Winter Storm Threat: Feb. 16th-18th, 2015

[Bango]

rooting for Nashville as well.  That place has been snow cursed as of late

[Mr Bob]

Hey Jag...certainly would not mind seeing the KCHA and KTYS tabulars from the latest Euro if you get a chance...Thanks!

[Bango]

The RGEM seems to be the warmest outlier, check out the temps at hour 33 when the storm is cranking:

 

850mb:

 

Surface:

 

 

Dang looks like Carver might be right.  I always watch for these  little trends right before the storm, this one pushes a slight warm nose almost into scott county. 

[1234snow]

Carver,i certainly don't doubt you but I was curious how you came to your conclusion for warm air aloft cutting totals for tri? The text outputs I looked at do have a period of .30-.40 where our ratio's are more reasonable, but then it's followed by pretty stout ratio's in the .45 zone. Is this a case where western counties, namely Lee, Scott, Wise, Hancock do a little better then Washington county and Bristol...nitpicking of course but it seems a little spread on the maps?

This happens in most storms around here. The Valley is lower in elevation and is surrounded on both sides by the Plateau and the Appalachian Mountains. This acts as a funnel for the warm nose straight up from Chattanooga to Kingsport.

The counties in SWVA and bordering the plateau will be further away from the low so it will be colder aloft and the elevation is higher so that always help some too. I think this will help areas like Crossville. Further south in the southern plateau the warm nose will probably be too strong for elevation to make a difference.

[tnweathernut]

Hey Jag...certainly would not mind seeing the KCHA and KTYS tabulars from the latest Euro if you get a chance...Thanks![/quote

Ditto for TRI please.

[jaxjagman]

Hey Jag...certainly would not mind seeing the KCHA and KTYS tabulars from the latest Euro if you get a chance...Thanks!

[ShawnEastTN]

Looks like a mess for TYS...  Hope that window around 0Z Tue is short..

[Mr Bob]

Thanks!

[ShawnEastTN]

Updated ice map for BNA....  Pushing ice totals up to KY border.

[ShawnEastTN]

MRX has updated grids...

 

Here is updated forecast for Knoxville:

 

 

[Stovepipe]

MRX changed my forecast to slop.

[Blue Ridge]

Getting close to go time for afternoon updates. I do not envy our friends at the various forecast offices affected by this storm. Experience and gut pitted against a group of models that can neither agree nor produce anything resembling consistency...

[Carvers Gap]

Dang looks like Carver might be right.  I always watch for these  little trends right before the storm, this one pushes a slight warm nose almost into scott county.

Not really a trend. Pretty much a certainty with every storm. If you ever notice sleet mix during a big snow, you experienced it. Trend today has been a very slight jog south of the rain snow line, increase in qpf, and an expansion of the precip.

[ShawnEastTN]

Potentially more than half an inch of freezing rain total...  Destructive.

[Stovepipe]

This could have been beautiful mother nature but you playin.

 

That warm nose means business!

[John1122]

Added it to my grid as well.

 

 

[Blue Ridge]

All in on the warm nose. For downtown Erwin, TN:

 

• Washington's Birthday Snow and sleet likely before 1pm, then snow, possibly mixed with freezing rain and sleet. The snow could be heavy at times. High near 28. Southeast wind 5 to 10 mph. Chance of precipitation is 100%. New ice accumulation of less than a 0.1 of an inch possible. New snow and sleet accumulation of 2 to 4 inches possible.
• Monday Night Snow, freezing rain, and sleet before 1am, then freezing rain and sleet likely between 1am and 4am, then a chance of snow after 4am. The snow could be heavy at times. Low around 22. Southeast wind around 10 mph becoming west after midnight. Chance of precipitation is 100%. New ice accumulation of around a 0.1 of an inch possible. New snow and sleet accumulation of 2 to 4 inches possible. 

[kvskelton]

For me, it's now calling for a mix for Church Hill (western Hawkins Co) as well...though looking at Kingsport it seems to still be calling for all snow. May not have been updated yet, however.

 

Washington's Birthday: Snow before 4pm, then snow, possibly mixed with freezing rain and sleet. The snow could be heavy at times. High near 29. Northeast wind around 5 mph. Chance of precipitation is 100%. Little or no ice accumulation expected. New snow and sleet accumulation of 3 to 5 inches possible.

 

Monday Night: Snow, freezing rain, and sleet before 4am, then a chance of snow. The snow could be heavy at times. Low around 24. Northeast wind 5 to 10 mph becoming west after midnight. Chance of precipitation is 100%. New ice accumulation of less than a 0.1 of an inch possible. New snow and sleet accumulation of 1 to 3 inches possible.

[Blue Ridge]

For me, it's now calling for a mix for Church Hill (western Hawkins Co) as well...though looking at Kingsport it seems to still be calling for all snow. May not have been updated yet, however.

 

Washington's Birthday: Snow before 4pm, then snow, possibly mixed with freezing rain and sleet. The snow could be heavy at times. High near 29. Northeast wind around 5 mph. Chance of precipitation is 100%. Little or no ice accumulation expected. New snow and sleet accumulation of 3 to 5 inches possible.

 

Monday Night: Snow, freezing rain, and sleet before 4am, then a chance of snow. The snow could be heavy at times. Low around 24. Northeast wind 5 to 10 mph becoming west after midnight. Chance of precipitation is 100%. New ice accumulation of less than a 0.1 of an inch possible. New snow and sleet accumulation of 1 to 3 inches possible.

A mix has been included across the border and into SWVA. 

The upcoming AFD will be a must-read. 

[John1122]

I seem to be in a reasonable spot for minimal freezing rain. Maybe some sleet here and in Southern Kentucky,

[Bango]

For TRI, it's interesting that .08 qpf falls Wednesday night into Thursday with  850 temps in that -5 to 7 degree range which should produce anywhere from 2-5 additional inches.  That's a lot of snow post storm if it's true

[ShawnEastTN]

MRX:

 

 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
310 PM EST SUN FEB 15 2015

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)...UNFORTUNATELY MODELS
LOOK CONSIDERABLY DIFFERENT THAN 24 HOURS AGO...AND FORECAST
CONFIDENCE IS STILL NOT HIGH ON THE DETAILS OF PRECIP TYPE DESPITE
THE SHORTER TIME FRAME. HIGH CONFIDENCE OF SOME VERY SIGNIFICANT
PRECIP AMOUNTS ACROSS THE AREA HOWEVER. LOW PRESSURE SYSTEM FORECAST
TO TRACK BY JUST TO OUR SOUTH WITH STRONG INVERTED TROUGHING INTO
OUR AREA. STRONG LOW LEVEL JET FROM THE SOUTH AND SOUTHWEST SURGES
VERY MOIST AND WARMER AIR OVER THE AREA...BUT QUITE COLD AND DRY AIR
AT THE SURFACE AT LEAST INITIALLY. WITH THE WARM AIR SURGING
OVERHEAD AND A COLD DOWN VALLEY LIGHT DRAINAGE FLOW KEEPING THE
SURFACE TEMPS BELOW FREEZING FOR SOME TIME...NOW APPEARS THERE IS A
SIGNIFICANT THREAT OF ICING...WELL UP INTO AT LEAST CENTRAL PARTS OF
THE AREA. WINTRY MESS EXPECTED TO BE MOSTLY SNOW FAR NORTH...SNOW
SLEET AND FREEZING RAIN IN BETWEEN...AND MOSTLY FREEZING RAIN AND
EVEN PLAIN RAIN FAR SOUTH. DETAILS STILL HAZY...BUT AT THIS TIME
WILL HAVE WINTER STORM WARNING ALL AREAS...WITH A QUARTER INCH OR
MORE OF ICE POSSIBLE SOUTH AND CENTRAL...AND VERY HEAVY SNOW NORTH.

[jaxjagman]

[Carvers Gap]

Anyone have data and pics from the 18z NAM...?

[jaxjagman]

Anyone have data and pics from the 18z NAM...?

slightly cooler and more qpf's

[jaxjagman]

slightly cooler and more qpf's

[jaxjagman]

tri.png

your ratios should be decent Carver

[PWRAndy]

Any ideas on Muscle Shoals, AL? NW corner of AL on the AL, MS, TN border. Looks like rain only?

[Stovepipe]

How much slop for TYS on 18z nam? Sorry I'm not able to check right now.

[jaxjagman]

18z NAM shifted S by the looks