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CAD storms thread.


dsaur

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http://68.226.77.253/text/NAMSFC/NAM_kgso.txt

Any idea why this is showing thundersleet for GSO?  Also has more cold air for GSO.  Gets down to 31 at 1pm.

TW

 

The aftn Raleigh disco mentioned the convective / showery nature of the precip...

WARM RAIN PROCESSES DRIVEN BYSHALLOW (BUT STRONG) ISENTROPIC LIFT - AMIDST A COMBINATION OFSYMMETRIC AND SHALLOW ELEVATED UPRIGHT INSTABILITY - WILL INSTEADDOMINATE OVER CENTRAL NC...WHERE PRECIPITATION WILL BE MORE OF AMIXED STRATIFORM/CONVECTIVE MODE...SUCH THAT NUMEROUS SHALLOWCONVECTIVE ELEMENTS WILL OCCUR WITHIN MUCH LIGHTER OR DRIZZL"Y"PRECIPITATION. THIS WILL SUPPORT THE HIGHEST PRECIPITATION AMOUNTSOVER THE NW PIEDMONT - AROUND A THIRD OF AN INCH - AND LESSERAMOUNTS OF AROUND A TENTH OR TWO OVER THE EASTERN SANDHILLS ANDSOUTHERN COASTAL PLAIN...BUT WITH A FOCUS TOWARD LESS UNIFORMITY ANDSMOOTH GRADIENTS OWING TO THE CONVECTIVE PRECIPITATION NATURE. INOTHER WORDS...PRECIPITATION AMOUNTS WILL VARY QUITE WILDLY OVERSMALL DISTANCES...INCLUDING OVER SINGLE COUNTIES.
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The aftn Raleigh disco mentioned the convective / showery nature of the precip...

WARM RAIN PROCESSES DRIVEN BYSHALLOW (BUT STRONG) ISENTROPIC LIFT - AMIDST A COMBINATION OFSYMMETRIC AND SHALLOW ELEVATED UPRIGHT INSTABILITY - WILL INSTEADDOMINATE OVER CENTRAL NC...WHERE PRECIPITATION WILL BE MORE OF AMIXED STRATIFORM/CONVECTIVE MODE...SUCH THAT NUMEROUS SHALLOWCONVECTIVE ELEMENTS WILL OCCUR WITHIN MUCH LIGHTER OR DRIZZL"Y"PRECIPITATION. THIS WILL SUPPORT THE HIGHEST PRECIPITATION AMOUNTSOVER THE NW PIEDMONT - AROUND A THIRD OF AN INCH - AND LESSERAMOUNTS OF AROUND A TENTH OR TWO OVER THE EASTERN SANDHILLS ANDSOUTHERN COASTAL PLAIN...BUT WITH A FOCUS TOWARD LESS UNIFORMITY ANDSMOOTH GRADIENTS OWING TO THE CONVECTIVE PRECIPITATION NATURE. INOTHER WORDS...PRECIPITATION AMOUNTS WILL VARY QUITE WILDLY OVERSMALL DISTANCES...INCLUDING OVER SINGLE COUNTIES.

Wow, interesting to say the least. Never seen thunder-sleet. However, I have seen 4 thunder-snows in my lifetime and one freezing rain event with thunder. Let us know how that turns out.

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For anyone interested in Asheville, new NAM and RAP support a chilly rain event with temperatures 34-36 degrees most of the day tomorrow. Neither model ever takes our surface temperature below freezing. This makes sense to me. The CAD regime is actually pretty moist compared to other setups, with current dewpoints still in the mid 30s all the way to central VA. To boot, winds are pretty light as well, so there isn't much surface cold advection. This is an instance where you just have to be closer to the cold air source, rather than relying on CAD dynamics, to generate much wintry precip.

 

 

 

Yeah...for me the writing was on the wall this morning when I woke up and noticed that we don't have a true CAD situation where the cold air was being strongly advected southward. You have to be closest to the cold air source in order to perform well, that's prob why Boone will be the only real place in North Carolina to have any issues.

 

At this time, I just don't see enough of a temp/dewpoint depression to lead me to believe that my particular area (Western McDowell County) will get to 32 degrees.

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For anyone interested in Asheville, new NAM and RAP support a chilly rain event with temperatures 34-36 degrees most of the day tomorrow. Neither model ever takes our surface temperature below freezing. This makes sense to me. The CAD regime is actually pretty moist compared to other setups, with current dewpoints still in the mid 30s all the way to central VA. To boot, winds are pretty light as well, so there isn't much surface cold advection. This is an instance where you just have to be closer to the cold air source, rather than relying on CAD dynamics, to generate much wintry precip.

Yeah...for me the writing was on the wall this morning when I woke up and noticed that we don't have a true CAD situation where the cold air was being strongly advected southward. You have to be closest to the cold air source in order to perform well, that's prob why Boone will be the only real place in North Carolina to have any issues.

At this time, I just don't see enough of a temp/dewpoint depression to lead me to believe that my particular area (Western McDowell County) will get to 32 degrees.

Absolutely correct. I'm still sitting at 38 deg just west of AVL in Buncombe county.

Sent from my steam-powered printing press.

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SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS COLLEGE PARK MD
1327Z SUN DEC 08 2013

12Z NAM RAOB RECAP...

76805/ACA - 10142.
76256/GYM - 10142.
78016/BDA - MISSING PART B.
72274/TWC - 10159.

ATTENTION: SPECIAL REQUEST FOR 18Z SOUNDINGS..AFTER SOME LOCAL
AND REGIONAL DISCUSSIONS.. WOULD LIKE TO REQUEST SPECIAL
SOUNDING LAUNCHES FROM THE FOLLOWING WFO OFFICES
..PIT(72520)..RNK(72318)..GSO(72317)..WAL(72402)..BUF(72528).
ATTM.
WILL ALSO MAKE THIS REQUEST VIA 12PLANET. THANK YOU.
THE 18Z SOUNDINGS ARE DESIRABLE WITH THIS DEVELOPING WINTER
STORM SITUATION ACROSS THE CWD AREAS OF NWS EASTERN REGION.
(PLEASE FEEL FREE TO REPLY VIA 12PLANET)


CRITICAL WEATHER DAY STATUS...
CWD WILL CONT TO BE IN PLACE UNTIL 12Z MONDAY.

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Only problem it's not cold enough! at my house anyway.... 32.4

 

BIG BUST from NWS, But Robert @ WxSouth spot on!!! now I'm speaking for my area only, don't know what's going on at other places.

How is this a BIG BUST from the NWS?! You are siting at 32.4 degrees for crying out loud and I'm sure there is some glazing going on around your area. It might not be living up to its potential by a few tenths of a degree, but for you to say this was a BIG BUST is absurd. The NWS did exactly what was expected of them to cover this situation for the public.  

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How is this a BIG BUST from the NWS?! You are siting at 32.4 degrees for crying out loud and I'm sure there is some glazing going on around your area. It might not be living up to its potential by a few tenths of a degree, but for you to say this was a BIG BUST is absurd. The NWS did exactly what was expected of them to cover this situation for the public.

A winter storm and ice warning is given when road conditions as well as when power outages are expected. This storm never had the temps for that and models never showed it. At best should only been an advisory. I don't study weather but I am a contractor that treats roads from piedmont to the Virginia line and when its 75 on Friday and temps get down to 32 it will never freeze on roads. The next storm the public will have a hard time trusting NWS after this. Yesterday temps we're around 50 and never got near freezing until this morning. I'm not complaining as we did have to work this morning but this was nowhere near what was predicted. Have to give credit where its due wxsouth called it a minor event for NC all week and he was right. Hopefully we get another one to chase shortly

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How is this a BIG BUST from the NWS?! You are siting at 32.4 degrees for crying out loud and I'm sure there is some glazing going on around your area. It might not be living up to its potential by a few tenths of a degree, but for you to say this was a BIG BUST is absurd. The NWS did exactly what was expected of them to cover this situation for the public.

Totally agree

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I've hae 3/4ths of an inch of ZR in marginal temperatures without any road issues before. Road issues were never going to be an issue in NC, IMO. Accretion on power lines, trees, and the resulting power outages was going to be the main threat.

A WSW or ISW is given for > 0.25" of ZR. Whether it sticks to the roads or not isn't that relevant. Perhaps we would have been fine with a Freezing Rain Advisory, but it isn't a big deal.

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A winter storm and ice warning is given when road conditions as well as when power outages are expected. This storm never had the temps for that and models never showed it. At best should only been an advisory. I don't study weather but I am a contractor that treats roads from piedmont to the Virginia line and when its 75 on Friday and temps get down to 32 it will never freeze on roads. The next storm the public will have a hard time trusting NWS after this. Yesterday temps we're around 50 and never got near freezing until this morning. I'm not complaining as we did have to work this morning but this was nowhere near what was predicted. Have to give credit where its due wxsouth called it a minor event for NC all week and he was right. Hopefully we get another one to chase shortly

No. WSW's are issued when severe winter weather is expected. In this case it continues until 4AM MONDAY and is not supposed to START until mid afternoon. Calling something a BIG BUST over TENTHS of a degree is facepalm worthy, besides the fact that it hasn't even ENDED yet.

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Need to look up definition of a winter storm warning. It states 4inches or more of snow and a large amount of ice. I didn't see either. Not worth arguing over we all have opinions. Just glad we got something

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE BLACKSBURG VA

1148 AM EST SUN DEC 8 2013

...SIGNIFICANT WINTER STORM CONTINUES INTO MONDAY...

LOW PRESSURE WILL MOVE NORTHEAST THIS AFTERNOON AND OFF THE MID

ATLANTIC COAST BY MONDAY MORNING. THIS LOW WILL TRANSPORT DEEP

MOISTURE OVER COLD AIR HELD OVER THE APPALACHIANS BY STRONG HIGH

PRESSURE. THIS WILL RESULT IN WIDESPREAD SLEET AND FREEZING RAIN.

SOME SNOW IS POSSIBLE...MAINLY NORTH OF THE ROANOKE VALLEY...IN

THE VIRGINIA AND WEST VIRGINIA HIGHLANDS...BEFORE PRECIPITATION

CHANGES TO FREEZING RAIN THERE AS WELL.

NCZ003>006-019-020-VAZ032-043-044-058-059-090100-

/O.CON.KRNK.WS.W.0008.000000T0000Z-131209T0900Z/

SURRY-STOKES-ROCKINGHAM-CASWELL-WILKES-YADKIN-PATRICK-HENRY-

PITTSYLVANIA-HALIFAX-CHARLOTTE-

INCLUDING THE CITIES OF...DOBSON...DANBURY...EDEN...YANCEYVILLE...

WILKESBORO...YADKINVILLE...STUART...MARTINSVILLE...DANVILLE...

SOUTH BOSTON...KEYSVILLE

1148 AM EST SUN DEC 8 2013

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM EST MONDAY...

* LOCATIONS...FOOTHILLS AND PIEDMONT OF NORTH CAROLINA...AS WELL

AS PARTS OF SOUTHSIDE VIRGINIA.

* HAZARD TYPES...SOME SNOW OR SLEET MAY OCCUR THIS MORNING... WITH

PRECIPITATION BECOMING FREEZING RAIN DURING THE AFTERNOON.

* ACCUMULATIONS...ONE QUARTER INCH OF ICE ACROSS MUCH OF THE

WARNING AREA...ALTHOUGH AROUND ONE HALF INCH IS EXPECTED ALONG

THE BLUE RIDGE. VERY MINOR ACCUMULATIONS OF SNOW AND SLEET ARE

ALSO EXPECTED.

* TIMING...UNTIL 4 AM MONDAY.

* IMPACTS...ICE WILL ACCUMULATE ON TREES AND POWERLINES CAUSING

POWER OUTAGES. ROADS AND SIDEWALKS WILL BECOME SLIPPERY AND

HAZARDOUS...ESPECIALLY BRIDGES AND OVERPASSES.

* TEMPERATURES...IN THE UPPER 20S AND LOWER 30S.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE

EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF ICE ARE FORECAST

THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF

YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...FOOD... AND WATER IN

YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

 

 

 

 

 

It has nothing to do with road conditions. Period. 

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How is this a BIG BUST from the NWS?! You are siting at 32.4 degrees for crying out loud and I'm sure there is some glazing going on around your area. It might not be living up to its potential by a few tenths of a degree, but for you to say this was a BIG BUST is absurd. The NWS did exactly what was expected of them to cover this situation for the public.

I did say for my area, I guess Different people look at it different ways? ,but in my mind it was a bust.... But if it changes for the worse i will eat my plate of crow.

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For RAH, the benchmark for an Ice Storm Warning is 1/4" ZR. I would expect that Blacksburg is the same or similar.

http://www.erh.noaa.gov/rah/criteria/

Ice Storm Warning: Freezing rain accumulations ¼ inch (6 mm) or greater resulting in significant, widespread power outages, tree damage and dangerous travel. Issued only in those rare instances where just heavy freezing rain is expected and there will be no "mixed bag" precipitation meaning no snow, sleet or rain.

EDIT: Yes, Blacksburg is the same: http://www.erh.noaa.gov/rnk/product_guide.htm#Winter%20Weather%20&%20Non-Precipitation%20Warnings,%20Watches,%20&%20Advisories

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For RAH, the benchmark for an Ice Storm Warning is 1/4" ZR. I would expect that Blacksburg is the same or similar.

http://www.erh.noaa.gov/rah/criteria/

EDIT: Yes, Blacksburg is the same: http://www.erh.noaa.gov/rnk/product_guide.htm#Winter%20Weather%20&%20Non-Precipitation%20Warnings,%20Watches,%20&%20Advisories

Correct but no WSW. But anyway. They all good
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I did say for my area, I guess Different people look at it different ways? ,but in my mind it was a bust.... But if it changes for the worse i will eat my plate of crow.

:lol:  It doesn't look like that will happen

 

That is just weather....accuracy will never be 100%. We are discussing a big bust over tenths of a degree and a slight glaze instead of 1/4" of ice. It's not like they put you under a warning for  4-6" of snow and you ended up with a 50 degree day. 

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:lol: It doesn't look like that will happen

That is just weather....accuracy will never be 100%. We are discussing a big bust over tenths of a degree and a slight glaze instead of 1/4" of ice. It's not like they put you under a warning for 4-6" of snow and you ended up with a 50 degree day.

Its all good I'm glad they extended it means we going back out.

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WxSouth has been right so far one this one along with DT. Now we have WxSouth calling for Warming temps and rain on its way with next round. NWS calling for more ice later on let's we who's right and who's wrong . Tv stations around here are not even running there usually weather advisories on Tv.

Looks like WXSouth is now saying we might be in trouble in some on NWNC now

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WxSouth has been right so far one this one along with DT. Now we have WxSouth calling for Warming temps and rain on its way with next round. NWS calling for more ice later on let's we who's right and who's wrong . Tv stations around here are not even running there usually weather advisories on Tv.

Looks like WXSouth is now saying we might be in trouble in some on NWNC now

I think we are too, it's still 28 and a solid band of precip is knocking on our door. Can't bode well

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I think we are too, it's still 28 and a solid band of precip is knocking on our door. Can't bode well

 

Yeah, per Roberts latest Facebook post, we're probably going to see a bad ice storm with this next band of precipitation. It's still 28-29 here in Boone and the temperature isn't budging. 

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