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January 3-4 Storm Thread part II


rduwx

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Here's my forecast map...

MthTq72.png

 

Thoughts:

1. I feel that the progressive nature of the trough will prevent heavy totals over a wide area, though I think the snow will come down heavily in the targeted locales on the map...just not a super long duration storm like some of the blockbusters.

2. I feel there will be a warm nose surging aloft from Myrtle Beach to Wilmington to the Outer Banks, limiting totals there.

3. The area I feel could be the biggest surprise is from Savannah to Beaufort, SC, and W / NW of those areas where a highly anomalous snowfall could occur.  These areas are similar to the NW side of Atlanta in the early Dec storm where they are a bit west and southwest of where the warm surge aloft will want to work in with the strengthening 850mb low.

4. I don't think the QPF is quite right in E NC.  As the 850 mb low develops, a solid band of snow should develop a little NW of the 850 0 deg line in the area of max convergence, as seen in the image below between Raleigh and Greenville, NC.  The band would slowly work east thereafter.

5. The Flake Stickage Index is at an all time high with all of this cold air the past few days and low sun angle.  Good luck down east, and enjoy.

PBMoLf7.png

 

 

 

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5 minutes ago, griteater said:

Here's my forecast map...

MthTq72.png

 

Thoughts:

1. I feel that the progressive nature of the trough will prevent heavy totals over a wide area, though I think the snow will come down heavily in the targeted locales on the map...just not a super long duration storm like some of the blockbusters.

2. I feel there will be a warm nose surging aloft from Myrtle Beach to Wilmington to the Outer Banks, limiting totals there.

3. The area I feel could be the biggest surprise is from Savannah to Beaufort, SC, and W / NW of those areas where a highly anomalous snowfall could occur.  These areas are similar to the NW side of Atlanta in the early Dec storm where they are a bit west and southwest of where the warm surge aloft will want to work in with the strengthening 850mb low.

4. I don't think the QPF is quite right in E NC.  As the 850 mb low develops, a solid band of snow should develop a little NW of the 850 0 deg line in the area of max convergence, as seen in the image below between Raleigh and Greenville, NC.  The band would slowly work east thereafter.

5. The Flake Stickage Index is at an all time high with all of this cold air the past few days and low sun angle.  Good luck down east, and enjoy.

PBMoLf7.png

 

 

 

I hate the result, but greatly appreciate the work!! Great stuff.

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1 hour ago, SENC said:

Afternoon folks,Just got back from a SHORT road trip inland,, PLENTY of Salt trucks out, going from Wilm up to I-95..

WEST of I-95,, not so much, (salt trucks)..

So My "other" comrade, here in Wilm.. is fretting.. We'll see cold rain & Ice,, Well I think not..

PM Me directly @TARHEELPROGRAMMER.. LOL I think We just might Jackpot.. Dynamics & rates will keep us  in SN, I think.. (I've a vested interest as Huge Live  Oaks surround the house here..), though at first I think we'll see some ice accretion, then rates overcome we'll be ALL SN..

Here's the KILM AFD..

Take it for what it is worth..

Near term /through Wednesday/...
as of 300 PM Tuesday...Arctic air is expected to continue overnight
as high pressure over the mid-Atlantic states feeds more cold, dry
air southward. Excellent radiational cooling conditions this evening
should allow temperatures to plummet through the 20s and into the
teens in some outlying spots by midnight. A strong upper level
disturbance moving through Oklahoma this afternoon will move across
the deep south tonight, spreading a slowly thickening layer of mid
and high clouds eastward. These should become dense enough to impede
radiational cooling between 2-3 am Wednesday morning. For this
reason my forecast temperatures are generally 16-20 degrees for most
areas away from ocean influence, a little warmer than GFS/NAM MOS
numbers.

As the upper disturbance reaches Florida around noon on Wednesday,
surface low pressure will develop across the northern Bahamas. Large-
scale ascent ahead of the trough will weaken/dissipate the subsidence inversion that has covered the western Atlantic since this Arctic outbreak began a few days ago. What has been widespread
shallow convection/cold air stratocumulus will Blossom into deeper convection focused near and east of the Gulf Stream off the Florida and Georgia coast. This should pull the developing surface low
northward about 200 miles east of Jacksonville, FL, then northeastward by late Wednesday afternoon well east of Savannah and Charleston. (It's been interesting watching many of the models show
explosive deepening of this system Wednesday night and Thursday as convection feeds back into excellent dynamics aloft. Not all feedback is model fakery!)

We believe the NAM is displaying a westward and warm bias, and are
following more of a GFS/Canadian/ECMWF blend for precip amounts and
type. Precipitation should begin several hours later than was thought at this time yesterday, and will take the form of light sleet developing during the mid-morning hours around Georgetown, SC.
Sleet and freezing rain should then spread northward toward Cape Fear by early afternoon. A narrow nose of warm air spreading back onshore between 1500-4000 feet above ground level should be responsible for creating this mixed bag of precip types.

It will take several hours for a layer of very dry air between 4000-
10000 feet above ground level to moisten up, but once that happens expect precip
rates to increase substantially during the late afternoon hours. Areas west of Elizabethtown, Whiteville, and Conway should be west
of the westernmost extent of the coastal warm nose aloft,and any precipitation should take the form of snow for these inland areas.
Clouds and low-level evaporational cooling should keep temperatures
cooler than virtually any MOS guidance is indicating, and we're
forecasting highs ranging from 31-32 to maybe some mid 30s in spots.

The western edge of the precip shield should line up fairly closely
with Interstate 95. Even though we are upgrading to a Winter Storm
Warning for Florence, Dillon, and Lumberton counties, warning-level
snowfall is not expected for those entire areas. As of 3 PM Tuesday...shortwave crossing the northeast Gulf of Mexico will induce surface low off the eastern Florida coast Wed. The low will
deepen as it lifts northeast later Wed into Wed night, spreading wintry precip across the area. If thermodynamic profiles are correct, precip would be snow across much the area by the time the
period begins. The only exception would be along the NC coast where freezing rain/sleet cannot be ruled out during the first hour or two of the period. Still a lot of uncertainty with respect to the
storm's ultimate track and its strength (both of which will play a role in how far inland precip spreads and how much precip falls).

At first isentropic lift will be generating light precip, which will be falling into a cool and dry airmass. Isentropic lift gives way to frontogenesis at 850 and 700 mb with enhancement from increasing positive vorticity advection overnight. The biggest forecast concern remains the strength of the low level warm nose and how much sleet/freezing rain will fall before the transition to all snow takes place. Feel confident that measurable precip will fall across the eastern third of the forecast area and will go ahead and raise pop for these area with gradually decreasing pop farther west. Later Wed night the GFS shows enhanced positive vorticity advection and 850 frontogenesis producing a period of enhanced snow across portions of southeast NC. Should this verify, current snowfall totals for these areas would be too low.

Bulk of the precip Wed night ends around midnight with deep dry air wrapping around the backside of the exiting low. Strong cold advection will commence as the low exits. The cold advection coupled
with snow on the ground will likely result in lows several degrees below guidance and well below climo. Strong cold advection continues Thu with highs struggling to reach mid 30s despite mostly sunny skies. Partial thickness values point to lows in the mid teens Thu night with continued cold advection, although in a much weaker state, clear skies and at least some form of snow pack across
portions of the area..........................
&&

 

I'm holding out hope for at least a few inches of snow (I'm up just north of Snows Cut) for sure.  It does look like a sloppy icy mix when it gets going in the afternoon, just hoping for an early changeover to snow around dusk.

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I know we all are hung up on Models and such, but eyes need to really focus on what is taking place REAL TIME down in the Gulf Coast and the Atlantic side of Florida. Looks like there is action taking place in the Gulf ATTM. This is BOUND to affect the area(s) of LP Development, hence, overall dynamics. Some interesting Radar returns from those areas. I wonder what is going on with pressures down that way?? Thoughts? 

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4 minutes ago, Rankin5150 said:

I know we all are hung up on Models and such, but eyes need to really focus on what is taking place REAL TIME down in the Gulf Coast and the Atlantic side of Florida. Looks like there is action taking place in the Gulf ATTM. This is BOUND to affect the area(s) of LP Development, hence, overall dynamics. Some interesting Radar returns from those areas. I wonder what is going on with pressures down that way?? Thoughts? 

was thinking the same thing, radar returns beginning to light up in places the models never showed precip

this is going to be fun to watch

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29 minutes ago, WakeCountyWX said:

Wall is a great follow on Twitter, BTW. Great info

This was said off of what the models are showing. I've been watching the GOES-16 satellite, but I wish there was a really good way to see what was actually happening in the 500 lvl in real time. :(

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