Anyway on to the current weather map, a weak trough over the Delaware River was generating a few sprinkles near its axis. This needs to be watched as light rain showers could drift into our area tonight. Otherwise, high pressure over the Great Lakes was dominating our weather.
Tonight: Guidance looks a bit too cool. Low clouds have been tough across the area, and I really see no reason for them leaving as fast as models have. Ultimately, I think low temperatures will be around 60, except mid 60s in city centers. For now, I'll keep the sprinkles out of the forecast. I think they'll die at about the Hudson River.
Tomorrow: I still think guidance is a few degrees too cool, but for different reasons. Tomorrow will become sunny, as the Great Lakes high transfers east. With higher starting temperatures than guidance and sunny skies tomorrow, we should be able to get a few degrees warmer than guidance. So, in general, look for highs around 80 tomorrow.
Tomorrow Night/Thu: An approaching cold front could trigger a widely scattered shower or thunderstorm by later in the day. The best chance of this would be North of I 84. South of there, any activity should wait until night. Temperatures on guidance look reasonable and are accepted. This yields highs of 75 to 80.
Long Term (the weekend and beyond): There is a lot of uncertainty regarding Friday's forecast for many reasons. First, there is uncertainty regarding how warm we get. Since it does look like the Bermuda High may try to flex its muscle a bit again, I'll cautiously go a bit warmer than guidance. There is also uncertainty as to the timing of the arrival of rain and thunderstorms with the next cold front. Meteorologically, if I am leaning with a stronger Bermuda High, I have to be consistent and go with later timing of showers and storms, so I won't begin any precipitation until nighttime. Finally, there is also uncertainty as to how far north the heavy rain makes it. Once again, I prefer to be "meteorologically consistent" and go with the rain penetrating pretty far north. Later shifts may need to make significant adjustments to this forecast depending on how things play out. For now, I'll go with high temperatures within a few degrees of 85. I will also keep the showers and thunderstorms out of the forecast until very late Friday night.
With everything trended later in the forecast package, I'll have showers and thunderstorms lingering into Saturday morning, ending from SW to NE from mid-morning through lunchtime. This will also result in trending temperatures down on Saturday, although not quite as low as the GFS guidance has them: think mainly mid 70s, with a few upper 70s possible in the I 91 corridor.
The rest of the long term looks to be dominated by high pressure, which should provide pleasant weather right through the rest of the long term period. With a downslope wind flow and plenty of sun, I'll go a little warmer than guidance all three days. This yields highs in the low 80s Sunday, and mid to upper 80s Monday and Tuesday.
Looking out into the long range, I still think the overall pattern of stormier weather than normal will continue. I also expect the Bermuda Ridge to begin flexing its muscles again, and a return to the proverbial "dog days of August" as we head into the month of August, with increasing heat and humidity.
Now, let's take a look at some of the systems to affect our area this upcoming week. Since there really is only one significant system, and that is not progged until later Friday, I'll first post tonight's low temperature map from the GFS model, since some areas could get a bit chilly if any clearing occurs, at least by July standards.
Now, let's look at Friday night's cold front. A couple notes about this map.. First, this is not your typical July cold frontal passage. There is a strong low near Cape Charles, VA, and high pressure over Northern IA, almost a winter setup. The GFS, depicted here, has a tendency to scoot these systems out to sea (incorrectly), and be too far to the south with them in the winter. Since this is a winter setup, the GFS could very well be wrong here, and we may need to move that heavy precipitation shield quite a bit further north- just something to think about!