We are feeling more and more confident that it will snow come Friday along most of the I-95 cities including DC, Baltimore, Philadelphia, Trenton, Allentown, Newark, NYC. The question becomes the track and if any mixing gets thrown in further south of Philadelphia.
THE MODEL SCORECARD AS OF 6:30 AM
It is now in range and pops a nice period of early storm snow for most areas in the Mid Atlantic. Now this is the off run of the NAM at 1am this morning and it only goes out until 1pm Friday so we'll get a better look at this through the day today and tonight.
The storm is about 70 hours from now so as you can see we are getting well within range of calling is a "GO" or "NO". Right now the chance of 2" or more is 75%.... 4" or more is at 65% and more than 6" is at 50%.
Oh it's plenty cold with lows Friday morning coming in at 21 at DC....20 Baltimore...17 Philadelphia...13 Allentown...10-12 in North Jersey and NYC Metro and 15-17 along Atlantic City and SNJ.
All locations from DC north start as snow...after that DC may be on the borderline for sleet and freezing rain. Looking at the NAM just now in range this is a 4-8" type of storm at this point.We'll get into Snow ratios (fluff factor) over the next few blogs.)
EURO MODEL RUN...
The Euro and the Euro ensembles love this storm for significant and the models are coming into better alignment even 70 hrs before the storm so this is a GOOD thing if you like snow.
The Euro like the NAM shows a nice burst of overunning snow by late morning Friday and Friday will become a HEAVY at times snow event through the afternoon. This is gonna cause either a SNOW DAY or the kids get out early. Looking at the timing of this storm...it may be more of a SNOW DAY at this point if this comes true.
The EURO is colder than the NAM and would keep DC in all snow and fluffy snow up through Philly and NYC so the snow ratio could make this 6-12" type of event on the EURO model in last night. It comes in with an update 1:30pm Eastern.
The EURO has
5-8" Philly.... 4-7" Lehigh Valley
5-8" DC and Baltimore... Delaware
6-10" North Jersey-NYC and Eastern NJ (Coastal)
The Canadian model is GAME ON as well with a very good snow track for Philly North but could be a mix issue Baltimore South. I still like the colder idea with the Euro but you gotta look at the trends on all models going into a significant storm.
The Canadian plays overunning snow to a snow storm event come Friday after 8am-10am with most of the snow in the afternoon and evening. The timing on the NAM EURO CANADIAN are all about same. The snow totals are not that far off either at this point. I will be including the GFS a little later just for the fact that it looks to have a few errors on model data coming in on the last 2-3 runs.
MY THINKING AT THIS POINT...
Wow about 70 hrs this looks good really good for 4"+ maybe 6" + with a few wildcards to play with it Friday.
1. Overunning Snow. This can be a very interesting event for a few areas with 1-2" per hour Friday afternoon. The Philly area to NYC has that potential as well as DC to Baltimore in the morning.
2. Ocean Temps. They are above normal and can tap an even bigger storm on the way out. The area with an extra pop would be NJ shore and DE beaches and NYC North Jersey and Long Island. We'll see.
3. Thundersnow. If the dynamics are right we could see that as warm moisture runs into the cold dense air. This is not likely at this point but a few things on #2 change and yeah it could.
4. ICE and SLEET factor. We have to watch DC and Baltimore over to Central and Lower DE Richmond and Lower SNJ shore for the exact track come Thursday night and Friday morning.
This is gonna be a fun storm with very cold Friday morning temps for many (teens) and yeah this could go down as one of those classic storm you oh so remember as a kid come Friday and Friday night.
I'm appreciative for the help even if you aren't a "professional", I have learned a lot looking at this site the last 2 years, still unsure on some definitions of things since we haven't had a real winter in 2 years.
Over running is when warm air ahead of the Low pressure system pushes a warm front ahead of it and along that warm front it forms precip as the warm air rides over the cold air and creates snow, sometimes can create pretty heavy snow if your close to the boundary zone.
Now Rob and Marcus, I'm not as familiar with the weather models as the two of you seem to be. WIth that said, what does this "over running" mean? I'm a die hard snow lover, just trying to get more knowledge on something I so dearly enjoy.
Over running almost over performs in these situations. 2003 for example? I can't really compare this to 2003 in terms of intensity...but overrunning wise it's looking similar in that regard, except no sleet at 18 degrees ruining my chance for high accumulations!
GFS will adjust the next few runs...The overunning snow into very cold air could as big as the storm itself Monday morning and afternoon. You don't need a big storm to get big snow in this set-up. In fact the weaker type storm will keep any mix further south
agree Marcus and snowtrain - I should have been more clear - that's what i meant by "looks". It definitely has differences - and should have stated via GFS maps. 0z Euro looks different. No worries here - normal model madness is in progress.
the 500mb maps and 300 wind hts make this look like more of a clipper than anything else. Jet streak on Friday doesn't look like it will give it time to develop or explode. Hopefully this changes in the next 24-36 hours. Today's runs start to become really important.