Dangerous 'High Risk' Midwest U.S. Tornado Outbreak Underway

By: Dr. Jeff Masters , 4:30 PM GMT on November 17, 2013

A rare and very dangerous late-season severe weather outbreak is underway over the Midwest U.S., where NOAA's Storm Prediction Center is predicting a "High Risk" of severe weather--their highest level of alert--over most of Indiana and Illinois, plus portions of Southern Lower Michigan and Western Ohio. This is just the second "High Risk" forecast for 2013, and the area at risk of severe weather is unusually large. According to a list of all "High Risk" forecasts issued since 1984 maintained at Wikipedia, today's High Risk area is the farthest north such a forecast has been issued so late in the year. A 992 mb low pressure system that was over Northern Illinois on Sunday morning will move northeast and rapidly intensify to 965 mb by Monday morning, dragging a strong cold front across the "High Risk" area on Sunday afternoon. Isolated supercell thunderstorms--the kind most likely to produce strong and violent tornadoes--are expected to form ahead of the front, and the SPC is expecting multiple long-track strong tornadoes to form during the early afternoon. Any tornadoes that form will be moving at highway speed--50 to 60 mph--and will be under low cloud bases around 2,000 feet, making these storms difficult to see and react to, particularly in wooded or hilly areas. If the sirens sound, seek shelter!


Figure 1. Severe weather outlook for Sunday, November 17, 2013.

A dangerous day in Chicago
Most of Illinois, including Chicago, has been placed under a special "PDS" Tornado Watch: a "Particularly Dangerous Situation." Severe thunderstorms spawning tornado warnings have already erupted over Southern Wisconsin and Western Illinois as of 10:15 am CST. Severe thunderstorms are likely to sweep through Chicago in the early afternoon during today's Ravens - Bears game, which starts at noon CST. According to NBC 5 in Chicago, loose objects are being removed from the stadium in anticipation of high winds, and officials are prepared to evacuate fans, if necessary. An NFL game will stop if there is lightning, and cannot continue until 30 minutes afterwards.


Figure 2. Prior to Sunday's severe weather outbreak, there were seven billion-dollar weather disasters in the U.S. in 2013. Five of these disasters were severe weather outbreaks--the third highest such total in history.

A slow but very expensive tornado season
It's been an unusually slow severe weather season, with the 2013 preliminary tally of 818 tornadoes the lowest year-to-date count since the extreme drought year of 1988. However, when severe weather outbreaks have come, they have been unusually destructive. According to Aon Benfield, there have been five severe weather outbreaks topping $1 billion in damages this year. This is the third highest number of such disasters on record, going back to 1980. The record is shared by 2011 and 2012, with seven billion-dollar-plus severe weather outbreaks, according to NOAA's National Climatic Data Center. The total damage from 2013's five billion-dollar severe weather outbreaks is $14 billion, which is the third highest on record, behind 2011 ($29.6 billion) and 2010 ($16.3 billion.) The most expensive and deadliest severe weather outbreak of 2013 hit on May 20, when Moore, Oklahoma was devastated by an Ef-5 tornado that killed 23 people and did $2 billion in damage.

Stay Safe!
November is a highly unusual time to be getting a dangerous severe weather outbreak, but people need to take this event seriously. The four previous November "High Risk" events (1989, 1994, 2002, and 2005) have resulted in a total of 148 tornadoes and 62 fatalities (thanks go to wunderground member Neapolitan for this stat). Stay Safe!

Jeff Masters

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461. DanBlum
1:14 AM GMT on November 19, 2013
Quoting 460. ScottLincoln:

Perhaps there hasn't been anyone around that has wanted to put forth the time and effort to do that kind of analysis. That's the thing... talk is cheap, effort isn't. I dont mean that to be accusatory toward anyone, I actually think it is kind of human nature that most do to some degree.

If someone wanted to do it, they would need the radar data for the closest radar to the landfall. Then that person would need to find the tilt angle of the radar to estimate the elevation of the scan through the eye. Next would be to geo-reference the imgagery, probably in a GIS program like ArcGIS. Then the person would need to track each individual point and connect them with lines, subjectively curving the lines between points. Then divide distance by the time. Then look to see what adjustment factors would be necessary to "correct" the estimate to the surface speeds.

Want to get your feet wet with some radar analysis?



Scott,
I doubt I would be qualified. Although I do have some background in computer science, and purely as a software/pattern recognition problem / sorting the signal from the noise / etc., I would think it would be pretty interesting. I have friends in that branch of computer science and they're frustrated that the only research that gets funded is thru DoD. Maybe I should mention this to them. In any case, please don't misunderstand, i don't mean to come off like an armchair critic. Obviously, there are a ton of important problems to solve and there aren't enough people to do it all.

Dan



Member Since: November 16, 2013 Posts: 0 Comments: 36
460. ScottLincoln
10:51 PM GMT on November 18, 2013
Quoting 459. DanBlum:



Scott,
Thanks for the reply. I did read through the paper, which was quite interesting and, fortunately, easily understood by a lay-person.

I guess I'm surprised that velocity inference from radar loops does not seem to be more widely used, given that seems to have been verified as pretty accurate. So why are we concluding that, "we will probably never know the true strength of Haiyan?" Seems like we should be able to determine it within 10-15% - not perfect, but better than the "dead reckoning" of Dvorak.

I also don't understand why this cannot be used to help with strength estimates of landfalling TCs, and therefore warnings, in areas not covered by hurricane hunters. I realize there is some additional uncertainty in how the winds translate to surface without other information from dropsondes, but...still, this is analysis that can be done from the other side of the world at extremely low cost, and, if it proves better than Dvorak, which is a pretty low bar, or even comparable in accuracy so the two could be averaged (an even lower bar) it could surely help places like the Philippines.

Anyway...thanks again for the comment and link.

Dan

Perhaps there hasn't been anyone around that has wanted to put forth the time and effort to do that kind of analysis. That's the thing... talk is cheap, effort isn't. I dont mean that to be accusatory toward anyone, I actually think it is kind of human nature that most do to some degree.

If someone wanted to do it, they would need the radar data for the closest radar to the landfall. Then that person would need to find the tilt angle of the radar to estimate the elevation of the scan through the eye. Next would be to geo-reference the imgagery, probably in a GIS program like ArcGIS. Then the person would need to track each individual point and connect them with lines, subjectively curving the lines between points. Then divide distance by the time. Then look to see what adjustment factors would be necessary to "correct" the estimate to the surface speeds.

Want to get your feet wet with some radar analysis?
Member Since: September 28, 2002 Posts: 5 Comments: 3521
459. DanBlum
10:03 PM GMT on November 18, 2013
Quoting 427. ScottLincoln:

Dan,

Sometimes scientists do try to infer winds in tropical cyclones using the method you suggest above. Have you read the paper detailing why Hurricane Andrew was changed to a category 5 after reanalysis? One of the lines of evidence came from tracking individual eyewall features as they rotated around the eye, then estimating the height of those features and making the necessary wind adjustments. If the radar system is doppler, one can also use the velocity data for wind going directly up/down radial for an estimate.
To my knowledge, these techniques are used in combination with other techniques and not by themselves.

Landsea et al. (2004):

Radar-derived wind vectors.
Low-altitude radar feature tracking presented by P. Dodge to the committee suggested surface winds similar to those implied by applying a 90% adjustment factor to the flight-level data.
...This technique has been demonstrated to provide lower-tropospheric wind vectors in the circulation of a hurricane that are comparable to those measured by aircraft. Tuttle and Gall (1999) reported agreement with 700-mb flight-level winds to within 10%, though the radar-derived winds have a relatively noisy signal and must be quality controlled before use.


In Landsea et al. (2004), they reference the following papers in regards to the radar tracking:
Tuttle and Gall (1999)
union and Powell (2002)



Scott,
Thanks for the reply. I did read through the paper, which was quite interesting and, fortunately, easily understood by a lay-person.

I guess I'm surprised that velocity inference from radar loops does not seem to be more widely used, given that seems to have been verified as pretty accurate. So why are we concluding that, "we will probably never know the true strength of Haiyan?" Seems like we should be able to determine it within 10-15% - not perfect, but better than the "dead reckoning" of Dvorak.

I also don't understand why this cannot be used to help with strength estimates of landfalling TCs, and therefore warnings, in areas not covered by hurricane hunters. I realize there is some additional uncertainty in how the winds translate to surface without other information from dropsondes, but...still, this is analysis that can be done from the other side of the world at extremely low cost, and, if it proves better than Dvorak, which is a pretty low bar, or even comparable in accuracy so the two could be averaged (an even lower bar) it could surely help places like the Philippines.

Anyway...thanks again for the comment and link.

Dan
Member Since: November 16, 2013 Posts: 0 Comments: 36
458. Torito
3:26 PM GMT on November 18, 2013
Quoting 457. Tazmanian:
check out the room prices vary cheap

Link


Wrong blog, and what is that? xD
Member Since: April 30, 2013 Posts: 6 Comments: 4554
457. Tazmanian
3:25 PM GMT on November 18, 2013
check out the room prices vary cheap

Link
Member Since: May 21, 2006 Posts: 5101 Comments: 118252
456. WunderAlertBot (Admin)
3:23 PM GMT on November 18, 2013
JeffMasters has created a new entry.
455. Torito
3:21 PM GMT on November 18, 2013
Quoting 453. VR46L:


No worky :)


RRRRRR.... See, wrong place. ;)

Hang on, I'm going to imgur this crap.
Member Since: April 30, 2013 Posts: 6 Comments: 4554
454. Torito
3:20 PM GMT on November 18, 2013
Ships calls this system fully tropical.... Shame on you, SHIPS.

Link
Member Since: April 30, 2013 Posts: 6 Comments: 4554
453. VR46L
3:19 PM GMT on November 18, 2013
Quoting 447. Torito:
HEHE wrong location... Heck, that's the GOM! (Or the EPAC....)



Once again, link if the image doesn't work.

Link


No worky :)
Member Since: March 1, 2012 Posts: 0 Comments: 7159
452. Torito
3:18 PM GMT on November 18, 2013
Quoting 448. GTstormChaserCaleb:
Melissa says lets dance.



Attack of the mustached storms..... ;)
Member Since: April 30, 2013 Posts: 6 Comments: 4554
451. barbamz
3:18 PM GMT on November 18, 2013
Sideglance to the Mediterranean: Another circulating cut-off low - called cyclone "Cleopatra" by the Italian Med Office - is dumping torrential rains to the coastlines of the western part of this Sea. Ongoing special alerts for Sardinia which is already severely affected by flooding and heavy winds, causing damage and evacuations. Reports about more than 4 inches (100mm) rain and locally considerably more are out.


Clouds over Sardinia (left side).




GFS 06Z. Accumulating precipitation forecast from today until Wednesday.
Member Since: October 25, 2008 Posts: 89 Comments: 9932
450. Torito
3:17 PM GMT on November 18, 2013
Quoting 448. GTstormChaserCaleb:
Melissa says lets dance.



Squished vortex at 15W 35N.... :P
Member Since: April 30, 2013 Posts: 6 Comments: 4554
449. VR46L
3:16 PM GMT on November 18, 2013
Quoting 446. GTstormChaserCaleb:
By that time it will already have become an extratropical storm.


I don't think it was ever not.....
Member Since: March 1, 2012 Posts: 0 Comments: 7159
448. GTstormChaserCaleb
3:15 PM GMT on November 18, 2013
Melissa says lets dance.

Member Since: June 30, 2013 Posts: 12 Comments: 9880
447. Torito
3:15 PM GMT on November 18, 2013
HEHE wrong location... Heck, that's the African coast!



Once again, link if the image doesn't work.

Link
Member Since: April 30, 2013 Posts: 6 Comments: 4554
446. GTstormChaserCaleb
3:12 PM GMT on November 18, 2013
Quoting 441. Torito:
DO NOT CURVE.



Compared to six hours ago....

By that time it will already have become an extratropical storm.
Member Since: June 30, 2013 Posts: 12 Comments: 9880
445. Torito
3:12 PM GMT on November 18, 2013
NHC gives Melissa about a 30% chance of strengthening to a hurricane per this chart.

Remember, Andrea had max winds near 70mph.... Much like the forecast for this system.




Link if image doesn't show up.
Link
Member Since: April 30, 2013 Posts: 6 Comments: 4554
444. GTstormChaserCaleb
3:11 PM GMT on November 18, 2013
FRONTAL BOUNDARIES
NEAR THE CENTER APPEAR TO HAVE DISSIPATED AND SO ADVISORIES ARE
BEING INITIATED AT THIS TIME. ALTHOUGH THERE ARE HINTS OF
ANTICYCLONIC OUTFLOW HAVING RECENTLY DEVELOPED OVER THE INNER CORE
CONVECTION...THE SYSTEM IS STILL WELL-EMBEDDED WITHIN AN
UPPER-LEVEL LOW AND THE MOST RECENT SCATTEROMETER WIND DATA SUGGEST
THAT THE CYCLONE MAY STILL HAVE A LARGE RADIUS OF MAXIMUM WINDS.

BUT ALSO ALLOW FOR THE
TRANSITION TO A TROPICAL CYCLONE.

A perfect example of a Tropical Transition.

Member Since: June 30, 2013 Posts: 12 Comments: 9880
443. Torito
3:10 PM GMT on November 18, 2013
INIT 18/1500Z 29.3N 53.6W 45 KT 50 MPH
12H 19/0000Z 30.2N 54.4W 50 KT 60 MPH
24H 19/1200Z 31.3N 54.3W 55 KT 65 MPH
36H 20/0000Z 33.6N 52.3W 60 KT 70 MPH
48H 20/1200Z 36.6N 48.9W 60 KT 70 MPH

72H 21/1200Z 42.8N 39.4W 55 KT 65 MPH...POST-TROP/EXTRATROP
96H 22/1200Z 50.0N 35.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 23/1200Z 55.0N 39.0W 45 KT 50 MPH...POST-TROP/EXTRATROP

Member Since: April 30, 2013 Posts: 6 Comments: 4554
442. Torito
3:09 PM GMT on November 18, 2013
SUBTROPICAL STORM MELISSA DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1100 AM EDT MON NOV 18 2013

DEEP CONVECTION HAS DEVELOPED DURING THE PAST SEVERAL HOURS NEAR THE
WELL-DEFINED CENTER OF A LARGE GALE-AREA LOCATED OVER THE CENTRAL
ATLANTIC WELL TO THE EAST-SOUTHEAST OF BERMUDA. FRONTAL BOUNDARIES
NEAR THE CENTER APPEAR TO HAVE DISSIPATED AND SO ADVISORIES ARE
BEING INITIATED AT THIS TIME. ALTHOUGH THERE ARE HINTS OF
ANTICYCLONIC OUTFLOW HAVING RECENTLY DEVELOPED OVER THE INNER CORE
CONVECTION...THE SYSTEM IS STILL WELL-EMBEDDED WITHIN AN
UPPER-LEVEL LOW AND THE MOST RECENT SCATTEROMETER WIND DATA SUGGEST
THAT THE CYCLONE MAY STILL HAVE A LARGE RADIUS OF MAXIMUM WINDS.
AS A RESULT...THE SYSTEM IS BEING DESIGNATED AS A SUBTROPICAL STORM
RATHER THAN A TROPICAL STORM...AT LEAST FOR NOW.

THE INITIAL MOTION ESTIMATE IS NORTHWESTWARD...OR 320/08 KT. NHC
MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON MELISSA MOVING
NORTHWESTWARD AND GRADUALLY SLOWING DOWN OVER THE NEXT 24 HOURS OR
SO AS IT MOVES AROUND THE WESTERN PERIPHERY OF A HIGH-AMPLITUDE
RIDGE LOCATED BETWEEN THE CYCLONE AND THE AZORES. THE CYCLONE COULD
POSSIBLY BECOME STATIONARY FOR A BRIEF PERIOD ON TUESDAY WHEN THE
SYSTEM MOVES UNDERNEATH A 200 MB LOW/TROUGH. HOWEVER...BY 48 HORUS
AND BEYOND...A DEEP-LAYER TROUGH LOCATED OVER THE EASTERN PORTIONS
OF CANADA AND THE UNITED SATES IS EXPECTED TO ACCELERATE MELISSA TO
THE NORTHEAST. BY DAYS 4 AND 5...MELISSA IS FORECAST OT INTERACT
WITH THE AFOREMENTIONED DEEPENING TROUGH AND TURN BACK TOWARD THE
NORTH AND NORTHWEST OVER THE FAR NORTH ATLANTIC. THE OFFICIAL
FORECAST TRACK IS CLOSE TO THE MULTI-MODEL CONSENSUS TVCA.

MELISSA HAS ABOUT 48 HOURS OR SO TO STRENGTHEN...AND THE SHIPS
INTENSITY MODEL INDICATES THAT THE VERTICAL SHEAR IS EXPECTED TO
DECREASE TO LESS THAN 10 KT BY 36 HOURS. THE WEAKENING SHEAR SHOULD
ALLOW FOR AT LEAST SOME MODEST STRENGTHENING TO OCCUR WHILE THE
CYCLONE REMAINS OVER RELATIVELY WARM WATER...BUT ALSO ALLOW FOR THE
TRANSITION TO A TROPICAL CYCLONE. THE NHC INTENSITY FORECAST IS
SIMILAR TO THE ICON INTENSITY FORECAST MODEL. HOWEVER...IT IS NOT
OUT OF THE QUESTION THAT MELISSA COULD ATTAIN HURRICANE STATUS IN
36-48 HOURS WHEN THE VERTICAL SHEAR IS AT A MINIMUM.
Member Since: April 30, 2013 Posts: 6 Comments: 4554
441. Torito
3:07 PM GMT on November 18, 2013
DO NOT CURVE.



Compared to six hours ago....

Member Since: April 30, 2013 Posts: 6 Comments: 4554
440. nrtiwlnvragn
3:07 PM GMT on November 18, 2013
HOWEVER...IT IS NOT
OUT OF THE QUESTION THAT MELISSA COULD ATTAIN HURRICANE STATUS IN
36-48 HOURS WHEN THE VERTICAL SHEAR IS AT A MINIMUM.


Link
Member Since: September 23, 2005 Posts: 21 Comments: 12346
439. GTstormChaserCaleb
3:05 PM GMT on November 18, 2013
13-2-0

Good morning Melissa, good morning everyone.

...SUBTROPICAL STORM MELISSA DEVELOPS OVER THE CENTRAL ATLANTIC...
11:00 AM EDT Mon Nov 18
Location: 29.3°N 53.6°W
Moving: NW at 9 mph
Min pressure: 987 mb
Max sustained: 50 mph

Already lower pressure.

Member Since: June 30, 2013 Posts: 12 Comments: 9880
438. Torito
3:03 PM GMT on November 18, 2013
Member Since: April 30, 2013 Posts: 6 Comments: 4554
437. pcola57
3:03 PM GMT on November 18, 2013
Morning Dak.. :)
Weather weather everywhere!!
Not boring..
Member Since: August 13, 2009 Posts: 13 Comments: 7058
436. ScottLincoln
2:59 PM GMT on November 18, 2013
Quoting 431. pcola57:


Thanks for that Scott..
Despite the noise thats pretty darn good for a Re-analysis..

The entire paper is a good read. The radar estimates were just a part of the entire argument for re-classification. They came at it from a few different angles, which all were fairly consistent.
Member Since: September 28, 2002 Posts: 5 Comments: 3521
435. Dakster
2:59 PM GMT on November 18, 2013
Quoting 434. KEEPEROFTHEGATE:
goes out the way it come in

12 days remain


Like a Baby kitten?
Member Since: March 10, 2006 Posts: 0 Comments: 12608
434. KEEPEROFTHEGATE (Mod)
2:57 PM GMT on November 18, 2013
goes out the way it come in

12 days remain
Member Since: July 15, 2006 Posts: 195 Comments: 62891
433. Dakster
2:56 PM GMT on November 18, 2013
Hello Melissa... Please follow the models and go out to sea. The NE US Coast doesn't need another 'super storm Sandy' at this time.
Member Since: March 10, 2006 Posts: 0 Comments: 12608
432. nrtiwlnvragn
2:51 PM GMT on November 18, 2013
Standard Time NHC, Standard Time
Member Since: September 23, 2005 Posts: 21 Comments: 12346
431. pcola57
2:49 PM GMT on November 18, 2013
Quoting 427. ScottLincoln:
This technique has been demonstrated to provide lower-tropospheric wind vectors in the circulation of a hurricane that are comparable to those measured by aircraft. Tuttle and Gall (1999) reported agreement with 700-mb flight-level winds to within 10%, though the radar-derived winds have a relatively noisy signal and must be quality controlled before use.In Landsea et al. (2004), they reference the following papers in regards to the radar tracking:
Tuttle and Gall (1999)
union and Powell (2002)


Thanks for that Scott..
Despite the noise thats pretty darn good for a Re-analysis..
Member Since: August 13, 2009 Posts: 13 Comments: 7058
430. KEEPEROFTHEGATE (Mod)
2:48 PM GMT on November 18, 2013
14L/STS/M/XX
Member Since: July 15, 2006 Posts: 195 Comments: 62891
429. VR46L
2:45 PM GMT on November 18, 2013
Quoting 426. Torito:



Wind swaths of subtropical systems look cool. :)


Just like your avi looks cool ... great comma shape but thats an Extropical storm...
Member Since: March 1, 2012 Posts: 0 Comments: 7159
428. Torito
2:44 PM GMT on November 18, 2013
...SUBTROPICAL STORM MELISSA DEVELOPS OVER THE CENTRAL ATLANTIC...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...29.3N 53.6W
ABOUT 695 MI...1120 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF SUBTROPICAL STORM MELISSA
WAS LOCATED NEAR LATITUDE 29.3 NORTH...LONGITUDE 53.6 WEST. THE
STORM IS MOVING TOWARD THE NORTHWEST NEAR 9 MPH...15 KM/H...AND THIS
GENERAL MOTION SHOULD CONTINUE TODAY AND TONIGHT. A SLOW TURN
TOWARD THE NORTH IS EXPECTED ON TUESDAY...FOLLOWED BY A TURN TOWARD
THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED ON WEDNESDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...
AND MELISSA IS EXPECTED TO TRANSITION TO A TROPICAL STORM BY
TUESDAY.

TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 275 MILES...445
KM...MAINLY NORTHWEST THROUGH NORTHEAST OF THE CENTER...AND MELISSA
IS EXPECTED TO REMAIN A LARGE SYSTEM FOR THE NEXT COUPLE DAYS.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB...29.15 INCHES.


HAZARDS AFFECTING LAND
----------------------
SURF...LARGE SWELLS ARE ALREADY AFFECTING PORTIONS OF THE LEEWARD
ISLANDS...PUERTO RICO...HISPANIOLA...AND THE SOUTHEASTERN BAHAMAS.
DANGEROUS SWELLS GENERATED BY MELISSA ARE EXPECTED TO AFFECT THESE
AREAS DURING THE NEXT COUPLE OF DAYS...CAUSING LIFE-THREATENING
SURF AND RIP CURRENTS. PLEASE SEE STATEMENTS FROM YOUR LOCAL
WEATHER SERVICE OFFICE FOR MORE DETAILS
Member Since: April 30, 2013 Posts: 6 Comments: 4554
427. ScottLincoln
2:43 PM GMT on November 18, 2013
Quoting 375. DanBlum:
Estimating land-falling TC velocities

Hi all.

New to this blog and have a question. I was recently reading about Dvorak estimates and was struck that our system of indirect wind velocity estimation has not improved since the 1980s.

My question is simple: why can't we infer wind-speed from the radar loops of land-falling hurricanes? Even to the naked eye it is easy to see the difference between a tropical storm and cat 2 hurricane, and easy to see them spin down after landfall. The eye is looking at specific cells of more intense rains as they rotate around the core, and "filling in the blanks" to ascribe an overall circulation. Surely pattern-recognition software could be developed that could do the same. And once we know the speed these cells are moving, we also altitude the radar beam is crossing at any point, so it should be easy to infer surface speed, or at the very least, parameterize any error based on back-testing with radar loops of storms of known velocities.

The method is more difficult for the strongest storms, as the movement from frame to frame is the greatest. The eye struggles to determine the movement. But I would bet that an algorithm could still be developed for a computer to do this with some accuracy.

I did a couple of searches and did not see anyone researching this.

Dan,

Sometimes scientists do try to infer winds in tropical cyclones using the method you suggest above. Have you read the paper detailing why Hurricane Andrew was changed to a category 5 after reanalysis? One of the lines of evidence came from tracking individual eyewall features as they rotated around the eye, then estimating the height of those features and making the necessary wind adjustments. If the radar system is doppler, one can also use the velocity data for wind going directly up/down radial for an estimate.
To my knowledge, these techniques are used in combination with other techniques and not by themselves.

Landsea et al. (2004):
Radar-derived wind vectors.
Low-altitude radar feature tracking presented by P. Dodge to the committee suggested surface winds similar to those implied by applying a 90% adjustment factor to the flight-level data.
...This technique has been demonstrated to provide lower-tropospheric wind vectors in the circulation of a hurricane that are comparable to those measured by aircraft. Tuttle and Gall (1999) reported agreement with 700-mb flight-level winds to within 10%, though the radar-derived winds have a relatively noisy signal and must be quality controlled before use.


In Landsea et al. (2004), they reference the following papers in regards to the radar tracking:
Tuttle and Gall (1999)
union and Powell (2002)
Member Since: September 28, 2002 Posts: 5 Comments: 3521
426. Torito
2:43 PM GMT on November 18, 2013
Wind swaths of subtropical systems look cool. :)


Link
Member Since: April 30, 2013 Posts: 6 Comments: 4554
425. VR46L
2:42 PM GMT on November 18, 2013
Quoting 421. Torito:



Meh. The NHC is just bored of having nothing to do for months straight. ;)


Looks like Padding to me :)

LMAO
Member Since: March 1, 2012 Posts: 0 Comments: 7159
424. nrtiwlnvragn
2:42 PM GMT on November 18, 2013
Member Since: September 23, 2005 Posts: 21 Comments: 12346
423. Torito
2:42 PM GMT on November 18, 2013
Quoting 422. nrtiwlnvragn:
SUBTROPICAL STORM MELISSA FORECAST/ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1500 UTC MON NOV 18 2013

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

SUBTROPICAL STORM CENTER LOCATED NEAR 29.3N 53.6W AT 18/1500Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 320 DEGREES AT 8 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 987 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT.......200NE 0SE 90SW 240NW.
12 FT SEAS..400NE 400SE 400SW 400NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.


See, NHC being pronto with their first system in weeks.... ;)
Member Since: April 30, 2013 Posts: 6 Comments: 4554
422. nrtiwlnvragn
2:41 PM GMT on November 18, 2013
SUBTROPICAL STORM MELISSA FORECAST/ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1500 UTC MON NOV 18 2013

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

SUBTROPICAL STORM CENTER LOCATED NEAR 29.3N 53.6W AT 18/1500Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 320 DEGREES AT 8 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 987 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT.......200NE 0SE 90SW 240NW.
12 FT SEAS..400NE 400SE 400SW 400NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
Member Since: September 23, 2005 Posts: 21 Comments: 12346
421. Torito
2:40 PM GMT on November 18, 2013
Quoting 418. VR46L:


I Guess the Arctic High that is Coming down prevents this one going where they usually do :)

Still don't get how a frontal system can be deemed Sub tropical *shrug*



Meh. The NHC is just bored of having nothing to do for months straight. ;)
Member Since: April 30, 2013 Posts: 6 Comments: 4554
420. pcola57
2:40 PM GMT on November 18, 2013
Quoting 413. Torito:


The intensity models were more wide spread yesterday as Skye pointed out..
The forecast tracks however look rather good in agreement actually..
I go with 5 days outlook..
Member Since: August 13, 2009 Posts: 13 Comments: 7058
419. hydrus
2:38 PM GMT on November 18, 2013
Member Since: September 27, 2007 Posts: 1 Comments: 27427
418. VR46L
2:38 PM GMT on November 18, 2013
Quoting 411. Torito:
Models are confused.



I Guess the Arctic High that is Coming down prevents this one going where they usually do :)

Still don't get how a frontal system can be deemed Sub tropical *shrug*
Member Since: March 1, 2012 Posts: 0 Comments: 7159
417. SLU
2:38 PM GMT on November 18, 2013
Quoting 371. washingtonian115:
Before the blog went down yesterday I suggested that it may have been a brief tropical depression before shear came and blasted it.It's still going on right now so it may have been one.


Fair statement.
Member Since: July 13, 2006 Posts: 13 Comments: 5847
416. hydrus
2:36 PM GMT on November 18, 2013
Member Since: September 27, 2007 Posts: 1 Comments: 27427
415. nrtiwlnvragn
2:35 PM GMT on November 18, 2013
Sweet Melissa


AL, 14, 2013111812, , BEST, 0, 290N, 533W, 45, 988, SS
Member Since: September 23, 2005 Posts: 21 Comments: 12346
414. Torito
2:33 PM GMT on November 18, 2013
Member Since: April 30, 2013 Posts: 6 Comments: 4554
413. Torito
2:30 PM GMT on November 18, 2013
Member Since: April 30, 2013 Posts: 6 Comments: 4554
412. Torito
2:27 PM GMT on November 18, 2013
Member Since: April 30, 2013 Posts: 6 Comments: 4554
411. Torito
2:27 PM GMT on November 18, 2013
Models are confused.

Member Since: April 30, 2013 Posts: 6 Comments: 4554

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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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