4/02 All Zones AM Update: Pleasant Weather Today, More Rain Late Monday night into Tuesday

Happy Sunday! Finally again more sunshine and blue skies has returned! High pressure will be in control through today and Monday with more pleasant, warmer and drier weather. But the pattern continues to be active. Another storm system which will is causing some severe weather over Deep South will head our away for late Monday night and Tuesday with more heavy rainfall likely for the local region.

Back up today however, skies will remain mostly sunny into this afternoon. Just some high clouds come in during late afternoon hours. Downsloping northwest winds off the higher terrain northwest, will support high temperatures in the mid-upper 50s to lower 60s over much of the region.

It will pleasant into the evening hours. Some mid-upper level disturbances passing by, may cause more clear to partly skies overnight. More high clouds will will prevent more radiational cooling from occurring. Overnight low temperatures will be mid-upper 30s in many of the suburbs to lower 40s in NYC and other urban areas. Some of Interior valley and Pine barrens may drop into lower 30s.

NAM model forecast for 2pm Monday afternoon

NAM model at 2pm Monday with light southeast flow keeping areas north of Central NJ slightly cooler

High pressure sliding offshore on Monday will allow for some more clouds to increase by the afternoon out ahead of the next storm system. It may turn mostly cloudy by the end of the day. But it will remain dry with temperatures still reaching the mid-upper 50s to lower 60s. The only exception may more light southeast winds or sea-breezes that could keep some coastal sections a little cooler during the afternoon.

But the weather conditions will gradually deteriorate, Monday night into Tuesday morning. Low pressure from the Deep South and Southern Plains will be tracking into the Great Lakes and pushing a warm front northward through the region. This will cause some areas of light to moderate rain to break late over parts of the region during the late evening and early overnight hours. Temperatures will only fall in down into the 40s for overnight lows over most of the region.

Then a strengthening southerly low-level jet with plume of deep Atlantic and subtropical moisture will come through region. This will cause rain to become steadier and more moderate to heavy at times, very late Monday night into Tuesday morning. Rainfall totals of 1” to 2” and possibly locally higher, are likely for much of the region. Some weak elevated instability may lead to some convection with very heavy downpours and rumbles of thunder.  Localized flooding is possible again in poor drainage and low-lying areas. Some rivers and streams may overflow the banks after this rainfall.

High-reslution NAM model showing strong 850mb southerly jet passing through region Tuesday morning

High-resolution NAM model showing strong 850mb southerly jet passing through region Tuesday morning

Then the warm front lifts north of most of the region with rain tapering off Tuesday afternoon. Temperatures could rise well into 60s or lower 70s if clouds could break for some sunshine. But this could lead to more instability for more scattered showers and thunderstorms to develop, ahead of cold front and a vigorous shortwave shortwave trough, moving through region late in the afternoon and early evening.

Finally, some more pleasant dry weather returns briefly on Wednesday before the next storm system approaches for Thursday. This will be from a large closed upper-level low positioned to our west, with potential for more heavy rainfall over the local region. The Storm Prediction Center even has 15% risk for some severe weather further south over the Mid-Atlantic region.  We will be monitoring this potential closely for the southern zones as well. Stay tuned for more zone forecast and other updates on both storm systems through this week. Have a great day!