Scattered thunderstorms are possible today across much of New Jersey. The North American Model indicates the highest chances for thunderstorms in Western New Jersey. While many areas will remain dry, where the thunderstorms develop could be problematic. The thunderstorms may contain heavy rainfall, strong wind gusts, and hail. The western fringes of New Jersey, especially Northwestern New Jersey, are under a slight risk of severe thunderstorms with the remainder of New Jersey in a “see text” risk of severe thunderstorms. This will constantly be readjusted throughout the afternoon by the Storm Prediction Center.
Confidence continues to increase that there will be a significant severe weather and heavy rainfall situation developing across New Jersey on Thursday. The computer modeling has been in agreement about a potential severe weather outbreak for our region since Saturday Night. This kind of consistency is rarely seen during severe weather season. It is also notable that the slight risk designation for all of New Jersey has been placed over our region as far as three days out. The Global Forecast System model seems to have a much better handle on the overall threat this time around and it is probably because the timing on the GFS seems more reasonable and is also more in line with the likely daytime heating before the arrival of the thunderstorms. The strong winds will be increasing aloft with the strengthening low over the Great Lakes driving the potent cold front eastward. With the wind fields strong aloft, heavy convection should be able to drag the strong winds to the surface in the form of downdrafts.
If the GFS is correct with its indication that at least a weak meso-frontal wave of low pressure develops along the front, the helicity values would increase and combine with the unusually strong unidirectional shear to form favorable conditions for isolated tornadoes. This storm system has been responsible for numerous tornado outbreaks this week and the history does strike me as interesting. However, several systems have been known to fizzle east of the Appalachian’s and thus this logic applied just by itself would fail most of the time if solely used. However, here in this situation, a combination of scientific factors makes it seem reasonable to allow for isolated tornadoes even here in New Jersey on Thursday. The sad truth is that there could be one tornado the entire day and yet if it impacts a populated area…it would be a much talked about and likely more serious scenario. I don’t think we will see a major tornado outbreak at this present time or strong, long-lived tornadoes. What is unfolding in the Tennessee Valley won’t happen here to that degree. But weak ones do kill and we can see some of the tomorrow. The strongest tornado ever to occur in New Jersey was a F3 tornado and therefore history would argue against it.
The severe weather threat we face tomorrow will be affected by the amount of daytime heating. Any ongoing thunderstorms moving ahead of the front could arrive as early as Thursday Morning, but some models are not showing this to be widespread during the night. However, this doesn’t necessarily mean we would escape the cloud debris from the leftover storm cells. This will have to be taken into account early in the morning on Thursday when we know for sure. But, given the dynamics in place, I still am confidence of a nasty thunderstorm situation transpiring without the best sunshine. Given the situation, should we sunshine on Thursday, it would only be self-destructive.
A flash flood watch was issued for Northeastern New Jersey with a flood watch issued for the Raritan River Valley. This is the area that has been the most vulnerable for weeks as repeated heavy rain events and major crests have centered on and around this area. The models are suggesting an inch to two inches of rain tomorrow, much of which is occurring in less than 8 hours. Therefore, flooding and flash flooding is possible. Flash flood guidance suggests 1 to 2 inches is needed for flash flooding in much of North and Central New Jersey. 3 to 4 inches of rain is needed in Southern New Jersey. The front will slow down quite a bit on Thursday and therefore thunderstorms could train over the same areas allowing for localized pockets of excessive rain, perhaps in excess of the 1 to 2 inch range that is forecasted for a widespread geographical area.
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