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January 3-4 Storm Thread part II

rduwx

By rduwx,
in Southeastern States

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SENC

SENC

Posted
Posted

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..........................
&&

 

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kvegas-wx

kvegas-wx

Posted
Posted
5 minutes ago, downeastnc said:

GFS finally on board with other models, pretty much all models give me 6-10" now.....starting to feel this is actually a possibility.

gfs_asnow_seus_11.thumb.png.a59bd747e434fb5aa31bdfc3f362da8c.png

Even if the QPF isn't what is modeled, this is based on 10:1 ratios.  For those inland folks, we should see plenty of 12:1 or 15:1 ratios so I like where the GFS landed here.  Nothing indicating this will cutoff and camp out around ILM so this has a coastal scraper written all over it....albeit a strong one.  Maybe some thundersnow under some of those beachy bands?

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SteveVa

SteveVa

Posted
Posted

Some people have to stop wishcasting...or just tone it down a little bit. From AKQ afd released minutes ago 

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
02/12Z Models are overall still in good agreement wrt handling
of developing coastal low off the coast of FL and things have
genly not changed much since last night`s cycle. The NAM has
been an outlier and deepens the sfc low faster than the model
consensus and has been depicting much greater potential snow
amounts as well as throwing deeper moisture all the way to the
Piedmont. WPC has noted that the NAM has a bias at
overforecasting QPF in the cold sector with winter storms and
this fcst package will continue to favor the GFS/ECMWF and GEFS
ensemble means with the NAM mostly disregarded.
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BillT

BillT

Posted
Posted

dont think i could see anything from this but it sure is fun watching this storm develop with the first element moving down through montana and today it being an upper low in kanasas and now a second wave flying down behind it and slightly to the east, observing the actual storm develop and unfold is the "fun" in these for me.

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Regan

Regan

Posted
Posted
10 minutes ago, PackGrad05 said:

NWS RAH isn't going to budge yet.  They just issued their newest briefing 11 minutes ago and said they are still going 95 east.  Probably waiting on 00Z guidance.

I see and they did include a map with high end totals. That’s new. A way of putting the idea out there without taking full responsibility yet. 

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snowlover91

snowlover91

Posted
Posted
3 minutes ago, SteveVa said:

Some people have to stop wishcasting...or just tone it down a little bit. From AKQ afd released minutes ago 


.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
02/12Z Models are overall still in good agreement wrt handling
of developing coastal low off the coast of FL and things have
genly not changed much since last night`s cycle. The NAM has
been an outlier and deepens the sfc low faster than the model
consensus and has been depicting much greater potential snow
amounts as well as throwing deeper moisture all the way to the
Piedmont. WPC has noted that the NAM has a bias at
overforecasting QPF in the cold sector with winter storms and
this fcst package will continue to favor the GFS/ECMWF and GEFS
ensemble means with the NAM mostly disregarded.

How is it wish casting when now the GFS is similar to the 3km NAM, the RGEM has solid totals, UK has high totals and the Euro/EPS bumped up totals too? If we followed the GFS and Euro we would be saying snow only at the coast up until today while the 3km and RGEM led the way with saying better chances inland and the globals are following that.

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mackerel_sky

mackerel_sky

Posted
Posted
7 minutes ago, SteveVa said:

Some people have to stop wishcasting...or just tone it down a little bit. From AKQ afd released minutes ago 


.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
02/12Z Models are overall still in good agreement wrt handling
of developing coastal low off the coast of FL and things have
genly not changed much since last night`s cycle. The NAM has
been an outlier and deepens the sfc low faster than the model
consensus and has been depicting much greater potential snow
amounts as well as throwing deeper moisture all the way to the
Piedmont. WPC has noted that the NAM has a bias at
overforecasting QPF in the cold sector with winter storms and
this fcst package will continue to favor the GFS/ECMWF and GEFS
ensemble means with the NAM mostly disregarded.

They obviously didn't see the 18z GFS before they wrote this!? Bet they don't toss it? The GFS ? Most NWS offices love the GFS.

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nam0806

nam0806

Posted
Posted
3 minutes ago, BornAgain13 said:

Knowing MBY looks to not get hardly much at all is disappointing,  but it's still been fun tracking this thing... I hope you Eastern areas dont just get snow, I hope you get A Lot of it! Especially since y'al miss out on a lot of opportunities. 

Agreed. 

After looking at the 18z model runs, I'm still not convinced that Greensboro area posters see very much (if anything). Like I and others have said earlier, we need something more than incremental shifts west at this point. At 24-30 hours away from go time, I just don't know much more this can shift west.

Unless 0z shows this major jump west, I will throw in the towel. I also believe we're close to the time to be "nowcasting" and looking at radar trends, etc. instead of following relying solely on the shorter range models.

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TARHEELPROGRAMMER88

TARHEELPROGRAMMER88

Posted
Posted
27 minutes 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..........................
&&

 

"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. " They never said this is going away though, sooooooooooo. I am sticking with Ice and the occasional sleet pellet for now. Hoping for snow though, but living here at the coast the past 4 years after leaving Fayetteville has taught me this area is not the place to be during winter storms. I have seen half an inch since moving here lol. Lots of ice though. LOTS OF ICE!
 

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Tornadocane

Tornadocane

Posted
Posted

Been observing development of low pressure down by the keys.  Surface observations indicate a 1015MB low just east of Marathon, FL.  Plenty of surface observations confirm a 1015MB Circulation that is dropping at a slow rate, within an area of 1016MB pressures, moving across South Florida from East to West.  Also noticed sporadic winds from the South and Southwest accompanying this area.  This has provided us with a rainy day hear in Broward County Florida (Ft. Lauderdale-Hollywood Metropolitan area), where we’ve picked up .75-1.25” of rain today, and expect to receive another inch or more before all is said and done. 

I think this developing area of low pressure is continuing to slowly track west towards and through the keys, which is located around the most extreme temperature gradient.  I think the models have noticed this western placement of the primary area of low pressure. 

I am questioning whether we may see the initial location of the low placed further west along the more extreme temperature gradient, and whether this played a factor in the recent shift west on the models.

http://www.windmapper.com/?Loc=FL

https://earth.nullschool.net/#current/wind/surface/level/orthographic=-79.22,24.95,3000/loc=-80.048,25.285

http://www.usairnet.com/weather/maps/current/florida/barometric-pressure/

 

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kvegas-wx

kvegas-wx

Posted
Posted
9 minutes ago, Tornadocane said:

Been observing development of low pressure down by the keys.  Surface observations indicate a 1015MB low just east of Marathon, FL.  Plenty of surface observations confirm a 1015MB Circulation that is dropping at a slow rate, within an area of 1016MB pressures, moving across South Florida from East to West.  Also noticed sporadic winds from the South and Southwest accompanying this area.  This has provided us with a rainy day hear in Broward County Florida (Ft. Lauderdale-Hollywood Metropolitan area), where we’ve picked up .75-1.25” of rain today, and expect to receive another inch or more before all is said and done. 

 

I think this developing area of low pressure is continuing to slowly track west towards and through the keys, which is located around the most extreme temperature gradient.  I think the models have noticed this western placement of the primary area of low pressure. 

 

I am questioning whether we may see the initial location of the low placed further west along the more extreme temperature gradient, and whether this played a factor in the recent shift west on the models.

 

http://www.windmapper.com/?Loc=FL

https://earth.nullschool.net/#current/wind/surface/level/orthographic=-79.22,24.95,3000/loc=-80.048,25.285

 

http://www.usairnet.com/weather/maps/current/florida/barometric-pressure/

 

 

For your 12th post......you piqued my interest!  Pop this thing in the gulf and we have a whole different evolution tomorrow.

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Richatdjacks

Richatdjacks

Posted
Posted

Captain of the Grandeur said we will sail as expected to Charleston tomorrow and tomorrow night from the Chesapeake Bay. I fully expect high Seas with swells, while he didn't mention that, he said anyone else prone to sea sickness, go ahead and start your meds now.

Looks like a "fun" ride.

Sent from my Pixel XL using Tapatalk

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kvegas-wx

kvegas-wx

Posted
Posted
4 minutes ago, Richatdjacks said:

Captain of the Grandeur said we will sail as expected to Charleston tomorrow and tomorrow night from the Chesapeake Bay. I fully expect high Seas with swells, while he didn't mention that, he said anyone else prone to sea sickness, go ahead and start your meds now.

Looks like a "fun" ride.

Sent from my Pixel XL using Tapatalk
 

Enjoy your hurricane party.  Pics would be great when this thing is over!

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