Saison 2010 : Ouragans, cyclones, typhons, tempêtes et dépressions

[paix 0]

Quelques autres images de Celia :

Le taux de précipitation estimé par satellite. Pour référence, 1 in / h, c'est 25 mm / h et 1,2 in / h, c'est 30 mm / h. Cela peut sembler peu, mais ce sont des valeurs estimées et ce sont des précipitations continues. Si dans nos régions, on se fait "facilement" des pointes à 100 mm / h, ici, c'est une valeur moyenne effective.

La température de brillance, avec cette faiblesse récurrente du mur Nord, même si globalement, l'organisation de Celia ne prête pas flanc à la critique :

à 89 GHz

à 37 GHz

Et enfin une petite composition :

Modifié 25 juin 2010 par paix

[paix 0]

L'œil de Darby cherche à poindre. Il s'agit bien du point jaune posé au creux à la droite de la tâche rouge falciforme :

[paix 0]

NHC monte Celia en catégorie 5. Perso, je trouve cela un peu limite, mais bon.

000

WTPZ44 KNHC 250243

TCDEP4

HURRICANE CELIA DISCUSSION NUMBER 24

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010

800 PM PDT THU JUN 24 2010

SATELLITE IMAGES INDICATE THAT CELIA HAS RAPIDLY INTENSIFIED DURING

THE PAST SEVERAL HOURS. THE LAST VISIBLE IMAGES SHOW A SYMMETRIC

HURRICANE WITH AN EXPANDING OUTFLOW PATTERN...WELL-DEFINED

EYE...AND STRONG CONVECTION IN THE THE EYEWALL. SUBJECTIVE DVORAK

CLASSIFICATIONS FROM BOTH TAFB AND SAB WERE T7.0...140 KT. THESE

DATA SUPPORT AN INITIAL INTENSITY OF 140 KT...MAKING CELIA A

CATEGORY FIVE HURRICANE. CELIA WILL SOON PASS OVER COOLER WATERS

AND INTO A MORE STABLE AIRMASS...WHICH SHOULD CAUSE A WEAKENING OF

THE SYSTEM. IN FACT...MOST OF THE GUIDANCE INDICATE RAPID

WEAKENING COMMENCING BEFORE THIS TIME TOMORROW. LATER ON... GLOBAL

MODELS SUGGEST THE SHEAR WILL INCREASE NEAR THE HURRICANE...WHICH

SHOULD AID THE WEAKENING PROCESS. GUIDANCE IS IN GOOD AGREEMENT ON

THIS SCENARIO...AND THE OFFICIAL FORECAST REFLECTS THIS LIKELIHOOD.

THE HURRICANE HAS TURNED TOWARD THE WEST-NORTHWEST...AND IS NOW

MOVING 285/11. A SUBTROPICAL RIDGE OVER MEXICO AND THE EASTERN

PACIFIC IS EXPECTED TO REMAIN IN PLACE FOR THE NEXT DAY OR SO AND

CONTINUE TO STEER THE HURRICANE GENERALLY TO THE WEST-NORTHWEST.

GLOBAL MODELS ARE IN VERY CLOSE AGREEMENT ON THE TRACK OF CELIA

DURING THAT TIME. HOWEVER...THERE IS A LARGE UNCERTAINTY ON WHAT

HAPPENS TO THE HURRICANE IN THE EXTENDED RANGE AS THE RIDGE OVER

THE EASTERN PACIFIC IS REPLACED BY A TROUGH NEAR THE WEST COAST OF

THE UNITED STATES. THE SPREAD IN THE GUIDANCE IS QUITE LARGE AT

THAT TIME... LEADING TO A LOWER-CONFIDENCE FORECAST. THE BEST BET

AT THIS POINT IS THAT THIS PATTERN CHANGE WILL RESULT IN STEERING

CURRENTS GETTING QUITE WEAK FOR DAYS 4 AND 5... AND THE OFFICIAL

NHC FORECAST WILL SHOW LITTLE MOVEMENT OF CELIA AT THAT TIME FRAME.

CELIA IS TIED FOR THE STRONGEST EASTERN PACIFIC HURRICANE ON RECORD

IN JUNE...WITH AVA OF 1973.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/0300Z 13.1N 115.9W 140 KT

12HR VT 25/1200Z 13.6N 117.5W 140 KT

24HR VT 26/0000Z 14.4N 119.5W 115 KT

36HR VT 26/1200Z 15.3N 121.1W 95 KT

48HR VT 27/0000Z 15.8N 122.5W 75 KT

72HR VT 28/0000Z 16.4N 124.3W 50 KT

96HR VT 29/0000Z 16.5N 125.0W 35 KT

120HR VT 30/0000Z 16.5N 126.0W 25 KT...POST-TROP/REMNT LOW

$$

FORECASTER BLAKE

On pourra noter qu'Ava en 1973 était aussi durant une transition vers La Nina... Curieux de savoir quels liens existent entre ces deux événements. Je vais essayer de creuser.

[ElNino27 0]

Un cat5 fin juin. Enorme !

Je n'ose même pas imaginer ce qu'il se passera lorsque la MJO négative passera dans l'Atlantique !

[paix 0]

Pour 93L, on peut noter que l'onde vient de passer au dessus de cette bouée : http://www.ndbc.noaa.gov/show_plot.php?sta...;time_label=EDT

dont les données ont servies au NHC pour établir que la pression était descendu à 1006,6 hPa.

[paix 0]

Pour Darby, l'oeil commence à s'établir :

[paix 0]

Darby est un tout petit système, mais qui se porte à merveille. Sa récente évolution pourrait le mener vers la catégorie 2 si elle persiste.

UW - CIMSS

ADVANCED DVORAK TECHNIQUE

ADT-Version 8.1.1

Tropical Cyclone Intensity Algorithm

----- Current Analysis -----

Date : 25 JUN 2010 Time : 044500 UTC

Lat : 13:06:42 N Lon : 100:08:28 W

CI# /Pressure/ Vmax

4.3 / 973.4mb/ 72.2kt

Final T# Adj T# Raw T#

4.3 4.8 5.2

Latitude bias adjustment to MSLP : +3.4mb

Estimated radius of max. wind based on IR :N/A km

Center Temp : -33.4C Cloud Region Temp : -64.6C

Scene Type : EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC

Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : MW AdjEnd

Weakening Flag : OFF

Rapid Dissipation Flag : OFF

****************************************************

[paix 0]

Et Darby continue son petit bonhomme de chemin en rejoignant la catégorie 2 avec des vents à 90 nœuds, en accord avec l'ADT :

UW - CIMSS

ADVANCED DVORAK TECHNIQUE

ADT-Version 8.1.1

Tropical Cyclone Intensity Algorithm

----- Current Analysis -----

Date : 25 JUN 2010 Time : 071500 UTC

Lat : 13:11:58 N Lon : 100:19:19 W

CI# /Pressure/ Vmax

4.8 / 962.1mb/ 84.8kt

Final T# Adj T# Raw T#

4.8 5.1 5.1

Latitude bias adjustment to MSLP : +3.3mb

Estimated radius of max. wind based on IR :N/A km

Center Temp : -31.8C Cloud Region Temp : -62.8C

Scene Type : EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC

Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT

Weakening Flag : OFF

Rapid Dissipation Flag : OFF

****************************************************

L'ADT est légèrement en dessous. Il faut savoir que 90 nœuds, c'est un T# 5.0. L'ADT y est presque, mais les contraintes de la technique font que le nombre final est légèrement inférieur du à des erreurs de positionnement de l'œil qui on fait sous estimé son intensité auparavant. Je ne sais pas si c'est très clair, mais en y réfléchissant, ça l'est...

Le nombre T subjectif :

25/0545 UTC 13.2N 100.4W T5.0/5.0 DARBY -- East Pacific

Et les données du Best Track

EP, 05, 2010062506, , BEST, 0, 132N, 1004W, 90, 967, HU, 34, NEQ, 60, 45, 45, 60, 1009, 180, 10, 0, 0, E, 0, , 0, 0, DARBY, D,

EP, 05, 2010062506, , BEST, 0, 132N, 1004W, 90, 967, HU, 50, NEQ, 30, 30, 30, 30, 1009, 180, 10, 0, 0, E, 0, , 0, 0, DARBY, D,

EP, 05, 2010062506, , BEST, 0, 132N, 1004W, 90, 967, HU, 64, NEQ, 20, 20, 20, 20, 1009, 180, 10, 0, 0, E, 0, , 0, 0, DARBY, D,

À ce rythme, il pourrait lui aussi devenir majeur

Je ne sais pas pourquoi, mais les inondations au Brésil me semblent avoir un lien avec cette situation un peu curieuse. Je vais regarder quand j'aurais du temps.

Modifié 25 juin 2010 par paix

[paix 0]

Pour Darby, aucune surprise de la part du NHC à la mise à jour de 09Z, je met juste pour info :

000

WTPZ45 KNHC 250852

TCDEP5

HURRICANE DARBY DISCUSSION NUMBER 10

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010

200 AM PDT FRI JUN 25 2010

DARBY HAS MAINTAINED A SMALL 10-N MI EYE FOR ABOUT THE PAST FIVE

HOURS BUT HAS DISPLAYED AN OBLONG CONVECTIVE PATTERN WITH THE

STRONGEST ACTIVITY LOCATED OVER THE SOUTHERN SEMICIRCLE. DVORAK

ESTIMATES FROM TAFB AND SAB ARE BOTH T5.0...AND THE INITIAL

INTENSITY IS RAISED TO 90 KT.

ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR SOME FURTHER

STRENGTHENING OVER THE NEXT DAY OR SO. ANALYSES FROM UW-CIMSS

INDICATE THAT DARBY HAS MOVED INTO A FAVORABLE NORTH-SOUTH CORRIDOR

OF HIGHER SSTS AND SHOULD REMAIN OVER THOSE WATERS FOR ANOTHER 12

TO 24 HOURS. IN ADDITION...VERTICAL SHEAR IS EXPECTED TO BE LOW

DURING THAT PERIOD. THE NEW OFFICIAL INTENSITY FORECAST BRINGS

DARBY TO MAJOR HURRICANE STRENGTH IN 12 HOURS...WHICH IS ABOVE ALL

OF THE GUIDANCE EXPECT FOR SHIFOR. THE SHIPS RI INDEX DOES

INDICATE A 1 IN 4 CHANCE OF A 30 KT INCREASE IN INTENSITY OVER THE

NEXT 24 HOURS...SO IT IS NOT OUT OF THE QUESTION FOR DARBY TO

STRENGTHEN MORE THAN INDICATED HERE. GRADUAL WEAKENING IS EXPECTED

AFTER 24 HOURS DUE TO INCREASED VERTICAL SHEAR AND LOWER SSTS...AND

THE OFFICIAL FORECAST LIES CLOSE TO SHIPS AND LGEM.

THE TRACK FORECAST IS HEAVILY DEPENDENT ON THE EVOLUTION OF THE AREA

OF LOW PRESSURE CURRENTLY OVER THE WESTERN CARIBBEAN. NEARLY ALL

OF THE GLOBAL MODELS SHOW DEVELOPMENT OF THIS SYSTEM BY THE TIME IT

GETS TO THE WESTERN GULF OF MEXICO IN A FEW DAYS...AND THESE MODELS

STALL DARBY BY DAY 2 FOLLOWED BY A NORTHEASTWARD ACCELERATION ON

DAYS 4 AND 5...MOST NOTABLY INDICATED BY THE ECMWF AND UKMET. THE

OFFICIAL FORECAST FOLLOWS THIS GENERAL PATTERN...BUT DOES NOT

INDICATE A POSITION AS FAR TO THE EAST ON DAY 5 AS THE MODEL

CONSENSUS TVCN...WHICH IS BEING INFLUENCED BY THE ECMWF AND UKMET

OUTLIERS. ON ANOTHER NOTE...THE GFS SHOWS ALMOST NO DEVELOPMENT OF

THE CARIBBEAN LOW AND THEREFORE KEEPS DARBY ON THE WESTERN SIDE OF

THE RATHER HELTER-SKELTER GUIDANCE ENVELOPE. ESSENTIALLY...THE

STRONGER THE CARIBBEAN LOW GETS WHILE IN THE GULF OF MEXICO...THE

FARTHER TO THE EAST DARBY COULD BE LOCATED BY THE END OF THE

FORECAST PERIOD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/0900Z 13.4N 100.7W 90 KT

12HR VT 25/1800Z 13.5N 101.6W 100 KT

24HR VT 26/0600Z 13.6N 102.6W 95 KT

36HR VT 26/1800Z 13.4N 103.5W 90 KT

48HR VT 27/0600Z 13.4N 103.7W 80 KT

72HR VT 28/0600Z 13.6N 103.7W 70 KT

96HR VT 29/0600Z 14.0N 103.0W 60 KT

120HR VT 30/0600Z 14.5N 102.0W 50 KT

$$

FORECASTER BERG

Et pour Celia non plus. je garde quand même mes doutes sur sa catégorie 5, mais seul un avion dans le bazar pourrait dire ce qui s'y passe exactement, et je ne vais pas pinailler pour 5 nœuds.

000

WTPZ44 KNHC 250841

TCDEP4

HURRICANE CELIA DISCUSSION NUMBER 25

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010

200 AM PDT FRI JUN 25 2010

CELIA IS A VERY IMPRESSIVE HURRICANE THIS MORNING...WITH A

WELL-DEFINED 15-20 N MI WIDE EYE EMBEDDED IN A CLOSED EYEWALL WITH

CONVECTIVE CLOUD TOPS OF -75C TO -80C. THE CLOUD TOPS HAVE WARMED

SLIGHTLY DURING THE PAST FEW HOURS...AND THE SATELLITE INTENSITY

ESTIMATES FROM SAB AND TAFB REMAIN 140 KT. THAT WILL BE THE

INITIAL INTENSITY FOR THIS ADVISORY. THE CIRRUS OUTFLOW IS GOOD IN

ALL DIRECTIONS EXCEPT THE SOUTH.

THE INITIAL MOTION IS 285/11. THERE IS LITTLE CHANGE TO THE

FORECAST PHILOSOPHY OR THE TRACK MODEL GUIDANCE FROM THE PREVIOUS

ADVISORY. A LOW/MID-LEVEL RIDGE OVER MEXICO AND THE EASTERN

PACIFIC IS EXPECTED TO REMAIN IN PLACE FOR THE NEXT DAY OR

SO...WHICH SHOULD RESULT IN CELIA CONTINUING WEST-NORTHWESTWARD.

AFTER THAT THE RIDGE IS FORECAST TO WEAKEN AS A MID/UPPER-LEVEL

TROUGH DEVELOPS NEAR THE U. S. WEST COAST. THE DYNAMICAL MODELS

ARE IN GOOD AGREEMENT THAT THIS WILL CAUSE CELIA TO SLOW ITS

FORWARD MOTION...WITH SEVERAL OF THE MODELS SHOWING THE CYCLONE

MOVING LITTLE AT DAYS 4-5. THE NEW TRACK FORECAST FOLLOWS THIS

SCENARIO AND IS ALMOST IDENTICAL TO THE PREVIOUS FORECAST. THE

TRACK IS DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE IN BEST

AGREEMENT WITH THE GUNA...TVCN...AND TVCC CONSENSUS MODELS.

IT IS LIKELY THAT CELIA HAS REACHED ITS PEAK INTENSITY...AND THE

FORECAST TRACK CALLS FOR THE HURRICANE TO MOVE OVER COOLER SEA

SURFACE TEMPERATURES. THUS...A SIGNIFICANT WEAKENING TREND IS

EXPECTED TO START LATER TODAY AS SHOWN IN ALL OF THE INTENSITY

GUIDANCE. CELIA IS FORECAST TO WEAKEN BELOW MAJOR HURRICANE STATUS

IN 24-36 HR...BELOW HURRICANE STRENGTH IN 48-60 HR...AND DECAY TO A

REMNANT LOW BY THE END OF THE FORECAST PERIOD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/0900Z 13.4N 117.0W 140 KT

12HR VT 25/1800Z 14.1N 118.6W 130 KT

24HR VT 26/0600Z 14.9N 120.4W 105 KT

36HR VT 26/1800Z 15.6N 121.9W 80 KT

48HR VT 27/0600Z 16.1N 123.1W 65 KT

72HR VT 28/0600Z 16.5N 124.5W 45 KT

96HR VT 29/0600Z 16.5N 125.5W 30 KT

120HR VT 30/0600Z 16.5N 126.5W 25 KT...POST-TROP/REMNT LOW

$$

FORECASTER BEVEN

[paix 0]

La probabilité n'a jamais été aussi élevé pour 93L, et même pour 92L, premier à expérimenter ce système de pourcentage

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. A LOW PRESSURE AREA CENTERED BETWEEN THE NORTHEAST COAST OF HONDURAS

AND GRAND CAYMAN CONTINUES TO SHOW SIGNS OF ORGANIZATION. SHOWER

ACTIVITY HAS BECOME A LITTLE MORE CONCENTRATED THIS MORNING...AND

SURFACE PRESSURES ARE FALLING. UPPER-LEVEL WINDS ARE GRADUALLY

BECOMING MORE CONDUCIVE FOR DEVELOPMENT...AND THE SYSTEM IS LIKELY

TO BECOME A TROPICAL DEPRESSION BEFORE IT REACHES THE YUCATAN

PENINSULA IN A COUPLE OF DAYS. THERE IS A HIGH CHANCE...70

PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE

NEXT 48 HOURS. AN AIR FORCE RECONNAISSANCE PLANE IS SCHEDULED TO

INVESTIGATE THIS DISTURBANCE LATER TODAY TO DETERMINE IF A TROPICAL

CYCLONE HAS FORMED.

2. A LARGE BUT DISORGANIZED AREA OF CLOUDINESS AND SHOWERS CENTERED

JUST EAST OF THE NORTHERN LEEWARD ISLANDS IS ASSOCIATED WITH A

TROPICAL WAVE INTERACTING WITH AN UPPER-LEVEL TROUGH. THIS ACTIVITY

IS EXPECTED TO MOVE TOWARD THE NORTHWEST AND ADDITIONAL

DEVELOPMENT...IF ANY...WILL BE SLOW TO OCCUR. THERE IS A LOW

CHANCE...10 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE

DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

$$

FORECASTER AVILA/ROBERTS

NNNN

La pression, toujours pour la même bouée qui est juste en dessous de 93L (ou dont 93L est juste au dessus, c'est selon ... ), a du bien aidé le NHC :

P.S. : T# 1.0 maintenu à 1145Z

DATE/TIME LAT LON CLASSIFICATION STORM

25/1145 UTC 15.3N 81.6W T1.0/1.0 93L -- Atlantic

Modifié 25 juin 2010 par paix

[paix 0]

Celia est en train de s'affaiblir maintenant. Sélection d'images pas vraiment choisies .

[paix 0]

Un zinc vient d'être envoyé dans 93L pour lui demander comment elle se porte. Pour l'instant, rien de transcendant, l'avion est au dessus du delta du Mississippi. On va lui laisser le temps d'arriver.

Time: 14:54:00Z

Coordinates: 29.95N 89.1667W

Acft. Static Air Press: 525.7 mb (~ 15.52 inHg)

Acft. Geopotential Hgt: 5,544 meters (~ 18,189 feet)

Extrap. Sfc. Press: -

D-value: 341 meters (~ 1,119 feet)

Flt. Lvl. Wind (30s): From 101° at 11 knots (From the E/ESE at ~ 12.6 mph)

Air Temp: -4.5°C (~ 23.9°F)

Dew Pt: -4.5°C (~ 23.9°F)

Peak (10s) Flt. Lvl. Wind: 11 knots (~ 12.6 mph)

SFMR Peak (10s) Sfc. Wind: -

SFMR Rain Rate: -

Modifié 25 juin 2010 par paix

[paix 0]

Et zou, un nouveau majeur pour le Pacifique Est, en l'ouragan de Darby. Toujours aussi petit, mais toujours aussi puissant.

000

WTPZ45 KNHC 251431

TCDEP5

HURRICANE DARBY DISCUSSION NUMBER 11

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010

800 AM PDT FRI JUN 25 2010

DARBY IS A SMALL BUT INTENSE HURRICANE. SATELLITE IMAGES AND

MICROWAVE DATA REVEAL AN EYE SURROUNDED BY A RING OF VERY DEEP

CONVECTION. T-NUMBERS FROM TAFB AND SAB HAVE INCREASED TO 5.5 ON

THE DVORAK SCALE AND THE INITIAL INTENSITY HAS BEEN ADJUSTED UPWARD

TO 100 KNOTS. THE HURRICANE HAS AN OPPORTUNITY TO STRENGTHEN A

LITTLE MORE BEFORE THE UPPER-LEVEL ENVIRONMENT BECOMES UNFAVORABLE

IN A DAY OR TWO. THEREFORE...A GRADUAL WEAKENING IS INDICATED.

DARBY HAS CONTINUED TO MOVE TOWARD THE WEST-NORTHWEST OR 285 DEGREES

AT 6 KNOTS. HOWEVER...AS THE RIDGE TO THE NORTH WEAKENS AND THE

STEERING CURRENTS COLLAPSE...THE HURRICANE SHOULD BEGIN TO MEANDER

AS INDICATED IN THE OFFICIAL FORECAST. GLOBAL MODELS ARE NOT IN GOOD

AGREEMENT ON THE TRACK OF DARBY...BUT MOST OF THEM WEAKEN THE

CYCLONE AS IT BECOMES EMBEDDED WITHIN A LOW-LEVEL WESTERLY FLOW.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/1500Z 13.6N 101.2W 100 KT

12HR VT 26/0000Z 13.9N 102.0W 105 KT

24HR VT 26/1200Z 13.9N 103.2W 100 KT

36HR VT 27/0000Z 13.5N 103.5W 90 KT

48HR VT 27/1200Z 13.5N 104.0W 80 KT

72HR VT 28/1200Z 13.8N 104.0W 70 KT

96HR VT 29/1200Z 14.0N 103.3W 60 KT

120HR VT 30/1200Z 14.5N 102.5W 50 KT

$$

FORECASTER AVILA

Modifié 25 juin 2010 par paix

[paix 0]

La saison Atlantique vient de commencer officiellement, merci l'avion. Si il n'était pas passé la dedans, on l'aurais toujours en invest avec un T3 1.0

ZCZC MIATCDAT1 ALL

TTAA00 KNHC DDHHMM

TROPICAL DEPRESSION ONE SPECIAL DISCUSSION NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010

600 PM EDT FRI JUN 25 2010

THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING THE

DISTURBANCE IN THE WESTERN CARIBBEAN SEA HAS FOUND A WELL-DEFINED

CIRCULATION CENTER WITH A MINIMUM CENTRAL PRESSURE OF AROUND 1004

MB. BASED ON DATA FROM THE AIRCRAFT...ADVISORIES ARE BEING

INITIATED ON TROPICAL DEPRESSION ONE AT THIS TIME. THE INITIAL

INTENSITY IS SET AT 30 KT BASED ON A BLEND OF WIND DATA FROM THE

AIRCRAFT AND SURROUNDING OBSERVATIONS.

THE DEPRESSION IS VERY CLOSE TO TROPICAL STORM STRENGTH...AND

CONDITIONS APPEAR FAVORABLE FOR SOME INTENSIFICATION BEFORE IT

REACHES THE YUCATAN PENINSULA IN A DAY OR SO. AFTER WEAKENING OVER

LAND...THE CYCLONE COULD REGAIN SOME STRENGTH WHEN IT ENTERS THE

SOUTHERN GULF OF MEXICO. THE OFFICIAL INTENSITY FORECAST IS CLOSE

TO THE DECAY SHIPS MODEL...WHICH INCLUDES THE EFFECTS OF

INTERACTION WITH THE YUCATAN PENINSULA.

THE INITIAL MOTION IS RATHER UNCERTAIN BUT THE BEST ESTIMATE IS

300/09. A MID-LEVEL RIDGE IS FORECAST TO PERSIST OVER THE GULF OF

MEXICO FOR THE NEXT 48 TO 72 HOURS...THEREFORE A GENERAL

WEST-NORTHWESTWARD MOTION IS EXPECTED DURING THAT TIME...WHICH

SHOULD BRING THE CYCLONE ACROSS THE YUCATAN PENINSULA AND INTO THE

SOUTHERN GULF OF MEXICO. AFTER 72 HOURS THE TRACK MODEL GUIDANCE

DIVERGES...WITH ONE GROUP...INCLUDING THE HWRF AND GFDL...TAKING

THE SYSTEM ON A MORE NORTHERLY OR NORTHEASTERLY TRACK. A SECOND

GROUP OF GUIDANCE...INCLUDING THE GFS...ECMWF AND NOGAPS KEEPS THE

SYSTEM ON A MORE WESTERLY TRACK OVER THE SOUTHERN GULF OF MEXICO.

THE OFFICIAL FORECAST IS A BLEND OF THESE TWO.

A TROPICAL STORM WARNING IS REQUIRED FOR THE EAST COAST OF THE

YUCATAN PENINSULA AT THIS TIME. IF THE CYCLONE MOVES SOUTH OF THE

OFFICIAL FORECAST TRACK...A TROPICAL STORM WARNING FOR BELIZE MAY

BE REQUIRED LATER THIS EVENING.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/2200Z 16.5N 83.5W 30 KT

12HR VT 26/0600Z 17.4N 84.7W 35 KT

24HR VT 26/1800Z 18.5N 86.5W 40 KT

36HR VT 27/0600Z 19.5N 88.0W 45 KT...INLAND

48HR VT 27/1800Z 21.0N 89.5W 25 KT...INLAND

72HR VT 28/1800Z 23.0N 91.5W 30 KT

96HR VT 29/1800Z 24.0N 92.5W 35 KT

120HR VT 30/1800Z 25.0N 93.5W 40 KT

$$

FORECASTER AVILA/BRENNAN

NNNN

[ElNino27 0]

Et donc Alex dans quelques heures ... Je me demande s'il survivra à la traversée du Yucatan quand même ...

[paix 0]

Si il survit, les conditions dans le golfe ne seront pas forcément plus favorable je pense. En attendant, TD1 se développe rapidement. Sa taille est tout simplement hallucinante pour une dépression. Cela me fait quelque peu penser à Wilma, qui avait une circulation tellement large qu'elle avait peiné à s'intensifier au début. On verra bien la suite des événements, mais le Yucatán a déjà une alerte à la tempête tropicale.

On pourra noter de manière plus anecdotique que l'ASCAT n'ai d'aucun secours. La proximité avec les terres brouille le satellite, qui ne voit toujours pas un LLC potable.

[ElNino27 0]

C'est vrai que sa circulation a la taille d'un ouragan de cat4 !

[paix 0]

David et Goliath ....

La petit machin riquiqui dans le Pacifique est bien l'ouragan majeur Darby, alors que la grosse boule de nuages un peu vrac est la TD1. Les bandes convectives effleurent quand même Haïti, affectent Cuba, la Jamaïque, le Yucatán, et toute l'Amérique centrale ....

À l'Est, avec le Soleil qui l'éclaire déjà moins, l'invest 94L

Ce sera sans doute une des dernières images visible de cette journée riche en émotions et en rebondissements de tous genres. Un catégorie 5 pour le Pacifique, un catégorie 3 pour le Pacifique, et la première dépression de l'Atlantique.

P.S. : La prochaine bouée sur la trajectoire de la première dépression

http://www.ndbc.noaa.gov/station_page.php?station=42056

Modifié 25 juin 2010 par paix

[paix 0]

Et voici Alex. Il est impressionnant, avec ses poussées convectives et la taille de sa circulation. Une bande convective associée se retrouve même au dessus du Pacifique....

Par contre, niveau organisation, ce n'est pas encore cela.

000

WTNT41 KNHC 260847

TCDAT1

TROPICAL STORM ALEX DISCUSSION NUMBER 3

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010

500 AM EDT SAT JUN 26 2010

AN AIR FORCE RESERVE HURRICANE HUNTER INVESTIGATING TROPICAL

DEPRESSION ONE REPORTED 925 MB FLIGHT-LEVEL WINDS OF 46 KT ABOUT 90

NM EAST OF THE CENTER...WHICH SUGGEST SURFACE WINDS OF NEAR 35 KT.

THE STEPPED FREQUENCY MICROWAVE RADIOMETER ON THE AIRCRAFT SHOWED A

LARGE AREA OF WINDS NEAR 35 KT THAT DID NOT APPEAR TO BE RAIN-

CONTAMINATED. BASED ON THIS...THE DEPRESSION IS UPGRADED TO

TROPICAL STORM ALEX WITH AN INITIAL INTENSITY OF 35 KT. THE

AIRCRAFT DATA SUGGESTS THAT THE CIRCULATION OF ALEX REMAINS

BROAD...AND THAT THE RECENTLY REPORTED CENTRAL PRESSURE OF 1004 MB

MAY HAVE BEEN MEASURED IN A MESOSCALE LOW PRESSURE AREA. IT SHOULD

BE NOTED THAT THE AIRCRAFT REPORTED SFMR WINDS IN EXCESS OF 40 KT

WHICH APPEAR SUSPECT DUE TO RAIN CONTAMINATION.

THE INITIAL MOTION REMAINS UNCERTAIN...WITH THE BEST ESTIMATE OF

285/7. FOR THE NEXT 24 TO 48 HOURS ALEX IS EXPECTED TO MOVE

WEST-NORTHWESTWARD OR NORTHWESTWARD TO THE SOUTH OF A LOW/MID-LEVEL

RIDGE CENTERED OVER THE EASTERN UNITED STATES. AFTER THAT...THE

LARGE-SCALE MODELS FORECAST THE RIDGE TO WEAKEN AS A DEEP-LAYER

TROUGH MOVES INTO THE EASTERN U. S. THERE REMAINS A SIGNIFICANT

SPREAD IN THE MODEL GUIDANCE ON HOW THIS EVOLUTION WILL AFFECT

ALEX. THE GFS...GFS ENSEMBLE MEAN...AND THE GFDL SHOW ENOUGH OF A

BREAK IN THE RIDGE TO STEER ALEX NORTHWARD TOWARD THE NORTHWESTERN

GULF COAST. THE ECMWF...NOGAPS...AND UKMET SHOW THE RIDGE REMAINING

STRONG ENOUGH TO STEER ALEX GENERALLY WESTWARD INTO NORTHEASTERN

MEXICO. THE HWRF AND THE CANADIAN MODELS ARE BETWEEN THESE

EXTREMES. OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED WESTWARD

SINCE THE LAST ADVISORY...SO THE NEW FORECAST TRACK WILL BE NUDGED

WESTWARD AS WELL. HOWEVER...THE NEW TRACK IS STILL A LITTLE TO THE

RIGHT OF THE CENTER OF THE GUIDANCE ENVELOPE AND THE VARIOUS

CONSENSUS MODELS. IT IS IN BEST OVERALL AGREEMENT WITH THE HWRF.

THE LARGE-SCALE MODELS FORECAST ALEX TO BE NEAR OR UNDER A LARGE

UPPER-LEVEL ANTICYCLONE THROUGH THE FORECAST PERIOD...WHICH SHOULD

CAUSE AN ENVIRONMENT OF LIGHT VERTICAL WIND SHEAR. AS A RESULT...

ALEX IS FORECAST TO INTENSIFY AS LONG AS IT REMAINS OVER WATER.

THE NEW INTENSITY FORECAST CALLS FOR A 50 KT INTENSITY AS THE

CENTER REACHES THE COAST OF BELIZE OR THE YUCATAN PENINSULA...

FOLLOWED BY WEAKENING OVER LAND. THE GFDL...SHIPS...AND LGEM

MODELS FORECAST ALEX TO BE A HURRICANE OVER THE GULF OF MEXICO.

THE INTENSITY FORECAST WILL NOT YET DO THAT...BUT WILL CALL FOR

MORE STRENGTHENING OVER THE GULF THAN THE PREVIOUS FORECAST.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0900Z 16.9N 84.9W 35 KT

12HR VT 26/1800Z 17.4N 86.3W 45 KT

24HR VT 27/0600Z 18.4N 88.0W 50 KT

36HR VT 27/1800Z 19.4N 89.5W 35 KT...INLAND

48HR VT 28/0600Z 20.5N 90.5W 30 KT...OVER WATER

72HR VT 29/0600Z 22.5N 92.5W 35 KT

96HR VT 30/0600Z 24.0N 94.0W 45 KT

120HR VT 01/0600Z 24.5N 95.5W 60 KT

$$

FORECASTER BEVEN

[paix 0]

Jeff Masters a fait tout un historique de ce qui peut arriver à une tempête dans la situation. Pas encore le courage de tout lire .... :lol2:

http://www.wunderground.com/blog/JeffMaste...l?entrynum=1518

On pourra noter que l'Atlantique est à peine en avance, avec une normale de 0,6 tempête et 0,1 ouragan déjà formé à cette date. En moyenne, la première tempête se forme le 10 Juillet.

Le Pacifique est lui aussi en avance, avec une normale de 2 tempêtes, 1 ouragan, et 0,5 ouragan majeur déjà formé à cette date.

Modifié 26 juin 2010 par paix

[paix 0]

Retour à la catégorie 2 pour Darby. Le NHC n'en est pas encore à perdre ses mots face à un aussi petit ouragan, mais il n'en sont pas loin ...

Je lui trouve une certaine similitude avec le cyclone Tracy, plus petit cyclone tropical connu. Diamètre à peine supérieur, intensité pratiquement équivalente, Darby lui ressemble beaucoup : http://en.wikipedia.org/wiki/Cyclone_Tracy

000

...MINIATURE DARBY WEAKENS TO A CATEGORY TWO HURRICANE...

WTPZ45 KNHC 260850

TCDEP5

HURRICANE DARBY DISCUSSION NUMBER 14

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010

200 AM PDT SAT JUN 26 2010

DARBY IS AN INCREDIBLY SMALL HURRICANE. AN ASCAT PASS AROUND 0345

UTC INDICATED THAT TROPICAL STORM FORCE WINDS DO NOT EXTEND ANY

FARTHER THAN ABOUT 35 N MI FROM THE CENTER. THE HURRICANE HAD BEEN

MAINTAINING A SMALL 10-N MI WIDE EYE SURROUNDED BY DEEP

CONVECTION...WHICH SUPPORTED 0600 UTC DVORAK ESTIMATES OF T5.5 FROM

BOTH TAFB AND SAB. HOWEVER...THE EYE HAS RECENTLY BECOME

OBSCURED...AND THE MOST RECENT ADT ESTIMATE FROM UW-CIMSS IS T5.1.

THE INITIAL INTENSITY IS THEREFORE LOWERED TO 95 KT. VERTICAL

SHEAR IS EXPECTED TO INCREASE OVER DARBY OVER THE NEXT SEVERAL

DAYS...WHICH IS EXPECTED TO INDUCE GRADUAL WEAKENING. THE

WEAKENING IS EXPECTED TO BE MORE RAPID FROM 72-120 HOURS AS A

STRONG UPPER RIDGE BUILDS OVER MEXICO...CREATING FAIRLY STRONG

UPPER-LEVEL EASTERLY WINDS NEAR THE CYCLONE. THE NEW OFFICIAL

FORECAST CLOSELY FOLLOWS THE SHIPS AND LGEM INTENSITY

GUIDANCE...AND IS NOT TOO DIFFERENT FROM THE PREVIOUS ADVISORY.

DARBY HAS BEEN MOVING ALMOST WEST-SOUTHWESTWARD OVER THE PAST FEW

HOURS...AND THE INITIAL MOTION IS 260/5. THE STEERING CURRENTS

AROUND THE HURRICANE ARE STILL EXPECTED TO COLLAPSE THROUGH THE

FORECAST PERIOD...AND DARBY SHOULD BEGIN TO MOVE VERY SLOWLY

WESTWARD OVER THE NEXT 24-36 HOURS. THEREAFTER...THE CYCLONE IS

EXPECTED TO BEGIN FEELING THE INFLUENCE OF NEWLY-NAMED TROPICAL

STORM ALEX IN THE WESTERN CARIBBEAN. THE OFFICIAL FORECAST

INDICATES A SLOW NORTHEASTWARD MOTION BETWEEN DAYS 3 AND 5...BUT IT

SHOULD BE NOTED THAT THE GUIDANCE ENVELOPE IS STILL RATHER

DIVERGENT AND DARBY COULD DRIFT OR MEANDER IN PLACE FOR SEVERAL

DAYS. THE ECMWF SHOWS A QUICK NORTHEASTWARD MOTION AND BRINGS

DARBY TO THE MEXICAN COAST IN 3 DAYS...BUT THIS SOLUTION IS

DISCOUNTED AT THIS TIME.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0900Z 13.5N 102.7W 95 KT

12HR VT 26/1800Z 13.4N 103.4W 90 KT

24HR VT 27/0600Z 13.4N 104.1W 85 KT

36HR VT 27/1800Z 13.6N 104.4W 75 KT

48HR VT 28/0600Z 13.9N 104.1W 70 KT

72HR VT 29/0600Z 14.3N 103.3W 55 KT

96HR VT 30/0600Z 14.7N 102.8W 45 KT

120HR VT 01/0600Z 15.0N 102.5W 35 KT

$$

FORECASTER BERG

On a vraiment tous les extrêmes sur le plateau en ce moment. Célia qui a accroché la catégorie 5, Darby qui se fait tout petit, et Alex qui est un bonne grosse tempête....

Tiens, j'avais raté ceci :

ZCZC MIATCDEP5 ALL

TTAA00 KNHC DDHHMM

HURRICANE DARBY DISCUSSION NUMBER 12

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010

200 PM PDT FRI JUN 25 2010

DARBY REMAINS A WELL-ORGANIZED HURRICANE WITH VISIBLE IMAGERY

SHOWING A DISTINCT EYE AND AN IMPRESSIVE OUTFLOW PATTERN. DVORAK

SATELLITE CLASSIFICATIONS FROM TAFB AND SAB AT 1800 UTC WERE

T5.5...102 KT. SINCE THAT TIME...THE SYSTEM HAS BECOME BETTER

ORGANIZED WITH DEEPER CONVECTION IN THE EYEWALL. THUS...THE INITIAL

INTENSITY IS NUDGED UPWARD TO 105 KT. EASTERLY SHEAR IS FORECAST

BY ALL OF THE GLOBAL MODELS TO INCREASE OVERNIGHT WHICH SHOULD

LIMIT FUTURE STRENGTHENING. THIS SHEAR WILL LIKELY PERSIST FOR

SEVERAL DAYS AND CAUSE DARBY TO GRADUALLY WEAKEN. MOST OF THE

INTENSITY GUIDANCE IS IN REASONABLE AGREEMENT ON THIS SCENARIO...

AND THE NHC FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS

ADVISORY.

[...]

DARBY IS THE EARLIEST SECOND MAJOR HURRICANE FORMATION IN THE

EASTERN PACIFIC SINCE RELIABLE RECORDS BEGAN IN 1971...ECLIPSING OF

THE PREVIOUS RECORD OF HURRICANE DANIEL ON JUNE 30 1978.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/2100Z 13.6N 101.5W 105 KT

12HR VT 26/0600Z 13.7N 102.3W 105 KT

24HR VT 26/1800Z 13.5N 103.3W 100 KT

36HR VT 27/0600Z 13.4N 103.8W 90 KT

48HR VT 27/1800Z 13.5N 104.2W 80 KT

72HR VT 28/1800Z 14.0N 103.5W 65 KT

96HR VT 29/1800Z 14.3N 102.7W 55 KT

120HR VT 30/1800Z 14.6N 102.0W 45 KT

$$

FORECASTER BLAKE

NNNN

Darby a établi des record de précocité en devenant le second ouragan majeur d'une saison Pacifique le 25 Juin.

Modifié 26 juin 2010 par paix

[paix 0]

Sunrise over Alex. I don't look if there is any element wich can indicate a rapide deepening, but I think it can explode. I have perhaps an erroneous opinion. The surface circulation remains broad and somewhat disorganized, but with this tremendous deep convection and this LLC, and the extremly hot water, I feel that it can surprise the Yucatán. To be continued....

Modifié 26 juin 2010 par paix

[ElNino27 0]

Très beau de voir les bandes de convection se former dans le Pacifique et être arrêtées par l'Amérique Centrale.

Développement convectifs très élevés au centre de la TS : couleurs grises !

Premier ouragan possible en approche de la frontière. A voir après le passage au-dessus du Yucatan !

[paix 0]

C'est démentiel... Alex est en train de constituer un CDO (Central Dense Overcast) extrêmement froid. Le centre est en dessous. J'ai un doute sur sa position exacte, je pense qu'il est un peu décalé à l'Est, par 86,5°O et 17,5°N, mais si il parvient à finalement se structurer autour de ce CDO, ce sera une intensification rapide qui sera l'hypothèse la plus probable. Les sommets de nuages sont à -80°/-85° Celsius...

Pour l'image que j'ai posté précédemment, le centre d'Alex était entre les deux masses convectives. Il semblerait maintenant que la masse convective de gauche prenne l'ascendant, et que la masse convective de droite s'affaiblisse en une "simple" bande convective. Le centre doit donc se relocalisé sous le CDO. Si il parvient, Alex va pouvoir faire trembler le Yucatán...

Modifié 26 juin 2010 par paix

[ElNino27 0]

Effectivement, même dans les gros ouragans en pleine expansion, j'ai rarement vu cela. Annonciateur de la saison qui nous arrive ?

En tout cas, le NHC nous met un ouragan avant de toucher terre quelque part à la frontière USA-Mexique, mais un truc pareil pourrait aller bien plus loin. Le Yucatan va se prendre une bonne douche !