Central PA - December 2013

[djr5001]

you have any worries of long duration frzn for us??

 

 

i have no pony in this race really, but i'm excited for you guys North and West! It seems so long ago we had any weather to be excited about!

For tonight I have a feeling we changeover for the last hour or two at best... probably a longer period of sleet than snow unless the cold air pushes east much quicker than expected

 

I still think Sunday event will be determined on how cold temperatures tonight/tomorrow end up... 850s will warm quite a bit so not sure how much below freezing we will manage to stay... could easily start as snow, then sleet, then freezing rain, then rain for MDT... a degree or two warmer or colder could make a huge difference... really tough to call before this first system moves through

[jm1220]

The 12z GFS now has greater then 6 inches for State College. I don't see at this point how State College receives less then 6 inches. Even though the storm is a fast mover the qpf is incredibly heavy. 5-8 inches is a good call for the region but someone will receive 10 inches.

Agreed-I think the heavier accumulation zone may be around I-99/I-220 given the colder modeling trend so far on the shorter range models. It wouldn't surprise me for the NWS to finally cave and expand the warnings south and east a little more. Maybe even south and east of there toward Selinsgrove and Lewistown could pick up a few inches. But it's a really quick shot, 6 hours at most, so unless it absolutely crushes it'll be hard to pick up more than 7", especially since some initial snow may not accumulate. Still though I really wish I was out at PSU instead of here for this one. Enjoy.

[JamieOber]

Agreed-I think the heavier accumulation zone may be around I-99/I-220 given the colder modeling trend so far on the shorter range models. It wouldn't surprise me for the NWS to finally cave and expand the warnings south and east a little more. Maybe even south and east of there toward Selinsgrove and Lewistown could pick up a few inches. But it's a really quick shot, 6 hours at most, so unless it absolutely crushes it'll be hard to pick up more than 7", especially since some initial snow may not accumulate. Still though I really wish I was out at PSU instead of here for this one. Enjoy.

If it crushes right away, it'll take about five minutes to start accumulating. 

[JamieOber]

if one more ****ing person asks me "why is the sun out if it's going to be bad this afternoon" Imma cut someone. 

[whiteout]

Starting to be more interested in this changeover tonight down here in the LSV more than the Sunday storm. That one has been trending drier with the precip being suppressed when it's cold enough to be frozen and then of course when it goes to town it's too warm.

[JamieOber]

Starting to be more interested in this changeover tonight down here in the LSV more than the Sunday storm. That one has been trending drier with the precip being suppressed when it's cold enough to be frozen and then of course when it goes to town it's too warm.

That's not even much of a storm anymore. 

[PennMan]

If it crushes right away, it'll take about five minutes to start accumulating.

Especially if we start with a period of sleet to ice things up quickly.

if one more ****ing person asks me "why is the sun out if it's going to be bad this afternoon" Imma cut someone.

Ah yes, people who don't seem to understand how weather condition changes work...

[sauss06]

if one more ****ing person asks me "why is the sun out if it's going to be bad this afternoon" Imma cut someone. 

and the snow won't lay either, it was 50 yesterday ya know!

[sauss06]

Starting to be more interested in this changeover tonight down here in the LSV more than the Sunday storm. That one has been trending drier with the precip being suppressed when it's cold enough to be frozen and then of course when it goes to town it's too warm.

don't waste your time

[JamieOber]

Especially if we start with a period of sleet to ice things up quickly.

Ah yes, people who don't seem to understand how weather condition changes work...

Elliot Abrams gave me the best way to explain this to the layperson. 

 

Just because you are in this spot right now doesn't mean you will be here in two hours. Weather is dynamic, not static, just like you. 

[IrishRob17]

if one more ****ing person asks me "why is the sun out if it's going to be bad this afternoon" Imma cut someone. 

Don't you just 'love' that..."So what time exactly will the rain change to snow?"  "When will it get bad?"  I love that because 'bad' is such a subjective term.

[Jmister]

Cut those amounts in half and that's a good forecast.

[Mallow]

Cut those amounts in half and that's a good forecast.

 

[NortheastPAWx]

Cut those amounts in half and that's a good forecast.

4-6" sound reasonable?

[F5TornadoF5]

Cut those amounts in half and that's a good forecast.

Is there any chance of obtaining such amounts? I agree that 5-7in in State college region is a good forecast, but are you saying there is a chance! haha

[jm1220]

Is there any chance of obtaining such amounts? I agree that 5-7in in State college region is a good forecast, but are you saying there is a chance! haha

I guess if it snows 2" per hour straight from 0z to 6z, and that at 0z it's all snow, haha. With a system like this though it's hard to get such dynamics to allow snow rates like that for long periods of time.

[Rick G]

I see the maps and I  am confuzzeled...  if a lot of the models are showing higher snowfall amounts, why aren't advisories getting upgraded? are NWS mets told to be conservative?

 

I did see NWS state college did issue some warnings.

[F5TornadoF5]

I see the maps and I  am confuzzeled...  if a lot of the models are showing higher snowfall amounts, why aren't advisories getting upgraded? are NWS mets told to be conservative?

 

I did see NWS state college did issue some warnings.

Probably being conservative as usual. Will probably upgrade to 3-6in in State College and other areas in a couple of hours.

[skiier04]

I see the maps and I  am confuzzeled...  if a lot of the models are showing higher snowfall amounts, why aren't advisories getting upgraded? are NWS mets told to be conservative?

 

I did see NWS state college did issue some warnings.

 

Check out the forecast discussion... suggesting more warnings could be issued later this afternoon

 

BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY

SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW

SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE

HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY

HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR TREND.

[paweather]

IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.

 

Just curious why the stall. Thanks.

[sauss06]

it was 48 this morning, 43 now.

[whiteout]

WSW up for PA bordering counties for the Sunday storm. 2-4" + .25 ZR in cities such as HGR and FDK

[canderson]

well in all honesty, MDT is East of us, they always have a different number. I'd almost bet where djr and me live we have at least 1" snow. Especially him, he is more West by a couple hundred yards, north by a couple hundred yards and he is elvated by about 30' then me

We three should do some kind of map showing our locations, I think it's almost a perfect triangle.

[NeffsvilleWx]

don't waste your time

 

 

 

Cut those amounts in half and that's a good forecast.

 

 

Is there any chance of obtaining such amounts?

 

No.

[canderson]

CTP's cut back any accumulation in the MDT grid, earlier they had up to an inch.

 

• Friday Rain, snow, freezing rain, and sleet before 1am, then rain, snow, and sleet likely between 1am and 4am, then snow likely after 4am. Low around 32. East wind 6 to 10 mph becoming northwest in the evening. Chance of precipitation is 100%. Little or no ice accumulation expected. Little or no snow accumulation expected.
• Saturday Snow showers likely before 7am. Mostly sunny, with a high near 38. Northwest wind 9 to 11 mph. Chance of precipitation is 60%. Little or no snow accumulation expecte

For the Sunday storm, they say up to 1/2" precip and mention all snow Sunday and then freezing rain overnight before turning to rain Monday.

[djr5001]

I see the maps and I  am confuzzeled...  if a lot of the models are showing higher snowfall amounts, why aren't advisories getting upgraded? are NWS mets told to be conservative?

 

I did see NWS state college did issue some warnings.

With the uncertainty in the warm layer aloft and the cold air slowly moving east there isn't much they can do but wait and see how things evolve before issuing advisories/warnings with this one this far east... otherwise if they issues advisories and warnings and it ends up all rain then it doesnt look good for future storms when we would have a better idea earlier on

[jm1220]

IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND

FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR

RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS

FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT

MIDNIGHT.

 

Just curious why the stall. Thanks.

The low pressure wave riding along the front will cause it to stall for a time, meaning the snow line won't race east anymore after a point. But the low is forcing lift which is generating the enhanced precip.

[jm1220]

Check out the forecast discussion... suggesting more warnings could be issued later this afternoon

 

BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY

SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW

SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE

HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY

HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR TREND.

I think it's very likely they have to issue warnings for Centre, Blair, Lycoming and Cambria. Maybe even the next tier of counties south given the trends at 12z.

[djr5001]

IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND

FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR

RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS

FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT

MIDNIGHT.

 

Just curious why the stall. Thanks.

This "storm" is a wave of energy moving along a frontal boundary when most systems we are used to seeing and tracking are a strong developed low pressure system.  The cold air is slowly shifting eastward, so no guarantees of a changeover to the areas further south and east such as Harrisburg/Lancaster/York... there doesnt need to be as much movement with the cold air for State College and west to benefit with snow potential than there does with Harrisburg/east

 

edit: jm beat me to it lol

[heavy_wx]

There is definitely the potential for some more intense mesoscale banding with this system. The 12z GFS has decent mid-level frontogenesis over central PA at 00z tonight. There is also some areas of negative EPV collocated with high relative humidity which may support the presence of some CSI.