Saturday, September 01, 2007

Sea to Shining Sea (Henriette in E-Pac, Felix in Atlantic)

Felix has a good chance of taking about the same track as Dean, as a hurricane. Bad news for Belize and the Yucatan. Henriette is still tracking right up the coast, and depending on steering will either make the weather very interesting in Baja and Southern California starting Tuesday or so, or it won't. Recreational boaters in these waters definitely need to watch Henriette.

Both storms will affect Mexico. Mexican military ALE and amateur relief frequencies may light up. It's a good chance to practice your Spanish.

Henriette:

000
WTPZ41 KNHC 011444
TCDEP1
TROPICAL STORM HENRIETTE DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112007
800 AM PDT SAT SEP 01 2007

THE CLOUD PATTERN REMAINS LARGE BUT HAS NOT CHANGED VERY MUCH IN ORGANIZATION AND THE CENTER CONTINUES TO BE DIFFICULT TO LOCATE. DVORAK T-NUMBERS SUGGEST THAT THE INITIAL INTENSITY REMAINS AT 45 KNOTS. THE CIRCULATION IS BEGINNING TO MOVE AWAY FROM LAND AND BOTH SHEAR AND SEA SURFACE TEMPERATURES ARE CONDUCIVE FOR STRENGTHENING. THEREFORE...THE OFFICIAL FORECAST CALLS FOR A GRADUAL INTENSIFICATION AND HENRIETTE IS FORECAST TO BECOME A HURRICANE IN A DAY OR SO.

HENRIETTE HAS BEEN MOVING ON A STEADY WEST-NORTHWEST TRACK OR 295 DEGREES AT 10 KNOTS. THE RIDGE TO THE NORTH IS FORECAST TO EXPAND A LITTLE DURING THE NEXT DAY OR TWO AND THIS PATTERN COULD FORCE THE CYCLONE TO MOVE TEMPORARILY ON MORE WESTERLY TRACK. THEREAFTER...THE RIDGE WEAKENS AND THE FORECAST BECOME HIGHLY UNCERTAIN. ONCE AGAIN A GROUP OF TRACK MODELS BRING THE CYCLONE WELL WEST OF BAJA CALIFORNIA WHERE THE OCEAN IS COOLER RESULTING IN A GRADUAL WEAKENING. ANOTHER GROUP OF MODELS BRINGS HENRIETTE OVER BAJA CALIFORNIA OR EVEN THE GULF OF CORTES WHERE THE WATER IS WARM AND STRENGTHENING COULD CONTINUE. THE OFFICIAL FORECAST OPTED FOR THE FIRST OPTION AND KEEPS HENRIETTE WEST OF BAJA CALIFORNIA AND WEAKENING. THIS IN FACT...SIMILAR TO THE PREVIOUS OFFICIAL FORECAST.


FORECAST POSITIONS AND MAX WINDS

INITIAL 01/1500Z 17.8N 104.3W 45 KT
12HR VT 02/0000Z 18.5N 105.7W 50 KT
24HR VT 02/1200Z 19.2N 107.4W 60 KT
36HR VT 03/0000Z 19.5N 109.0W 65 KT
48HR VT 03/1200Z 20.0N 110.5W 70 KT
72HR VT 04/1200Z 21.5N 113.0W 70 KT
96HR VT 05/1200Z 23.0N 114.1W 60 KT
120HR VT 06/1200Z 26.0N 115.5W 50 KT

$$
FORECASTER AVILA


Felix:

000
WTNT41 KNHC 011444
TCDAT1
TROPICAL STORM FELIX DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062007
1100 AM EDT SAT SEP 01 2007

RADAR IMAGES FROM MARTINIQUE INDICATED THE CENTER PASSED VERY NEAR GRENADA OVERNIGHT...WITH THE ISLAND OBSERVING 1005 MB BEFORE THE WEATHER STATION STOPPED REPORTING. SINCE THAT TIME...SATELLITE AND RADAR DATA INDICATE THAT FELIX IS FORMING A SMALL INNER CORE WITH TIGHTLY-WOUND BANDS AROUND THE CENTER. IN FACT...AN AIR FORCE PLANE JUST MADE IT TO THE CENTER AND REPORTED FLIGHT LEVEL WINDS OF 69 KT...CORRESPONDING TO ABOUT 55 KT AT THE SURFACE...AND 55 KT WILL BE USED AS THE INITIAL INTENSITY.

ALL ATMOSPHERIC AND OCEANIC PARAMETERS SUPPORT A CONTINUED STRENGTHENING OF THE STORM. WITH SUCH A FAVORABLE ENVIRONMENT...IT IS LIKELY THAT FELIX WILL BECOME A POWERFUL HURRICANE BY THE TIME IT REACHES THE NORTHWESTERN CARIBBEAN SEA. THE GFDL/HWRF ONLY SLOWLY INTENSIFY THE SYSTEM...BUT THE SHIPS/LGEM MODELS SUGGEST THIS STORM COULD BE A MAJOR HURRICANE IN ABOUT 3 DAYS. THE NHC INTENSITY FORECAST GOES WITH THE LATTER SCENARIO AND IS JUST A LITTLE LOWER THAN THE STATISTICAL MODELS FOR THIS FORECAST PACKAGE.

FELIX HAS BEEN MOVING BASICALLY TO WEST FOR THE PAST 6-12 HOURS AND MY INITIAL MOTION ESTIMATE IS 270/16. A STRONG RIDGE IS FORECAST TO STEER THE STORM A LITTLE NORTH OF DUE WESTWARD FOR THE NEXT FEW DAYS. TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO. BEYOND 3 DAYS...THERE IS A QUESTION OF HOW MUCH RIDGING WILL BE PRESENT IN THE GULF OF MEXICO. A FEW MODELS HAVE ENOUGH OF A WEAKNESS IN THE RIDGE TO FORCE A WEST-NORTHWEST OR NORTHWEST MOTION NEAR THE END OF THE PERIOD. HOWEVER...THE RELIABLE GFS/ECMWF ARE KEEPING A STRONG RIDGE. THE OFFICIAL FORECAST IS A LITTLE SOUTH OF THE PREVIOUS ONE DUE TO THE WESTWARD MOTION EARLY ON...BUT THEN IS VERY CLOSE TO THE PREVIOUS FORECAST BY THE END OF THE PERIOD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/1500Z 12.3N 63.6W 55 KT
12HR VT 02/0000Z 12.8N 66.1W 60 KT
24HR VT 02/1200Z 13.4N 69.4W 65 KT
36HR VT 03/0000Z 14.1N 72.9W 70 KT
48HR VT 03/1200Z 14.8N 76.2W 80 KT
72HR VT 04/1200Z 16.0N 82.0W 90 KT
96HR VT 05/1200Z 17.0N 87.0W 100 KT
120HR VT 06/1200Z 18.5N 91.5W 55 KT...INLAND

$$
FORECASTER BLAKE/AVILA