Caribbean-On-Line's Caribbean Hurricane Blog



Hurricane Danielle

Hurricane Danielle Open Thread

Published on August 25, 2010 2:34 AM | Comments

Discuss and ask questions about Hurricane Danielle using this thread.



Hurricane Danielle 5 Day Cone

Published on August 25, 2010 2:27 AM | Comments



TROPICAL STORM DANIELLE DISCUSSION NUMBER 6

Published on August 23, 2010 1:48 AM | Comments

The best thing about this storm is that early tracking has it steering clear of the Caribbean, although it may pose some threat to Bermuda:

TROPICAL STORM DANIELLE DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
1100 PM AST SUN AUG 22 2010

DEEP CONVECTION NEAR THE CENTER OF DANIELLE...WHICH DEVELOPED AROUND
1900 UTC...HAS PERSISTED OVER THE PAST SEVERAL HOURS WITH CLOUD TOPS
AS COLD AS -90 C. AN SSMI/S MICROWAVE PASS AT 2151 UTC SUGGESTS
THAT THE LOW-LEVEL CENTER OF DANIELLE REMAINS NEAR THE EASTERN EDGE
OF THE DEEP CONVECTIVE MASS...INDICATIVE OF PERSISTENT EASTERLY
SHEAR. SATELLITE INTENSITY ESTIMATES FROM BOTH TAFB AND SAB ARE
3.0...AND SUPPORT AN INCREASE IN THE INITIAL INTENSITY TO 45 KT. A
RECENTLY ARRIVING ASCAT PASS SHOWED 35 TO 40 KT WINDS OVER THE
WESTERN PERIPHERY OF THE CIRCULATION...WHICH ALSO SUPPORTS RAISING
THE INITIAL INTENSITY.

DANIELLE CONTINUES TO MOVE NORTHWESTWARD WITH AN INITIAL MOTION
ESTIMATE OF 315/11. A SUBTROPICAL RIDGE TO THE NORTH OF THE
CYCLONE IS EXPECTED TO GRADUALLY TURN DANIELLE TOWARD THE
WEST-NORTHWEST DURING THE NEXT 24 TO 48 HOURS...WITH AN INCREASE IN
FORWARD SPEED. THEREAFTER...A TURN TOWARD THE NORTHWEST IS FORECAST
AS A WEAKNESS IN THE RIDGE DEVELOPS. THE NEW OFFICIAL TRACK
FORECAST IS NUDGED SLIGHTLY TO THE RIGHT OF THE PREVIOUS
ADVISORY...NEAR THE MULTI-MODEL CONSENSUS.

EASTERLY SHEAR IS EXPECTED TO DECREASE WITHIN THE NEXT 12 HOURS OR
SO. OTHER ENVIRONMENTAL FACTORS ALSO SUPPORT ADDITIONAL
INTENSIFICATION AND THE NHC OFFICIAL FORECAST SHOWS STEADY
STRENGTHENING. THIS IS IN LINE WITH MUCH OF THE INTENSITY
GUIDANCE...WHICH BRINGS DANIELLE TO HURRICANE STATUS WITHIN THE
NEXT COUPLE OF DAYS.



TROPICAL DEPRESSION SIX DISCUSSION NUMBER 3

Published on August 22, 2010 10:36 AM | Comments

TROPICAL DEPRESSION SIX DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
500 AM AST SUN AUG 22 2010

SATELLITE IMAGES INDICATE THAT THE DEPRESSION IS GRADUALLY BECOMING
BETTER ORGANIZED...WITH THE DEVELOPMENT IN THE LAST SEVERAL HOURS
OF A DISTINCT CURVED BAND WRAPPING NEARLY HALFWAY AROUND THE WESTERN
SIDE OF THE CIRCULATION. HOWEVER...THE CIRCULATION CENTER REMAINS
SEPARATED FROM THE DEEP CONVECTION. SATELLITE INTENSITY ESTIMATES
ARE AT 2.0 AND 2.5 FROM SAB AND TAFB...RESPECTIVELY. WITH THE LACK
OF A CONSENSUS FROM BOTH SATELLITE AGENCIES AND LITTLE DEEP
CONVECTION NEAR THE CENTER...THE INTENSITY IS HELD AT 30 KT FOR
THIS ADVISORY.

RECENT CENTER FIXES ARE A BIT UNCERTAIN GIVEN A LACK OF MICROWAVE
DATA BUT YIELD AN INITIAL MOTION OF 295/08...A LITTLE TO THE RIGHT
AND FASTER THAN THE PREVIOUS ESTIMATE. A DEEP LAYER EAST-
SOUTHEASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE SHOULD STEER THE
CYCLONE ON A GENERAL WEST-NORTHWESTWARD COURSE FOR THE NEXT COUPLE
OF DAYS...WITH SOME INCREASE IN FORWARD SPEED. WATER VAPOR IMAGERY
INDICATES A MID- TO UPPER-LEVEL LOW NEAR 27N41W THAT IS FORECAST BY
THE GLOBAL MODELS TO MOVE SOUTHWEST AND CAUSE A DEVELOPING WEAKNESS
IN THE RIDGE BETWEEN 45-50W IN ABOUT 72 HOURS. THE WEAKNESS IN THE
RIDGE BECOMES MORE PRONOUNCED AS A LARGER MID-LATITUDE TROUGH IS
FORECAST TO DIG OVER THE EAST CENTRAL ATLANTIC LATE IN THE FORECAST
PERIOD. MODEL GUIDANCE IS NOW A BIT MORE DIVERGENT BUT SHOWS THE
DEPRESSION MOVING WEST-NORTHWESTWARD TO NORTHWESTWARD WITH A
DECREASE IN FORWARD SPEED AS IT MOVES INTO THE WEAKNESS. THE
OFFICIAL NHC FORECAST TRACK IS SLOWED AT LATER FORECAST TIMES AS A
RESULT OF A SLOWER TREND IN THE GUIDANCE AND INCREASING MODEL
SPREAD.

SHIPS MODEL OUTPUT AND UW-CIMSS SHEAR ANALYSES INDICATE MODERATE
EAST-NORTHEASTERLY VERTICAL WIND SHEAR OVER THE CYCLONE...SEEMINGLY
CONFIRMED BY THE EXPOSED NATURE OF THE CIRCULATION CENTER.
HOWEVER...THE SHEAR IS EXPECTED TO DECREASE AS THE DEPRESSION MOVES
OUT OF THE LOW-LEVEL MONSOONAL FLOW OVER THE EASTERN TROPICAL
ATLANTIC. THE LOWER SHEAR ENVIRONMENT ALONG WITH INCREASING SSTS
SHOULD FAVOR A GRADUAL INTENSIFICATION...AND THE DEPRESSION IS
FORECAST TO REACH HURRICANE STRENGTH WITHIN 3 DAYS. THEREAFTER...
AN INCREASE IN SOUTHWESTERLY VERTICAL WIND SHEAR ASSOCIATED WITH
THE DIGGING TROUGH OVER THE CENTRAL ATLANTIC COULD HAMPER FURTHER
INTENSIFICATION. THE OFFICIAL WIND SPEED FORECAST IS REDUCED ONLY
SLIGHTLY FROM THE PREVIOUS ONE THROUGHOUT THE FORECAST PERIOD AND
IS IN BEST AGREEMENT WITH THE LGEM STATISTICAL INTENSITY GUIDANCE.



TROPICAL DEPRESSION SIX DISCUSSION NUMBER 1

Published on August 21, 2010 7:24 PM | Comments

It is very early on for this system, but the NHC has it on their radar and is predicting it could become a named stormed. The early track at least looks like the Caribbean is safe, but it could be trouble for Bermuda in several days. We'll keep and eye on this one:

TROPICAL DEPRESSION SIX DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
500 PM EDT SAT AUG 21 2010

SATELLITE IMAGES INDICATE THAT THE AREA OF LOW PRESSURE SOUTHWEST OF
THE CAPE VERDE ISLANDS HAS BECOME CONSIDERABLY BETTER ORGANIZED
DURING THE PAST SEVERAL HOURS. THE LOW APPEARS TO HAVE BECOME
MORE SEPARATED FROM THE LARGE AREA OF SOUTHWESTERLY FLOW WHICH HAS
BEEN PRESENT OVER THE TROPICAL ATLANTIC FOR THE PAST SEVERAL
DAYS....THOUGH IT IS STILL A BIT ELONGATED TO THE NORTHEAST. A LONG
CURVED BAND OF CONVECTION ALSO WRAPS AROUND THE SOUTHERN AND
WESTERN SEMICIRCLE. THE INITIAL INTENSITY WILL BE 25 KT...WHICH
AGREES WITH DVORAK CLASSIFICATIONS FROM TAFB/SAB OF T1.5...25
KT...AND A 25 KT ASCAT PASS FROM THIS MORNING.

A LARGE UPPER-LEVEL ANTICYCLONE IS FORECAST TO BE NEAR THE
DEPRESSION...WHICH SHOULD CAUSE ONLY WEAK TO MODERATE NORTHEASTERLY
SHEAR FOR THE NEXT SEVERAL DAYS. COMBINED WITH WARM SSTS...AT LEAST
STEADY STRENGTHENING IS EXPECTED UNTIL THE END OF THE FORECAST
PERIOD. BY THAT TIME...SOME INCREASE IN SOUTHWESTERLY SHEAR IS
POSSIBLE AS THE CYCLONE APPROACHES THE MID-OCEANIC TROUGH. THE
INTENSITY GUIDANCE IS IN RELATIVELY GOOD AGREEMENT FOR SUCH A WEAK
SYSTEM WITH ALL RELIABLE GUIDANCE MAKING THE DEPRESSION A HURRICANE
WITHIN A FEW DAYS. THE NHC FORECAST IS CLOSE TO THE SHIPS/LGEM
MODELS...SHOWING A LARGE POWERFUL HURRICANE OVER THE CENTRAL
ATLANTIC OCEAN IN A FEW DAYS.

THE INITIAL MOTION ESTIMATE IS 285/7. A WEST-NORTHWEST MOTION WITH
INCREASING FORWARD SPEED IS EXPECTED AS THE DEPRESSION LEAVES THE
STRONG WESTERLY LOW-LEVEL FLOW ENVIRONMENT OF THE TROPICAL ATLANTIC
AND BECOMES STEERED BY A RIDGE OVER THE CENTRAL ATLANTIC OCEAN.
MOST OF THE MODELS SHOW THE CYCLONE TURNING TOWARD THE NORTHWEST
DUE TO A WEAKNESS IN THE RIDGE ALONG 50W IN ABOUT 3 DAYS. MODEL
GUIDANCE IS FAIRLY CLUSTERED AROUND THIS SOLUTION...WITH THE BIG
OUTLIERS TO THE NORTHEAST BEING THE CMC AND THE ECMWF MODELS. THESE
MODELS SHOW THE SYSTEM MOVING NORTHWEST SOON...WHICH ALLOWS THE
SYSTEM TO RECURVE TOWARD THE NORTH DUE TO A TROUGH ALONG 50W. THE
OFFICIAL FORECAST IS CLOSE TO...BUT SLIGHTLY TO THE LEFT OF...THE
DYNAMICAL MODEL CONSENSUS.