Winter storm/, 12/14-12/15

[Nashville_wx]

 As we get through this event and break into the new week, temperatures are going to be down right cold. Its early still, but I see this threat become a possibility to cause more widespread hazards than this event unfolding Saturday night.... Recent model runs have shown some sort of low pressure developing over Tx. The 12Z gfs shows this unfolding at 132 hours. Keep in mind the placement of the High Pressure to the NE. To be very simple here, we are looking at low level cold with warm air riding above.Earlier this fall I made a comment that I felt this year would produce a ice storm that would be of some significance. At this frame out lots can happen as we know that from our recent fun watching the models. What I am doing is keeping in mind surface temps will be cold, QPF look to be generated but with SW flow @ 850mb you tell me how this seems to pan out.





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Looking at 150 we see the Low pressure over Middle Tennessee. One thing that I can be confident in is that there is going to be a lot of snow cover to the north and low level cold air that is left in place. That is it for now.

[tennessee storm09]

yeppers, that setup there screams ice my friend. something to keep a eye on for sure

[toastido]

As we get through this event and break into the new week, temperatures are going to be down right cold. Its early still, but I see this threat become a possibility to cause more widespread hazards than this event unfolding Saturday night.... Recent model runs have shown some sort of low pressure developing over Tx. The 12Z gfs shows this unfolding at 132 hours. Keep in mind the placement of the High Pressure to the NE. To be very simple here, we are looking at low level cold with warm air riding above.Earlier this fall I made a comment that I felt this year would produce a ice storm that would be of some significance. At this frame out lots can happen as we know that from our recent fun watching the models. What I am doing is keeping in mind surface temps will be cold, QPF look to be generated but with SW flow @ 850mb you tell me how this seems to pan out.

Looking at 150 we see the Low pressure over Middle Tennessee. One thing that I can be confident in is that there is going to be a lot of snow cover to the north and low level cold air that is left in place. That is it for now.

Yep.  HUN is already concerned about this as well.  Could get bad around the TN valley...  ICE.  Ick.

[Nashville_wx]

OHX is talking about this as well and has it in the AFD which I would like to say is the longest I have seen in awhile 

[kailynleto | Nightwolf]

Yeah this thing is longer than John Kerry's face:

area forecast discussion
national weather service nashville tn
419 pm cst fri dec 10 2010

.discussion...
active weather pattern coming up. but currently...sfc ridge
stretches along the atlantic coast with southerly winds and warmer
temps across the mid state.

the next weather maker for the mid state is still located back in se
montana. but we will see this system dig quickly to the southeast
and form a closed low over in by 12z sunday.

we can expected sct light showers to develop across western zones as
early as late tonight but more so on saturday morning. then...the
widespread rain should move in from the west during the afternoon as
the cold front approaches the ms river. isol t will still be
possible during the day. rainfall amounts through saturday night
will be from 1/2 to 1 inch for most areas.

then...the cold front will push through around midnight saturday
night and temps will drop. within the cold sector of this storm
system...substantial moisture depth does exist. thus...we do
expected a transition to snow showers behind the front.
additionally...several upper level impulses are expected to rotate
down on sunday and provide additional snowfall to the area.
accumulations are possible. current thinking in terms of possible
snow accumulations is as follows....1-3 inches northern/central
plateau...1-2 inches southern plateau and highland rim...around 1
inch for much of the remainder of the mid state...less than 1 inch
far sw counties.

sct snow showers and flurries will continue into sunday night and
finally end on monday. the northern and central plateau could
receive an additional inch on sunday night.

aside from the snowfall...conditions during the day on sunday will
be very cold and blustery as w to nw winds of 15-25 mph combine with
temps holding in the 25 to 30 degree range for most areas. this will
equate to wind chill values from 10 to 20 degrees. even worse...as
temps drop sunday night the arctic sfc ridge will still be to our
west and the northwesterly flow will continue to the tune of 10 to
20 mph. this will equate to wind chill values of between 0 and 10
degrees below zero for much of the area by monday morning. there is
a reasonable potential that a wind chill advisory may be posted in
the near future for sunday night...so stand by.

otw...partial sunshine to return on monday. monday night looks to be
the coldest night of the year as the arctic high settles on top of
the mid state. look for low temps of between 2 and 12 degrees above
zero. wind speeds will be lighter at that time.

a slow warmup will begin on tuesday. and then...a mid week storm
system has us in its sights. a low pressure system will move west to
east along a warm front. precip in the form of sleet/freezing rain
may develop during the day on wednesday into wednesday night.
however...given the northward movement of the warm front...the sleet
and freezing rain should change over to rain by thursday morning. we
will continue to monitor this potential winter system as it is still
5 to 6 days away.

for the short term temps...will go above guidance within the pre
frontal airmass. then...i will undercut guidance within the cold
sector. nam and gfs agree with 6 hr delta-t 850 mb values of -4c
between 12z and 18z sunday. thus no diurnal warm up expected.

for the ext temps...will deviate just slightly. i will undercut a
few degrees on tuesday morning as the sfc ridge is in close
proximity at that time.

I am very concerned with freezing rain later in the week, have been looking at it for a couple days, don't like what I see...freezing rain forecasting however is more sensitive than snow forecasting so it still bears watching and some math...

[Cameron K.]

Crapzilla. I have my last final that day. Most definitely will keep my eyes on that.

[Woodvegas]

Yeah, this bears watching and shows up on both the GFS and the ECMWF. Latest runs have it starting out as freezing rain then changing over to plain rain. One or two degrees could make a big difference in the storm's impact.

[Clay]

Yeah this thing is longer than John Kerry's face:

I am very concerned with freezing rain later in the week, have been looking at it for a couple days, don't like what I see...freezing rain forecasting however is more sensitive than snow forecasting so it still bears watching and some math...

Haha, good to have you back!

[Woodvegas]

12/11 0Z GFS gives my location about 0.2 inches of freezing rain before the change-over to plain rain Wednesday afternoon. If the timing is right Wednesday afternoon rush hour traffic could get ugly.

[ams30721us]

00z GFS:

[Eric]

00z GFS:

 

[Woodvegas]

Looks like things start to fall apart when ice accumulation reaches 1/4 in.

 

ICE STORM TYPES
 
"Nuisance"-(less than 1/4 inch of ice)
Windshields coated
Bridges tricky
Light ice on trees 

"Disruptive"-(1/4 to 1/2 inch of ice)
Tree limbs sag
Most roads icy
Power outages

"Crippling"-(1/2 inch or more of ice)
Widespread tree and powerline damage
Roads impassable or dangerous

(Source: The Weather Channel)

 
 
 

[maryvillereb2003]

wow, looks grim for ETN...grab some  tomorrow AM

[OakRidgeWinter]

wow, looks grim for ETN...grab some  tomorrow AM

What do you mean by "looks grim for East tn" ??

[maryvillereb2003]

icing could be a major problem but its a little ways out