentioned that as well).  It really needs to stay suppressed.  The SOI is still a headache.  But overall, we needed the EPS to start showing some cold at 2m...and it has done that here recently.   That was a cold run today.  Long story short...every ensemble is singing the same song now to albeit minor variations of the tune. 

[jaxjagman]

Seems like a potential  system with the recent rise and drop of the SOI recently towards the end of Dec into Jan.

 

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
11 Jan 2019	1012.30	1007.20	2.31	4.19	3.51
10 Jan 2019	1011.56	1008.50	-7.30	4.56	3.75
9 Jan 2019	1011.75	1007.65	-2.40	4.94	3.94
8 Jan 2019	1012.44	1007.80	0.15	5.05	3.98
7 Jan 2019	1012.09	1008.40	-4.33	4.93	3.97
6 Jan 2019	1010.17	1007.40	-8.66	5.15	3.97
5 Jan 2019	1008.86	1008.20	-18.60	5.64	3.97
4 Jan 2019	1009.55	1009.25	-20.30	6.46	4.11
3 Jan 2019	1009.90	1008.05	-13.00	7.42	4.31
2 Jan 2019	1009.71	1007.10	-9.42	7.94	4.48
1 Jan 2019	1009.66	1006.60	-7.30	8.53	4.66
31 Dec 2018	1010.49	1006.85	-0.42	9.23	4.67
30 Dec 2018	1010.45	1005.45	6.64	9.46	4.50
29 Dec 2018	1011.15	1004.35	15.98	9.44	4.16
28 Dec 2018	1010.84	1003.60	18.27	9.33	3.79
27 Dec 2018	1008.54	1004.50	1.66	9.23	3.48

 

System'(s) coming off East Asia,the EPS shows this (I like the one coming off Korea) which should be towards the end of the month

 

 

As you can see where the GEFS shows we could possibly have a  winter system towards the end of the month

 

 

 

 

If you look at today's AO signs of it really crashing to around -3/-4 sigma with a few odd balls warmer or even colder.With a +PNA,nothing but a cold look pattern upcoming.But i believe we should see a  storm somewhere around the 25th-26th.Certainly could be wrong 

 

 

 

 

[jaxjagman]

Prognostic Discussion for Week 3-4 Temperature and Experimental Precipitation Outlooks 
NWS Climate Prediction Center College Park MD 
300PM EST Fri Jan 11 2019 

Week 3-4 Forecast Discussion Valid Sat Jan 26 2019-Fri Feb 08 2019 

A host of well-defined teleconnection modes and centers of action are currently in play, and could continue to influence the Weeks 3 and 4 outlook. Over the past week the Madden-Julian Oscillation (MJO) pushed across much of the Western Hemisphere, and is currently approaching the Prime Meridian. Historically, the lagged response to MJO Phases 8/1 tend to be more of a transitional mode for the U.S., with anomalous troughing building over the West and ridging along the Canadian border. The Arctic Oscillation (AO) has flipped to negative, in line with past observations of the MJO crossing the Pacific during boreal winter. Model guidance supports the AO remaining negative during the next two weeks, despite the MJO reaching the Indian Ocean typically supporting a return to AO+ conditions. Some of this influence in the model guidance could be tied to the recently observed split in the stratospheric polar vortex, although models are notorious for how poorly stratospheric/tropospheric exchange is handled, so this should be taken with some caution. Yesterday (10 January) CPC officially extended its El Nino watch another month, with a coupled tropical response remaining unobserved over the tropical Pacific, leading to concerns about any substantial extratropical response for North America despite the persistently warm sea surface temperatures (SSTs) over the Central Pacific. On the whole, model guidance is fairly consistent with an amplified wavetrain emerging from the Central Pacific and resultant ridge-trough pattern over the CONUS, despite statistical guidance supporting a less robust trough-ridge that would be more in line with the MJO pushing towards the Indian Ocean. The resulting temperature and precipitation outlooks are rooted primarily in this dynamical model guidance, although resulting probabilities are damped somewhat given the empirical expectations from the statistical tools. 

Dynamical model guidance is remarkably consistent in depicting an amplified wave train emanating from the Pacific during the Weeks 3 and 4 period, resulting in a ridge-trough dipole across the CONUS. Unsurprisingly, this supports elevated chances for above-normal (below-normal) temperatures from the Pacific Coast through Great Plains (approximately the Mississippi River through Eastern Seaboard). Highest confidence for each respective region is associated with the primary anomalous ridge and trough axis, centered over the Pacific Northwest and Central Appalachians. Substantial decadal warming trends over the Southern Plains tilt the official outlook towards equal chances, rather than the slight increase in below-normal temperature odds that dynamical guidance would support. The MJO response for Phases 8/1 would suggest increased chances for below-normal (above-normal) temperatures focused on the Great Basin (Northern Tier), that damp the out of phase dynamical model guidance probabilities that form the basis of the forecast. Anomalous troughing forecast over the Aleutians would support enhanced southerly flow and increased odds for above-normal temperatures for much of Alaska, with the highest probabilities closest to the Gulf of Alaska. 

The anticipated ridge-trough dipole is supportive of a fairly dry pattern for the CONUS, with the primary storm track in the Norhteast Pacific shifted north into Alaska and Canada, in addition to increased chances for continental polar air masses to intrude into the East. Highest confidence for below-normal precipitation exists over the West, in association with the anticipated anomalous ridge axis, and over the western Gulf states that are likely to see the import of Gulf moisture limited by the anomalous northerly flow. Above-normal precipitation is favored across a portion of the High Plains tied to shortwave activity potentially diving into the longwave trough, and across Florida where guidance suggests the mean frontal zone becomes established downstream of the anomalous trough. Anomalous southerly flow forecast for Alaska leads to increased (decreased) chances of above-normal precipitation across the southern portion of the state (interior and western mainland). 

[Carvers Gap]

Another really good ensemble 0z suite last night.  Right now, I am just looking for the pattern and not storms.  I look at the snow means to see if there are upticks there. For those new to the wx hobby, snow means rarely verify...but if they are increasing and/or stout that usually signals a stormy pattern.  Here are a couple of slides from overnight.  The actual hammer coming down is around d8 now.  By hammer, I mean trough in the eastern half of NA.  Below are the 6z GEFS 16d snow mean(w individuals...snow mean is the last slide) and the 0z Euro d9 850 temps.  There are two time frames where the snow means really moves...d8-10 and d10-15.  Notice how far south some members are(likely means a cold front heading well into the Deep South) and how some seem to indicated the potential for a strong storm.  The 850 map shows the EPS now losing the washed out look that it had.  It is really amplifying the eastern trough w cold 2m temps underneath.  For now, it looks like most models are centered on Jan 20 as the final step into what hopefully will be a blocky, cold, stormy pattern.  The temperature change between d7.5 and 8.5 is impressive.

[weathertree4u]

10 minutes ago, Carvers Gap said:

Another really good ensemble 0z suite last night.  Right now, I am just looking for the pattern and not storms.  I look at the snow means to see if there are upticks there. For those new to the wx hobby, snow means rarely verify...but if they are increasing and/or stout that usually signals a stormy pattern.  Here are a couple of slides from overnight.  The actual hammer coming down is around d8 now.  By hammer, I mean trough in the eastern half of NA.  Below are the 6z GEFS 16d snow mean(w individuals...snow mean is the last slide) and the 0z Euro d9 850 temps.  There are two time frames where the snow means really moves...d8-10 and d10-15.  Notice how far south some members are(likely means a cold front heading well into the Deep South) and how some seem to indicated the potential for a strong storm.  The 850 map shows the EPS now losing the washed out look that it had.  It is really amplifying the eastern trough w cold 2m temps underneath.  For now, it looks like most models are centered on Jan 20 as the final step into what hopefully will be a blocky, cold, stormy pattern.  The temperature change between d7.5 and 8.5 is impressive.

Safe to say, if a few inches of snow can be laid down, there will not be much if any opportunity for moderation of any cold air dropping down from Canada!

[Carvers Gap]

On 1/9/2019 at 7:09 PM, Carvers Gap said:

TRI stands at an incredible +13.6 departure after yesterday through the first nine days of January.  Going to be fun watching the next three weeks potentially reel that number back.  Not posting this to prove anyone right or wrong...just thought it was an impressive departure.  Here is some more interesting number tinkering.  Last January through the first nine days it looks like we were roughly -13.6.   Talk about nature balancing things out to near perfection!  We are 27 degrees warmer than we were during the first nine days of January 2018.  I find that remarkable.   January 2018 finished at -3.4(It was a month full of wild, wild temp swings) .  February 2018 would finish at +10.4 . (Insert strat split here.) March would finish at -1.4.  April would finish at -2.9.  May would finish at +6.2.  We had about two months of strong blocking, and then flipped to summer.  As Jeff noted, the potential blocking should be roughly a month earlier this year.   So, are we going to see last winter in reverse?  I think this is quite possible.  I did note that the 500 pattern on the EPS looked really, really good.  Underneath...AN temps over this area?!  That model has perplexed me all winter...with that tough configuration, the motherload should be turned loose.  It may well be that it just didn't have time to send everything south.  Anyway, just some pretty interesting observations.  And again, not taking shots at anyone's forecasts.  If anything, we can bump this post at the end of the month and see how much it changes..February will be interesting as well to see if we can pull the seasonal average back to average or below.  Hopefully, the differences will be stark....see the nice GoT inference there.  Their house motto?...Winter is coming!  One can only hope!!! 

TRI has fallen to +9.3.  If the EPS is correct, the monthly average will have a chance to fall all of the way back to normal and maybe below.  The last ten days of the month will feature two impressive cold shots which may be similar in duration and strength as the warmth that we saw to begin the month.  

[Holston_River_Rambler]

It's interesting how many of the GEFS ensembles try to spin up a second low in the 19-21 time frame along the stalled front, by streaking an initial piece of energy ahead of the bigger one. That storm heads NE and the arctic front gets through. 

Several of the EPS members have it too, but they blow it up offshore. Many of those wouldn't look bad with 8-10 days of a NW trend. 

[AMZ8990]

9 minutes ago, weathertree4u said:

Safe to say, if a few inches of snow can be laid down, there will not be much if any opportunity for moderation of any cold air dropping down from Canada!

E17 coming in for the win!!!  It’s hard not to get excited about our potential pattern over the next few weeks.  Maybe just maybe we can pull out an I-40 special and get the whole state involved in a big time wintry event.  

[Carvers Gap]

On 1/12/2019 at 8:01 AM, weathertree4u said:

Safe to say, if a few inches of snow can be laid down, there will not be much if any opportunity for moderation of any cold air dropping down from Canada!

There may be a slight moderation after the first cold shot, and the second is already heading down the Plains.  That said, I am using the term "moderation' loosely.  The moderation might just be normal and looks short lived(24-48hrs).  Now, I still look over my shoulder with this cold pattern.  Tough to know how long it will last.  The Weeklies show a long term cold pattern, but are notorious for perpetuating whatever pattern is the dominant pattern early on(meaning they miss the next pattern change).  I do like 4-6 weeks as a common denominator for patterns during winter.  The warm pattern that we are transitioning out of lasted roughly five weeks.  The only thing that I would be concerned about(and it is not a major concern at this point) is that this becomes a relaxation in a base warm pattern.  I do think we are entering a base cold pattern...but need to see this cold last for a couple of weeks(with more on the way) before declaring this a base cold pattern.  I am that skittish w how models have been behaving in relation to the MJO.  Overall, tough not to like the duration and strength of the cold shot on the way and fits nicely with the Euro Weeklies and now JMA Weeklies.  Lastly, while we want the MJO to lose its amplitude..we do want the STJ to remain active which is a fine line to walk.  As Jeff mentioned, if the cold sets up shop in the nation's mid-section, a SER is possible.  Hence, I am tentatively optimistic about this continuing into February. 

[weathertree4u]

1 minute ago, AMZ8990 said:

E17 coming in for the win!!!  It’s hard not to get excited about our potential pattern over the next few weeks.  Maybe just maybe we can pull out an I-40 special and get the whole state involved in a big time wintry event.  

Hard not to get excited but what is E17?

[Carvers Gap]

And I should add, with cold arriving during our best climatology(as John noted) it is tough not to like our chances when it comes to wintery weather.  We have an active STJ and cold coming off the pole coupled with blocking.  Give me that all day long, and I will take my chances during the last 1/3 of January and all of February.

[AMZ8990]

4 minutes ago, weathertree4u said:

Hard not to get excited but what is E17?

My bad weathertree, I meant to quote carvers post with the snowfall maps on it, instead i accidentally Quoted your message.  That’s my bad, sorry for the confusion.  E17 is one of the maps in carvers post that looks really juicy for the whole state.

[weathertree4u]

1 minute ago, AMZ8990 said:

My bad weathertree, I meant to quote carvers post with the snowfall maps on it, instead i accidentally Quoted your message.  That’s my bad, sorry for the confusion.  E17 is one of the maps in carvers post that looks really juicy for the whole state.

No worries, that is what I thought but wanted to ask. I secretly wanted it to be a new model I had not seen yet lol