For tomorrow, it will still be a generally cloudy day, although some of the guidance is hinting at a few breaks in the clouds for a while during the midday hours. It won't make all that much of a difference anyway, with warm air advection, temperatures will get into the low to mid 40s regardless of whether or not we see sun. Once again, despite the cloud cover, no precipitation is expected.
The first storm system of interest in this forecast period is slated to affect the area from late Friday night into part of the day on Saturday. As far as timing, precipitation should overspread the entire state around midnight Friday night, and ending time on Saturday should be within a few hours of noon- earliest south and west. Models have come into much better agreement regarding the extent of precipitation. Yesterday, there was some disagreement as to whether or not Northern Connecticut would see any precipitation at all. Today's models have moved the storm closer to the coast. This means we are now fairly certain that the entire state will see precipitation. In fact, the south coast may even see rain heavy at times. So here are the issues with this upcoming storm:
Precipitation Type: Models remain in good agreement that the only precipitation that will fall in the state will be in the form of rain. So for now, going with just a rainy forecast seems like the prudent course of action. However, it should be pointed out that temperatures at the start of the event Friday night are progged to be just above the freezing mark in some of the colder interior valleys by the latest models. Any warm bias from the modeling at all could result in some freezing rain in those locations. For now, I'll leave it out of the forecast, but it's something for future shifts to watch. In addition, at the end of the event, especially in the north, temperatures aloft crash fairly rapidly during the day on Saturday. If the precipitation lingers any longer than expected, and/or upper level temperatures fall earlier than expected, there could be a brief period of sleet or snow at the end of the storm. Right now, both of these possibilities are fairly remote, and the more impactful one would be freezing rain, but this is just something to be noted.
Wind and Coastal Flooding: Right now, taking the modeled storm track verbatim, winds would not be a major issue, since the storm is progged to be just far enough offshore to keep the strong winds offshore with it. In addition, there is no significant high pressure to the northwest to create a strong pressure gradient. However, as I noted, guidance has trended west and another shift west toward the coast would bring stronger winds inland. Coastal flooding should not be an issue, no ,matter what track this storm takes. Generally coastal flooding becomes an issue with slow-moving systems. Since this system will be in and out in 12 hours, I can't see how coastal flooding could be a concern.
On Sunday, temperatures will return to more normal levels for mid-January. The combination of strong cold air advection, lake effect streamers, and a secondary push of cold air approaching, could result in a few snow flurries, especially during daytime heating. Temperatures on Sunday should rise into the upper 30s in most places.
For Sunday night and Monday, the combination of an offshore coastal low and an inverted trough that hangs back to the coast could touch off a period of light, but accumulating snow. Inverted troughs are very hard to predict. It isn't so hard to predict if one will exist, but it is very hard to predict the exact location of where the snows will fall. In general, the best course of action right now at this juncture, would be to call for the potential for a light, 1-2" type snowfall just about anywhere in the state in this time period. Even if the inverted trough does not form, snow squalls from the unstable air mass are also possible. So for this reason, I feel fairly confident that there is the potential for a light snowfall across the state. In addition, winds will pick up as the low passes offshore, with wind gusts into the 30s likely. Monday will also be a cold day, with high temperatures ranging from the upper 20s to low 30s. Obviously, the wind will only add to the chill.
Tuesday: A cold, dry, breezy air mass, typical of this time of year settles into the region. High temperatures will be similar to those of Monday, but maybe a degree or two warmer, due to sunshine.
Wednesday: High pressure overhead. Sunny with normal temperatures. Highs should be in the mid to upper 30s.
Thursday: A bit of a push of "fresher" Canadian high pressure moves in. Again sunny, with temperatures a few degrees below normal, in the low to mid 30s.
Longer Range: There is increasing model support for some type of a coastal storm around next Friday or Saturday. Of course, being this far out, there are a lot of different possibilities as to whether the storm tracks inland, and gives more of a rain event, or tracks offshore, and just brings some clouds and wind. Of course, in between would result in a snowy solution for the area. With this potential storm system being so far out, a lot of things can and probably will change, but this section of the discussion is dedicated to these long range potentials.
Beyond that storm, there are some indications of a moderation in the pattern, which would yield more mild temperatures for the area. However, most of the guidance indicates a few things: First off, it isn't going to be an extreme warm up. Secondly, it is probably transient in nature, so that a return to cold would not be far off. Finally, the stormier than normal pattern would continue, and would not be affected by the temperature pattern, so the continuation of storm threats would not cease.
This map shows the period of heavy rain very early Saturday morning.
The next map is a long range map and shows the potential storm around the 1/22-23 time frame.
That's all for now!