Hurricane Agnes

12z 3k NAM in range (12z EC just started).

It threw in a baby dryslot (showing a quick pause between systems).

I think that Watch up there was aimed at snow for up that way (since the early morning and current AFDs) - I think they are going to throw a WWA up for the LV and maybe have a SPS for the northern portions of the next set of counties below that and then nothing for Philly metro S/E where a mix/rain would not have much of an impact outside of nuisance stuff.

Here is a link to Mt. Holly's Winter Weather Criteria for Warnings/Advisories (the page uses a mouse-over feature to show the regions and it will display the criteria legends at the bottom but I snap-shotted them to make it easier) - https://www.weather.gov/phi/criteria-winter Each region within the CWA has different criteria for what triggers use of each product.

The 7 am update from Mt. Holly - The NAM continues with the dryslotting although a bit more drawn-out type of event.

Had an earlier "low" (because that won't end up being today's "low") of 57 and am currently overcast and 61 w/dp 56. You can sortof see the front on the move on satellite!

Generally we do switch from a mix to rain down this way but we have a number of members who are from up there and even the closer-in NW 'burbs, so I definitely wouldn't dismiss this. I don't think it will get to be 70 outside of maybe the most southern parts of the CWA (e.g., Delmarva, etc) and that warmth is ahead of the down-sloping caused by an incoming cold front with some serious (but modified as it moves east) cold from the upper MW. Right now, the cold air has just moved across the western PA border from OH (image from NCEP's 9:30 am surface temp obs) and the front is supposed to come through later this afternoon. The high tomorrow is going to be in the low to mid 30s before the event actually starts (which is supposed to be in the afternoon and go overnight). It will be a thread the needle thing depending on where the freezing line sets up.

6z Euro - same song different verse, a little bit louder and a little bit worse.

WPC's note last evening on the upcoming event's impact - And this morning's update focusing on the more extreme outcomes in the south central U.S. along with the significant snow north.

Looks like each side remains in their corners. GFS/EC with some kind of precip through the storm and NAM doing the dryslotting (although the NAM has some kind of antecedent brushes with some precip before the main low comes into play). I think the message is that there will be some kind of overrunning event that will be impacted by whereever the freezing line sets up.

That signal has been pretty consistent for all the models today. It seemed to be more sleety up that way and then some kind of atmospheric warming that would change it to rain but the temps would be much colder up there too compared to down here in Philly metro, south and east, so the ZR issue.

Looks like the 0z NAM did a blend. Not completely caving but moving in that direction.

Mt. Holly afternoon update -

NAM still stands alone as the Euro holds tight.

While the 18z is running the RGEM holds its ground.

Hit 59 as a high today (so far as the temps have been up and down with the rain). The low was 38 and it's currently 56 with light rain, 0.16" in the bucket, and dp 55.

18z GFS still standing it's ground although dries up at the end.

18z NAM still dryslotting.

Here was Mt. Holly's take a few hours ago -

Was looking at the EC's temps for the period. It's gonna depend on where the warm sector ends up and who gets under it.

12z Euro looks real ugly.

The Ukie doesn't seem to distinguish so am guessing it would be something that could include sleet/IP, etc.

EC has started so will soon see which way it goes! The Ukie did throw some snow down this way.

LOL

NBM trying to keep it real with the ice and throws some snow up north (might be weighted more to the NAM solution).