Currently: Low pressure was currently over E NC, high pressure was over Quebec. This is keeping it cloudy and cool today, with a deep-layered marine air mass in place. As that storm and warm front shift north, expect increasing rain chances with it.
Tonight: Steady rain will generally arrive before dawn west of 91 and south of 84. North and east of there, it will be more towards dawn. Non-NAM based statistical guidance would have you believe the rest of the night is dry. While I am not going to buy the NAM wholeheartedly as there is not nearly enough lift to produce steady rain so early, there already have been sprinkles across NNJ and as the deep-layered marine flow continues into the night, drizzle will become more likely, especially along the S coast. So I will forecast spotty drizzle and even an isolated shower for the first half of the night, with the highest chances south, then introduce steadier rain from SW to NE very late at night. Temperatures will be tricky. We are currently running below statistical guidance everywhere, and since that high pressure system is still holding on, I will go a few degrees below temperature guidance, as temperatures should be able to fall for a few hours, as long as that high holds on. Temperatures may very well begin to rise toward morning. I'll go with fairly uniform lows, around 40 degrees, as the south coast may cool more effectively than other areas with drizzle and wind off the cold Long Island Sound.
Tomorrow: Heavy rain is likely in the morning, with rain ending in most areas by early afternoon. Temperatures will be very tricky, dependent upon how far north the warm front makes it. It is a very strong warm front, so there will be a sharp thermal gradient and a small error in warm frontal placement could result in a large error in temperatures. I feel the cooler NAM guidance is more correct, and will ride it. For example, the GFS has 70 degrees in Manhattan tomorrow afternoon, and I don't think that is going to happen. So we'll go with highs within a few degrees of 60. Two more issues are present tomorrow. First, there is a chance of thunderstorms in the morning. Based on soundings, there is enough instability to mention thunderstorms in the SW 1/2 of the state (basically south of 84 and west of 91). Nothing severe, just thunder and lightning imbedded within the rain. The second issue will be strong and gusty winds behind the cold frontal passage, mainly later in the afternoon hours. Winds will be relatively strong for a few hours, with gusts to 30-35 MPH, but nothing all that impressive. The GFS has stronger winds, with more instability and warmer temperatures, but since I am ignoring that solution, I toned down the winds a bit.
Tomorrow Night/Sat: Cooler, but still a bit above normal. (It's amazing how warm we've been that when it's only a few degrees above normal, it feels chilly). GFS-based guidance tends to struggle when we have cold air advection. The NAM guidance is closer to reality, but I'll tweak that down a degree or two as well in certain areas. All in all, sunny and not a bad day. Highs should be around 50 statewide.
Long Term: (Sunday and beyond): Generally quiet through this period. The only system of concern comes right on St Patrick's Day. Sunday should be a bit warmer than guidance, as it looks sunny and a downsloping type day. Look for highs in the mid to upper 40s. Clouds increase Monday and probably a legit chilly day, with high temperatures in the low 40s.
Looking at soundings, Tuesday appears to be generally an all-rain event. It may start as some sleet and/or wet snow, and possibly even an hour or two of decent snow falling N of 84. However, even there temperatures are pretty warm at the sfc, so any accumulations would be minimal and limited to grassy and cold surfaces. Rain should fall all day, and should be moderate at times, but nothing extremely heavy. I am going to go 4-7 degrees lower than all guidance on Tuesday. Contrary to tomorrow, where you have a strong low passing very near the area, Tuesday's storm is much weaker and further west. Therefore, that does not look like a situation where the warm front will blast through. So look for highs generally in the upper 40s. Somewhere along I 91 may touch 50, but no need to get too cute with temps this far out.
Wednesday and Thursday should be tranquil. Guidance looks reasonable, and to be bluntly honest, it isn't such a big deal if it's a degree or two warmer or cooler in this regime. So there is no reason to go crazy over temperatures those two days. I only made a few minor tweaks, given microclimates in the state. Highs should be in the low 50s Wednesday and near 50 Thursday. Thursday is one of those days where valleys along I 91 could be a couple degrees warmer, for whatever this is worth.
Looking into the long range, we may actually get into a below normal temperature pattern for the last week of March. As far as winter weather/snow lovers go, it may very well be a case of "too little, too late", especially near the coast, but we'll have to wait and see on that.
Now,let's look at a couple of systems slated to affect our area this week. Since there really are only two systems, we'll look at tomorrow and Tuesday. This map is a little earlier than when the real "action" gets into our state, but you can see the heavy rain back over NY, PA, and NJ, getting ready to move into our area.
Anyway, that's all for now... See you again next week!