Wednesday, November 30, 2011

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.     


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