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Super-Rainstorm Nicole

By: Christopher C. Burt, 2:34 PM GMT on October 02, 2010

For lack of a better moniker, I’m naming the super rainstorm which affected the Eastern Seaboard of the United States Sept. 26 - Oct. 1 after Tropical Storm Nicole, which supplied the stream of sub-tropical moisture that fueled this rain event. Tropical Storm Nicole itself dissipated well south of the Florida Peninsula on Sept. 29.

UPDATE: A number of vigilant readers have pointed out (correctly) that TS Nicole had only a tangental role in contributing to this rain event. As Dr. Masters emailed me "the rain event in NC was a PRE (Predecessor Rain Event) associated with the plume of moisture that accompanied Nicole, and very little of the rain was actually the remnants of Nicole". So, I guess, I should rename the storm as 'Super Rainstorm Diffluence Aloft'. Hmmm..doesn't have quite the cachet...!

The recent rainfall totals rival those of Hurricane Floyd (Sept. 15-17, 1999), the flooding from which was considered a 100-year event in many of the same places affected by this recent storm. The flooding was less severe this time around since the event was preceded by widespread drought conditions in most areas affected, and the rainfall from Floyd fell almost entirely within a 24-hour period for most locations; the ‘Nicole’ rainfall was spread over a three- to five-day period. Below is a chart comparison between the highest measured storm totals by state:



Some of the totals above are preliminary, COOP, CORAHS and spotter reports (as reported in the various NWS public information statements) and may not be final or official.

*NOAA has erroneously reported this total as 24.06”, but close examination of the COOP form for Southport indicates the actual total was 23.56”.

** NOAA reports this total as 14.00”, but the USGS states 12.59” was the total at this same site.


Figure 1. Rainfall totals from Hurricane Floyd of 1999. Image credit: NOAA/NCEP/HPC.


Figure 2. Rainfall totals for the 7-day period ending at 8am EDT October 2, 2010. Image credit: NOAA/AHPS.

Nicole references:

Wilmington, NC National Weather Service report

Floyd references:

NHC report on Hurricane Floyd
USGS report. "Two Months of Flooding in Eastern North Carolina, September - October 1999: Hydrologic Water-Quality, and Geologic Effects of Hurricanes Dennis, Floyd, and Irene"
USGS report, "Flooding in Delaware and the Eastern Shore of Maryland From Hurricane Floyd, September 1999"

Christopher C. Burt

Flood

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

"Super-Rainstorm Nicole". Yeah, I like that... :-)

Those are some absolutely incredible rainfall numbers, especially for a non-hurricane event. Amazing, just amazing.

Oh, and thanks. Your new blog is already near the top of my list.
Nice page & map. I've also been trying to find the top finishers for the rainfall totals but this sums it up greatly. Thnx!
Nicole should have never been named. But record breaking storms do deserve a name, tropical or not. I wish there was some naming scheme for Nor-easters at least! Also extratropical storms like this. It's remarkable how similar this event looks to floyd. Thanks for the post.
Quoting winter123:
Nicole should have never been named. But record breaking storms do deserve a name, tropical or not. I wish there was some naming scheme for Nor-easters at least! Also extratropical storms like this. It's remarkable how similar this event looks to floyd. Thanks for the post.

Ya know I agree with that. It shouldn't just be limited to Tropical Systems.

But nor-easters definitely IMO.
Hey there Weatherhistorian?
Would my "Weather Machines" make history if they can control/regulate the climate by manipulating SSTs?



img src="">
Oh, no, not the "tunnels" again...
Quoting winter123:
Nicole should have never been named.


Really? You should take that up with the NHC; I'm sure they'd appreciate the input of someone with your unparalleled meteorological education and experience. :-)

Seriously, though: the NHC classified Nicole as a tropical storm because the system met the qualifications to be one. Period...
Hey Chris,
Great post.Wow we're talking about ALOT of water.With that graphic it really sinks in.
Thanks for your input.
v/r
Moe
Quoting hcubed:
Oh, no, not the "tunnels" again...


I concur - I have no idea why he keeps bringing them up at every chance; I have even told him that if he is serious, he should present his idea to scientists who would know what he is talking about since he will never get anywhere posting on this blog, although even I know that they probably wouldn't work, especially his claims of "weather control" to eliminate all natural disasters, by selectively cooling the ocean surface, originally intended to "stop" hurricanes but extended to stop everything, including global warming, plus they would supposedly produce an infinite supply of energy.

Also, more on-topic, I am wondering how the rainfall in Pakistan would rank in terms of world records, since this article says that one area had 5 meters of rain in 5 days:

In more than 60 hours of non-stop torrential rainfall, the floods washed all that away. The north-west normally receives 500mm (20in) of rain in the month of July; over one five-day period 5,000mm fell. "It was incredible," said Sameenullah Afridi, a local United Nations official.


That is close to what Dr. Masters lists in this blog from 2007 for world record rainfall for a 5 day period (4.98 meters in 5 days; the amount in the Pakistan article above is probably approximate).
Quoting MichaelSTL:


I concur - I have no idea why he keeps bringing them up at every chance; I have even told him that if he is serious, he should present his idea to scientists who would know what he is talking about since he will never get anywhere posting on this blog, although even I know that they probably wouldn't work, especially his claims of "weather control" to eliminate all natural disasters, by selectively cooling the ocean surface, originally intended to "stop" hurricanes but extended to stop everything, including global warming, plus they would supposedly produce an infinite supply of energy.

Also, more on-topic, I am wondering how the rainfall in Pakistan would rank in terms of world records, since this article says that one area had 5 meters of rain in 5 days:


In more than 60 hours of non-stop torrential rainfall, the floods washed all that away. The north-west normally receives 500mm (20in) of rain in the month of July; over one five-day period 5,000mm fell. "It was incredible," said Sameenullah Afridi, a local United Nations official.


That is close to what Dr. Masters lists in this blog from 2007 for world record rainfall for a 5 day period (4.98 meters in 5 days; the amount in the Pakistan article above is probably approximate).


Oh come on Michael you and I both know that even the universe doesn't have an infinate amount of energy but they do produce an enormous amount of energy. Also about the part of the cooler water not radiating heat to space in proportion to warmer water. What happens is as our climate warms more water vapor will form thus blocking more heat from getting to space. That portion which is blocked just gets transferred to the atmosphere thus heating it more. As the tunnels cool ssts which in turn will cool the air that comes in contact with it less water vapor is formed and so more heat is radiated to space.The Greenhouse blanket becomes thinner so more heat can come and go more effectivly without getting trapped. So with that I hope you can see how they can work???? There is so much good they can do for us if someone would computer model them I am sure they will see the light.
OOPS!
IMHO, Nicole had very little to do with NC's rains.

A post of mine in Dr. M's blog a few days back with TPW anomaly:

--------
Where is the double TPW? Where is the great big contribution of Nicole over normal moisture available to be pulled along this front?

Morning of the 28th, before Nicole did much:


About the time the last advisory on Nicole was posted:


Yeah, so TPW anomaly was around 100% of normal up to 150% of normal in some places. But some especially higher than normal TPW with Nicole's signature on it simply doesn't appear here.


Full loop: http://www.osdpd.noaa.gov/bTPW/TPW_Animation.html?fromDate=20100926&fromHour=23&endDate=20100929&en dHour=23&product=CONUS_PCT&interval=6hours

I personally think you guys are hanging your "Nicole's moisture" hat on what is simply convergence, bringing very high moisture totals to the frontal boundary, nothingmore. This front is doing just that (heck, check out Pennsylvania's TPW 2 days before Nicole got into the mix).
---------

I've seen nothing that suggests that the NC rains would have been any different if there wasn't even a tropical wave in the vicinity.

For another example of frontal-induced convergence and tropical moisture draw, without a tropical system (but similar dynamics), see the NESDIS TPW presentation about the Nashville river flooding here: ftp://satepsanone.nesdis.noaa.gov/Presentations/Conferences/NWA_Annual_Oct2010.ppt

Aside: Floyd was obviously a different setup.
The storm that struck the east coast was TROPICAL STORM NICOLE!!!!!!!! I'm convinced the National Hurricane Center wouldn't know a tropical storm if they tripped over it.
Hey atmo!
Must be a pretty convoluted process to determine TPW over the ocean using a blend of satellites that take 3-5 days to cover the earth-in combination with weather balloons for "land" TPW.

Yes?

Another look at that tropical moisture from MIMIC.

Quoting atmoaggie:
IMHO, Nicole had very little to do with NC's rains.

A post of mine in Dr. M's blog a few days back with TPW anomaly:

--------
Where is the double TPW? Where is the great big contribution of Nicole over normal moisture available to be pulled along this front?

Morning of the 28th, before Nicole did much:


About the time the last advisory on Nicole was posted:


Yeah, so TPW anomaly was around 100% of normal up to 150% of normal in some places. But some especially higher than normal TPW with Nicole's signature on it simply doesn't appear here.


Full loop: http://www.osdpd.noaa.gov/bTPW/TPW_Animation.html?fromDate=20100926&fromHour=23&am p;endDate=201 00929&en dHour=23&product=CONUS_PCT&interval=6hours

I personally think you guys are hanging your "Nicole's moisture" hat on what is simply convergence, bringing very high moisture totals to the frontal boundary, nothingmore. This front is doing just that (heck, check out Pennsylvania's TPW 2 days before Nicole got into the mix).
---------

I've seen nothing that suggests that the NC rains would have been any different if there wasn't even a tropical wave in the vicinity.

For another example of frontal-induced convergence and tropical moisture draw, without a tropical system (but similar dynamics), see the NESDIS TPW presentation about the Nashville river flooding here: ftp://satepsanone.nesdis.noaa.gov/Presentations/Conferences/NWA_Annual_Oct2010.ppt

Aside: Floyd was obviously a different setup.


This is an excellent post and one that is quite accurate (for the most part). That being said, it is still not entirely accurate to suggest that the moisture from the remnants of Nicole did not play a role in our record rainfall totals for the five day period. It would be far more accurate to state that this historical event was a combination of all the aforementioned factors-with the remnants and the moisture of "Nicole" playing a role in the process, but was not the primary contribution to it.

The fact is that the remnant circulation of "Nicole" and the direct moisture associated with it did in fact bring additional rainfall to our area. So, it would not be entirely accurate to suggest that the NC rainfall totals would have been "no different" had there been no "Nicole" or a "tropical wave" in the general vicinity.

With all the aforementioned in mind, I too agree that the vast majority of the record rainfall was not directly attributed to TS Nicole and you did an excellent job of highlighting that particular aspect of this rather historic weather event.

The fact of the matter is that there were other areas of low pressure that developed and rode up along the relatively stalled frontal boundary. As a result, it would be fair to say that these areas of low pressure were just as significant-if not more so-than the area of low pressure know as "Nicole" that ultimately moved through our area.
A unique combination of things at the least.

A couple of anomalies:
A strong (20-40kt low-level EPAC jet.
The large (Caribbean-wide) depression that ultimately got a name.

Monsoon Nicole did a great job in converging the EPAC tap and ITCZ moisture S of the front into a single moisture channel between the upper trough/front and a stubborn mid-Atlantic ridge.

But yeah, It woulda rained anyway.
:)


Speaking of rain,

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

PREV DISCUSSION... /ISSUED 410 AM CDT TUE OCT 5 2010/

...AFTERNOON INTERIOR RHS LOWER INTO THE LOWER 20 PERCENTILE
UNDER LIGHT EASTERLY WINDS. PER THIS .2-.4 INCH PWAT AIR
MASS...
Quoting beell:
Hey atmo!
Must be a pretty convoluted process to determine TPW over the ocean using a blend of satellites that take 3-5 days to cover the earth-in combination with weather balloons for "land" TPW.

Yes?

Another look at that tropical moisture from MIMIC.

Actually, beell, the land-based obs in the blended TPW product are updated hourly, outside of data outages. From GPS lag time, inferred mixing ratio for whole column.
PRE (Predecessor Rain Event)
I never can seem to remember those terms when I need them...
lol