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Already 4-5” from the foothills to the NC/VA line on 85 by 18z Friday.
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Wintry 1/20 - 1/23 Winter Storm
- Thread starter packfan98
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Big oof for the Pee Dee of SC and Wilmington
That would be lights out here.
Clem282340
Member
Do you have the snowfall map
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F5 does the best job with filtering Ptypes on the UKMET. Still looks like a foot for Burlington and Durham.
RAH Discussion (euro leading the pack, they're going with a GFS/ECMWF/GEFS blend):
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 345 AM Tuesday...
The well-advertised arctic cold front has continued to trend slower,
with the location of the front early Thursday morning forecast to be
located northeast to southwest over the Appalachians and stretching
southwest into southern Texas, with a roughly 1046mb arctic high
over the upper Midwest. Likely rain is forecast ahead of the front
with good these-e advection and moisture transport from the
southwest and a shortwave perturbation tracking through that is
currently located over southern California. Amounts should generally
be under a half inch. Highs were lowered a few degrees from the
earlier forecast to the low to middle 40s in the north and lower to
middle 50s in the south, owing to extensive clouds and light rain.
The front roughly passes through from north to south in the late
afternoon to early evening, with low-level thicknesses dropping to
around 1270-1300m and overnight lows turning quite cold in the upper
teens in the north to the middle 20s in the south. As front sags
south through the overnight, it should favor a changeover from rain
to snow, possibly a mix of sleet/ice as evident in forecast
soundings, as anafrontal isentropic upglide overrides the arctic
front. At the same time, precipitation will slowly taper off through
the overnight as the energy at mid-levels shifts out of the area.
Projected snow amounts are currently under an inch, though it is
worth noting that considerable uncertainty exists in these amounts
(including potential ptypes) and the forecast is likely to change,
so stay tuned for further updates.
Fri-Mon: The 00Z suite of deterministic and ensemble data has come
into better agreement on the overall pattern during this period,
though the finer details still need to be ironed out. The 00Z GFS,
which appeared an outlier relative to the GEFS/ECMWF
ensemble/Canadian, has trended wetter toward the 00Z ECMWF/Canadian
and GEFS. A mid-level trough over the Midwest on Friday, as well as
a secondary shortwave over southern Texas and northern Mexico will
track east into the Carolinas and Mid-Atlantic region by Saturday.
There continues to remain differences in the models on these two mid-
level shortwaves and whether or not they can phase to influence the
downstream pattern and a resultant surface low tracking off the
coast Friday night and Saturday. Regardless, the GFS/ECMWF show
evidence that the polar jet and subtropical jet may phase Fri-Sat,
putting central NC in the favored right entrance region, favorable
for precipitation and winter weather. There remains a lot of
questions, especially since the trend has been for the 850 mb low to
be further inland, which would potentially favor a wintry mix of
rain/snow/ice. Confidence in these details are low at the moment,
but suffice to say that it appears winter precipitation is likely in
the Fri-Sat period, so be sure to stay tuned as the details are
likely to change. The current forecast is largely a blend of the
GFS/ECMWF/GEFS. Temperatures during this time will be in the
20s/30s, some 15-25 degrees below normal, owing to the arctic air in
place. By Saturday night, the guidance indicates a 1030mb high
pressure settling in from the west, favoring a dry period for the
rest of the extended. The main story for the late weekend will be
temperatures remaining some 10-20 degrees below normal.
&&
So at least they believe something winter weather is coming now... My grid forecast for snow has also jumped from 40% to 70% for Friday night.
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 345 AM Tuesday...
The well-advertised arctic cold front has continued to trend slower,
with the location of the front early Thursday morning forecast to be
located northeast to southwest over the Appalachians and stretching
southwest into southern Texas, with a roughly 1046mb arctic high
over the upper Midwest. Likely rain is forecast ahead of the front
with good these-e advection and moisture transport from the
southwest and a shortwave perturbation tracking through that is
currently located over southern California. Amounts should generally
be under a half inch. Highs were lowered a few degrees from the
earlier forecast to the low to middle 40s in the north and lower to
middle 50s in the south, owing to extensive clouds and light rain.
The front roughly passes through from north to south in the late
afternoon to early evening, with low-level thicknesses dropping to
around 1270-1300m and overnight lows turning quite cold in the upper
teens in the north to the middle 20s in the south. As front sags
south through the overnight, it should favor a changeover from rain
to snow, possibly a mix of sleet/ice as evident in forecast
soundings, as anafrontal isentropic upglide overrides the arctic
front. At the same time, precipitation will slowly taper off through
the overnight as the energy at mid-levels shifts out of the area.
Projected snow amounts are currently under an inch, though it is
worth noting that considerable uncertainty exists in these amounts
(including potential ptypes) and the forecast is likely to change,
so stay tuned for further updates.
Fri-Mon: The 00Z suite of deterministic and ensemble data has come
into better agreement on the overall pattern during this period,
though the finer details still need to be ironed out. The 00Z GFS,
which appeared an outlier relative to the GEFS/ECMWF
ensemble/Canadian, has trended wetter toward the 00Z ECMWF/Canadian
and GEFS. A mid-level trough over the Midwest on Friday, as well as
a secondary shortwave over southern Texas and northern Mexico will
track east into the Carolinas and Mid-Atlantic region by Saturday.
There continues to remain differences in the models on these two mid-
level shortwaves and whether or not they can phase to influence the
downstream pattern and a resultant surface low tracking off the
coast Friday night and Saturday. Regardless, the GFS/ECMWF show
evidence that the polar jet and subtropical jet may phase Fri-Sat,
putting central NC in the favored right entrance region, favorable
for precipitation and winter weather. There remains a lot of
questions, especially since the trend has been for the 850 mb low to
be further inland, which would potentially favor a wintry mix of
rain/snow/ice. Confidence in these details are low at the moment,
but suffice to say that it appears winter precipitation is likely in
the Fri-Sat period, so be sure to stay tuned as the details are
likely to change. The current forecast is largely a blend of the
GFS/ECMWF/GEFS. Temperatures during this time will be in the
20s/30s, some 15-25 degrees below normal, owing to the arctic air in
place. By Saturday night, the guidance indicates a 1030mb high
pressure settling in from the west, favoring a dry period for the
rest of the extended. The main story for the late weekend will be
temperatures remaining some 10-20 degrees below normal.
&&
So at least they believe something winter weather is coming now... My grid forecast for snow has also jumped from 40% to 70% for Friday night.
Shaggy
Member
We need a colder trend!!!!
Morehead sounding serious alarm bells
Thursday night through Friday night...A high impact winter
weather event appears to be unfolding this period, with a signal
for potential significant icing for parts of ENC. The
aforementioned sfc cold front will stall off of the Southeastern
Seaboard this period. A wave of low pres develops along this
boundary Thur night. 18/00Z global models indicating a frontal
inversion developing over ENC Thu night and into Fri, and with
most guidance indicating 850 mb temps above freezing, limiting
the chances for snow (GFS is colder aloft and indicating some
snow, though a known bias of the GFS is cold thermal profiles
aloft). With sfc temps at or below freezing, the threat for a
prolonged period of ice/sleet will come into play, as upper flow
will be nearly parallel to the frontal boundary. ECMWF/CMC
continue to be especially concerning, indicating significant
freezing rain totals across much of the Coastal Plain counties.
GFS is now catching on to this scenario as well for the swrn
counties as it has trended further north with the warm nose with
this latest cycle.
Relied heavily on raw model T`s for temp forecast, as MOS
guidance is much too warm with sfc T`s in strong frontal
inversion/CAD events. Most of the FA along and west of a
Jacksonville to Plymouth line will not get above freezing on
Friday, and far wrn counties will remain in the 20s. This does
not bode well for ice accretion, which would be efficient and
significant with these temperatures.
Morehead sounding serious alarm bells
Thursday night through Friday night...A high impact winter
weather event appears to be unfolding this period, with a signal
for potential significant icing for parts of ENC. The
aforementioned sfc cold front will stall off of the Southeastern
Seaboard this period. A wave of low pres develops along this
boundary Thur night. 18/00Z global models indicating a frontal
inversion developing over ENC Thu night and into Fri, and with
most guidance indicating 850 mb temps above freezing, limiting
the chances for snow (GFS is colder aloft and indicating some
snow, though a known bias of the GFS is cold thermal profiles
aloft). With sfc temps at or below freezing, the threat for a
prolonged period of ice/sleet will come into play, as upper flow
will be nearly parallel to the frontal boundary. ECMWF/CMC
continue to be especially concerning, indicating significant
freezing rain totals across much of the Coastal Plain counties.
GFS is now catching on to this scenario as well for the swrn
counties as it has trended further north with the warm nose with
this latest cycle.
Relied heavily on raw model T`s for temp forecast, as MOS
guidance is much too warm with sfc T`s in strong frontal
inversion/CAD events. Most of the FA along and west of a
Jacksonville to Plymouth line will not get above freezing on
Friday, and far wrn counties will remain in the 20s. This does
not bode well for ice accretion, which would be efficient and
significant with these temperatures.
6z ICON looks the same. Here is the total QPF. But some of it does initially fall as rain. For RDU, it shows 1" totals. It looks like ~.75" falls as either snow or ice.
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Single wave at that.
Here's the 6z ICON snow, again this can be miss leading because of the other p-types that would occur.
Yeah it threw me off at first, when I didn't see the break between two systems.
6z GFS nw trend.. matching up decently with ECMWF and MMFS
NW shift
Yep I see it now. I think models are converging on a solution. Model agreementNW shift
Not only two waves, but three for some southern/eastern folks. Basically, Friday to Sunday storm...
Total Kucheria for hour 135 (all waves):
Total freezing rain at hour 135 (definitely a more impactful storm for eastern SC/NC folks, central GA):
I think it’s a real possibility that the central midlands will be involved in a big way this go around.
Forevertothee
Member
From GSP
ONG TERM /SATURDAY THROUGH MONDAY/...
As of 230 AM EST Tuesday: An active extended is in store as
models come into better agreement about a potent system entering
the eastern CONUS over the weekend. Deterministic guidance is
struggling to handle the system consistently, with the last 2 runs
of the ECMWF finally converging on a strong cyclone affecting
the Carolinas, even as latest run of the GFS begins to diverge
fromt his solution. The CMC has consistently depicted a solution
in line with the latest ECMWF. Such a solution would result in
cyclogenesis along a stalled frontal boundary south and east of
the forecast area, in turn producing a cyclone that shifts east
too quickly to appreciably warm 850mb temps. So, precipitation
develops atop bitterly cold low-level air, resulting in an all-snow
solution throughout Friday night and much of Saturday.
About 75% of GEFS members now depict some amount of wintry precip
occurring with this system, indicating the latest dry solution from
the deterministic run is an outlier; nonetheless, there remains
significant uncertainty with the timing and intensity of this
system, as well as what, if any, accumulations could be expected
should another winter system actually materialize.
In any case, the upper pattern becomes much less perturbed behind
this system, and cold, dry air builds in at the surface. A weak
reinforcing cold front should arrive Monday evening, but looks
too dry to warrant any PoPs.
ONG TERM /SATURDAY THROUGH MONDAY/...
As of 230 AM EST Tuesday: An active extended is in store as
models come into better agreement about a potent system entering
the eastern CONUS over the weekend. Deterministic guidance is
struggling to handle the system consistently, with the last 2 runs
of the ECMWF finally converging on a strong cyclone affecting
the Carolinas, even as latest run of the GFS begins to diverge
fromt his solution. The CMC has consistently depicted a solution
in line with the latest ECMWF. Such a solution would result in
cyclogenesis along a stalled frontal boundary south and east of
the forecast area, in turn producing a cyclone that shifts east
too quickly to appreciably warm 850mb temps. So, precipitation
develops atop bitterly cold low-level air, resulting in an all-snow
solution throughout Friday night and much of Saturday.
About 75% of GEFS members now depict some amount of wintry precip
occurring with this system, indicating the latest dry solution from
the deterministic run is an outlier; nonetheless, there remains
significant uncertainty with the timing and intensity of this
system, as well as what, if any, accumulations could be expected
should another winter system actually materialize.
In any case, the upper pattern becomes much less perturbed behind
this system, and cold, dry air builds in at the surface. A weak
reinforcing cold front should arrive Monday evening, but looks
too dry to warrant any PoPs.
NCWeatherhound
Member
GFS 6Z appears a bit further south, giving hope that NW trends are on hold this time around. Icing extends from SENC through the SC Midland to the CSRA. These are the FRAM totals, not total frozen precip.
Yep? I don’t see too many more big shifts on models.GFS 6Z appears a bit further south, giving hope that NW trends are on hold this time around. Icing extends from SENC through the SC Midland to the CSRA. These are the FRAM totals, not total frozen precip.
I might be eating those cold chasing moisture rarely work words lol
No change from me at the moment I’m still leaning on the GFS over the euro and a combination of some of the dry solutions. Below and east of the pink line however needs to watch out for winter weather chances with greater moisture returns. This will still teeter (red line) west or east but if anything I believe it ticks east occasionally in the days ahead! My max zone is still north east NC and south east Virgina. We wait and see how much showers can make it west torwards Charlotte. *Not a final forecast or depiction of any amounts for anyone. Please do not get upset at me. 
Snownut
Member
Still big NW shift, whether you think it did or not.
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new MMFS run coming in
This is a private model right? Extremely experimental made by like two dudes? I can't remember
Pretty easy to see where this is going, already .35 QPF in Charlotte 
It's me and my colleague's model. It's still experimental but it's 2 years old now & has gone through extensive testing. It has performed exceptionally the past 6 months.
I posted the last run earlier on pg 59 I believe. It had a nice ice storm for south carolina/ga last run.
Knew it! Thanks for posting it here man.
Snownut
Member
Yep NW Trend is evident, just how far NW it goes is still a guess. There gonna be a lot more people in the game for snow time this one is done. Even NE Ga gonna see some snow
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