Radar looks impressive at 6AM but the big swath over IN/OH is virga right now. That means precip is not reaching the ground but it is snowing aloft. The stuff down south was initially virga but they saturated pretty quickly and much of that is hitting the ground. Compared to models the focus of this precip is already a little further north and east most likely a result of a slightly deeper s/w and the strong isentropic lifting.
Models are fairly good with the inverted pressure trough down south with our developing southern low. This low is not expected to be strong, but an observation along with the precip being further north and east is the low wanting to move northeast where the pressure falls are greatest. Most models take this weak wave on a more east heading but will keep an eye on it. Also notice the convection firing up to the NW, nighttime soundings and forecast soundings show a good amount of instability aloft. Around 100J/KG over Little Rock, AR so this is good news as the precip being more dynamic will only help us downstream.
The moisture transport shows what we expect to be a continued rapid fill in of the radar to the north an East highlighted by the vectors. The isentropic lift with arctic air out ahead usually overperforms. Will see if that correlates with observations later today.
We do expect evaporational cooling (virga) later today so an impressive radar does not correlate well with a surprise unless we can saturate quickly. Down south they were in a similar situaton and saturated fairly quickly. Chicago took a little longer but still nothing like we went through with the last event. Here is to hoping the trend continues.
Virga is knocking on the door of the five county area of southeast PA. Given that snow began reaching the ground, quickly becoming moderate over western PA much quicker then one would've thought, with very low dewpoints at that, i take that as a good sign.
Anyway - i'm looking for the GOM beast. The GOM is really warm and waiting. The STJ will become much more active/favorable in the next couple of weeks. We don't need a perfect pattern - we just need parts and timing to align. I like the potential in the first week of Feb.
Chris, snow is reaching the ground into central PA, with some areas reporting moderate snow with dewpoints in the low single digits. Three also seems to be more forcing than earlier forecast and more WAA which hopefully means my 2-4" forecast is safe, though I'll admit I am concerned this might be my first blown one of the season.
Chris long it's snowing pretty quick once virga starts it seems like once the moderate/light snow moves in it gets going. Western pa is seeing 1"/hr rates similar to what south jersey saw the other night.
Ok snow lovers, I take back everything I said about the dry air taking away most of what little moisture we were giong to get out of this storm. It is now going to be a full on blizzard. How do I know this? Well it's not my bum right hip. However, one of my problem children at work who cannot seem to turn in her timecard on time and has to be hunted down every single time, has just turned in her timecard without being asked and not just on-time but early.
Well the gfs was the first to realize how flat this storm would be and we threw that run out. All I can say is you gotta give credit where credit is deserved here and cannot completely count out the gfs.
It didnt really flip flop at all with storm. It went from significant snow run after run albeit in a different spot, until that one run where it finally gave up, and got it right.
Is the arrival time still between 3-4 PM for Philly Metro? I'm going to be driving home from Bustleton to Coatesville around 3:15, and considering the way people drive around here when there's just a few flurries, I'm hoping my drive home won't be extended by an hour or two.
Freeze-mizer: the great lakes cutter has to happen to get rid of that 2 day thaw, after that its Feb 1st and things will get real interesting with the MJO heading towards phase 8. If we see one storm cut up the coast, 3 or 4 might follow a similar path. Snowmaggedon part 2?
ASSUMING SNOW TO LIQUID RATIOS SOMEWHERE BETWEEN 12 AND 15:1 (CLIMATOLOGY IS CLOSER TO 11:1)...WE ARE STILL EXPECTING A GENERAL 1 TO 2 INCH SNOWFALL ACROSS THE REGION. THE BETTER MID LEVEL FORCING COULD ALLOW SOME PLACES IN NORTHEAST MARYLAND...DELAWARE AND SOUTHEAST NEW JERSEY TO APPROACH 3 INCHES. THERE IS A LOW PROBABILITY BANDING COULD FORM IN THIS AREA...AS IT IS CLOSEST TO THE AXIS OF THE BEST MID LEVEL FRONTOGENETIC FORCING...WHICH COULD ADD TO SNOW TOTALS. THIS MAY NEED TO BE WATCHED THIS EVENING.