Post-Tropical Storm Ophelia

Thurs Sept 21 2023

Keeping an eye on a system off the east coast of Florida this afternoon and its potential impacts for this coming weekend.

Currently a disorganized set of showers, most models have the system developing better organization and then running up the eastern seaboard from the Carolinas through Philly and out to sea and over Long Island, with a long window of rain lasting from very early Saturday morning into Sunday and perhaps Sunday evening.

There is still a fairly wide spread in the models for track and intensity. In the images below I am showing the total rain over the four day period from now until Sunday night from the GFS and Euro models.* You can see a range from 1 to 2.5 inches total over the 36 hours. The total period of rain is likely to be 36 hours but some of the showers in this storm could be heavy and there will likely be dry slots, too.

Right now, this storm does not look like it will become a hurricane or tropical storm but it is likely to come close. Becoming a tropical or extra-tropical storm is still on the table, though.

The biggest risk in the MAPSO area is likely to be the minor flooding of roads and fields that is typical of heavy rain on saturated ground. The Rahway River should stay in its banks. Winds likely to be gusty but not howling. Next update in the morning.

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* Model output is not a forecast, it is only one element in a forecast. These results at this point are likely to be quite different every 6 - 12 hours when these models run again.


Thanks! Supposed to do a Boy Scout hike in Sandy Hook Saturday morning. Not looking good.


Thanks, have 5 tickets for family going to Yankees game on Saturday. What to do? 


Let’s name her sweet sixteen. 
This weekend looks like last weekend. Downpours and dry slots. 


Jasmo said:

Thanks, have 5 tickets for family going to Yankees game on Saturday. What to do? 

Go to the game. Might be in a dry slot. 


Friday Sept 22

Update on potential post-tropical storm this weekend.

Currently known as potential tropical storm 16, likely to become tropical storm Ophelia some time today, this rapidly organizing area of wind and rain is unlikely to reach hurricane size before coming ashore in South Carolina.

Effects on our area are likely to be a long rain and moderate winds from very early Saturday morning until sometime Sunday night. Possibly a thunderstorm Saturday afternoon, but also possibly a dry slot at some point Saturday afternoon or evening. By the time the storm reaches us, it will be post tropical and likely more disorganized, weakened by its run up the inland side of the mid Atlantic coast.

Total rain now forecast to be 2 to 2.5 inches* over 36 to 48 hours. Rain may be heavy at times, but generally moderate over the period. Winds likely be steady in the 30 - 39mph **range with some gusting into the 40s. Do not expect wind advisories at this time though we are close so that may change. This apparently large but not particularly powerful storm looks like it will track north from the Carolinas, drench Washington and Philly, and hook east either just south or right over us,tracking out to sea.

All in all a long wet breezy weekend is likely

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* yes, my forecast is a bit dryer than the NWS. I think there will be a dry slot Saturday. Bear in mind the NWS are a lot smarter than I am so take that into account in your planning

** after looking more closely at the models and a large cup of coffee I am revising this down to 15mph with gusts in the mid 30s


What about Sunday evening through sundown on Monday?


Ophelia is going to be a massive rainmaker; slowly decaying tropical systems like this almost always are. Expect this to persist around the area through Monday, as there’s nothing to push it out of the way. Wouldn’t at all be surprised if this outperforms forecasts in terms of rain production. 


WxNut2.0 said:

Ophelia is going to be a massive rainmaker; slowly decaying tropical systems like this almost always are. Expect this to persist around the area through Monday, as there’s nothing to push it out of the way. Wouldn’t at all be surprised if this outperforms forecasts in terms of rain production. 

Well, ****.


WxNut2.0 said:

Ophelia is going to be a massive rainmaker; slowly decaying tropical systems like this almost always are. Expect this to persist around the area through Monday, as there’s nothing to push it out of the way. Wouldn’t at all be surprised if this outperforms forecasts in terms of rain production. 

I’m still traumatized by Ida… don’t scare me.


Jaytee said:

WxNut2.0 said:

Ophelia is going to be a massive rainmaker; slowly decaying tropical systems like this almost always are. Expect this to persist around the area through Monday, as there’s nothing to push it out of the way. Wouldn’t at all be surprised if this outperforms forecasts in terms of rain production. 

I’m still traumatized by Ida… don’t scare me.

Same here, which explains my comment.


Jaytee said:

WxNut2.0 said:

Ophelia is going to be a massive rainmaker; slowly decaying tropical systems like this almost always are. Expect this to persist around the area through Monday, as there’s nothing to push it out of the way. Wouldn’t at all be surprised if this outperforms forecasts in terms of rain production. 

I’m still traumatized by Ida… don’t scare me.

Highly doubt it’s anywhere close to that. My guess is this resembles those once-a-year spring rain events we get where it’s just an extended period of rain. Ida was a true once-in-a-century event.


Let me clarify my comment based on the most recent WPC forecast (image). I think 2-4 seems like a reasonable baseline, but I wouldn’t be surprised if we ended up near or slight above the top end of that. The airmass is being primed as we speak for a long duration rain event and this storm is moving quite slow. That said, it will mostly depend — similar to with a winter storm and snow — where the most persistent and efficient rain bands/thunderstorms develop. If we are within an area of persistent deeper convection/thunderstorms, I’d expect rainfall totals to be on the higher end. 


Ophelia! Might be a good weekend to hunker down and watch Trading Places. 


WxNut2.0 said:

Let me clarify my comment based on the most recent WPC forecast (image). I think 2-4 seems like a reasonable baseline, but I wouldn’t be surprised if we ended up near or slight above the top end of that. The airmass is being primed as we speak for a long duration rain event and this storm is moving quite slow. That said, it will mostly depend — similar to with a winter storm and snow — where the most persistent and efficient rain bands/thunderstorms develop. If we are within an area of persistent deeper convection/thunderstorms, I’d expect rainfall totals to be on the higher end. 

so, we’re looking at getting something in the middle of Ida’s total, which was 8 inches? Spread over two days? 
I feel like we’ve had so much rain this summer that we might have a very snowy winter if these patterns hold up. 


Jaytee said:

WxNut2.0 said:

Let me clarify my comment based on the most recent WPC forecast (image). I think 2-4 seems like a reasonable baseline, but I wouldn’t be surprised if we ended up near or slight above the top end of that. The airmass is being primed as we speak for a long duration rain event and this storm is moving quite slow. That said, it will mostly depend — similar to with a winter storm and snow — where the most persistent and efficient rain bands/thunderstorms develop. If we are within an area of persistent deeper convection/thunderstorms, I’d expect rainfall totals to be on the higher end. 

so, we’re looking at getting something in the middle of Ida’s total, which was 8 inches? Spread over two days? 
I feel like we’ve had so much rain this summer that we might have a very snowy winter if these patterns hold up. 

Yes to the first part (4” spread over 2 days). Maybe to the second (snowy winter). We just shifted into an El Niño phase from a persistent La Niña phase. This typically pushes the jet stream a bit further south, which can sometimes lead to snowy patterns. El Niño has been acting a bit funny so far this year though, so hard to know what the winter will do. 


Saturday, Sept 23

Forecast is on track today for steady rain, possibly heavy at times. Can't rule out a bit of thunder. Winds 15-20 mph with gusts in the 30s. There are no warnings or advisories at this time; flooding is expected to be no more than typical road and field ponding. 1-2" total rain possible today.

Tomorrow, Sunday, showers,breezy, with steady 10-15 mph winds and gusts in the 20s. Perhaps another 1" of rain.

Monday, possible showers and breezy.

Tropical Storm Ophelia made landfall in North Carolina this morning. With no major steering features in the larger environment right now, Ophelia will progress slowly north through Virginia and Maryland, possibly exiting east into the Atlantic Monday from South Jersey. The storm will lose power steadily over the weekend and by midday tomorrow will be a tropical depression.

Although the center of the storm will probably pass us by, all the rain is on the north side of the system. This is likely to be a steady soaker, raising ground water levels, so while we are unlikely to see flash flooding or streams over their banks, if your basement gets we through infiltration then your sump should be busy this weekend. Another concern is soft soaked ground, fully leafed trees, and 35 mph gusts could bring some trees down.


Sunday September 24th

Post tropical cyclone Ophelia remains on track.

Rain today, showers, could be heavy at times with perhaps an afternoon thunderstorm. Winds 15mph with gusts in the low 20s, decreasing throughout the day. Higher gusts could come if we get a thunderstorm.

Rain continues tonight and tomorrow. Overnight, as Ophelia degrades into a post tropical depression, rain should become steady but not as heavy. Ophelia is moving slowly east northeast and will pass south of our area late Monday or early Tuesday. Breezy but fewer, milder gusts.

Rain and showers taper off during the day Tuesday. Expect some sun by Tuesday afternoon.

Total rain for the next few days 1.75 to 2.25 additional inches. So far, about an inch total. I'll have the exact reading after 8:30 this morning. ETA 1.55" in the past 24 hours


I had to take my son to a game in Atlantic City yesterday, and it was a real mess.  Roads were flooding all over the place.  And we got stomped.  Thanks for all of these updates.



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