Upper Level Low Exits the Region. Dry Conditions for a Few Days Before the Next Round of Rain.

What a storm this turned out to be.  Many places in the favorable snow zones managed to reach in the 1-4 inch range that I forecasted.  However, some places across TN and even back into AR managed to get higher totals going from 5-8 inches! Here are a few (haven't found out the final totals for the last one):

Paragould, AR: 8"
Madison, TN: 5"
Beech Mountain, NC: At least 2"



Meanwhile, nothing but mostly cold rain fell through parts of the Carolinas east of the Apps with the exception of a few spots reporting some sleet and flakes mixing with the rain.  I never had either mix in at my house but got a report that Charlotte had some sleet earlier in the afternoon, confirmed by a local met from News 14 named Jeff Crum.  If temperatures had been just a tad cooler, I guarantee many more of us would have seen a rain/snow mix or perhaps a brief burst of all snow before ending or switching back to rain.  Overall, I was not disappointed, as I only expect a few flakes at best for areas outside the mountains but am glad to know that places further west managed to get their snow.  Congratulations to you folks.  You got the good stuff this go around with the cut-off.  Temperatures for the most part seem to have hanged anywhere from the low 30s to mid 40s across much of the Southeast excluding eastern section of NC and further south in FL where it was actually in the 50s and even upper 60s.  Tonight should feature lows dropping quickly as skies clear and as of this post, I have ice on objects and areas where the rain never dried so you may have ice on your vehicle this morning if you happen to be one of the folks affected by the colder temperatures.  There are some remnant flurries (if you could say that) occurring across the mountains so that looks to continue for a while before tapering off.

Rest of this week and into Sunday look dry with temperatures returning to normal and slightly above average for highs until Sunday through Monday where the next system is expected to move in but I only anticipate rain with this one.  No winter weather expected with that one.

So to recap, how did this event came to be?  We had an upper level system that detached from the main westerlies (hence the term cut-off) and began to tighten, becoming stronger with closing contours indicating the strengthening process with significant CAA developing behind it.  This managed to wrap around so tightly that the system ultimately became a cold core cut-off which caused the rain to change over to snow (heavy in spots) to its west and underside.  Dynamic cooling was also a key feature, allowing those colder temperatures aloft to drop to the mid and low levels, not to mention receiving aid from the northern stream due to its interaction with it.  As this occurred, since it's departure from the main flow, there was not much of anything to move it allowing the system to progress in a slow bowling ball kind of motion, and dumping very heavy and persistent rainfall ahead causing quick flooding to occur in spots favorable for such.  That explains its 2 day stay across the Southeast before finally lifting away.  Same can be said for the snow as it also means that it did not move out so quickly, thus some areas received significant accumulations especially by southern state standards.  With such strong dynamics in place, some areas even experienced thundersnow and anyone underneath those convective snow bands got nailed a good bit.  Going back to the rain, before the colder temperatures moved in we had some areas receive more than 5" of rain (nearly 7.5" at Lake Toxaway, NC)! This is a typical feature found in a powerful ULL like this when it has access to the Gulf to tap copious amounts of moisture and such.  It was not as bad further east but still amounted to an inch or two so definitely beneficial and is the way to go instead of getting dumped by bucketfuls consistently.  Finally through the evening hours this system began to leave northeastward from the Southeast, leaving behind some loose sprinkles/flurries and eventually clearing things out as it is now.

Lots of variability was found with this system.  Rain, snow, mixing, flooding, even a bit of gusty winds to toss into as well.  It's always exciting to get a system like this, and it's not often that you have one so strong like this across the South so this will be a memorable one.  Hope you all enjoyed what you got, especially those of you who received the snow.  If you don't mind, I would like to hear from y'all the snow totals if you have such to report.  I want to be able to compile a list for this event.

Later folks.     

Round 1 Over. Round 2 for Tuesday.

What an exciting storm this is turning out to be.  Areas across western and west-central TN, northeastern AR, northern (maybe central) MS and now parts of northern (and perhaps central) AL are getting into the wintry weather as the ULL continues to wrap the cold air around itself dropping snow, sleet, and such west of and underneath itself.  I have reports of thundersnow taking place as dynamics support convective development but with snow as the main precipitation.  There are also reports of some areas already having the ground covered so it definitely looks like at least an inch of snow was doable.  I'm still sticking with my general 1-4 back west with areas caught in the heaviest persistent snows getting 3-4".  Meanwhile,  moderate to very heavy rain has fallen across parts of GA and the Carolinas through the day yesterday, dropping a general 1-5 inches.  There were a few spots reporting rainfall totals of 6 to even 7 inches with flooding issues in the favorable locations.  Dangerous stuff and for those of you underneath those flash flood warnings and advisories, please take it easy and don't attempt to drive through deep water.  6 inches is all it takes to carry a whole car down the road and that is the last thing we need to hear from a news station or in the newspaper.

The cut-off should continue to persist across the Southeast for today but this will begin the departure of the  system as it will lift northeast and bring some snow showers across the rest of TN, northern (possibly  portions of north-central) GA and across the NC mountains.  As unusual as it sounds, due to such strong wrap-around cold air, winds coming out of the southwest will bring chillier temperatures instead of the usual warmth.  There has been a slight increase in the chance for a few flakes of snow eastward across the foothills and down into the piedmont locations of NC/SC, particularly the western sections.  Still not feeling safe about guaranteeing the concept but should be noted and watched as we may have a few folks surprised to see some fall.  I still expect perhaps some more showers to push through with the next batch of precipitation but again this could mix with some snowflakes as air temperatures look just cold enough to support them reaching the surface in spots so not everyone would see this if the scenario were to play out (strictly coming from the RUC and NAM by the way so be careful about trusting this).  Keep an eye on radar and should it show up, look around if you happen to be underneath a good spot.  This is playing the game of "Conservatism" as to not rile up people over something that can easily fail. Eventually later today this system will begin to lift up and away from our region, clearing things out for Wednesday with dry conditions for a while until early next week for more rain chances.


More to come later.

Radar as of 2:15am:

Temperatures (Created using Weatherscope):

Alerts (Note: For LA and a portion of SE TX, those are freeze warnings not winter storm watches/warnings or advisories):

Massive Cut-Off Still In Store for the Southeast. Details Regarding Snow Potential and Accumulations

What an event this is shaping up to be.  This has to be one of the most interesting storms I've ever followed since it first showed up in the modeling.  Already significant rainfall has occurred over much of the region, with a general 2-4 inches of rain racked up and isolated areas picking up about 5 inches!  That definitely spells flooding for folks caught by the much heavier and persistent rain bands, which seems to have verified on the map I made previously.  This system will continue to affect the Southeast over the next couple of days at least as rain will continue to fall but there are signs in the near future that the cut-off, once it gets going, will begin to wrap the colder air around itself quite rapidly, setting the stage for potential backside/underside snowfall.  Anyone affected by the change of the airmass will likely experience a quick drop in temperatures, likely down into the 30s through the day tomorrow.  This is associated with the process of dynamic cooling in combo with the already advancing colder airmass behind the front.  It should eventually cause the moisture present at the time to fall completely as snow as we progress through the rest of Monday into the nighttime hours and for the day Tuesday.

With that said, my thoughts are that rain will still be present for a while through a part of Monday perhaps mixing with some snow before changing over to all snow across MS/AL/GA (particularly the northern and possibly central sections ) and TN, before the system begins its trek northeastward toward and along the Appalachians.  It's still too early to tell exactly how much snow some will see out of this but I would have to guess that for anyone underneath the heaviest bands,  a general 3-4" wouldn't be far-fetched with areas outside seeing 1-3" and if the nowcast modeling is under-doing the precipitation a little bit, then we can add a couple more inches to that.  Ground temperatures are going to put up a fight against anything attempting to stick onto the surface but with heavy enough snowfall, grassy areas shouldn't be a problem so take that into consideration.  There have been ULLs in the past that were so strong that despite warm ground temperatures, the snow was able to build which makes my confidence in any sort of accumulation low but the chance is there nonetheless.  For the higher elevations across the mountains, I can easily see this standing a better chance and possibly cause some travel issues in the most likely areas.  Some people continue to wonder the chances of some snowflakes just east of the Appalachians and right now that still looks quite low but that's not to say that I don't think our chances could improve a bit for maybe flurries across the western piedmont and along the foothills.  Wouldn't get my hopes up on that but would be nice to see, even if it doesn't equate to accumulation.

One thing I should mention is that per the recent trend in the modeling, particularly the NAM, with such a significant system in store we also can't rule out that this becomes sort of a nasty severe weather event ahead in the warm sector due to increased potential for slightly more available instability and astounding shear.  I don't think a big tornado threat is in store, though there could be a few isolated ones but it looks like the worst case scenario would be strong gusty winds associated with a linear-style convective mode.  We'll have to keep watch and see how that plays out.  Could be smaller or it may become a big deal of some sort.

Take care folks and hopefully some of you back west will see a good snow break out.      

     

Nice Saturday. Models Madness Continues with the Return of Our Next Storm

I have to say, Thanksgiving went better than I thought.  Two fantastic dinners; one at the house and the other at my dad's mama's house.  Got to spend some time with a few friends as well afterwards.  Overall, great weather to end a great day with temperatures a tad warmer than expected.  As usual, I worked on Black Friday but I work second shift so no issues with customers for the early morning.  That looks to have stayed in control better than the previous year thank goodness (around here at least).  Hopefully all of you had a fantastic Thanksgiving and everything went as planned.  Today looks great for most of the Southeast with 60s for highs across much of the region under dry conditions.  Enjoy it while you can because things are looking VERY interesting early next week (November 27-29).

It has been absolute madness with the modeling regarding this upcoming event; one of the toughest I've ever seen for them to agree on until recently.  Models were losing it and now have brought it back.  We have a shortwave trough that will traverse eastward with an attending cold front on Sunday.  There is also an upper level system that will develop into a rather potent cut-off low (an upper level system that closes and detaches itself from the main flow), allowing it to slowly move through the Southeast.  This intensifies and as it does so, it will create a substantial amount of moisture in addition to what is gathered from the Gulf.  This moisture will surge northeastward across the Southeast with major heavy rainfall, which obviously will mean some flooding concerns in areas.  With such a strong flow around this system, this will ultimately become a scenario where the low will create its own cold air by dynamical means, allowing it to become a cold core cut-off and cool the air significantly especially in areas underneath where moisture falls the heaviest.  Under the influences of such, snow could be in the offing for the favorable areas.  In fact, on the 0z NAM, it prints out a huge snow event for northwestern MS (up to nearly a foot in isolated locations) which this is assuming that particular part of the state is underneath intense banding.  The snow potential also includes much of northern and central MS, northeastern half of AL, northwestern GA, TN and the NC mountains.  There are some questions as to how far south and east this would reach though it looks like it could reach far enough south that Atlanta would get some flakes and maybe far enough east that places just east of the Apps may see the same but lighter.  If that were the case, I would only expect flurries at best but it looks like rain is the word for folks across most of the Carolinas, southeastern half of AL, southern MS, and most of GA at the moment.  What I really like about the modeling is that they all agree on the following: There is a cut-off system and it will affect the Southeast with snow and rain.  What remains to be known is the timing and exact track of the system so that will have to be monitored.  Still, this is one of the most interesting setups I have seen in quite a long while and can't wait until it rears its head on radar.

Here's the 0z GFS at 90 hrs. (Note I do not have a subscrip. to Accuwx.  This is from someone else):

0z NAM Snowfall Total:

0z GFS, NAM, ECMWF 500mb chart (All showing the cut-off):

Upper level systems are very tricky in that they seem to have a mind of their own, as this saying goes: An upper level low is a forecaster's woe.  Can't be any closer to the truth than that.  We will see how this evolves but it has been a long while since we began to watch this threat show up in the mid to long range and it is finally looking like things are about to get exciting for all of us.  How much rain and snow are we looking at I can't say.  However, rest assured you will want to stay tuned to this as we still have all of today and tomorrow .  Let the games begin...

Happy Thanksgiving! Models Perform a 180 Regarding Next Week

Before I get into the details, I just want to wish everyone a Happy Thanksgiving and may you stay safe and enjoy the day with your friends and family.  Weather should be perfect across much of the Southeast so I expect no travel issues with rain or anything of the sort (except for the potential highway congestion).

Ever since the latter part of yesterday, models seem to either not anticipate that cut-off system to develop in our region or it's been weakened substantially (e.g. 0z ECMWF).  It's been a long road of ups and downs with this potential scenario and right now it's looking more like a frontal passage with precipitation ahead of the cold front and possibly backside snow for the NC mountains and maybe Eastern TN.  Still not sold on any of the solutions yet, though I'm now beginning to lean more toward a less action than previously thought.  It still bears watching though, as it does suggest yet ANOTHER round of rain for some.  This will likely be our last event for the month since next week is when we will fall into December.  It continues to remain "cloudy" on how our pattern will behave but if you are to believe the 0z GFS, this will set the stage for the development of a potential -NAO blocking as it interacts with a nearby rossby wave that is located in the Hudson Bay area with increasing chances for a +PNA to be popped.  Nothing set in stone but definitely something to keep watch on.