Caribbean-On-Line's Caribbean Hurricane Blog



Hurricane Katia

Katia regains hurricane status

Published on September 2, 2011 2:57 PM | Comments

The forecast remains mixed and unclear, but it should cause rough surf conditions for many Caribbean Islands:

HURRICANE KATIA DISCUSSION NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
1100 AM AST FRI SEP 02 2011

THE CONVECTIVE DEPICTION OF KATIA HAS IMPROVED THIS MORNING AS BOTH
MICROWAVE IMAGERY FROM SSMIS AND CONVENTIONAL VISIBLE SATELLITE
IMAGERY INDICATE THAT AN EYE MAY BE FORMING. BECAUSE OF THE
IMPROVED STRUCTURE...BOTH TAFB AND SAB DVORAK CLASSIFICATIONS CAME
IN AT A 4.0...OR 65 KT...AS DID A 1053Z CIMSS AMSU INTENSITY
ESTIMATE. THUS KATIA HAS REGAINED HURRICANE STATUS.

THE HURRICANE IS MOVING TOWARD THE WEST-NORTHWEST AT ABOUT 12
KT...AS IT IS BEING ADVECTED AROUND THE SOUTHWEST PERIPHERY OF A
DEEP-LAYER RIDGE. KATIA SHOULD MOVE TOWARD THE WEST-NORTHWEST OR
NORTHWEST FOR THE NEXT FEW DAYS AT A SLIGHTLY SLOWER RATE OF SPEED.
ALL OF THE RELIABLE GUIDANCE...WITH THE EXCEPTION OF THE UKMET WHICH
HAS A MUCH MORE EQUATORWARD SOLUTION DUE TO A SHORT-WAVE TROUGH OFF
OF THE U.S. EAST COAST LIFTING OUT TO THE NORTHEAST MORE QUICKLY...
IS IN EXCELLENT AGREEMENT. THE TRACK FORECAST IS VERY SIMILAR TO
THE PREVIOUS ADVISORY AND THE CONSENSUS OF THE GLOBAL AND HURRICANE
MODELS LESS THE UKMET MODEL.

DESPITE BECOMING A HURRICANE AGAIN...KATIA FACES A RELATIVELY
HOSTILE ENVIRONMENT WITH SOUTHWEST VERTICAL SHEAR OF 15-20 KT
SUGGESTED FOR THE NEXT DAY OR TWO. BEYOND 48 HOURS...THE SHEAR
FROM THE GLOBAL MODELS IS ANTICIPATED TO DECREASE...BUT THE
THERMODYNAMICS MAY NOT BE IDEAL WITH LOW HUMIDITIES AND A MORE
STABLE ENVIRONMENT ANTICIPATED. SOME OF THE UPPER-LEVEL
TEMPERATURE INCREASES ANALYZED IN THE SHIPS/LGEM STATISTICAL
MODELS...HOWEVER...MAY BE SPURIOUS...AS THE STRONGER VORTEX FROM
THE GFS MAY BE THE CAUSE OF THESE VALUES RATHER THAN THE
ENVIRONMENT. THUS THE SHIPS/LGEM GUIDANCE MAY BE TOO LOW AT DAYS
THREE TO FIVE. THE INTENSITY PREDICTION IS SLIGHTLY LOWER THAN A
SHIPS/LGEM/HWRF BLEND BUT HIGHER THAN THE PREVIOUS ADVISORY DURING
THE NEXT TWO DAYS.



Tropical Storm Katia is out there...

Published on August 30, 2011 10:22 AM | Comments

Tropical Storm Katia is out in the Atlantic. Most models have it becoming a major hurricane, but tracking to the north of the Caribbean Sea. It is very far off to tell, but it could possible be something for Bermuda and/or the Bahamas to worry about. Again, this is why we constantly push Trip Insurance on this website - if you don't have insurance before a storm is named, it won't cover you - and the season is looking active as we come up to the peak hurricane month of September. If you are traveling to the region for any reason this coming month, make sure you get your insurance NOW.

Katia looks like it could be another east coast storm - but I will be gone from NJ before it gets here!

TROPICAL STORM KATIA DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122011
500 AM AST TUE AUG 30 2011

THE CONVECTIVE PATTERN OF THE CYCLONE HAS IMPROVED OVERNIGHT...WITH
A LARGE AREA OF COLD CLOUD TOPS NOW SITUATED TO THE WEST AND
SOUTHWEST OF THE ESTIMATED CENTER LOCATION. THE 06Z DVORAK
INTENSITY ESTIMATES FROM TAFB AND SAB WERE BOTH 2.5/35 KT...AND ON
THIS BASIS THE CYCLONE IS UPGRADED TO A TROPICAL STORM. THE
STRUCTURE OF KATIA IS CONSISTENT WITH THE 15-20 KT OF
EAST-NORTHEASTERLY SHEAR OVER THE CYCLONE ANALYZED BY THE SHIPS
MODEL AND UW-CIMSS. THIS SHEAR SHOULD DECREASE IN THE NEXT 12 HOURS
OR SO...AND AFTER THAT TIME STEADY INTENSIFICATION SHOULD COMMENCE
AS THE CYCLONE MOVES OVER PROGRESSIVELY HIGHER OCEAN HEAT CONTENT.
MOST OF THE INTENSITY GUIDANCE HAS TRENDED UPWARD THIS CYCLE...AND
THE OFFICIAL FORECAST HAS AS WELL. KATIA IS EXPECTED TO BE NEAR
HURRICANE STRENGTH WITHIN 36 TO 48 HOURS WITH CONTINUED
STRENGTHENING TO NEAR MAJOR HURRICANE STATUS BY THE END OF THE
PERIOD. THE NHC FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS THAT
INCLUDES THE HFIP INTENSITY AIDS.

A TIMELY AMSR-E PASS FROM 0326Z WAS HELPFUL IN LOCATING THE CENTER
ON THE EASTERN EDGE OF THE DEEP CONVECTION...WHICH WAS A BIT NORTH
OF PREVIOUS ESTIMATES. THE INITIAL MOTION ESTIMATE IS 290/15...AS
KATIA CONTINUES TO BE STEERED WEST-NORTHWESTWARD BY THE SUBTROPICAL
RIDGE TO ITS NORTH. THE MODEL GUIDANCE IS IN GOOD AGREEMENT ON A
CONTINUATION OF THIS GENERAL MOTION THROUGH THE PERIOD AS THE
MID-LEVEL RIDGE BUILDS WESTWARD TO THE NORTH OF THE CYCLONE. AT
DAYS 4 AND 5...THE WESTERN EDGE OF THE RIDGE BEGINS TO WEAKEN AS A
MID-LEVEL TROUGH AMPLIFIES OVER THE WESTERN ATLANTIC...WHICH SHOULD
RESULT IN SOME DECREASE IN FORWARD SPEED. THE TRACK GUIDANCE
REMAINS TIGHTLY CLUSTERED BUT THERE ARE SOME FORWARD SPEED
DIFFERENCES...WITH THE UKMET AND GFDL MODELS ON THE FAST SIDE OF
THE GUIDANCE AND THE GFS CONTINUING TO BE A SLOW OUTLIER. FOR THIS
CYCLE THE MODELS HAVE TRENDED FASTER DURING THE FIRST 72 HOURS...
AND SO HAS THE OFFICIAL FORECAST. OTHERWISE...THE NHC FORECAST IS
VERY CLOSE TO THE PREVIOUS ONE AND LIES NEAR OR A LITTLE TO THE
RIGHT OF THE TVCA MULTI-MODEL CONSENSUS THROUGH THE PERIOD.



Tropical Storm Katia 5 Day Track

Published on August 30, 2011 9:52 AM | Comments



Tropical Storm Katia Open Thread

Published on August 30, 2011 9:50 AM | Comments

Ask questions or leave comments about Tropical Storm Katia here.