A weak coastal low developing offshore will brush the region today with clouds and light rain, generally under a tenth of an inch, with highs in the low to mid 50s. Clearing skies are expected tonight with a breezy west wind on Thursday and highs in the upper 40s-low 50s inland and low-mid 50s for the rest of the area. Similar temperatures are expected again for Friday, but with the coldest overnight lows on Thursday and Friday nights with lows falling into the upper 20s inland, low-mid 30s in the north/west suburbs of NYC, southern CT and interior Long Island, and upper 30s near NYC and the coast. As a result, the first frost of the fall is likely in this time frame away from the coast for locations that have not experienced it yet.
A weak low pressure will stay north of the area on Saturday night, with a slight warm up into the low-mid 50s inland and the mid-upper 50s elsewhere for highs on Sunday and Monday, while lows stay in the 30s away from NYC and the immediate coast. By later next week, however, there is little doubt that the cold air mass surging south through Canada will not be directed at the region, but rather at the western US, which will result in a strong upper level low and low pressure developing in that region, while ridging builds over the eastern US, bringing back the southeast ridge influence that was present earlier in the month. How warm temperatures get at the surface, however, depends on the setup of the western US low pressure and the position of the Canadian high pressure; if the high pressure stays near or north of the region, it would prevent temperatures from warming up by much relative to this week, while the next frontal system could affect the area at the very end of the month or early November with the next potential for rain. Otherwise, a sustained cold pattern appears unlikely given latest indications, as a strong +NAO/+AO pattern develops going into the start of November and the current +PNA/-EPO pattern, fueled in part by the frequent recurving super typhoons in the West Pacific ocean, weakens and transitions into a -PNA/neutral EPO pattern.
Continue reading for observations from Tuesday, October 22.