75kts - 980mb

El nhc dice que puede sufrir fluctuaciones en intensidad. Si sucedio dicho remplazo de ojo, muy posiblemente se volvera a intensificar

Hola chicos, sigo amenudo vuestras andansas de los sistemas, aunque soy poco experto intento entender y comprender las cosas, quiero aportar algo , que no es mucho  pero si llegara
a impactar en bermudas serviria de mucho, el radar de bermudas, que lo disfruteis, ya se puede apreciar ecos en el radar.


http://www.weather.bm/radarLarge.asp

Pues la verdad no me creo que Bertha sea categoria uno. Tan siquiera yo le daria fuerza de huracan categoria 2 Segun el nhc 2 dias mas durara como huracan y luego se convertira en tormenta tropical

Parece que sí se trata de un reemplazamiento del ojo, pues este hecho es comentado en el boletín nº33 del Centro Nacional de Huracanes del NOAA:

000
WTNT42 KNHC 110849
TCDAT2
HURRICANE BERTHA DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
500 AM EDT FRI JUL 11 2008

THE LATEST SATELLITE MICROWAVE DATA AT 02Z INDICATED THAT BERTHA WAS
CONTINUING ITS EYEWALL REPLACEMENT CYCLE...WITH A FRAGMENT OF THE
OLD INNER EYEWALL REMAINING INSIDE THE 60 N MI WIDE OUTER EYEWALL.
INFRARED IMAGERY SINCE THEN SUGGESTS LITTLE CHANGE IN THE STRUCTURE
OF THE HURRICANE.  SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB
REMAIN 77 KT...SO THE INITIAL INTENSITY REMAINS 75 KT.  THE CIRRUS
OUTFLOW IS NOW FAIR TO GOOD IN ALL DIRECTIONS.

THE INITIAL MOTION IS NOW 315/6.  TRACK GUIDANCE IS IN GOOD
AGREEMENT THAT BERTHA WILL TURN NORTHWARD DURING THE NEXT 36 HR AS
A MID-LEVEL RIDGE NORTH OF THE HURRICANE MOVES EASTWARD.  SERIOUS
GUIDANCE DIVERGENCE OCCURS BEYOND THAT TIME.  THE GFS IS NOW
CALLING FOR A SLOW EASTWARD MOTION FROM 48-120 HR...THE UKMET
CALLING FOR A SLOW NORTHWARD MOTION...AND THE ECMWF AND CANADIAN
MODELS TRAPPING BERTHA IN THE SUBTROPICAL RIDGE AND STALLING IT
NEAR 31N61W.  THE OTHER DYNAMICAL GUIDANCE FORECAST BERTHA TO MOVE
SLOWLY NORTH-NORTHEASTWARD IN RESPONSE TO WEAK RIDGING TO THE EAST
AND A SERIES OF MID/UPPER-LEVEL SHORTWAVE TROUGHS MOVING THROUGH
THE EASTERN UNITED STATES.  SINCE THE ECMWF AND GFS ARE NOT SHOWING
MUCH RUN-TO-RUN CONSISTENCY...THE ONLY CHANGE TO THE FORECAST TRACK
FROM THE PREVIOUS ADVISORY WILL BE TO CALL FOR A SLOWER NORTH-
NORTHEASTWARD MOTION AFTER 48 HR.  THE NEW TRACK LIES ON THE LEFT
SIDE OF THE MODEL CONSENSUS IN BEST AGREEMENT WITH THE FLORIDA
STATE SUPERENSEMBLE.

BERTHA IS CURRENTLY UNDER A LARGE UPPER-LEVEL ANTICYCLONE...WITH THE
LARGE-SCALE MODELS FORECASTING THIS TO CONTINUE FOR AT LEAST 36 HR.
BASED ON A CONSENSUS OF THE INTENSITY GUIDANCE...THE INTENSITY
FORECAST WILL KEEP BERTHA AT 75 KT DURING THIS TIME.  HOWEVER...
THERE IS STILL A CHANCE OF SOME STRENGTHENING AT THE END OF THE
EYEWALL REPLACEMENT CYCLE.  STARTING IN 48-72 HR...IT IS EXPECTED
THAT BERTHA WILL SLOWLY MOVE OUT FROM UNDER THE ANTICYCLONE AND
ENCOUNTER VERTICAL WIND SHEAR.  THIS...COMBINED WITH DECREASING SEA
SURFACE TEMPERATURES ALONG THE FORECAST TRACK...SHOULD CAUSE BERTHA
TO WEAKEN.  OCEAN ANALYSES FROM THE ATLANTIC OCEANOGRAPHIC AND
MARINE LABORATORY SHOW THAT THE WARM WATER UNDER BERTHA IS
RELATIVELY SHALLOW...AND THERE IS A CHANCE THAT THIS SLOW-MOVING
SYSTEM COULD UPWELL COLDER WATER UNDERNEATH IT.  THIS COULD
PARTICULARLY BE A FACTOR IF BERTHA STALLS FOR 24 HR OR MORE.

THE LATEST WIND SPEED PROBABILITIES INDICATE THAT...GIVEN
UNCERTAINTIES IN THE FORECASTS OF BERTHA'S TRACK...INTENSITY...AND
SIZE...THERE REMAINS ROUGHLY A 50% CHANCE THAT WINDS OF TROPICAL
STORM FORCE WILL AFFECT BERMUDA DURING THE NEXT FIVE DAYS.  A
TROPICAL STORM WATCH MAY BE ISSUED FOR THE ISLAND LATER TODAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL      11/0900Z 28.0N  61.7W    75 KT
 12HR VT     11/1800Z 28.8N  62.3W    75 KT
 24HR VT     12/0600Z 29.7N  62.6W    75 KT
 36HR VT     12/1800Z 30.4N  62.5W    75 KT
 48HR VT     13/0600Z 31.3N  62.0W    70 KT
 72HR VT     14/0600Z 32.5N  61.0W    65 KT
 96HR VT     15/0600Z 34.0N  60.5W    60 KT
120HR VT     16/0600Z 36.0N  59.0W    55 KT

$$
FORECASTER BEVEN

No me había dado cuenta de que los Hurricane Hunters tenían (y tienen) trabajo para hoy.............. Van a hacer su primera "visita" a BERTHA, según he podido ver:

000
NOUS42 KNHC 101400
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1000 AM EDT THU 10 JULY 2008
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 11/1100Z TO 12/1100Z JULY 2008
         TCPOD NUMBER.....08-040

I.  ATLANTIC REQUIREMENTS
    1. HURRICANE BERTHA.....AL022008
       A. 11/1800Z
       B. AFXXX 0102A BERTHA
       C. 11/1215Z
       D. 28.9N 61.9W
       E. 11/1730Z TO 11/2000Z
       F. SFC TO 10,000 FT

    2. OUTLOOK FOR SUCCEEDING DAY: FIX HURRICANE BERTHA
       NEAR 30.4N 62.0W AT 12/1800Z.

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

Y parece que para mañana también tienen fijada una misión de reconocimiento. A ver qué datos ofrece el Centro Nacional de Huracanes del NOAA cuando regresen...

La imagen que ofrece BERTHA a estas horas es muy interesante! Parece que la pared del ojo exterior está finalmente reemplazando a la interior que casi ha desaparecido, dando la apariencia de que BERTHA tiene un ojo enorme


Imagen (c) NOAA/CIRA/RAMMB

La isla de Bermuda ya está bajo aviso de tormenta tropical. Es posible acceder a la página de los Servicios Meteorológicos de Bermuda en el siguiente link. Será muy interesante si BERTHA se acerca más de lo esperado: http://www.weather.bm/index.asp

Estas son las condiciones actuales en su aeropuerto:

Time Sky / Weather Wind Speed/Gusts Temp. R.H. Pressure
                                  knots (mph)  °C (°F)  %  mb / "Hg
 12:55  Mostly Cloudy   NE  8/0 (9/0)  29(84)  68  1021 / 30.15

Incluso tienen su propio mapa con la posible trayectoria de BERTHA (adjunto mapa):

00
WTNT42 KNHC 111437
TCDAT2
HURRICANE BERTHA DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
1100 AM EDT FRI JUL 11 2008

MICROWAVE DATA CONTINUES TO SHOW A SMALL FRAGMENT OF THE INNER
EYEWALL WITHIN A BETTER DEFINED AND LARGER RING OF CONVECTION
ASSOCIATED WITH THE OUTER EYEWALL.  CONVENTIONAL VIS/IR IMAGES SHOW
THAT BERTHA'S CLOUD PATTERN HAS CHANGED LITTLE WITH GOOD OUTFLOW IN
ALL QUADRANTS. DVORAK T-NUMBERS STILL SUGGEST AN INITIAL INTENSITY
OF 75 KNOTS. THE FIRST RECONNAISSANCE MISSION INTO BERTHA WILL BE
LATER TODAY...SO I WILL BE MORE CONFIDENT WITH THE INITIAL
INTENSITY WHEN THE PLANE GETS THERE. THE CURRENT CLOUD PATTERN
CONFIGURATION...ANNULAR TYPE...AND LOW SHEAR SUGGEST THAT THE
INTENSITY WILL NOT CHANGE IN THE NEXT DAY OR SO. THEREFORE...BERTHA
IS KEPT AT 75 KNOTS UNTIL SHEAR INCREASES AND MOVES OVER A COOLER
OCEAN. THEN...A GRADUAL WEAKENING IS INDICATED. ALTHOUGH IT APPEARS
THAT THE OUTER EYEWALL COULD SHRINK RESULTING IN INTENSIFICATION...
I AM NOT CONSIDERING IT IN THIS FORECAST BECAUSE I HAVE NO IDEA
WHEN OR IF THIS CYCLE WILL OCCUR.

BERTHA IS MOVING VERY SLOWLY...AS ANTICIPATED...TOWARD THE NORTHWEST
OR 320 DEGREES AT 5 KNOTS IN BETWEEN A SMALL SUBTROPICAL RIDGE AND
AN APPROACHING SHORTWAVE TROUGH. THIS PATTERN SHOULD KEEP BERTHA
WITHIN VERY WEAK STEERING CURRENTS FOR THE NEXT 2 OR 3 DAYS.
BERTHA IS EXPECTED TO TURN MORE TO THE NORTH AND EVENTUALLY MORE TO
THE NORTH-NORTHEAST. THIS WILL BE VERY SLOW AND BERTHA IS NOT
EXPECTED TO MOVE MORE THAN 300 N MI IN THREE DAYS. THIS IS
CONSISTENT WITH LATEST GUIDANCE WHICH SHOWS THE CORE OF BERTHA
MOVING WELL EAST OF BERMUDA BUT TROPICAL STORM FORCE WINDS EXTEND
FARTHER OUT AND COULD REACH THE ISLAND AND ADJACENT WATERS.
THEREFORE...GIVEN UNCERTAINTIES IN THE FORECASTS OF
BERTHA'S...TRACK... INTENSITY...AND SIZE...THE WEATHER SERVICE OF
BERMUDA HAS ISSUED A TROPICAL STORM WATCH FOR BERMUDA.


FORECAST POSITIONS AND MAX WINDS

INITIAL      11/1500Z 28.5N  62.0W    75 KT
 12HR VT     12/0000Z 29.2N  62.5W    75 KT
 24HR VT     12/1200Z 30.2N  62.6W    75 KT
 36HR VT     13/0000Z 30.8N  62.2W    75 KT
 48HR VT     13/1200Z 31.5N  61.5W    70 KT
 72HR VT     14/1200Z 32.5N  60.5W    65 KT
 96HR VT     15/1200Z 34.5N  59.5W    60 KT
120HR VT     16/1200Z 37.0N  58.5W    55 KT

$$
FORECASTER AVILA