Major Hurricane Raymond: Slow, Erratic Movement

By: 24hourprof , 5:15 PM GMT on October 21, 2013

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Hurricane Raymond rapidly intensified precariously close to the western coast of Mexico yesterday afternoon and early today in response to warm waters (check out the analysis of sea-surface temperatures below) and a moderate ocean heat content).


The analysis of sea-surface temperatures (in degrees Celsius) over the eastern Pacific basin on October 21, 2013. Courtesy of the University of Miami.

By way of background, the depths of the isotherms (20 and 26 degrees Celsius) obtained by radar altimetry are blended with sea-surface temperatures to estimate ocean heat content (OHC). I include the most recent analysis below.


The analysis of ocean heat content (in kilojoules per square centimeter) over the eastern Pacific basin on October 21, 2013. Courtesy of the University of Miami.

As readers already know, tropical cyclogenesis depends, in part, on a relatively deep, well-mixed oceanic layer (see the most current analysis below). That's because strong winds associated with a developing or intensifying tropical cyclone increase mixing of water in the uppermost layer of the ocean. This turbulent mixing, in turn, increases the depth of the well-mixed oceanic layer. As a result, cooler water "entrains" into the well-mixed layer from below. In turn, this cooler water gets mixed throughout the the now deeper well-mixed layer, lowering ocean heat content and decreasing sea-surface temperatures. In the case of a slow-moving or stationary tropical cyclone, the stage is set for the storm to weaken because lower sea-surface temperatures go hand in hand with reduced fluxes of heat energy and moisture from the sea to the overlying air. In effect, a stationary tropical cyclone dissipates by its own hand.


The analysis of the depth of the mixed layer (in meters) over the eastern Pacific basin on October 21, 2013. Courtesy of the University of Miami.

As of 15Z this morning (8 A.M. PDT), the minimum central pressure of Major Hurricane Raymond was 954 mb, which is consistent the mean wind in the layer between 850 mb (roughly 1.5 kilometers) and 300 mb (approximately nine kilometers) acting as a steering current. I introduced the concept of a tropical cyclone's steering layer as a function of minimum central pressure in an earlier blog (the graph below summarizes the point of my earlier blog).


The steering layer for tropical cyclones as a function of minimum central pressure. Courtesy of CIMSS.

The 12Z analysis of the mean wind in the layer between 850 mb and 300 mb over Hurricane Raymond (below; larger image) indicates a weak steering flow, which is consistent with the storm's slow, somewhat erratic movement over the short term. As a result of the induced stress on the ocean by hurricane-force winds, the well-mixed layer should deepen in time (see current analysis below), allowing colder water to entrain near the bottom of the deepening well-mixed oceanic layer. In turn, ocean heat content and sea-surface temperatures in the vicinity of Hurricane Raymond should decrease with time, paving the way for Raymond's maximum sustained winds to weaken.


The mean wind direction (white streamlines) and wind speed (pink isotachs expressed in knots) between 850 mb and 300 mb at 12Z on October 22, 2013. Larger image. Courtesy of CIMSS.

Still, there is much uncertainty about the predicted track and intensity of Hurricane Raymond. One's things for sure...the threat of heavy rain to neighboring coastal areas is very, very real.

Lee

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18. WunderAlertBot (Admin)
11:28 AM GMT on October 23, 2013
24hourprof has created a new entry.
17. WunderAlertBot (Admin)
11:14 AM GMT on October 23, 2013
24hourprof has created a new entry.
16. 24hourprof
8:45 PM GMT on October 22, 2013
Quoting 15. 1900hurricane:
Well, I messed that one up! The microwave passes last night had me sold that Raymond could strengthen a little more, but as you said, upwelling is now visible starting to take a toll on Raymond.


You did fine!

I should also give a shout-out to NHC, who noted moderate wind shear (southerly) also came into play.
Member Since: October 24, 2012 Posts: 90 Comments: 798
15. 1900hurricane
2:43 PM GMT on October 22, 2013
Well, I messed that one up! The microwave passes last night had me sold that Raymond could strengthen a little more, but as you said, upwelling is now visible starting to take a toll on Raymond.
Member Since: August 2, 2006 Posts: 46 Comments: 11666
14. 24hourprof
12:02 PM GMT on October 22, 2013
Quoting 12. 1900hurricane:

Sea surface temperatures are very warm but somewhat shallow, so the OHC isn't very high in that area.



I imagine Raymond may be showing some signs of being impacted by upwelling by this time tomorrow, but he doesn't seem affected right now, with him firing some new deep convection following a completed eyewall replacement cycle.



My unoffical forecast is maybe 5-10 kts of strengthening into tomorrow morning followed by some weakening thereafter.


I don't see any further strengthening. I'm pretty sure upwelling of cooler water is already starting to take its toll.

We'll see, but many thanks for your insights and opinion.

Lee
Member Since: October 24, 2012 Posts: 90 Comments: 798
13. 24hourprof
11:55 AM GMT on October 22, 2013
Quoting 11. rpointwx:
If my memory serves me well Hurricane Opal in 1995 was a good example of OHC and upwelling. What also made that storm interesting was the intensification of the storm when encountering a loop current. I think it intensified around 50hPa in a 14 hour period.

For me, in my area, even greater than Superstorm Sandy (as we approach the anniversary) was Hurricane Gloria in 1985. That was the storm that captivated my interest in weather as a child and prompted me to study meteorology as an undergrad. That storm to my memory really starting the immense tv coverage or obsession with weather that we know todayy

For those interested in Hurricane Gloria here is a great site with statistics and even some old weather forecast clips with the great John Hope.

http://www.hurricanes-blizzards-noreasters.com/HU RRICANE-GLORIA.html


I also remember Gloria in '85. The forecast for the Rutgers-PSU football game in New Jersey was not good, but Gloria roared up the coast, and the sun came out and the wind subsided for the game.
Member Since: October 24, 2012 Posts: 90 Comments: 798
12. 1900hurricane
3:41 AM GMT on October 22, 2013
Quoting 9. 24hourprof:


Thanks 1900hurricane. Yes, I see the weakening. I'm kind of surprised NHC didn't mention the upwelling of cooler water. Aren't you?

I'm also wondering if it will weaken more quickly.

Any thoughts?

Sea surface temperatures are very warm but somewhat shallow, so the OHC isn't very high in that area.



I imagine Raymond may be showing some signs of being impacted by upwelling by this time tomorrow, but he doesn't seem affected right now, with him firing some new deep convection following a completed eyewall replacement cycle.



My unoffical forecast is maybe 5-10 kts of strengthening into tomorrow morning followed by some weakening thereafter.
Member Since: August 2, 2006 Posts: 46 Comments: 11666
11. rpointwx
2:43 AM GMT on October 22, 2013
If my memory serves me well Hurricane Opal in 1995 was a good example of OHC and upwelling. What also made that storm interesting was the intensification of the storm when encountering a loop current. I think it intensified around 50hPa in a 14 hour period.

For me, in my area, even greater than Superstorm Sandy (as we approach the anniversary) was Hurricane Gloria in 1985. That was the storm that captivated my interest in weather as a child and prompted me to study meteorology as an undergrad. That storm to my memory really starting the immense tv coverage or obsession with weather that we know todayy

For those interested in Hurricane Gloria here is a great site with statistics and even some old weather forecast clips with the great John Hope.

http://www.hurricanes-blizzards-noreasters.com/HU RRICANE-GLORIA.html
Member Since: December 27, 2009 Posts: 0 Comments: 10
10. 24hourprof
11:45 PM GMT on October 21, 2013
Quoting 7. georgevandenberghe:


Rain amounts from landfalling tropical cyclones are not linearly related to intensity. In particular, weak TC can produce a lot of rain and loss of intensity generally does NOT reduce the inland flooding threat very much until 24H after weakening to TD stage. Other risk points are any significant orography downwind, sometimes days downwind of the steering flow, and absorption into frontal zones.
Deep low and midlevel tropical origin moisture remains a threat until it encounters strong sinking or actually rains out.


Agreed. Relatively "weak" tropical cyclones can dump a lot of rain, especially the slow-moving ones. I still remember Allison in June, 2011.



Member Since: October 24, 2012 Posts: 90 Comments: 798
9. 24hourprof
11:38 PM GMT on October 21, 2013
Quoting 5. 1900hurricane:
NHC has raised max winds slightly with the latest advisory. The discussion also talks a little bit about the weak steering.

000
WTPZ42 KNHC 212036
TCDEP2

HURRICANE RAYMOND DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP172013
200 PM PDT MON OCT 21 2013

OVER THE PAST FEW HOURS...THE EYE OF RAYMOND HAS BECOME A LITTLE
MORE DISTINCT IN SATELLITE IMAGERY. IN FACT...EARLIER MICROWAVE AND
GEOSTATIONARY IMAGERY SHOWED A VERY SMALL EYE AROUND 15Z...SO
PERHAPS THE STORM HAS GONE THROUGH AN EYEWALL REPLACMENT CYCLE
TODAY. DVORAK SATELLITE ESTIMATES AT 18Z WERE T6.0/115 KT FROM SAB
AND T5.5/102 KT FROM TAFB...AND BASED ON A BLEND OF THESE...THE
INITIAL INTENSITY IS SET TO 110 KT FOR THIS ADVISORY. THE INTENSITY
GUIDANCE SUGGESTS THAT RAYMOND IS NEAR ITS PEAK...ALTHOUGH EYEWALL
REPLACEMENT CYCLE AND INNER-CORE DYNAMICS COULD LEAD TO SHORT-TERM
FLUCTUATIONS IN INTENSITY DURING THE NEXT 12 TO 24 HOURS THAT ARE
NOT SHOWN IN THE OFFICIAL FORECAST. GRADUAL WEAKENING SHOULD BEGIN
AFTER THAT TIME...AS THE SHEAR VECTOR BECOMES SOUTHWESTERLY AND
RAYMOND MOVES OVER SLIGHTLY COOLER WATERS LATER IN THE PERIOD. THE
NHC INTENSITY FORECAST IS LARGELY UNCHANGED FROM THE PREVIOUS ONE
AND IS CLOSE TO OR A LITTLE ABOVE THE LGEM MODEL.

RAYMOND HAS BEEN STATIONARY FOR SEVERAL HOURS NOW...AND LITTLE
MOTION IS EXPECTED DURING THE NEXT 24 TO 36 HOURS WHILE THE
STEERING CURRENTS REMAIN WEAK. THE GFDL AND HWRF CONTINUE TO BRING
RAYMOND NORTHWARD CLOSER TO THE COAST DURING THE NEXT DAY OR
SO...WHILE THE GLOBAL MODELS STILL SHOW A SLOW SOUTHWARD OR
SOUTHEASTWARD MOTION. THE NHC TRACK INDICATES LITTLE MOTION DURING
THE NEXT 24 TO 36 HOURS...BUT CONFIDENCE IS LOW AND SOME ERRATIC
MOTION IS POSSIBLE DURING THIS TIME. LATER IN THE PERIOD...THE
GLOBAL MODELS SHOW A MID-LEVEL RIDGE BUILDING NORTH OF THE
CYCLONE...WHICH SHOULD RESULT IN A WESTWARD MOTION THROUGH THE END
OF THE FORECAST PERIOD. THERE REMAINS CONSIDERABLE NORTH/SOUTH
SPREAD IN THE TRACK MODEL GUIDANCE LATER IN THE PERIOD...SO
CONFIDENCE REMAINS LOW IN THE DETAILS OF THE TRACK FORECAST
THROUGHOUT THE PERIOD. OVERALL...THE NHC TRACK IS CLOSE TO THE
PREVIOUS ONE AND IS NEAR THE GEFS ENSEMBLE MEAN BY DAY 5.

REGARDLESS OF THE EXACT TRACK OF THE HURRICANE AND HOW CLOSE IT GETS
TO THE COAST...HEAVY RAINFALL WILL CONTINUE OVER SOUTH-CENTRAL
MEXICO DURING THE NEXT FEW DAYS...CAUSING LIFE-THREATENING FLASH
FLOODS AND MUD SLIDES.

FORECAST POSITIONS AND MAX WINDS

INIT 21/2100Z 16.3N 102.2W 110 KT 125 MPH
12H 22/0600Z 16.4N 102.1W 110 KT 125 MPH
24H 22/1800Z 16.3N 102.1W 105 KT 120 MPH
36H 23/0600Z 16.3N 102.3W 100 KT 115 MPH
48H 23/1800Z 16.2N 103.0W 95 KT 110 MPH
72H 24/1800Z 15.8N 105.2W 80 KT 90 MPH
96H 25/1800Z 15.5N 108.0W 75 KT 85 MPH
120H 26/1800Z 15.5N 111.0W 70 KT 80 MPH

$$
FORECASTER BRENNAN


Thanks 1900hurricane. Yes, I see the weakening. I'm kind of surprised NHC didn't mention the upwelling of cooler water. Aren't you?

I'm also wondering if it will weaken more quickly.

Any thoughts?
Member Since: October 24, 2012 Posts: 90 Comments: 798
8. 24hourprof
11:36 PM GMT on October 21, 2013
Quoting 6. Patrap:


Symmetry of Irony,Beauty and the Beast for sure Dr. Grenci.

Thanks for your entry as well.

Always appreciated by many here.

RAMMB Storm Page


EP172013 - Major Hurricane RAYMOND

Storm Relative 1 km Geostationary Visible Imagery


Another stunning image. Thanks. Your kind words are much appreciated.

Lee
Member Since: October 24, 2012 Posts: 90 Comments: 798
7. georgevandenberghe
10:46 PM GMT on October 21, 2013
Quoting 4. 24hourprof:


Please call me Lee.

That's a really tough question, but I think the entrainment of colder water into the bottom of the well-mixed oceanic layer will start to lower OHC and SST's (and thus weaken the storm) pretty soon...I think we would "notice" a weakening within 12-24 hours. Maybe sooner. It looks to me like the storm has peaked already, ??? so I might be too conservative. Again, this is only my opinion, and no one should use my unofficial forecast to make any kind of important decision.

But I'm talking wind speed here...heavy rain is another matter altogether.

Great question!

Lee

Lee


Rain amounts from landfalling tropical cyclones are not linearly related to intensity. In particular, weak TC can produce a lot of rain and loss of intensity generally does NOT reduce the inland flooding threat very much until 24H after weakening to TD stage. Other risk points are any significant orography downwind, sometimes days downwind of the steering flow, and absorption into frontal zones.
Deep low and midlevel tropical origin moisture remains a threat until it encounters strong sinking or actually rains out.
Member Since: February 1, 2012 Posts: 17 Comments: 1630
6. Patrap
9:41 PM GMT on October 21, 2013
Quoting 3. 24hourprof:


Wow! Absolutely stunning.

While I recognize the amazing nature of the IR loop you posted, I am also aware of the ongoing toll to human life and property.

Truly a dichotomy.

Lee



Symmetry of Irony,Beauty and the Beast for sure Dr. Grenci.

Thanks for your entry as well.

Always appreciated by many here.

RAMMB Storm Page


EP172013 - Major Hurricane RAYMOND

Storm Relative 1 km Geostationary Visible Imagery
Member Since: July 3, 2005 Posts: 421 Comments: 127650
5. 1900hurricane
9:33 PM GMT on October 21, 2013
NHC has raised max winds slightly with the latest advisory. The discussion also talks a little bit about the weak steering.

000
WTPZ42 KNHC 212036
TCDEP2

HURRICANE RAYMOND DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP172013
200 PM PDT MON OCT 21 2013

OVER THE PAST FEW HOURS...THE EYE OF RAYMOND HAS BECOME A LITTLE
MORE DISTINCT IN SATELLITE IMAGERY. IN FACT...EARLIER MICROWAVE AND
GEOSTATIONARY IMAGERY SHOWED A VERY SMALL EYE AROUND 15Z...SO
PERHAPS THE STORM HAS GONE THROUGH AN EYEWALL REPLACMENT CYCLE
TODAY. DVORAK SATELLITE ESTIMATES AT 18Z WERE T6.0/115 KT FROM SAB
AND T5.5/102 KT FROM TAFB...AND BASED ON A BLEND OF THESE...THE
INITIAL INTENSITY IS SET TO 110 KT FOR THIS ADVISORY. THE INTENSITY
GUIDANCE SUGGESTS THAT RAYMOND IS NEAR ITS PEAK...ALTHOUGH EYEWALL
REPLACEMENT CYCLE AND INNER-CORE DYNAMICS COULD LEAD TO SHORT-TERM
FLUCTUATIONS IN INTENSITY DURING THE NEXT 12 TO 24 HOURS THAT ARE
NOT SHOWN IN THE OFFICIAL FORECAST. GRADUAL WEAKENING SHOULD BEGIN
AFTER THAT TIME...AS THE SHEAR VECTOR BECOMES SOUTHWESTERLY AND
RAYMOND MOVES OVER SLIGHTLY COOLER WATERS LATER IN THE PERIOD. THE
NHC INTENSITY FORECAST IS LARGELY UNCHANGED FROM THE PREVIOUS ONE
AND IS CLOSE TO OR A LITTLE ABOVE THE LGEM MODEL.

RAYMOND HAS BEEN STATIONARY FOR SEVERAL HOURS NOW...AND LITTLE
MOTION IS EXPECTED DURING THE NEXT 24 TO 36 HOURS WHILE THE
STEERING CURRENTS REMAIN WEAK. THE GFDL AND HWRF CONTINUE TO BRING
RAYMOND NORTHWARD CLOSER TO THE COAST DURING THE NEXT DAY OR
SO...WHILE THE GLOBAL MODELS STILL SHOW A SLOW SOUTHWARD OR
SOUTHEASTWARD MOTION. THE NHC TRACK INDICATES LITTLE MOTION DURING
THE NEXT 24 TO 36 HOURS...BUT CONFIDENCE IS LOW AND SOME ERRATIC
MOTION IS POSSIBLE DURING THIS TIME. LATER IN THE PERIOD...THE
GLOBAL MODELS SHOW A MID-LEVEL RIDGE BUILDING NORTH OF THE
CYCLONE...WHICH SHOULD RESULT IN A WESTWARD MOTION THROUGH THE END
OF THE FORECAST PERIOD. THERE REMAINS CONSIDERABLE NORTH/SOUTH
SPREAD IN THE TRACK MODEL GUIDANCE LATER IN THE PERIOD...SO
CONFIDENCE REMAINS LOW IN THE DETAILS OF THE TRACK FORECAST
THROUGHOUT THE PERIOD. OVERALL...THE NHC TRACK IS CLOSE TO THE
PREVIOUS ONE AND IS NEAR THE GEFS ENSEMBLE MEAN BY DAY 5.

REGARDLESS OF THE EXACT TRACK OF THE HURRICANE AND HOW CLOSE IT GETS
TO THE COAST...HEAVY RAINFALL WILL CONTINUE OVER SOUTH-CENTRAL
MEXICO DURING THE NEXT FEW DAYS...CAUSING LIFE-THREATENING FLASH
FLOODS AND MUD SLIDES.

FORECAST POSITIONS AND MAX WINDS

INIT 21/2100Z 16.3N 102.2W 110 KT 125 MPH
12H 22/0600Z 16.4N 102.1W 110 KT 125 MPH
24H 22/1800Z 16.3N 102.1W 105 KT 120 MPH
36H 23/0600Z 16.3N 102.3W 100 KT 115 MPH
48H 23/1800Z 16.2N 103.0W 95 KT 110 MPH
72H 24/1800Z 15.8N 105.2W 80 KT 90 MPH
96H 25/1800Z 15.5N 108.0W 75 KT 85 MPH
120H 26/1800Z 15.5N 111.0W 70 KT 80 MPH

$$
FORECASTER BRENNAN
Member Since: August 2, 2006 Posts: 46 Comments: 11666
4. 24hourprof
9:11 PM GMT on October 21, 2013
Quoting 2. DonnieBwkGA:
Dr. Grenci how soon do you expect upwelling to weaken Raymond if he remains stationary?


Please call me Lee.

That's a really tough question, but I think the entrainment of colder water into the bottom of the well-mixed oceanic layer will start to lower OHC and SST's (and thus weaken the storm) pretty soon...I think we would "notice" a weakening within 12-24 hours. Maybe sooner. It looks to me like the storm has peaked already, ??? so I might be too conservative. Again, this is only my opinion, and no one should use my unofficial forecast to make any kind of important decision.

But I'm talking wind speed here...heavy rain is another matter altogether.

Great question!

Lee
Member Since: October 24, 2012 Posts: 90 Comments: 798
3. 24hourprof
9:03 PM GMT on October 21, 2013
Quoting 1. Patrap:


Wow! Absolutely stunning.

While I recognize the amazing nature of the IR loop you posted, I am also aware of the ongoing toll to human life and property.

Truly a dichotomy.

Lee

Member Since: October 24, 2012 Posts: 90 Comments: 798
2. DonnieBwkGA
9:01 PM GMT on October 21, 2013
Dr. Grenci how soon do you expect upwelling to weaken Raymond if he remains stationary?
Member Since: June 29, 2013 Posts: 21 Comments: 1964
1. Patrap
8:58 PM GMT on October 21, 2013
Member Since: July 3, 2005 Posts: 421 Comments: 127650

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Retired senior lecturer in the Department of Meteorology at Penn State, where he was lead faculty for PSU's online certificate in forecasting.

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