Last night, I had posted to the blog about the likelihood of heavy rains through today and part of tomorrow across much, if not all, of New Jersey. After writing that post to the blog, I saw on CNN that the National Weather Service was indicating the possibility of a derecho developing in the Midwest, and traveling eastward into the Mid-Atlantic. At the time, Southern Jersey appeared to be more likely in the crosshairs of the derecho.

After looking at the National Weather Service forecast discussions and info from the Storm Prediction Center, I learned that there was more of a threat for Central Jersey including Middlesex County as well. In the least, our area was going to get gusty winds and heavy rains. This morning, the headline in today’s Star-Ledger said, “SEVERE WEATHER ALERT.” Now, it is possible that we could get some hail, dangerous lightning, and maybe even a tornado. We’ll see.

If you recall, last year almost to the day, there was a powerful derecho system that formed in the Midwest near Iowa, rambled through Chicago and the Ohio Valley, and battered the extreme southern portion of the state as well as West Virginia, Virginia, Maryland, Delaware, and Washington D.C. with hurricane force winds up to 81 miles per hour. For those, who do not know what a derecho is, it is a weather term for a squall line, or powerful line of storms that travel a very long distance and bring strong winds over that distance.

Derechos are often fueled by strong domes of high pressure that bring extreme heat and humidity over a part of the United States. At the time of the derecho, the Eastern portion of the U.S. was dealing with a serious heatwave. Another example of a derecho was the Labor Day Storm of 1998 that brought strong winds throughout much of the Garden State including here in Northwestern Middlesex County. The Labor Day derecho had its origins in Michigan on that warm, humid morning, and then traveled several hundred miles into the Garden State, where it brought powerful straight line winds by the mid-afternoon.

Already there have been thunderstorms moving through the area, and they have produced some rainfall. Severe weather has mostly been contained to the south in Southern Jersey from Camden County through Cumberland County, and into Ocean and Atlantic County. More could be on the way though since the storm system with a trailing cold front is still approaching the region. Be sure to pay attention to your local news outlets, NOAA Weather Radio, or the Weather Channel for updates. Also, make sure that you have batteries, flashlights, and radios available in case the power goes out.

For the third time in less than two weeks, a significant storm system with heavy rainfall will be making a visit to the Garden State. The nice weather that we have been experiencing on Wednesday will give way to a storm system approaching from the west, and it is expected to bring anywhere between 2 and 4 inches of rain along with gusty winds. Places in South Jersey could have severe weather including tornadoes from this upcoming storm.

The National Weather Service Office in Mount Holly has put Middlesex County as well as much of the rest of the Garden State under a Flood Watch until early Friday morning. Within the past 45 days or so, the Garden State has seen anywhere from 7 to 10 inches of rain. The previous two rain events: Tropical Storm Andrea late last week, and a low pressure system on Monday brought exactly four inches alone in Northwestern Middlesex County. On top of that, there has been some additional rain this month, and over three inches for the month of May.

Prior to that, things had been fairly dry in New Jersey. While it had been cooler than it was during the first four and a half months with more snow this year than last, the overall precipitation pattern has been quite similar to last year. A relatively wet January was followed by a mostly tranquil February despite the blizzard during the second weekend of the month, and a mostly dry March and April. However, during the month of May, things picked up just like last year, and the first half of June has almost been a carbon copy of last year.

Areas prone to flooding in Central Jersey including Manville and Bound Brook along the Raritan River as well as places along the Millstone River such as Griggstown, will have to be on guard again. The Millstone went up to major flood stage during the deluge from Tropical Storm Andrea late last week, and had been gradually receeding. Wednesday is looking like the best day or the week with the forecast indicating rain tomorrow and part of Friday. With the recent rains, there has been 17.54 inches of rain so far this year at GWC in south Plainfileld. Over 40 percent of that rain has come in the last month and a half.

The first tropical storm of the 2013 Atlantic Hurricane Season is in the books as post-tropical cyclone, Andrea departed from the United States this morning.  There has been some instability around the Central Jersey area.  The various forecasts including one from the local National Weather Service office in Mount Holly indicated a possible stray thunderstorm developing during the course of the day.  However, despite the development of some cumulus clouds, there has not been any shower or thunderstorm activity.

Looking back on Andrea, the storm did bring some gusty winds before coming through the Central Jersey area very early Saturday morning.  Winds increased to between 20 and 30 miles per hour while the barometric pressure fell to 29.55 inches of Hg, or 1001 millibars here at GWC.  There was a bit of rain during the early morning hours to round out the storm total of 2.73 inches.  Thankfully, dry air had been getting entrenched near the center of circulation, where the last batch of rain was located.  The batch came in early this morning, but only brought about another tenth of an inch.

With the storm moving very rapidly in upwards of 35 miles per hour as of Friday night, rainfall totals in Northwestern Middlesex County were not as bad as in West Jersey.  Portions of Hunterdon County received about 5 inches of rain.  Other locales around South Plainfield and Middlesex County received between 2 to 3 inches.  The storm did take down a tree in Manhattan while causing a great deal of flooding around not only the New York area, but also in Massachusetts.  Even Miami was still suffering from the rainfall it had gotten from Andrea earlier in the week.

Andrea, which fell shy of becoming a hurricane with peak winds at 65 miles per hour prior to landfall north of Cedar Key in the Big Bend area of Florida, brought a variety of severe weather including heavy rain, strong winds, and even some tornadoes.   At least 10 were spawned by the storm in Florida while a few more were unleashed in the Carolinas.  A Tornado Watch was still in effect for a good portion of the Mid-Atlantic from the Carolinas to Virginia as of Friday night.  While the storm wasn’t the classic Cape Verde storm that we are accostumed to dealing with a peak season in September, it was an important reminder that hurricane season is upon us, and it is time to get prepared if we haven’t done so already.

More heavy rain is moving through the Garden State as what is left of Tropical Storm Andrea, the first named storm of the 2013 Atlantic Hurricane Season, is rapidly moving up the East Coast into the Mid-Atlantic and Northeast.  Despite being reclassified as a post-tropical system late this afternoon, Andrea is still packing a punch with torrential rain and gusty winds.

Between 5:00 and 6:00 PM EDT, there was a lull in the action after rain had been falling steadily throughout the day.  The rainfall total at that point at the GWC weather station here in South Plainfield, New Jersey was 1.51 inches for the day, and 1.67 since rain started falling during the late afternoon on Thursday.   However, after 6:00 PM, the rain resumed with almost three  quarters of an inch falling up to the time that I started writing this report.

There has been 2.22 inches of rain from the combination of the cold front and Andrea on Friday, and 2.38 total since late Thursday afternoon.  After this latest burst is done (9:00 PM EDT), there is another round of heavy rain coming through during the 11:00 PM hour.    Prior to this storm, there had been 3.26 inches of rain in May and 0.66 inches earlier this week.  Flooding in the neighborhood is possible with the heaviest rain already adding to the swollen creek, stream, and lake levels in town.  

Currently, the barometric pressure is at 29.64 inches of Hg, or about 1004 millibars.  The pressure has fallen another 0.14 inches, or 4 millibars since this afternoon.  Winds have picked up in the past several hours to be running consistently between 10 and 20 miles per hour.  Stronger winds are expected to stay offshore as the storm moves closer to the area.  Conditions will start to improve in the early morning hours of Saturday. 

As of the 8:00 PM EDT advisory from the National Hurricane Center, post-tropical cyclone Andrea still had 45 mile per hour winds and a minimum central pressure of 996 millibars, or 29.41 inches of Hg.  The storm has continued to accelerate with its forward speed now up to 35 miles per hour in a Northeasterly direction.   Andrea is located some 45 miles to the North-Northeast of Norfolk, Virginia, or 70 miles to the Southwest of Ocean City, Maryland on the Delmarva Peninsula.

A Tropical Storm Warning is still in effect from Surf City, North Carolina to Cape Charles Light, Virginia.  Gale force wind conditions could still occur in the Delmarva Peninsula and Southern New Jersey as well as Rhode Island and Southern Massachusetts.