Deep South Winter 2017-2018 (LA, MS, GA, FL, NC, SC)

[Sleet/Snow]

Also, keep a wary.eye on the developing Low Pressure system off the immediate Southeast Atlantic coast the middle of this week. GFS shows rapid cyclogenesis with this storm, forecasting 960 mb off New England by Thursday evening.

All it would take is for this system to wobble left closer to the coast than what the models are showing to significantly change the forecast the next couple of days.for everyone along the Southeast U.S. coastal region northward.

Just a quick observation.

Yep, 12z NAM shows some frozen precip across northeast FL and coastal portions of the Carolinas Wednesday into Thursday.

We need it to move along the gulf coast prior to that for my area.

[northjaxpro]

Yep. I have been discussing the potential wintry mix scenario for middle of this week on the forums, especially in this thread and the Florida Weather thread since I live here in Jax area. Yeah, both the NAM and now even the GFS shows potential of wintry precip along the coast from Jacksonville northward up the coast. Keeping a close watch on this interesting potential situation.

[South Texas Storms]

Also, keep a wary.eye on the developing Low Pressure system off the immediate Southeast Atlantic coast the middle of this week. GFS shows rapid cyclogenesis with this storm, forecasting 960 mb off New England by Thursday evening.

All it would take is for this system to wobble left closer to the coast than what the models are showing to significantly change the forecast the next couple of days.for everyone along the Southeast U.S. coastal region northward.

Just a quick observation.

Yep, 12z NAM shows some frozen precip across northeast FL and coastal portions of the Carolinas Wednesday into Thursday.

We need it to move along the gulf coast prior to that for my area.

I hear you! I want snow too...hoping for a surprise!

[northjaxpro]

12Z GFS inches the potential storm system a bit closer to the coast. GFS now showing potential snow accumulations along the South and North Carolina coasts northward, a significant change from just earlier today at 6Z when it did not show accumulations.

Interesting. The model runs the next 24 hours are really going to be quite intriguing.

Also 12Z GFS deepens this storm further to 953 mb off the New England coast by 18Z Thursday afternoon.

[JSDS]

Is it showing anything for SE Louisiana?

[StormingB81]

Local met saying possible snow flurries as far south as Orlando

[northjaxpro]

Is it showing anything for SE Louisiana?

Yes. 12Z NAM shows light snow for Southeast LA around New Orleans, south to the coast. The NAM has become a bit more aggressive with the upper level disturbance moving along the Northern Gulf Coast region during the period from late Tuesday evening - Wednesday. afternoon.

[bella_may]

Is it showing anything for SE Louisiana?

Yes. 12Z NAM shows light snow for Southeast LA around New Orleans, south to the coast. The NAM has become a bit more aggressive with the upper level disturbance moving along the Northern Gulf Coast region during the period from late Tuesday evening - early Wednesday.

Are we looking at the same 12z NAM? Mine doesn't show anything like that

[northjaxpro]

Oops... I was looking at NAM yesterday's run regarding LA/ Gulf region . Got the model runs accidentally mixed up. Sorry about that.

[LarryWx]

Excellent posts, Jax! Plain and simple, this remains the biggest threat for a significant to major SE coastal winter storm (and much of N FL including even Gainesville) since 1989 by a mile since the great 12/1989 storm and the threat is only increasing.

[northjaxpro]

Take the time if you have the opportunity Larry to read the AFD from the Jax NWS office mets. They devoted much of the discussion to the wintry precip potential on Wednesday. It took them awhile to really start putting more attention to this. They are now.

[LarryWx]

The 18Z NAM clobbers practically the entire GA/SC/far NE FL immediate coast with 0.75" of qpf, the biggest hit of any model run yet except the 6Z ICON (German model) clobber! So, 0.75" of qpf that is practically all wintry except maybe not practically all wintry NE FL (but still probably majority wintry). The 0.50" line now goes inland 50+ miles much of SE. A bullseye of 1.5" is 20 miles offshore Hilton Head. Often the NAM is wet biased (and ICON may be too). So, I'm quite wary about that. However, even if the qpf is cut in half, this is still a major hit. Also, the trend has been wetter. So, these amounts may not be as inflated as usual, if at all.

The key to me as to whether or not this would likely be a major SE coastal hit is the direction of movement of the surface low from Grand Bahama Island. If it moves NE from there like most models, including the 18Z GFS, have been showing, it likely not be an historic hit though it could still have major impact in some areas. However, if it were to move NNE from Grand Bahama like recent NAM and ICON runs have been showing, the chances of this ending up historic would go up significantly.

[Jag95]

The short wave trough will swing through here early Wednesday morning, so any chance of flurries (however low that might be) around the northern Gulf Coast will be around that time. GFS shows some precipitation just off shore during that time. The dew point is going to be really low though.

[northjaxpro]

The 18Z NAM clobbers practically the entire GA/SC/far NE FL immediate coast with 0.75" of qpf, the biggest hit of any model run yet except the 6Z ICON (German model) clobber! So, 0.75" of qpf that is practically all wintry except maybe not practically all wintry NE FL (but still probably majority wintry). The 0.50" line now goes inland 50+ miles much of SE. A bullseye of 1.5" is 20 miles offshore Hilton Head. Often the NAM is wet biased (and ICON may be too). So, I'm quite wary about that. However, even if the qpf is cut in half, this is still a major hit. Also, the trend has been wetter. So, these amounts may not be as inflated as usual, if at all.

The key to me as to whether or not this would likely be a major SE coastal hit is the direction of movement of the surface low from Grand Bahama Island. If it moves NE from there like most models, including the 18Z GFS, have been showing, it likely not be an historic hit though it could still have major impact in some areas. However, if it were to move NNE from Grand Bahama like recent NAM and ICON runs have been showing, the chances of this ending up historic would go up significantly.

Yes Larry I saw the changes earlier after the 6Z runs. The earlier GFS runs maintained up until today that the intensifying Low Pressure system would move farther off shore and not impact the Eastern U.S. seaboard.

However, the upper shortwave disturbance on this afternoon's NAM run looks rather strong and the disturbance is also showing a better moisture field by Wednesday. Also. the shortwave. is hanging back a bit over the Northeast GOM/Big Bend region by 18Z Wednesday afternoon. The broad upper trough axis is really deepening at this juncture. This afternoon's NAM and to some extent, the 18Z GFS, are hinting at the upper trough axis possibly being slightly more negatlively tilted. That orientation most definitely would help pull the intensifying storm closer to the Southeast U.S coast on Wednesday and Wednesday evening, before pulling northeast away from the region by Thursday morning.

So, this situation is getting more intriguing by the hour. The prospects imo of seeing potential wintry precip across extreme inland Northeast Florida northeast up into Southeast Georgia are beginning to increase. The prospects also farther north along the coast from the Carolinas to New England also are increasing with this storm. It will all come down to the usual placement/track of the Low Pressure and how far inland the precipitation will get into that very cold air. which will already be well entrenched across the Deep South middle of this week.

More later....

[Sleet/Snow]

NWS in Jackson has added a 10% chance of light snow for Tuesday night for the Hattiesburg, Ms area.. could this be a trend toward more moisture being available ?

[Jag95]

NWS in Jackson has added a 10% chance of light snow for Tuesday night for the Hattiesburg, Ms area.. could this be a trend toward more moisture being available ?

I see where New Orleans put a slight chance of flurries in their forecast as well. That is a fairly potent looking upper level system depicted on the models. Hopefully it'll squeeze out a few flakes on the way through.

[GTStorm]

The 18Z NAM clobbers practically the entire GA/SC/far NE FL immediate coast with 0.75" of qpf, the biggest hit of any model run yet except the 6Z ICON (German model) clobber! So, 0.75" of qpf that is practically all wintry except maybe not practically all wintry NE FL (but still probably majority wintry). The 0.50" line now goes inland 50+ miles much of SE. A bullseye of 1.5" is 20 miles offshore Hilton Head. Often the NAM is wet biased (and ICON may be too). So, I'm quite wary about that. However, even if the qpf is cut in half, this is still a major hit. Also, the trend has been wetter. So, these amounts may not be as inflated as usual, if at all.

The key to me as to whether or not this would likely be a major SE coastal hit is the direction of movement of the surface low from Grand Bahama Island. If it moves NE from there like most models, including the 18Z GFS, have been showing, it likely not be an historic hit though it could still have major impact in some areas. However, if it were to move NNE from Grand Bahama like recent NAM and ICON runs have been showing, the chances of this ending up historic would go up significantly.

Yes Larry I saw the changes earlier after the 6Z runs. The earlier GFS runs maintained up until today that the intensifying Low Pressure system would move farther off shore and not impact the Eastern U.S. seaboard.

However, the upper shortwave disturbance on this afternoon's NAM run looks rather strong and the disturbance is also showing a better moisture field by Wednesday. Also. the shortwave. is hanging back a bit over the Northeast GOM/Big Bend region by 18Z Wednesday afternoon. The broad upper trough axis is really deepening at this juncture. This afternoon's NAM and to some extent, the 18Z GFS, are hinting at the upper trough axis possibly being slightly more negatlively tilted. That orientation most definitely would help pull the intensifying storm closer to the Southeast U.S coast on Wednesday and Wednesday evening, before pulling northeast away from the region by Thursday morning.

So, this situation is getting more intriguing by the hour. The prospects imo of seeing potential wintry precip across extreme inland Northeast Florida northeast up into Southeast Georgia are beginning to increase. The prospects also farther north along the coast from the Carolinas to New England also are increasing with this storm. It will all come down to the usual placement/track of the Low Pressure and how far inland the precipitation will get into that very cold air. which will already be well entrenched across the Deep South middle of this week.

More later....

The NWS forecast for SAV (from CHS) doesn't really latch on to any significant precip just yet...only 30% for snow / sleet on Wed AM then clearing out. from my amateur eyes, looks like the 18Z GFS more-or-less supports this. The 00Z NAM, on the other hand...now that would be fun. Which means we're not likely to see it. But one can dream...

[northjaxpro]

Happy New Year!! Well, after I have. chatted on the threads about the potential of seeing frozen precipitation going all.the way back to last week, this morning's models are in good agreement that from late tomorrow night, all day Wednesday, and up to early Thursday morning, The NWS Jax WFO has now a 60% chance (likely probability) that Northeast Florida and Southeast Georgia will have rain, freezing rain, sleet and eventually the changeover to all snow

The Low Pressure area will undergo rapid cyclogenesis as the potent upper air disturbance moving over the Northern GOM deepens and sharpens the base of the broader, large scale upper trough right over North Florida. on Wednesday.

Thermal profiles suggest that the changeover to all snow should be complete sometime from between 15Z to 21Z late Wednesday afternoon.

There will be much more coming later about this potential HUGE event in the next 48- 72 hours across this area.

I am pretty sure we will have the anticipated winter weather special statements to potential advisories by the NWS, especially beginning late Tuesday, and especially during all day on Wednesday during the height of this event.

All this, and I have yet to really get into how cold these temps are going to be this week. Hard Freezes (temps at or below 28 degrees) are likely, especially Thursday- Saturday mornings across interior Noth and Northeast Florida.

More later....

[northjaxpro]

Also, the prospects for significant snowfall accumulations look really good all along the Southeast U.S. coastal region, especially Wednesday through Thursday morning, from the Carolinas northward to the DELMARVA region.as the intensifying Low Pressure area moves by just off the coast, but close enough for the.significant wrap-around moisture on the back side of the storm system to impact that region as well.

[Jag95]

When that short wave phases with the developing low off of Florida it really blows the lid off. NAM is showing 19 inches centered on SC with a lot being ZR but capping off with heavy snow. Still hoping for just a few flurries over here. NAM and GFS show precip just off shore when the trough passes. New Orleans still has a chance for light snow in their forecast but further north there will be a lot of dry air to work out.