The Jan 9-10 Storm Part 4

[Wow]

00z ruc is hanging onto the s/w even a little bit longer. good news. thru hour 13 still very much intact.

850's also trending colder over SW NC. Sfc high also trending stronger.

[RevDodd]

both probably. i think eventually the precip will smooth out over nc on the models. the only reason it stops in eastern NC is b/c the American models over shear in these situations. i'm not saying totals are going to ramp up, but smooth out further east.

Which would confirm what folks were suspecting all along ... there was something strange about how everything just stopped over in that area. We spent the last two days looking for the cause of something that might well have never occurred.

[Cold Rain]

both probably. i think eventually the precip will smooth out over nc on the models. the only reason it stops in eastern NC is b/c the American models over shear in these situations. i'm not saying totals are going to ramp up, but smooth out further east.

Thanks, I was thinking that if it were to stay in tact longer that it would keep the precip from dying as rapidly as the models had shown. I was also thinking that it could help to warm the mid levels quicker too, since it would be tracking up west of here. Don't know if that is correct or not. Good disco on the examiner, by the way.

[beanskip]

21z SREF out -- note the 1 inch precip bubble over NE Ga./extreme western SC.

[burrel2]

21z SREF and 18z NAM sets up the heavy axis of precip from huntsville to athens,GA.

The RUC is setting up the axis of heavy precip from huntsville to the NC/SC border.

I think judging by radar that the sref/NAM is going to win out on this one, we'll see...

[LMA1973]

Until the dry air moves in and that will limit QPF. What you are seeing on the radar now wont be there in 12-24 hours. Not for this area.

Radar is really impressive and it sure looks like QPF is way underdone simply because its gonna start sooner for most folks. Our local NWS doesnt have our snow starting till 1 pm tommorrow afternoon. Looking at thre radar I gotta think it will be here in less than 16 hrs, I hope this is the case since then obviously the QPF for us ( which is ugh) will be higher and we can actually get something outta this thing.

[packfan98]

A very good read from NWS in Raleigh:

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...

-- Changed Discussion --AS OF 830 PM SUNDAY...

OVERVIEW:

AN H5 LOW CURRENTLY IN EASTERN TX WILL DEAMPLIFY AND LIFT NORTHEAST

TO NEAR MEMPHIS TN BY 06Z TONIGHT...AND TO NEAR NASHVILLE BY 12Z

MON. THE ASSOCIATED SFC LOW PRESSURE SYSTEM CURRENTLY LOCATED JUST

SOUTH OF THE LA GULF COAST AT ~1006 MB WILL WEAKEN OVERNIGHT AS THE

ASSOCIATED H5 LOW DEAMPLIFIES AND LIFTS NORTHEAST INTO THE TN

VALLEY...WITH THE SFC LOW AT 1011 MB WHEN IT APPROACHES THE FL

PANHANDLE BY 12Z MON. PRECEDING THE ADVANCING LOW PRESSURE

SYSTEM...1028-1030 MB ARCTIC HIGH PRESSURE WILL BE IN PLACE OVER

CENTRAL NC. MEANWHILE...UPSTREAM OVER THE NORTHERN ROCKIES...AN H5

TROUGH WILL DEEPEN AND DIG INTO THE MIDWEST DURING THE DAY MON. A

SHEAR AXIS IS PROGGED TO EXTEND ESE FROM THE MIDWEST INTO THE DEEP

SOUTH AND CAROLINAS MON AFT/EVE...LIFTING NORTH INTO THE

MID-ATLANTIC BY 06Z TUE. THE SFC LOW IS PROGGED TO CROSS THE FL

PANHANDLE AND MOVE JUST OFFSHORE ALONG THE GA/SC COAST BETWEEN

00-12Z TUE...THEN DEEPENING AND TRACKING NORTHEAST ALONG THE

MID-ATLANTIC COAST BY 00Z WED AS THE H5 TROUGH DIGGING INTO THE

MIDWEST AMPLIFIES AND CLOSES OFF INTO A DEEP H5 LOW OVER THE OH

VALLEY.

PRECIPITATION CHANCES:

CHANCES FOR PRECIPITATION ACROSS THE AREA ARE NEAR 100%. LIFT WILL

PRIMARILY BE IN THE FORM OF LOW LEVEL WARM ADVECTION/ISENTROPIC LIFT

ASSOC/W THE RELATIVELY TIGHT MSLP/HEIGHT GRADIENT BETWEEN THE SFC

LOW ALONG THE GULF/SE COAST AND HIGH PRESSURE IN PLACE OVER THE

CAROLINAS. UPPER LEVEL LIFT WILL PRIMARILY BE ASSOC/W THE

AFOREMENTIONED SHEAR AXIS EXTENDING ESE FROM THE MIDWEST INTO THE

DEEP SOUTH/SE STATES...LIFTING NORTH THROUGH THE AREA BETWEEN

ROUGHLY 18Z MON AND 03-06Z TUE. WEAK LOW LEVEL WARM ADVECTION/

ISENTROPIC LIFT AND VERY LIGHT PRECIPITATION WILL CONTINUE ACROSS

THE AREA DURING THE DAY TUE AS THE LOW MOVES SLOWLY ALONG THE NC

COAST...ENDING BY 00Z WED AS THE LOW TRACKS NORTHEAST UP THE

MID-ATLANTIC COAST.

PRECIPITATION TIMING/TYPES:

THE LATEST 18Z MODEL RUNS CONTINUE TO SHOW PRECIP BEGINNING IN THE

SW PIEDMONT AND SANDHILLS BY OR SHORTLY AFTER 12Z...THE TRIAD/

TRIANGLE BETWEEN 18-21Z...AND THE NORTHERN PIEDMONT/NE COASTAL PLAIN

BY 21-00Z. WITH AN ARCTIC AIRMASS IN PLACE (TEMPS CURRENTLY IN THE

20S AND DEWPOINTS IN THE SINGLE DIGITS)...AND THE AFOREMENTIONED LOW

PRESSURE SYSTEM PROGGED TO REMAIN WELL SOUTH ALONG THE GA COAST

THROUGH 00Z TUE...FCST SOUNDINGS INDICATE THERMAL PROFILES

SUPPORTIVE OF ALL SNOW ACROSS THE ENTIRE AREA THROUGH 00-03Z TUE.

WITH PERVASIVE CLOUD COVER AND AN ARCTIC AIRMASS IN PLACE...TEMPS

WILL LIKELY HAVE TROUBLE MAKING IT MUCH ABOVE FREEZING ON

MON...ESPECIALLY IN THE SOUTH/SW WHERE PRECIP WILL BEGIN EARLIER.

EXPECT TEMPS TO FALL INTO THE MID/UPPER 20S EVERYWHERE AT THE ONSET

OF PRECIP GIVEN SUCH A DRY ANTECEDENT AIRMASS IN PLACE. AFTER 00Z

THE FORECAST BECOMES MUCH MORE COMPLICATED. FIRST...AS THE LOW

PRESSURE SYSTEM MOVES FURTHER NORTH UP THE SC COAST...LOW LEVEL

EASTERLY FLOW OFF THE ATLANTIC WILL STRENGTHEN AND A 3-5C H85 WARM

NOSE WILL PROGRESS WESTWARD INTO THE AREA...FIRST AT FAY/RWI...THEN

RDU...AND FINALLY (ALBEIT WEAKER) AT INT/GSO. THE LATEST 18Z

GUIDANCE SHOWS THE WARM NOSE MOVING ACROSS CENTRAL NC BETWEEN 03-09Z

TUE. SECOND...THE AFOREMENTIONED H5 SHEAR AXIS WILL MOVE NORTH

THROUGH THE CAROLINAS BETWEEN 18Z MON AND 03-06Z TUE...WITH

MID-LEVEL SUBSIDENCE/DRYING IN ITS WAKE...AND FCST SOUNDINGS SHOW

THE DENDRITIC GROWTH ZONE RAPIDLY DRYING OUT EVERYWHERE BETWEEN

00-06Z. WITH ALL THIS IN MIND...EXPECT PRECIPITATION TO TRANSITION

FROM SNOW TO SLEET AND THEN TO FZRA/FZDZ FROM EAST TO WEST IN

ASSOC/W THE H85 WARM NOSE IN THE 03-09Z TIME FRAME...HOWEVER...IF

SUBSIDENCE IN THE WAKE OF THE H5 SHEAR AXIS SHUTS OFF THE DENDRITIC

GROWTH ZONE BY 03-06Z...WE MAY SEE A TRANSITION TO LIGHT SLEET OR

FZRA/FZDZ EVERYWHERE BY 06Z...REGARDLESS OF THE PROGRESS OF THE WARM

NOSE OR THE FACT THAT THERMAL PROFILES COULD REMAIN SUB-FREEZING

BENEATH THE DENDRITIC GROWTH ZONE IN THE WEST/NW PIEDMONT. ONCE THE

TRANSITION OCCURS...GIVEN THE DEPTH/STRENGTH OF THE LOW LEVEL COLD

POOL AND PERSISTENT WEAK WARM ADVECTION ASSOC/W THE SLOW MOVING LOW

PRESSURE SYSTEM...EXPECT LIGHT FZRA/FZDZ TO PERSIST THROUGH LATE TUE

MORNING AT THE LEAST...WITH TEMPS EVENTUALLY APPROACHING OR POSSIBLY

EXCEEDING THE FREEZING MARK BY TUE AFTERNOON VIA LIMITED INSOLATION

THROUGH A 5 KFT THICK CLOUD DECK AND THE LATENT HEAT OF FUSION.

PRECIPITATION AMOUNTS/ACCUMULATIONS:

STORM TOTAL LIQUID EQUIV FOR THIS EVENT IS EXPECTED TO GENERALLY

RANGE FROM 0.25-0.50"...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. EXPECT

THE BEST CHANCE FOR WARNING CRITERIA SNOW (3-4"+) IN THE SW PIEDMONT

WHERE PRECIP IS EXPECTED TO BE THE HEAVIEST...ARRIVING THE

EARLIEST...AND REMAINING SNOW THE LONGEST. IT IS POSSIBLE THAT THE

WINTER STORM WARNING MAY NEED TO BE EXTENDED TO INCLUDE THE TRIAD IN

THE WEST/NW PIEDMONT AND CUMBERLAND/LEE/ HARNETT COUNTIES IN THE

SANDHILLS (ALL CURRENTLY UNDER A WINTER WEATHER ADVISORY)...FOR THE

POSSIBILITY OF WARNING CRITERIA SNOW (3-4")...DEPENDING PRIMARILY ON

THE ONSET AND INTENSITY OF PRECIP. ELSEWHERE...EXPECT A POTENTIAL

FOR 1-3" OF SNOW DEPENDING PRIMARILY ON THE ARRIVAL OF PRECIPITATION

AND THE SUBSEQUENT TRANSITION TO SLEET AND THEN FZRA...WITH THE

LEAST AMOUNT OF SNOW (PERHAPS <1") N/NE OF THE TRIANGLE. EXPECT ICE

ACCUMULATIONS GENERALLY ~1/10" IN MOST LOCATIONS ACROSS CENTRAL

NC...WITH THE POSSIBILITY OF A `SWEET SPOT` OUTSIDE OF THE WESTERN

PIEDMONT GETTING 1/10" TO 1/4" OF ICE ACCRUAL. -VINCENT-- End Changed Discussion --

[strongwxnc]

I also agree. The 00 is looking to follow those same thoughts!

21z SREF and 18z NAM sets up the heavy axis of precip from huntsville to athens,GA.

The RUC is setting up the axis of heavy precip from huntsville to the NC/SC border.

I think judging by radar that the sref/NAM is going to win out on this one, we'll see...

[beanskip]

0z NAM not nearly as yummy for N.C. re: precip starting early. Looks more like the 18z run (which was still great!).

I know, I know, nowcasting and radar, yada, yada, yada.

[burgertime]

0z NAM not nearly as yummy for N.C. re: precip starting early. Looks more like the 18z run (which was still great!).

I know, I know, nowcasting and radar, yada, yada, yada.

@6 hrs it looked like it was off so I wasn't even worried about it

[Wow]

I also agree. The 00 is looking to follow those same thoughts!

Precip shield still good, although there's some convection feedback it seems. DOn't need to worry about it now. We're in the nowcasting phase.

[sctvman]

Berkeley County Schools now are on a three-hour delay for tomorrow.

[beanskip]

18 Hours:

Precip shield still good, although there's some convection feedback it seems. DOn't need to worry about it now. We're in the nowcasting phase.

[Wow]

Still snowing here 24 hours from now per NAM

[futuremet]

Quick evening update

[downeastnc]

Until the dry air moves in and that will limit QPF. What you are seeing on the radar now wont be there in 12-24 hours. Not for this area.

I dunno I bet the SREF and RUC trend wetter for us and prolly by more than a little bit, I cant think of a single time in the past we have had a storm like this, with that kinda radaar setup that didnt end up giving us a decent amount of moisture. IF the shear stays strong and this thing shunts east then yeah I can see it killing our chances but the overall trend seems to indicate this is gonna be a wetter event for us. I bet by morning there are radar returns over most of NC.....

[beanskip]

Yeah, KEHO still snow at 27 hours -- we just lost all the QPF the 18z NAM gave us -- it took it back!

[strongwxnc]

With a wnc all in the .5. That would be better and help with the decrease amounts on this run/.

Still snowing here 24 hours from now per NAM

850 is a little more SE @30 compared to the 18 NAM run..

[FoothillsNC]

The NAM may be just a little colder in its progs. Just compared the first 18 hours with the RUC through 18 hours. Both utterly pound northeast GA and all the Upstate, western NC and the western and southern Piedmont. The RUC maintains the moisture throughout 18 (still more in GA), but it does bring the 850 just to near GSP by the end of its run, when that is getting close to the end of the event, or so I though. The damming shows up nicely on both models for extreme NE GA and the western Carolinas from CLT west. The UVV on RUC are excellent beginning by 6 am, really the rates are impressive the whole 18 hour run, esp bowing back from the Savannah Riv. Valley to the Upstate and the western piedmont NC. Imagine the snow could get to 1" per hour rates in some areas at times.

NAM has 1" in western Upstate and Athens, and southeast TN. CLT around .50", but the waffles in each run is to be expected...glad to see the basic same thing of approx .75" from southern TN to southern NC and below, which is about the SREF members. The event may last longer than 12 hours, but usually they don't, however the RUC is giving me pause as well as tonights NAM with the comma head so slow to leave. The door is still open to 1 foot totals somewhere.

[RaleighWx]

As far as timing goest, I think the band over N-C Georgia will translate ENE over the next few hours and I think by midnight to 1am a band of snow is setting up from the Upstate SC, SW NC reaching Charlotte by 1am. This band will take it's time spreading NE reacihng the southwest piedmont and Sandhilsls between 3-5am, but alof of guidance shows only slow painful progression NE for the Triangle, and we may not really get into precipitation untill mid to late afternoon tomorrow.

[burgertime]

Not to worried about what the NAM has to say TBH. Mother nature is gonna do what she does from here on out. I think this baby over performs.

[NEGa]

The NAM may be just a little colder in its progs. Just compared the first 18 hours with the RUC through 18 hours. Both utterly pound northeast GA and all the Upstate, western NC and the western and southern Piedmont. The RUC maintains the moisture throughout 18 (still more in GA), but it does bring the 850 just to near GSP by the end of its run, when that is getting close to the end of the event, or so I though. The damming shows up nicely on both models for extreme NE GA and the western Carolinas from CLT west. The UVV on RUC are excellent beginning by 6 am, really the rates are impressive the whole 18 hour run, esp bowing back from the Savannah Riv. Valley to the Upstate and the western piedmont NC. Imagine the snow could get to 1" per hour rates in some areas at times.

NAM has 1" in western Upstate and Athens, and southeast TN. CLT around .50", but the waffles in each run is to be expected...glad to see the basic same thing of approx .75" from southern TN to southern NC and below, which is about the SREF members. The event may last longer than 12 hours, but usually they don't, however the RUC is giving me pause as well as tonights NAM with the comma head so slow to leave. The door is still open to 1 foot totals somewhere.

wow - seeing some of the videos and webcams in atl has really whetted my appetite lol

that sounds too good to be true...thanks for all your analysis!

[Wow]

The NAM may be just a little colder in its progs. Just compared the first 18 hours with the RUC through 18 hours. Both utterly pound northeast GA and all the Upstate, western NC and the western and southern Piedmont. The RUC maintains the moisture throughout 18 (still more in GA), but it does bring the 850 just to near GSP by the end of its run, when that is getting close to the end of the event, or so I though. The damming shows up nicely on both models for extreme NE GA and the western Carolinas from CLT west. The UVV on RUC are excellent beginning by 6 am, really the rates are impressive the whole 18 hour run, esp bowing back from the Savannah Riv. Valley to the Upstate and the western piedmont NC. Imagine the snow could get to 1" per hour rates in some areas at times.

NAM has 1" in western Upstate and Athens, and southeast TN. CLT around .50", but the waffles in each run is to be expected...glad to see the basic same thing of approx .75" from southern TN to southern NC and below, which is about the SREF members. The event may last longer than 12 hours, but usually they don't, however the RUC is giving me pause as well as tonights NAM with the comma head so slow to leave. The door is still open to 1 foot totals somewhere.

This sounds like a solid 24 hr to me for W NC. 850 0 line doesn't cross into NC get into our area until 30 hrs. The NAM reducing QPF over us seems to be attributed to convective feedback. The precip amounts near the coast is much stronger.

[strongwxnc]

I second this statement. Looking good folks!!

wow - seeing some of the videos and webcams in atl has really whetted my appetite lol

that sounds too good to be true...thanks for all your analysis!

[BIG FROSTY]

The NAM may be just a little colder in its progs. Just compared the first 18 hours with the RUC through 18 hours. Both utterly pound northeast GA and all the Upstate, western NC and the western and southern Piedmont. The RUC maintains the moisture throughout 18 (still more in GA), but it does bring the 850 just to near GSP by the end of its run, when that is getting close to the end of the event, or so I though. The damming shows up nicely on both models for extreme NE GA and the western Carolinas from CLT west. The UVV on RUC are excellent beginning by 6 am, really the rates are impressive the whole 18 hour run, esp bowing back from the Savannah Riv. Valley to the Upstate and the western piedmont NC. Imagine the snow could get to 1" per hour rates in some areas at times.

NAM has 1" in western Upstate and Athens, and southeast TN. CLT around .50", but the waffles in each run is to be expected...glad to see the basic same thing of approx .75" from southern TN to southern NC and below, which is about the SREF members. The event may last longer than 12 hours, but usually they don't, however the RUC is giving me pause as well as tonights NAM with the comma head so slow to leave. The door is still open to 1 foot totals somewhere.

I know it's not your area, But how does it look in the n.foothills and n.piedmont ? TIA

[packfan98]

FWIW the new 0z NAM for your viewing pleasure:

[Carvers Gap]

For those living in NE TN, the 0z NAM shifted the 0.5 - 0.75 qpf line just a bit to the northwest - maybe like 25 miles. That may not sound like much. But the I-81 corridor is closer to that interval. That could make a big difference for folks living in Mountain City, Roan Mountain, Erwin, Johnson City, and maybe even Bristol. I have been having my doubts as to whether we can get 3" in this area due to the RUC. However, the NAM does give some hope. BTW, pulling for folks in SE TN, NE GA, SW NC, Upstate SC.

[Shawn]

FWIW the new 0z NAM for your viewing pleasure:

Ah, looks really close to that last 18z of the RGEM with that heavy moisture around NE GA/NW SC.

[FoothillsNC]

This sounds like a solid 24 hr to me for W NC. 850 0 line doesn't cross into NC get into our area until 30 hrs. The NAM reducing QPF over us seems to be attributed to convective feedback. The precip amounts near the coast is much stronger.

Usually our winter precip events don't go much past 12 hours of good precip, not including the tail end light spotty stuff. However I might see it lasting longer this time due to the comma head on all models being so slow to leave, and the pivot that goes on from the Savan. Valley up to western NC. I still do think the 74 corridor changes over to something other than snow at the last few hours of the event, but after a good snow has accumulated.

I know it's not your area, But how does it look in the n.foothills and n.piedmont ? TIA

everything is slowly inching upwards for you (and most of NC ) in the precip qpf overall. You're not likely to get a whole lot, but more than you were expecting, and I don't see why you can't get 4 to 6" from this, but further west closer to the south and west of your area probably begins going up faster. Still, all that matters are trends, and the event is almost upon us. In my opinion , the models are underestimating the precip in NC overall, and the models always have a time playing catchup..this case is no different. Still, the dumpzone is nw SC and ne GA and possibly southern third of NC from Rockingham, west.

[Cold Rain]

As far as timing goest, I think the band over N-C Georgia will translate ENE over the next few hours and I think by midnight to 1am a band of snow is setting up from the Upstate SC, SW NC reaching Charlotte by 1am. This band will take it's time spreading NE reacihng the southwest piedmont and Sandhilsls between 3-5am, but alof of guidance shows only slow painful progression NE for the Triangle, and we may not really get into precipitation untill mid to late afternoon tomorrow.

The new NAM shows around 3-4 inches of snow/sleet for Wake Co. The trend is up. Hopefully, that can continue and the precip can sneak in a bit earlier. If the trends are to be believed, I don't see how the NWS can't upgrade the advisories to warnings for a good portion of the area (seems they're already thinking of doing it for some portion of the advisory area).