Atlantic Tropical Action 2013 - Part 2

[hurricaneman]

It hasn't just been the GFS doing it.  Two runs of the Euro also show more love for the disturbance behind 97L.

 

 

Edit

 

NHC disco

 

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 18N46W

TO A 1011 MB LOW NEAR 11N48W MOVING W NEAR 10 KT. WAVE IS

EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE

TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED CLUSTERS OF

SCATTERED MODERATE CONVECTION ARE FROM 10N-15N BETWEEN 43W-50W.

 

and unlike 97L this has a moist environment and has decent convergence

[WE GOT HIM]

Man, I got a trip to DR fro the 5-9th - What are you guys thinking right now?

[Supercane]

In the old Atlantic thread, bluewave posted a map comparing this season's precipitation rate in the basin with recent seasons and also with the banner seasons from the previous decade. Thewxmann responded with this:

 

 

The maps bluewave posted show a pretty strong inverse relationship between convection on land and convection over sea. Maybe we are in a negative phase of some yet undiscovered oscillation where the former is enhanced and the latter is suppressed?

 

I thought this was an interesting observation, so I looked back at the precipitation rate for every year since 1948 to see if there is any cyclical behavior. I say there is, but you can judge for yourself:

 

 

A couple notes...

 

-Pay particular attention to the precip rate over South America and Mexico/Latin America vs the Caribbean. Strongest hints of a cycle in those regions.

-The cycle isn't as prominent in the winter or spring, so I focused on the Jun-Oct timeframe (which also corresponds to most of the hurricane season).

-Africa seems to be a whole other matter. It's been wetter than normal since 2007 like Central/South America, but it was also wetter than normal when Central/South America was in a dry spell in the 1950s through 1970s.

-It's extremely interesting that one of the phase switches occured around 1995, right around when the AMO transitioned to its positive state. But the AMO flip to a negative state in the 1960s did not correspond to any shift in this cycle. And the AMO is still warm even though we seemed to have entered a new precipitation rate phase since 2007. 

-The first cycle lasted for at least 33 years, the second for 14 years, the third for 12 years, and the current one so far for 7 years. 

-The years the phases switched were not always clear-cut (for example 2006 was sort of in-between), but I tried to place the transitional years with the cycle they most closely matched.

 

As for what could be causing this, I have no ideas yet. But I plan to expand on this research since there's not much else going on in the weather.

[WE GOT HIM]

More of an agreement for the 0z, Lets see what the Euro says

[wxmx]

People is too focused with the wave entering the Caribbean (justifiably), but I think the next named system might come from the wave currently approaching the Yucatan peninsula. It looks like a Fernand redux, but a tad north...the MJO wave strongest effects are crossing that area and we are very close to climo peak. Models are showing a surface trough or weak TD/TS at most, but this area usually outperforms a bit.

[wxmeddler]

For lol's... Very NOT likely not going to happen since the initialization assumes a near perfect vortex.

[HurricaneJosh]

People is too focused with the wave entering the Caribbean (justifiably), but I think the next named system might come from the wave currently approaching the Yucatan peninsula. It looks like a Fernand redux, but a tad north...the MJO wave strongest effects are crossing that area and we are very close to climo peak. Models are showing a surface trough or weak TD/TS at most, but this area usually outperforms a bit.

 

Why do you think this?  The Euro and GFS don't look like they're into this one, either.

[phil882]

00z ECMWF finally has a decent reflection of 97L, although it looses the system after it crosses Hispaniola. One interesting note is that its been too quick with the low-level flow drawing 97L into the Caribbean. The radar at Barbados is back up and the animation shows a very broad circulation located between 13-15N / 58-60W, essentially the same location as earlier this morning. The ECMWF does depict the 500 hPa and 850 hPa centers maintaining alignment over the next 24-36 hours, allowing for development into a weak TC in the northeastern Caribbean. 

[phlwx]

Fernand part two doesn't seem that likely. The wave that the fernand one fired from was probably more organized at this point then the mess that's down near the Yucatan now. 

 

Not saying that wave WON'T develop...I don't think the odds are very high for it.

 

And lolz on 97L...I can't waste much time on it at this point if the track it's going to take has Hispaniola all over it.

[Ed Lizard]

The good news, CIMSS analysis suggests it has built a small little anticyclone right over the top, and is under favorable shear, and low level convergence has increased.  Storms firing near the low level vort max.   Still on the Eastern edge of a monsoon trough like feature.  Low level flow is accelerating (divergent) in the Eastern Caribbean, but would take an undeveloped system almost due West towards the more favorable areas past 75W.  The wave behind it (hotlink below) and competition/interaction is something of a wild card.

 

 

 

I had some hopes for the West Caribbean wave, but low to mid vorticity is still rather meager and farther South than I'd prefer.

[ineedsnow]

I think the wave behind has the best shot to pop something up I guess we wait and see

[HurricaneJosh]

Lolz, demoted to Lemon.

[EasternUSWX]

Lolz, demoted to Lemon.

 

Still 50% for 5 days though. Looks like there is defiantly something just to the east of the Lesser Antilles. Some spin and convective blow up. If that can get it together maybe something will finally go. 

 

[AutoPenalti]

Whatever hope I had for that Manadarin just got reduced by 20% then I saw the convective blow behind it.

Gah. Blah. Ugh.

[jconsor]

As others have said, any consolidation of 97L will be a gradual process. Despite the fairly impressive convection associated with the ITCZ wave about 300 miles east of 97L, I believe it has significantly less chance of developing than 97L.

 

700 mb vorticity with the ITCZ wave is virtually non-existent, while for 97L it has been increasing and consolidating past 6-12 hours.

 

I believe the UKMET and FIM (as well as the Fox Tampa Bay WRF - http://www.myfoxhurricane.com/custom/models/wrf/wrf_atl_mer.html) are onto the right idea in concentrating most of the energy with 97L, while the ITCZ wave gets absorbed into 97L's circulation in ~4-5 days.

[Ed Lizard]

I'm starting to think the global models that see more development with the wave East of 97L might be on to something, despite lack of significant vorticity at this time.

 

The whole thing is a head scratcher.  On a semi-related note, if 97L itself actually is the 'big show', BAM models show the best possible path for a system if it did absolutely have to cross part of Haiti.

[Ed Lizard]

Would like to hear Bendy Mods ideas.

 

BTW, the blob near 65W, on the Western side of the stretched vorticity anchored on the East by 97L, has almost calm winds on the South side of it staring at vis loops with lat/long lines turned on, and is also far more convectively active than 97L.  I wonder if it is possible to get 2 different cyclones out of this, far enough apart to allow both to develop as much as environmental conditions would permit towards MPI.

[Ed Lizard]

Recon action with WC-130Js, Global Hawk drones and sharks with frikking lasers.

 

 

NOUS42 KNHC 021419
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1015 AM EDT MON 02 SEPTEMBER 2013
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 03/1100Z TO 04/1100Z SEPTEMBER 2013
         TCPOD NUMBER.....13-093

I.  ATLANTIC REQUIREMENTS
    1. SUSPECT AREA (CARIBBEAN)
       FLIGHT ONE -- TEAL 70
       A. 03/2100Z
       B. AFXXX 01DDA INVEST
       C. 03/1500Z
       D. 16.0N 63.0W
       E. 03/2030Z TO 03/2330Z
       F. SFC TO 10,000 FT

    2. OUTLOOK FOR SUCCEEDING DAY: FIX MISSION @ 04/2100Z NEAR
       19N 67W IF SYSTEM DEVELOPS.

    3. REMARKS: THE NASA 871 GLOBAL HAWK WILL FLY A 24-HOUR RESEARCH
                MISSION OVER THIS SYSTEM
       A. NASA 871 TAKE-OFF: 03/1100Z
       B. STORM/AREA OF INTEREST:  DEPRESSION 97L-
       C. DEPARTURE WFF: 1100Z, 03 SEP
       D. MISSION DURATION: 24H 00M
       E. IP: 1500Z, 03 SEP; 25.0 N, 68.0 W
       F. EP: 0600Z, 4 SEPT; 25.0 N, 68.0 W
       G. ON-STATION DURATION:  15H 00M
       H. ETA WFF: 1100Z, 04 SEPT
       I. DROPSONDES DEPLOYED: 0, NO SONDE SYSTEM
       J. ALTITUDE: 55,000 TO 65,000 FT
       K. PATTERN: RACE TRACK ACROSS REGION OF TD 
          CIRCULATION IN BOX BOUNDED BY 25.0N 68.0W 
          17.0N 68.0W, 14.0N 55.0W, 19.0N 52.0W
          FOLLOWED BY BUTTERFLY WITHIN REGION OF
          CONVECTION ~ 200 NM RADIUS FROM 18.0N 67.5W            
   4. OUTLOOK FOR SUCCEEDING DAY- BACK TO BACK GH MISSIONS:
       A. NA871 LANDING, 1100 Z, 04 SEP
       B. NA872 TAKE OFF 1500Z, 04 SEP

II. PACIFIC REQUIREMENTS
    1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
    2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

$$
JWP

 

[Ed Lizard]

One question, if the Global Hawk flies at 55,000 but carries no dropsondes, will it just be doing radar wind and precip observations?

 

Theoretically, if data from the Global Hawk was used to direct the low level invest mission to the area with the most interesting wind and precip, that could be a good thing. 

[TropicalAnalystwx13]

This is worse than an El Niño year.

[bluewave]

This is worse than an El Niño year.

 

Only 23% of normal ACE and falling by the day.

[Derecho!]

Only 23% of normal ACE and falling by the day.

 

I never would have believed this was remotely possible outside of a strong El Nino.

[Ed Lizard]

4 posts in a row feels rude, but GFS still going with two weak systems competing with each other and drifting towards the Bahamas without significant development.  GFS did a good job on a recent East Pac system that had two competing centers.  TD9/Ivo, IIRC.  That system underperformed, and GFS had a decent handle on it.

 

NAM is more enthusiastic, with a well developed wave from the Western Caribbean wave about to make landfall Texas/Mexico at the end of the run, GFS has the wave as seen in 850 winds and PW, but is less enthusiastic.

 

A nice looking quick developing (and therefore probably fishy) system before the truncation on the GFS.  I'm sure it fishes, but GFS forecast heights should keep it below 20N for several days, long enough to become the seasons first hurricane.  I just hope, if it happens, it waits until September 12th to be upgraded so I can live to see a weather record of the post satellite/recon era.  Post truncation, September 12th, below 20N, and with 2.5 inch plus PW over the center.

[Amped]

I never would have believed this was remotely possible outside of a strong El Nino.

2001 and 2002 could not have been doing much better at this point.    I am concerned about the lack of ACE in other basins. It may mean something just isn't right with the state of the atmosphere in the tropics this year.  The later half of the season typically has  a better hurricane to TS ratio.

[TropicalAnalystwx13]

What a troll.

 

[hurricaneman]

2001 and 2002 could not have been doing much better at this point.    I am concerned about the lack of ACE in other basins. It may mean something just isn't right with the state of the atmosphere in the tropics this year.  The later half of the season typically has  a better hurricane to TS ratio.

 

Its kind of like when theres an expected tornado outbreak and theres a cap and nothing happens, the tropics are doing something very similar with a strong cap

[Ed Lizard]

What a troll.

 

 

If we miss setting the record by a day, I'll be cheesed off.  If 97L and surrounding blobs becomes a hurricane and threatens Florida in a week, I'd deal with it, but a fish ruining the record would royally suck.

 

 

 

Edit to add.  Just has to make it to the 5 pm EDT advisory to be upgraded if it forms...

 

 

 

ZCZC MIATCDAT3 ALL

TTAA00 KNHC DDHHMM

HURRICANE GUSTAV DISCUSSION NUMBER  13

NATIONAL WEATHER SERVICE MIAMI FL

11 AM EDT WED SEP 11 2002

JUST AFTER THE 5 AM ADVISORY...THE AIR FORCE RESERVE HURRICANE

HUNTER AIRCRAFT FOUND 80 KT WINDS AT 850 MB SOUTHWEST OF THE

CENTER.  VISIBLE SATELLITE IMAGERY SHOWS A WELL-DEVELOPED TROPICAL

CYCLONE WITH CONVECTION WRAPPED ALL THE WAY AROUND THE CENTER.

BASED ON THIS...THE 975 MB CENTRAL PRESSURE...AND SATELLITE

INTENSITY ESTIMATES OF 65 KT FROM TAFB AND SAB...GUSTAV IS UPGRADED

TO A 65 KT HURRICANE.  WHILE LITTLE ADDITIONAL STRENGTHENING

IS EXPECTED AS A TROPICAL CYCLONE...SURFACE OBSERVATIONS INDICATE

THAT BAROCLINIC CYCLOGENESIS IS OCCURRING OVER THE NEW ENGLAND

STATES AND THE CANADIAN MARITIMES.  GUSTAV IS FORECAST TO MERGE

WITH THIS DEVELOPING NON-TROPICAL LOW AND BECOME A LARGE AND

POWERFUL EXTRATROPICAL STORM AS IT CROSSES NOVA SCOTIA AND

NEWFOUNDLAND DURING THE NEXT 24-36 HR.

THE INITIAL MOTION IS 055/20.  LARGE-SCALE GUIDANCE INDICATES

GUSTAV SHOULD ACCELERATE NORTHEASTWARD FOR 24-36 HR...THEN SLOW AND

TURN LEFT ONCE IT REACHES THE LABRADOR SEA.  THE OFFICIAL FORECAST

TRACK REFLECTS THIS GUIDANCE.

FORECASTER BEVEN

FORECAST POSITIONS AND MAX WINDS

INITIAL     11/1500Z 38.6N  69.7W    65 KTS

12HR VT     12/0000Z 42.4N  64.8W    65 KTS

24HR VT     12/1200Z 47.2N  59.5W    60 KTS...EXTRATROPICAL

36HR VT     13/0000Z 51.5N  54.6W    55 KTS...EXTRATROPICAL

48HR VT     13/1200Z 54.7N  52.5W    55 KTS...EXTRATROPICAL

72HR VT     14/1200Z 60.0N  56.0W    45 KTS...EXTRATROPICAL

NNNN

 

[phil882]

Convection is starting to recover over 97L.... definitely still having issues with dry air intrusion, but the low-level vortex is markedly better defined. It also hasn't moved in more than 24 hours, which is giving it time for the mid-level center to remain over the low-level vortex and become a more vertically deep disturbance. I'm growing more confident 97L is going to develop, and could be an interesting player down the road beyond Hispaniola if the latest runs of the GFS and ECMWF are to be believed. 

 

[EasternUSWX]

So many lemons we can make lemonade.

 

[AutoPenalti]

So many lemons we can make lemonade.

You want some dry air with that?