Currently: The cold front that made it through last night has made it all the way to Viriginia Beach. A weak wave of low pressure has actually developed there along the front, but weak high pressure ridging extending from Long Island to Southern Canada is enough that that low will just scoot out to sea.
Tonight: The big question regarding tonight's temps is how much the sky will clear. Most of the clouds today, I believe, are diurnally-driven, and if that's the case, they should dissipate with the loss of daytime heating. Clouds ahead of the next system are still a long way's away. Therefore, I'll go with the clear(er) of the guidance sets for tonight. This should allow temperatures to fall a bit, due to radiative processes. Because of all this, I've opted to go a bit below statistical guidance for lows tonight. Lows should range 50-55 degrees, except a bit warmer in the cities and along the immediate south coast.
Tomorrow: Tomorrow should easily be the nicest day of this forecast period, and possibly beyond. This is very easy to say. High pressure ridging should control our weather and skies should be sunny. A few high clouds could sneak into the far SW Zones late in the day, but even this should not be a hindrance to a beautiful day. Guidance temperatures look good and are accepted. High temperatures should be 70 to 75 degrees, except maybe a shade cooler in New London County.
Tomorrow Night into Friday: The weather then turns worse. Warm air advection (overrunning) precipitation ahead of a warm front will break out across the state. The most likely start time is around lunchtime from SW to NE. In addition, the warm front will not make it to Connecticut, at least not during the day on Friday, so it will likely be a chilly day. With clouds, precipitation, and the likelihood that the warm front will not go through Friday, I have gone several degrees below guidance in anticipation of this. Therefore, expect high temperatures to only be in the mid 60s.
Long Term (the weekend and beyond): This period will largely be unsettled. The main problem in the long term is not going to be determining whether or not there will be measurable precipitation- most days will have some- but rather determining when precipitation will fall. Unfortunately, this may not be resolved until we can see the precipitation on the radar.
So first, for Saturday, guidance temperatures look good. However, this is making an assumption... and that assumption is that showers from the warm front clear out during the morning and we really don't see much rain the rest of the day, and at this point, that is a fairly large assumption to make. The reason I am making this assumption is that once the warm front does go through, there will not really be much forcing to produce showers and thunderstorms. However, the air mass is marginally unstable, and if there is more sun than I am forecasting it is very conceivable that showers and thunderstorms could develop, especially in the NW hills. For now, I'll keep Saturday (mostly) dry, with high temperatures of 75 to 80.
On Sunday, again, most of the day should be dry, with increasing chances of showers and thunderstorms toward sunset. However, once again, the air mass is marginally unstable, so we'll have an outside chance of a shower or thunderstorm at any time during the day. Once again, guidance temperatures look good, based on the assumption that most of the day is dry. High temperatures, based on this assumption, should be generally 80 to 85, except cooler in New London County.
Sunday night into Monday, the next system approaches. This system will bring widespread showers and thunderstorms to the area. That is certain. There are a lot of uncertainties surrounding the event, however, such as where the exact position of the frontal boundary would be and timing the various waves along the front. Locally torrential downpours, severe thunderstorms, and perhaps even a small tornado threat could exist, depending on the positioning of the front. Obviously, the only thing set in stone at this point is that this period will be unsettled, to say the least. Now, as far as temperatures, with clouds and precipitation around much of the time, I've gone well under guidance, and am calling for mid 70s for highs. This could be much too cool, however, if we can get warm-sectored and the sun can break out. I am taking the under based on the pattern this spring.
Yet another difficult forecast looms for Tuesday. This forecast was originally pretty cut and dried, that the front would clear out and Tuesday would be a nice day. However, recent guidance has been slowing the front down, which would mean a good chance of showers and thunderstorms Tuesday morning, and even a lingering, smaller chance of showers during the day on Tuesday. I will trend the forecast in that direction, because it makes meteorological sense, given the strength of the Bermuda high creating resistance to Eastward-moving cold fronts. Another big conundrum is where to go with Tuesday's high temperatures. Obviously, questions such as "Did the front clear? Is the sun out?", etc will make a big difference regarding Tuesday's temperatures. This is a very low-confidence forecast, but since I have to make a forecast, I'll just go close to a guidance blend for now. This would mean highs generally in the low 80s.
Wednesday looks like a fairly nice day. There is a possibility that showers and thunderstorms, some strong, could arrive at night in the Western zones. However, if we go by the logic that the Monday front will be slowed by the Bermuda Ridge, then the same logic would have to be applied to Wednesday's front. So we'll slow that front down, as well. (This is like a math equation, where you have to do the same to one side as you do to the other). In meteorology, if one front slows down because of a pattern, then the next front must slow down, as well. Therefore, we'll keep Wednesday entirely dry. Temperatures Wednesday are fairly easy. Assuming we're in between cold fronts, guidance may be a degree or two too warm, but no big deal. So highs on Wednesday should be 75 to 80.
Long Range: I do not see any indication in the long range that leads me to believe a significant deviation from the pattern outlined in this discussion is in store. In other words, a generally unsettled pattern with a nice day or two here or there sandwiched in between days of shower and thunderstorm chances. Temperatures all in all through the long range look to be at or a bit above normal.
Now, let's take a graphical look at some of the systems that will be affecting our area... I'll focus on Friday and Monday, since they are the two most probable days for significant amounts of precipitation. First, let's take a look at Friday's warm frontal rains. On this map, valid early Friday afternoon, steady rain is just entering Connecticut. The heavier rain over New Jersey will soon move Northeast into Connecticut. The warm front can be traced along the 570 (red) thickness line, and runs from near Erie, Pennsylvania, to Atlantic City, New Jersey,
-GP!