A warm front will be entering our region on Thursday Night. A strong area of low pressure will be attached with this warm front as it lifts into our region. A strong moisture connection will become established and this setup will most definitely result in a drenching rain across the region. Two to four inches remains my call for the areas that see all liquid rain. This rainfall will combine with the melting snow in the Northern and Southern parts of New Jersey to increase the potential for flooding of creeks and streams. Should it rain heavily in Northeast Pennsylvania or in Southern-Central New York, that water would runoff down the Delaware River and combine with the runoff from our counties. There is some uncertainty as to whether it will be rain, freezing rain, or a mixture of rain and wet snow in Northwestern New Jersey and Northeastern Pennsylvania. The best chance of any frozen mix would be Thursday Night in Northwest New Jersey. I would encourage those who have been impacting by flooding in the past to prepare for possible road closures and rising water.
The initial surge of warm air will be accompanied by gusty winds with stronger winds aloft. Will these winds reach the surface at night? A few weeks ago the winds did pretty well at night with the surge. The warm front will have difficulty moving into Northern and Central New Jersey and whether it lifts completely through New Jersey remains a challenging situation to predict. The result is questions about instability, shear, temperatures, and dew points. At this stage of the game, it is expected that most of Southern New Jersey could enter the warm sector Friday Morning into Friday Afternoon. Temperatures may be holding in the forties north of Interstate 195 while areas south of this line are in the fifties, if not the lower and mid-sixties. There could even be some partial clearing in portions of Southern New Jersey. If portions of New Jersey get into the warm sector during the daylight hours, strong southwest winds approaching wind advisory criteria are certainly possible. By this time the ground should be soaked, unlike prior events, and this could mean some issues. Then, some of the models show enough shear, instability, and moisture to trigger a line of squall line or at least isolated cellular features in this warm sector ahead of a strong cold front and these features would pose a risk for damaging wind gusts. The cold front will be moving through the entire region and as it approaches and behind it, into Saturday, some strong to high winds could once again begin our weekend. If this is the case, unlike last weekend, our ground will be very saturated by this period in time which could result in an increased chance of downed trees.
I also continue to wonder whether the NAM model has any credibility with some snow behind the cold front as colder air comes rushing in. 20 degree temperature drops or more would definitely be possible in just a few hours. I think the NAM could be overdoing the cold rush that would catch up to measurable precipitation in time. The GFS had this possibility, but the latest model run shows the colder air too late for much more than a few snow showers. The low deepens rapidly off the Maine coastline, which would drive in the colder air. The events this season have done pretty well for backend snow, which usually in most seasons’ ends up being a fluke on the models.
A weak clipper system will pass to our north on Sunday. This could deliver a period of snow showers or light snow, particularly in Northern and Central New Jersey.
Another strong warm front, low pressure center, and cold front approach our area for the early week period. More heavy rain, strong winds, strong to severe thunderstorms, and flooding is possible with this system. This one could have a better chance for a squall-line of thunderstorms if the 00z GFS is correct.
Friday and Monday, there is very low confidence on the temperatures in the graphics. There is going to be big gradients and sharp differences across the state. There is a very high bust potential here.
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