Major arctic outbreak Tuesday-Wednesday

A significant cold front will cut through the region tomorrow. High temperatures will rise to the mid 30's on Monday, but fall back 35 to 40 degrees as the front passes. Temperatures Monday Night will reach zero or just below in Keene. The NWS is going much colder than the MOS data with -4. Winds gusting around 25mph behind the front will create wind chill values of -15 to -25 through Tuesday Morning. A wind chill advisory may be necessary. Temperatures on Tuesday will struggle to get out of the single digits. The NWS has a high of 7 forecasted. I'm going with 10. Tuesday Night will be the most impressive. The NWS forecast low is -10, and has support for at least below -5. This could turn out to be the coldest temperatures of the winter. If this occured, it would be somewhat unusual considering meteorological winter (DEC - FEB) is techniquely over and astronomical winter is coming to a close. If this very intense arctic front had come through a month or two earlier, we would be talking about lows nearing -20!

Snow possibilities:
WINDEX (Winter Instability Index) values will be high today through tomorrow night, so we will be talking about a chance of snow showers for the next 36 to 48 hours. Any accumulation will be limited to a dusting.
The only other snow chances during this arctic intrusion will be on Wednesday when a clipper passes to the south of the region. Right now, it looks like all precipitation will be to our south, and mostly cloudy skies will be the rule here, however a trend northward is starting to show on the models, so we should watch this potential anyway.

Rest of the week:
Temperatures will moderate a bit on Wednesday and Thursday before a sharp turn back to the low 40's on Friday accompanied by a chance of showers Friday Night into Saturday.

Rest of the month:
Highs in the 40's and possibly reaching the 50's will be common next week at least through the 18th. The operational GFS has been indicating a -NAO development and strong blocking next weekend, however the ensembles do not support this and the NWS has all but thrown the op GFS in the trash. It later develops a -AO by the 18th and arctic intrustion in the midwest and Great Lakes, but keeps average temperatures locked in over New England. The -AO has support from the ensemble guidence and it is probably the start of the -NAO development for the very end of March into early April. I will not completely blow off the op GFS through the 15th, and will give it some credit after that. So, although I'm still expecting temperatures around 5 degrees above average through the middle of March, I can't rule out a few 48-hour cold snaps generated by the brief presence of a low around 50N 50W. Temperatures will moderate down to normal for the 18th through the 22nd, and then a high-precipitation lower plains storm will become a solid 50/50 low that will set up a -NAO for the last few days of March.

All in all, the warmth I said would be present this month will still occur however for a shorter period of time. As for precipitation, dry weather will hold strong through the 18th, with our only storm chances when we get some short-lived blocking. We will be talking about a storm around the 23rd of March which will ultimately be our pattern changer. April's outlook remains the same: cold with a few snow chances still around. The way the next two months are looking, we could still end the 06-07 winter with a respectable amount of snow.