?DOES ANYBODY REALLY KNOW???

[RNS]

Sure....the amounts COULD go up...but i dont think that RIC will see a 20:1 snow/liquid ratio.

[Stormsfury]

Sure....the amounts COULD go up...but i dont think that RIC will see a 20:1 snow/liquid ratio.

Bingo ...

1) The atmosphere and the HIGH is nowhere near as cold as the December 4th-5th, 2002 event exactly one year ago or the PDS last February 15th-17th ... those highs last year were well over 1040 mb (more like 1046 mb) ... this high is nowhere near that strong ... or cold ...

2) The current SFC high is only 1030mb and also moving offshore and NOT locked in ideal position to continue funneling cold and dry air, although the cold air was underestimated to a degree by the models (as usual) ... CHS today actually warmed as the coastal trough and southerly flow today overwhelmed the wedge as the SFC winds turned EASTERLY ... and hence, I warmed up into the mid 50's and as the SFC low took shape over CHS, very heavy convective rains unloaded on the area ...



SF

[Heady Guy]

RNS : what are your feelings for about 20 miles & N & W of Philly ?

Thanks

[RNS]

RNS : what are your feelings for about 20 miles & N & W of Philly ?

Thanks

Ah Bucks county...great area ... 12-20 inches...

[Stormsfury]

And also, the ECMWF is by far, superior in the MR, it isn't the model of choice for SR forecasting ... I use for Days 3-7 (and the day 8-10, 3 day average) ...

Once we get into the event itself, or go time, it's the RUC, GFS, ETA, MM5, MESOETA ... and the SREF, plus radar trends ...

SF

[RNS]

Bingo ...

1) The atmosphere and the HIGH is nowhere near as cold as the December 4th-5th, 2002 event exactly one year ago or the PDS last February 15th-17th ... those highs last year were well over 1040 mb (more like 1046 mb) ... this high is nowhere near that strong ... or cold ...

2) The current SFC high is only 1030mb and also moving offshore and NOT locked in ideal position to continue funneling cold and dry air, although the cold air was underestimated to a degree by the models (as usual) ... CHS today actually warmed as the coastal trough and southerly flow today overwhelmed the wedge as the SFC winds turned EASTERLY ... and hence, I warmed up into the mid 50's and as the SFC low took shape over CHS, very heavy convective rains unloaded on the area ...

SF

This system will be bringing in colder air as it transfers to the coast (and BTW the models are too weak with the SLP area it should be in the 990s while near the Delmarva). So what is a marginally cold snow to mixed precipitation event in the big cities should end as a wind whipped heavy snowfall situation.

[greg81988]

does that mean u think that richmond, va will end in a heavy snowfall?

[Dave C]

My area should be very interesting as to the setup of all snow verses mix and or plain rain. My location 20 miles NW of the of Cape Cod area has good potential of the "kitchen sink" scenerio When looking back to early Dec. Noreaster we had in I believe "93" the intensity of the precip. dictated our snow vs rain results. As heavier bursts moved through it was snow, when lighter areas moved through it was rain. I think the cold high to our north this time is a bit colder than "93". What do you think RNS? :-?

[RNS]

And also, the ECMWF is by far, superior in the MR, it isn't the model of choice for SR forecasting ... I use for Days 3-7 (and the day 8-10, 3 day average) ...

Once we get into the event itself, or go time, it's the RUC, GFS, ETA, MM5, MESOETA ... and the SREF, plus radar trends ...

SF

I was waiting to see if someone would pick up on that. Not to mention the fac that the H5 set-up is completely dis-similar to the surface pattern. The SLP area should be further NW and prehaps inland at the beginning of the period.

Bottom line you dont run the H5 low between 35 and 40N while have the SFC feature track off the NC coast...IOW...the solution is likely BS

[RNS]

My area should be very interesting as to the setup of all snow verses mix and or plain rain. My location 20 miles NW of the of Cape Cod area has good potential of the "kitchen sink" scenerio When looking back to early Dec. Noreaster we had in I believe "93" the intensity of the precip. dictated our snow vs rain results. As heavier bursts moved through it was snow, when lighter areas moved through it was rain. I think the cold high to our north this time is a bit colder than "93". What do you think RNS?

That scenario which you describe to me with the violent swings back and forth in P-type comes back to the existance of Conditional Symmetric instability (yes...its one of my favorite meteorological processes...lol) Convective cooling associated with CSI and banded snowfall can result in such swings in precipitation type when thermal profiles are near freezing throughout a deep layer.

You may deal with similar conditions but this time the scales should be tipped toward snow moreso than mixed precip...so banded snowfall would likely result in heavier snow accumulations as opposed to determining precipitation type.

[RNS]

does that mean u think that richmond, va will end in a heavy snowfall?

It/s possible but as i said previously...i think my Aforementioned ideas are best right now. we/ll see wha the 0z model cycle has to say in regard to any changes to that idea.

[Stormsfury]

This is a current barometric pressure map (MSLP) and clearly one can see the energy transfer occurring and still the wedge in the Western Carolinas ... however, that wedge wasn't strong enough to hold the coastal trough at bay today ... very amazing, the temperatures here this morning fell to 38º and there was sleet mixed with rain just a bit farther north ...

[RNS]

BTW...there appears to be a nice banded feature forming over eastern MD and DE as we speak...

http://www.srh.noaa.gov/radar/latest/DS ... kdix.shtml

[RNS]

This is a current barometric pressure map (MSLP) and clearly one can see the energy transfer occurring and still the wedge in the Western Carolinas ... however, that wedge wasn't strong enough to hold the coastal trough at bay today ... very amazing, the temperatures here this morning fell to 38º and there was sleet mixed with rain just a bit farther north ...

precisely...our coastal system appears to be forming very nicely.

[Stormsfury]

<IFRAME border=0 name=tag align=center src="http://weather.cod.edu/cgi-bin/radarloop.pl?station=LWX&product=BREF1&loopdir=brefs" frameBorder=0 width="100%" height=400 target="_blank"></IFRAME>

[RNS]

The precipitation looks as like its having a hard time making it northward...likely the result of the high pressure over the northeast.

[Stormsfury]

The precipitation looks as like its having a hard time making it northward...likely the result of the high pressure over the northeast.

Yep, the high, although, nowhere near as strong as exactly one year ago, and on the PDS, it's still strong enough to reinforce enough cold/dry air to put up a fight in that region ...

SF

[RNS]

even in spite of the resistence...i still think there will be a prolonged period of freezing rain and sleet in DC and PHL before going back to snow...cutting down on accumulations.

[Stormsfury]

even in spite of the resistence...i still think there will be a prolonged period of freezing rain and sleet in DC and PHL before going back to snow...cutting down on accumulations.

I agree, the 850mb temperatures do warm above 0ºC in the short term, but as I see it, as the 500mb low swings eastward, the 850mb temperatures tumble once again below 0ºC, and would turn the precip back over to snow ...

850mb Temperatures
http://www.rap.ucar.edu/weather/model/d ... tmp&loop=1

Color graphic 850mb Temperatures
http://weather.cod.edu/forecast/loop.rucus850t.html

Precip-Type
http://weather.cod.edu/forecast/loop.rucusptype.html

SF

[RNS]

looks as if a very heavy burst of snow will be headed into the DC area within the next 1/2 hr...the latest nexrad pics out of LWX show an area of enhanced echos/bright banding approaching from the S. Should arrive in the form of snow or SN/PL mixing.