The one thing that stands out to me this afternoon is the fact that some many little and medium features are showing up on the models and in the pattern that the models are going to change quick a bit from day to day and run to run.
We are going into several cold periods so most of the events will be snow or no snow at this point. The February 5th event has been advertised for some time now and at this point may bring the best potential the next 10 days.
COLD WAVE #1
This is in the wake of the noah's ark event tomorrow along the east coast. We have other blogs on this event so I will not get into the rain, wind and storms since this is a winter blog.
COLD WAVE #1 is later Thursday night until Monday and the NAM GFS EURO all agree on the cold wave so the cold air will be in place from North Carolina to Maine and back through the Ohio Valley and Midwest.
BACK END SNOW THURSDAY ??
This is always a tough call and more times than not the front will clear with colder drier air moves in as the precip moves out. We have seen from Allentown PA and points north into NY PA a snowy nding but this will be a tough call until really the last minute.
GFS BACK END SNOW BELOW
EURO BACK END SNOW BELOW
NAM BACK END SNOW
So what do we have on the models for Thursday morning? It's interesting that we have some snow on the back end but it could be nothing more than let over cold as the moisture moves out.
The dotted blue line on the left map is th 540 snow line and the precip is in green..darker the color the more precip.
The red line on the right is the 850mb snow lineat 5000 feet. Clearly all the models have the cold air rushing in from 5000 feet to the ground.
It has happen this time year as the cold rushes in so for now Allentown North to NYC...40% of snow on the back end...Philly to Baltimore 25% chance. We'll watch if for you but the issue may be the surface temps are too warm as the precip rolls out Thursday morning.
It's interesting on the NAM and GFS and since this is 72 hours away it's now in play to watch. The NAM and GFS rolls a small band of high snow ratio snow on Friday with a period of light snow from PA to DC MD including DE and NJ. It's all snow so here is how the models play it out.
NAM LOOK FOR FRIDAY GFS LOOK FOR FRIDAY
PHILLY METRO GFS FRIDAY .11" x 12:1 = 1.3" SNOW
PHILLY METRO NAM FRIDAY .12" x 12:1 = 1.4" SNOW
ALLENTOWN GFS FRIDAY.05" x 13:1 = 0.7" SNOW
ALLENTOWN NAM FRIDAY.00" x 13:1 = 0.0" SNOW
READING PA GFS FRIDAY .09" x 13:1 = 1.2" SNOW
READING PA NAM FRIDAY .02" x 13:1 = 0.3" SNOW
LANCASTER PA GFS FRIDAY .11" x 12:1 = 1.3" SNOW
LANCASTER PA NAM FRIDAY .09" x 12:1 = 1.1" SNOW
WILM DE GFS FRIDAY .09" x 12:1 = 1.1" SNOW
WILM DE NAM FRIDAY .17" x 12:1 = 2.0" SNOW
DOVER DE GFS FRIDAY .02" x 12:1 = .25" SNOW
DOVER DE NAM FRIDAY .08" x 12:1 = 1.00" SNOW
MILLVILLE NJ GFS FRIDAY .05" x 12:1 = 0.6" SNOW
MILLVILLE NJ NAM FRIDAY .14" x 12:1 = 1.7" SNOW
BALTIMORE GFS FRIDAY .02" x 12:1 = .25" SNOW
BALTIMORE NAM FRIDAY .05" x 12:1 = .60" SNOW
WASHINGTON DC GFS FRIDAY Flurries WASHINGTON DC NAM FRIDAY .01" x 11:1 = .20" SNOW
MORRISTOWN NJ GFS FRIDAY .03" x 13:1 = .40" SNOW
MORRISTOWN NJ NAM FRIDAY .01" x 13:1 = .13" SNOW
NEWARK NJ/ NYC GFS FRIDAY .03" x 12:1 = .36" SNOW
NEWARK NJ/ NYC NAM FRIDAY .01" x 12:1 = .12" SNOW
TRENTON NJ GFS FRIDAY .08" x 12:1 = 1.0" SNOW TRENTON NJ NAM FRIDAY .01" x 12:1 = 0.1" SNOW
MY THINKING AT THIS POINT...
Wednesday and Thursday are gonna be wild for some with a pop in warmth with a line of thunderstorms, heavy rain and wind. Thursday it could snow for some.
Tomorrow & Tomorrow night aWind Advisory...a Severe Thunderstorm Watch and a Flood Watch may be posted along the Mid Atlantic and Northeast. I expect to see temps drop pretty quick into the Thursday morning rush hour..how fast they drop will decide if we get rain to snow. The best chance of that is Allentown to Binghamton NY over to Suburban North and Central NJ.
Thursday is a day of change with colder temps maybe a few snow showers and gusty winds.
Fridayis still a watch and wait with periods of light snow or flurries from Allentown to DC including the NJ DE MD beaches.
One thing i notice with the NAO its not the position pos, or neg thats so important its the rate of change of the NAO if it suddenly crashes we get powerful storms but if it gently crashes or rises we get light snow events. Who would agaree or disagree
Im glad the backend snow is still on the table because i mentioned his before over last weekend when the 12utcNAM first flashed it on the screen. Been away for awhile. The question to ask here is how much and how fast will the cold air penetrate while the cold front is passing by. Orographic factors withe the terrain would eat up QPF and we all know that diving cold air from the lee side of the mountains always dries and warms due to frictional factors but the models are still keeping this onbthe table. Its rare but not impossible. It has happened before. Lets see wew talking about a 28 deg drop in less than 3 hours according to the GFS and NAM. Nice !!!! The only thing is the QPF will there still be some left.
Well - at least it's becoming more active in a good way! A couple of clipper potentials (small but fun), and maybe something more in potential next week. It's better than just our wishing the pattern would change!
Freeze....good point...the front tend to mess with the models until they clear and get a better idea. With so many pieces of energy (clippers) I think we'll see some interesting changes to the models day to day
I like the 5th, but as I stated in my blog the other day - tele-connection concerns (PNA & NAO) will drive us nuts - so I agree with you guys. Still - it's been showing potential on the runs - so we'll see. I think this mega-front needs to get through so the models can see what's next better. Looks like a lot of energy with this front.