Mid to Long Term Discussion 2018

[JoshM]

1 minute ago, CAD_Wedge_NC said:

That's pretty much just what the ensembles and the Euro have been trying to tell us for the past few days.

Sounds good to me. 10 inches of snow or 1" ZR, I'll take the first one

[UpstateSCGamecock]

GSP

LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
As of 435 AM Sunday: The latter part of the week looks quiet
and seasonally cool with temps remaining below normal as high
pressure moves across the region on Thursday and weakens offshore
Friday. From that point onward, the situation gets much more
interesting and complicated because of a split flow pattern
that supports a cold continental high over the nrn Plains and a
developing srn stream system on Friday into Saturday. Have been
looking at this one for the last few days with some interest and it
still looks like a race between the arrival of the cold air spilling
over the mtns and the precip developing along a warm front caught
up in the fast-moving confluent flow aloft. The model trends are
looking more compelling early this morning, as for the last few
runs the models show decent consistency with the sfc high moving
over the Midwest and bridging over the mtns by Friday evening in
time to bring the low level dry air into the nrn tier just ahead
of the precip, which arrives from the WSW after midnight. In other
words, the cold air wins the race, at least for the area along/N
of I-40. In this scenario, the precip development would quickly
lock in a cold air damming wedge that would bring even more cold
air down from the north. The result would be a wintry mess across
at least the nrn parts of the fcst area starting by sunrise and
continuing thru Saturday and into Saturday night as the primary
sfc low moves past to the south and then off the mid-Atlantic
coast Sunday morning. The GEFS plume diagrams bear out this trend
across the NW Piedmont and mtns as well, with the p-type looking
like an equal chance of all four types on Saturday/Saturday
night. As for the forecast, some tweaks have been made to delay
the onset into Saturday morning, but eventually a likely prob
will be featured. Have followed the temp trend downward, which
improves the chances of wintry precip across the NC part of the
fcst area. For this issuance, the consensus among neighboring
offices was to limit the precip to rain v. snow, but the reality
would be something quite a bit more messy if the model guidance
was to verify. There is plenty of time to fine tune this. For
the time being, suffice to say that readers should start paying
attention to the winter storm potential next weekend.


.

[Blue_Ridge_Escarpment]

6Z FV3 no longer cuts. 

[BretWx]

Another pleasant clown map. 

[BullCityWx]

GEFS at 6z has significantly lower snow means

[FallsLake]

RAH highlights the western piedmont as the favored location to see wintery precip (for their forecast area):

Models differ a bit with timing of said disturbance (GFS roughly 12 hours faster than the ECMWF), but are rather consistent with a Miller "A" type winter storm pushing northeast out of the Gulf Coast states late week, likely to cross portions the Carolinas sometime pre-dawn Saturday through pre-dawn Sunday. With a strengthening high to the north of the region, a pretty strong CAD type regime will be in place, especially across the northwester Piedmont counties. This should allow for at least some sub-freezing temperatures during the favored portion of the diurnal cycle, helping a wintry mix of snow/sleet/freezing rain/rain to be possible, primarily across western NC and the foothills. The setup is a bit too uncertain to point to exact impacts, however, areas most likely to see a period of wintry mix will be along the northern and western Piedmont counties of the state, including portions of the Triad region.

The current setup does remind me of the 2009 storm. Wasn't great for my location (~2" of snow then rain) but good for folks farther west. 

https://climate.ncsu.edu/climate/winter/event_details?e=503

 

[ajr]

FV3 is nice, temperature outputs still seem strange.. with the PV in SE Canada and a 1035+ HP just to the north of us it seems temps should be lower than modeled

[Blue_Ridge_Escarpment]

3 minutes ago, Queencitywx said:

GEFS at 6z has significantly lower snow means

Makes sense as soon as the OP comes on board....

[FallsLake]

8 minutes ago, ajr said:

FV3 is nice, temperature outputs still seem strange.. with the PV in SE Canada and a 1035+ HP just to the north of us it seems temps should be lower than modeled

That look would strengthen the low level cold (CAD); as long as there is cold air available to the north. On this model there are dew points in the teens initially over us and then up in VA at 168. So again, you would think surface temps would be colder. 

[Buddy1987]

That 6z FV3 run was an absolute thing of beauty! Complete text book with the banana high setup and thus the end result with precip. You have dual structured highs in the Green Bay WI and the main high situated in the Poughkeepsie NY area funneling the cold. If the FV3 taken at face value verified many people on this board would be very happy with the end result. 

[CentralNC]

I think Dec 8-9 deserves it's own thread.

[olafminesaw]

Much more reasonable FV3 map, to balance out the general clownishness around here. I would take this to the bank. Of course, we still have an eternity for things to go wrong, never forget that.

[Orangeburgwx]

7 hours ago, UpstateSCGamecock said:

.

8/50 show me snow... I'm starting to like those chances

[SENC]

Well dern @Orangeburgwx, We are just about the same Latitude, (well, more south &  West), though you are West of Me.. I had to look up your local..  

I Always have the Warm~nose worries as I'm, "on the Beach".. Though those Ensemble members are starting to look promising for Us?..    We need just alil more Southward "trend"..  Sorry upstate Folks.. Hopefully It's Our Turn, though I hope Everyone see some Flakes! 

[Orangeburgwx]

3 minutes ago, SENC said:

Well dern @Orangeburgwx, We are just about the same Latitude, (well, more south &  West), though you are West of Me.. I had to look up your local..  

I Always have the Warm~nose worries as I'm, "on the Beach".. Though those Ensemble members are starting to look promising for Us?..    We need just alil more Southward "trend"..  Sorry upstate Folks.. Hopefully It's Our Turn, though I hope Everyone see some Flakes! 

No doubt about that, everyone is going to get something (which is why I started the thread) now the question is who gets what and how much

[griteater]

I moved my post to the storm thread that was started - https://www.americanwx.com/bb/topic/51790-early-christmas-present-event/

 

[FallsLake]

<besides the upcoming storm>

Not sure what to think about the indices today:

PNA - Looks to drop negative in the medium range but go back positive in the LR - Good

AO - Goes positive then negative in the medium range, and then is a tossup in the LR - Not sure

NAO - Goes strongly positive in the medium range and then drops to negative in the LR  - Good

Definitely better than the last few days. Hoping for at least a cold Christmas. 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

 

[Orangeburgwx]

10 minutes ago, FallsLake said:

<besides the upcoming storm>

Not sure what to think about the indices today:

PNA - Looks to drop negative in the medium range but go back positive in the LR - Good

AO - Goes positive then negative in the medium range, and then is a tossup in the LR - Not sure

NAO - Goes strongly positive in the medium range and then drops to negative in the LR  - Good

Definitely better than the last few days. Hoping for at least a cold Christmas. 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

 

That feels very foreboding for a Christmas storm...

[FallsLake]

9 minutes ago, Orangeburgwx said:

That feels very foreboding for a Christmas storm...

That would be great but I would be good with just the cold. A warm Christmas sucks.. 

[Orangeburgwx]

LONG TERM /WEDNESDAY THROUGH SUNDAY/...
No significant changes in the longer term pattern.  Surface high
pressure will remain across the region into Friday morning, with
another cold front then moving into through the area Friday
afternoon, and pushing well south of the cwa into Saturday.   Dry
conditions will occur Wednesday into Friday, then expect precip
chances to be on the increase Friday night through Saturday due to
overrunning wedge pattern setting up east of the Appalachians.
Temperatures behind the front in the wedge will be much colder, with
overnight lows in the 30s, and highs in the 40s to lower 50s Friday
night into Saturday.  With overnight lows forecast in the lower 30s
over the northernmost counties of the cwa, models do indicate the
potential for precip challenges across northern portions of the cwa
early Saturday morning, with a rain/snow mixture possible over the
Pee Dee/Catawba regions near the state line.  Confidence low and
much can change between now and then, but will continue to monitor
through the week.

&&

Oh boy they said the "s word"...

 

[cbmclean]

34 minutes ago, FallsLake said:

That would be great but I would be good with just the cold. A warm Christmas sucks.. 

Ah, the fond memories of Christmas 2015 when I had to swat the gnats and mosquitoes away.

[FallsLake]

26 minutes ago, cbmclean said:

Ah, the fond memories of Christmas 2015 when I had to swat the gnats and mosquitoes away.

Lol.. yep, had to turn the AC on. 

[mackerel_sky]

15 hours ago, JoshM said:

Ladies and gents, your clown map (if the soundings are to be believed, it might not be so clownish west of 77)

Says initialize 6z??

[griteater]

After our storm, Canada goes warm mid month in a big +EPO pattern.  It looks like we will be up and down with temperatures in the southeast, not torching.  Potential looms in January though as the stratospheric polar vortex continues to be under the attack and may get a heavy blow in late December - https://twitter.com/MJVentrice/status/1069689390195187712

Also, the tropical forcing will be returning back to the El Nino-like / Western Hemisphere phases by month end / into January...positive signs ahead.

 

[cbmclean]

A very encouraging post from psuhoffman over on the MA thread (he seems like the real deal, so I put a lot of stock in what he says)

Note of course that his thoughts on snow are really only applicable when it comes to the MA, but the thoughts on overall patters should be applicable for us as well.

3 hours ago, psuhoffman said:

I don't believe them because the weeklies show what they show. I believe them because they show what we logically expected the pattern to evolve into given nino climo and all the signs so far this season. I definitely don't regret keeping my bullish snowfall forecast unedited. 

I don't know what more to wait for. The mjo keeps cycling cold then dying without any grand tours of the warm phases. The enso looks pretty close to the composite of all our big years. The PV is a weak pathetic pos this year that's getting beat around like a piñata. Everytime we get a trough in the east its storms galore. We're running cold and every attempt to flip quickly reverts. The nao looks ok and tends to only trend better later in nino years. 

 Im all in. If I'm wrong I'm wrong. Won't be the first or last time but I've seen enough. I expect this to be a big year and will be disappointed (and very wrong) if it's not. 

 

[FallsLake]

Maybe a few snow showers tonight across the NE Piedmont / Northern Coastal Plain:

Tonight, the fast moving upper disturbance will continue to approach from the west northwest. The lift associated with this system will work with available moisture in the lower half of the atmosphere to produce extensive cloudiness across the northern counties. Well after midnight, a few showers expected to develop over the northern Piedmont. Temperature profiles aloft suggest that enough saturation in the favored dendrite layer to produce a few snow showers or rain/snow showers during the pre dawn hours into early Wednesday morning across the northeast Piedmont and northern Coastal Plain. Where the snow showers occur, they should last no more than 15-30 minutes with the snow melting on impact due to the warm ground temperatures. Min temperatures generally in the low-mid 30s.

[griteater]

Saw this posted, but the updated solar cycle chart is going for deep solar minimum over each of the next 4 winters, at least

[Orangeburgwx]

4 hours ago, griteater said:

Saw this posted, but the updated solar cycle chart is going for deep solar minimum over each of the next 4 winters, at least

Woah

[WinstonSalemArlington]

Winston-Salem airport reporting snow showers now. Anyone seeing this?

[GreensboroWx]

Yes, I saw a few flurries on my way in to work.