Friday Night/Saturday Morning Freezing Rain Threat

[cg2916]

0Z NAM:

18Z NAM:

[Jonathan]

I've never seen anything like this on a weather model before

Peep the gap.

[Bsudweather]

41 minutes ago, Jonathan said:

I've never seen anything like this on a weather model before

Peep the gap.

Something is just not right about the GFS with this event. Not sure what it is but its been crazy for a couple days now. About 5 days ago it was showing close to what the NAM is showing now. Not saying the NAM will be right but it has not backed off for quite a few runs now.

[AshevilleCityWx]

It's right its going to be super dry with areas recovering from negative dew points; makes it so much harder to precipitate.

[FallsLake]

From RAH:

Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
412 AM EST THU DEC 15 2016

NCZ007>011-021>028-038>043-073>077-083-084-160915-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE-
ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE-
JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-ANSON-RICHMOND-
412 AM EST THU DEC 15 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THERE MAY BE A BRIEF PERIOD OF VERY LIGHT FREEZING RAIN OR LIGHT
FREEZING MIST LATE FRIDAY NIGHT OR EARLY SATURDAY MORNING. THIS
CHANCE OF ANY LIGHT FREEZING RAIN WILL END QUICKLY AS TEMPERATURES
WARM ABOVE 32 BY MID-MORNING SATURDAY... WITH ONLY RAIN EXPECTED
THEREAFTER.


$$

BADGETT

[FallsLake]

Something to think about. We're probably talking about very light amounts; generally less than .1" with maybe some spots greater. But if this occurs, the impacts could be significant. One the pavements will be very cold from the previous days temps; and two the overnight / early morning timing will be optimal.

I'll have to admit that this is not much of an event, but it's the only thing really going on..

[mackerel_sky]

Future cast temps on Foxcatolina , have GSP at 35 at 5 AM!? Not really seeing that happening, also had our low Friday night at 32! I guess all the clouds flooding in by afternoon, will limit max cooling

[oconeexman]

52 minutes ago, mackerel_sky said:

Future cast temps on Foxcatolina , have GSP at 35 at 5 AM!? Not really seeing that happening, also had our low Friday night at 32! I guess all the clouds flooding in by afternoon, will limit max cooling

Find that hard to believe.

[mackerel_sky]

25 minutes ago, oconeexman said:

Find that hard to believe.

Upon thinking about it, if the thick high/ mid level clouds are here before sunset, then I could see that happening, I guess!? It doesn't seem to matter how cold the airmass is, clouds seem to work miracles around here to keep the temps up just enough!

[Jon]

Something to think about. We're probably talking about very light amounts; generally less than .1" with maybe some spots greater. But if this occurs, the impacts could be significant. One the pavements will be very cold from the previous days temps; and two the overnight / early morning timing will be optimal.

I'll have to admit that this is not much of an event, but it's the only thing really going on..

Yeah. Nam holds the CAD extremely long into late morning/noon but I agree even though no huge impacts are expected, bridges and overpasses could be an issue for anyone driving early Saturday. If it plays out like the Nam no doubt we'll hear of a few wrecks as I doubt DOT is running out to brine before this one. With accums less than 0.1" I'm not holding my breath with this one though.

[Jon]

Something to think about. We're probably talking about very light amounts; generally less than .1" with maybe some spots greater. But if this occurs, the impacts could be significant. One the pavements will be very cold from the previous days temps; and two the overnight / early morning timing will be optimal.

I'll have to admit that this is not much of an event, but it's the only thing really going on..

Yeah. Nam holds the CAD extremely long into late morning/noon but I agree even though no huge impacts are expected, bridges and overpasses could be an issue for anyone driving early Saturday. If it plays out like the Nam no doubt we'll hear of a few wrecks as I doubt DOT is running out to brine before this one. With accums less than 0.1" I'm not holding my breath with this one though.

[drfranklin]

4 hours ago, mackerel_sky said:

Future cast temps on Foxcatolina , have GSP at 35 at 5 AM!? Not really seeing that happening, also had our low Friday night at 32! I guess all the clouds flooding in by afternoon, will limit max cooling

In my experience, never/ever discount Kendra Kent (Fox Carolina) - she is extremely conservative and most often right - example: the infamous snow/ice forecast by Robert (Foothills) several years ago ("chunks of ice falling from the sky, roof collapses", etc etc) - I believe Kendra mentioned 2 inches of snow with a little ice for that event - well, that's what most rec'd in the Upstate

[burrel2]

12km Nam has a solid swath of >.10 inch of liquid falling along a line following I-85 from Georgia up through NC by 4am Saturday morning. At which point temperatures are around 30 degree's from Gainesville, GA up through Spartanburg, SC. Temps in NC are around 29 degree's at this time. It looks like temperatures bottomed out at 1 or 2am around 28 or 29 degree's from this same area. (Taking the model Verbatim)

By 7am, Northest Ga and the Upstate of SC have warmed to 32 degree's while the piedmont of NC is still holding in the 30 to 31 range.  the >.10 are has expanded in this time frame. The Southern Escarpment area of the mountains is up up over .3 inches of liquid by this time,(but they go above freezing around 4am).

 

 

 

[FallsLake]

4 minutes ago, burrel2 said:

12km Nam has a solid swath of >.10 inch of liquid falling along a line following I-85 from Georgia up through NC by 4am Saturday morning. At which point temperatures are around 30 degree's from Gainesville, GA up through Spartanburg, SC. Temps in NC are around 29 degree's at this time. It looks like temperatures bottomed out at 1 or 2am around 28 or 29 degree's from this same area. (Taking the model Verbatim)

 

 

 

 

Yep NAM still holding its ground. RAH stated that there would be possibilities of very light freezing rain or freezing drizzle (which could easily make it to .1" values). I'm wondering if the GFS is having a hard time determining this very light precip; or if it's just saying no way precip makes it to the ground with those low dew points.

[burrel2]

I would be very, very surprised if the temps the coldest models are spitting out.. Hi-Res NAM,RGEM, are still way too warm Friday night.

 

Looking back at February 2016, We had an almost identical high placement and the day of that event my temperature wound up bottoming out a good 4 or 5 degree's colder than any short range model was showing just the day before.  Here is an image of the high placement for February 2016 storm.

 

Edited: Had my storms mixed up, and fixed now!

[burrel2]

The other storm was in February 2015. All the short range models had me bottoming out around 32 degree's with pre-dominatly rain falling for the duration of the storm.

That storm also had very dry dew points with in-situ wedging.

I wound up with a few inches of sleet and 1/4 inch of ice from that storm. Here is a post from 2015 right as the event was ending for mby...

February 2015 "Well the last band of precip is pivoting through here. I wound up with about 1.5 inches of sleet followed by about 1/4 inch of freezing rain. My temp bottomed out at 28.3 and had risen to only 31.7 at the time the last bit of precip moved out."

 

I'm not saying this storm will bust as badly, but I think it's a safe bet that CAD area temperatures will bottom out at least a degree or two colder than what the Hi-Res models are showing, and mostly likely take longer to warm above freezing than what they are showing as well.

 

[burrel2]

FWIW, here is the progged high position for Fridays storm..... Identical to the February 2016 storm as you can see.

[Jon]

24 minutes ago, burrel2 said:

The other storm was in February 2015. All the short range models had me bottoming out around 32 degree's with pre-dominatly rain falling for the duration of the storm.

That storm also had very dry dew points with in-situ wedging.

I wound up with a few inches of sleet and 1/4 inch of ice from that storm. Here is a post from 2015 right as the event was ending for mby...

February 2015 "Well the last band of precip is pivoting through here. I wound up with about 1.5 inches of sleet followed by about 1/4 inch of freezing rain. My temp bottomed out at 28.3 and had risen to only 31.7 at the time the last bit of precip moved out."

 

I'm not saying this storm will bust as badly, but I think it's a safe bet that CAD area temperatures will bottom out at least a degree or two colder than what the Hi-Res models are showing, and mostly likely take longer to warm above freezing than what they are showing as well.

 

Yeah, but that storm had much more moisture. No doubt in my mind the CAD will be there...if it was wetter we'd all be singing a different tune about this one for sure.

[mackerel_sky]

1 minute ago, Jon said:

Yeah, but that storm had much more moisture. No doubt in my mind the CAD will be there...if it was wetter we'd all be singing a different tune about this one for sure.

Yeah, that frame of the Canadian, looks very , very dry!

[burrel2]

5 minutes ago, Jon said:

Yeah, but that storm had much more moisture. No doubt in my mind the CAD will be there...if it was wetter we'd all be singing a different tune about this one for sure.

I'm not sure if you remember, but the storm from February of last year was very dry prior to the frontal passage that night.   That day, Greenville, SC only recorded 3/100th's of liquid, but it was enough to cause mass chaos on the roadways, (and models still busted badly on temperatures in spite of us only getting 3/100th's of liquid). I believe the Raleigh area had lots of traffic trouble as well.

 

My point being, you don't need high qpf and/or heavy precip for models to bust badly on temperatures with a wedge. This set up is identical to that one in terms of high placement and even in terms of how the precip is evolving, (lower level shallow moist layer rising over a cold dome), so I wouldn't be surprised if we see similar results.

[mackerel_sky]

9 minutes ago, burrel2 said:

I'm not sure if you remember, but the storm from February of last year was very dry prior to the frontal passage that night.   That day, Greenville, SC only recorded 3/100th's of liquid, but it was enough to cause mass chaos on the roadways, (and models still busted badly on temperatures in spite of us only getting 3/100th's of liquid). I believe the Raleigh area had lots of traffic trouble as well.

 

My point being, you don't need high qpf and/or heavy precip for models to bust badly on temperatures with a wedge. This set up is identical to that one in terms of high placement and even in terms of how the precip is evolving, (lower level shallow moist layer rising over a cold dome), so I wouldn't be surprised if we see similar results.

This is kind of under the radar for the general public, IMO! People will go about their regular business Saturday morning and there will be some wrecks, if we get some precip 

[packfan98]

FWIW, the Euro QPF totals have ticked up just a bit from 0z. Now has a max of .1 just south of the Triad and a little strip up I-85.

[HWY316wx]

The ice accumulation in NE GA will be brief Saturday morning and the CAD starts to erode and that freaking warm nose just ROCKETS the temps by Saturday afternoon.

[mackerel_sky]

This topic is dead quiet

[FallsLake]

6 minutes ago, mackerel_sky said:

This topic is dead quiet

The 18z NAM seems to have held its ground and continues to show about the same. As other have said it looks like temps will jump above freezing by mid morning Saturday.

[Snowless in Carrollton]

2 minutes ago, FallsLake said:

The 18z NAM seems to have held its ground and continues to show about the same. As other have said it looks like temps will jump above freezing by mid morning Saturday.

I'm not worried about Saturday. I'm just worried about Friday night. I have to be driving somewhere until about 10pm tomorrow night. I'm hoping the roads will be fine. I live halfway up a mountain and any amount of ice on the roads would probably make it impossible to get up the mountain.

[No snow for you]

1 hour ago, FallsLake said:

The 18z NAM seems to have held its ground and continues to show about the same. As other have said it looks like temps will jump above freezing by mid morning Saturday.

And how many times have the models been wrong and a CAD holds on much longer than expected. Not saying that is going to happen this time but the models always seem to struggle with these setups. 

[FallsLake]

28 minutes ago, No snow for you said:

And how many times have the models been wrong and a CAD holds on much longer than expected. Not saying that is going to happen this time but the models always seem to struggle with these setups. 

I think it comes down to how much and how long the duration of precipitation. Wetter and longer duration will help lock the CAD in stronger. Dryer and we all warm up quicker.

[mackerel_sky]

6 minutes ago, FallsLake said:

I think it comes down to how much and how long the duration of precipitation. Wetter and longer duration will help lock the CAD in stronger. Dryer and we all warm up quicker.

Meh, this "dud" event is getting duddier! It's going to be mostly cloudy all day tomorrow, by looking at the current satellite, and that will keep it cold tomorrow, but will stop the temp from dropping a lot tomorrow night, obviously! My forecast low is now 35

[cg2916]

2 hours ago, mackerel_sky said:

Meh, this "dud" event is getting duddier! It's going to be mostly cloudy all day tomorrow, by looking at the current satellite, and that will keep it cold tomorrow, but will stop the temp from dropping a lot tomorrow night, obviously! My forecast low is now 35

0Z says for our area, the issue is just a lack of precip. Much drier this run.