Storm Summary for Tropical Storm Gil Advisory 3

Tuesday, July 30, 2013 at 5 PM HST

(Output from Hurrevac, based on National Hurricane Center Forecast Advisory # 3)

Tropical Storm Gil 3 is currently a tropical storm on the Saffir-Simpson Hurricane Wind Scale, with maximum sustained winds of 45 mph (40 kts), moving west-northwest at 15 mph. The estimated minimum central pressure is 1002 mb. Tropical storm-force winds extend outward up to 35 miles (55 km) from the storm center.

WTPZ32 KNHC 310251

TCPEP2

BULLETIN

TROPICAL STORM GIL ADVISORY NUMBER 3

NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013

800 PM PDT TUE JUL 30 2013

…TROPICAL STORM GIL GETTING BETTER ORGANIZED…

SUMMARY OF 800 PM PDT…0300 UTC…INFORMATION

———————————————-

LOCATION…13.1N 117.6W

ABOUT 845 MI…1360 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA

MAXIMUM SUSTAINED WINDS…45 MPH…75 KM/H

PRESENT MOVEMENT…WNW OR 285 DEGREES AT 15 MPH…24 KM/H

MINIMUM CENTRAL PRESSURE…1002 MB…29.59 INCHES

WATCHES AND WARNINGS

——————–

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK

——————————

AT 800 PM PDT…0300 UTC…THE CENTER OF TROPICAL STORM GIL WAS

LOCATED NEAR LATITUDE 13.1 NORTH…LONGITUDE 117.6 WEST. GIL IS

MOVING TOWARD THE WEST-NORTHWEST NEAR 15 MPH…24 KM/H. A

WEST-NORTHWESTWARD MOTION WITH A DECREASE IN FORWARD SPEED IS

EXPECTED OVER THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 45 MPH…75 KM/H…WITH HIGHER

GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS…

AND GIL COULD BECOME A HURRICANE BY THURSDAY.

TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 35 MILES…55 KM

FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB…29.59 INCHES.

HAZARDS AFFECTING LAND

———————-

NONE.

NEXT ADVISORY

————-

NEXT COMPLETE ADVISORY…200 AM PDT.

$$

FORECASTER STEWART

WTPZ42 KNHC 310255

TCDEP2

Storm Summary for Tropical Storm Gil #3 – Page 3

TROPICAL STORM GIL DISCUSSION NUMBER 3

NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013

800 PM PDT TUE JUL 30 2013

CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY CONTINUES TO SHOW

INCREASED ORGANIZATION OF BOTH THE INNER CORE CONVECTION AND

OUTER CONVECTIVE BANDING FEATURES. A RECENT AMSU OVERPASS AT

30/2227 UTC INDICATED A LARGE CURVED BAND OF CONVECTION WRAPPING

MORE THAN 70 PERCENT AROUND THE CIRCULATION CENTER. THE INITIAL

INTENSITY OF 40 KT IS BASED ON A BLEND OF SATELLITE INTENSITY

ESTIMATES OF T2.5/35 KT FROM TAFB AND ADT…AND A 2124 UTC AMSU

ESTIMATE OF 48 KT. UPPER-LEVEL OUTFLOW IS SYMMETRICAL AND

EXPANDING…WITH A WEAK POLEWARD OUTFLOW CHANNEL HAVING BECOME

BECOME ESTABLISHED SINCE THE LAST ADVISORY.

THE INITIAL MOTION ESTIMATE REAMINS 285/13 BASED ON VISIBLE AND

MICROWAVE SATELLITE FIX DATA. A MID-LEVEL RIDGE EXTENDS WESTWARD

FROM THE SOUTHWESTERN UNITED STATES ACROSS THE EASTERN NORTH PACIFIC

TO THE NORTH OF GIL. THIS VERY STABLE STEERING FLOW PATTERN IS

EXPECTED TO KEEP THE CYCLONE MOVING IN A GENERAL WEST-NORTHWESTWARD

MOTION FOR THE NEXT 3-4 DAYS…FOLLOWED BY A GRADUAL TURN TOWARD

THE WEST THEREAFTER. A GRADUAL DECREASE IN FORWARD SPEED IS

FORECAST BY 24-36 HOURS AS GIL APPROACHES A WEAKNESS IN THE

SUBTROPICAL RIDGE. THE OFFICIAL FORECAST IS BASICALLY JUST AN

UPDATE OF THE THE PREVIOUS ADVISORY TRACK…AND IS CLOSE TO BUT

SLIGHTLY SLOWER THAN THE MULTI-MODEL CONSENSUS TVCE.

BASED ON THE LAST FEW VISIBLE SATELLITE IMAGES SHOWING A CDO-LIKE

FEATURE DEVELOPING…PLUS THE PRONOUNCED BANDING FEATURE NOTED IN

THE LATEST AMSU MICROWAVE DATA…GIL APPEARS POISED TO STEADILY

INTENSIFY FOR AT LEAST THE NEXT 48 HOURS. GIVEN THE CURRENT OUTFLOW

PATTERN THAT IS FORECAST BY THE GFS MODEL TO CONTINUE TO DEVELOP

AND EXPAND…THE OFFICIAL INTENSITY FORECAST COULD BE TOO LOW.

REGARDLESS…OF THE DEVELOPMENT RATE…ENVIRONMENTAL CONDITIONS ARE

CONDUCIVE FOR AT LEAST MODEST STRENGTHENING TO OCCUR…AND THE

CYCLONE IS EXPECTED TO BECOME A HURRICANE BY 48 HOURS. AFTER A

SHORT LEVELING OFF PERIOD…GIL IS EXPECTED TO BEGIN A SLOW

WEAKENING TREND BY 96 HOURS AS THE CYCLONE MOVES OVER SLIGHTLY

COOLER WATER AND INTO A DRIER AND MORE STABLE AIRMASS. THE

INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE

TO A BLEND OF THE SHIPS AND LGEM STATISTICAL-DYNAMICAL MODELS.

FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 13.1N 117.6W 40 KT 45 MPH

12H 31/1200Z 13.6N 119.3W 50 KT 60 MPH

24H 01/0000Z 14.2N 121.5W 55 KT 65 MPH

36H 01/1200Z 14.7N 123.5W 60 KT 70 MPH

48H 02/0000Z 15.2N 125.5W 65 KT 75 MPH

72H 03/0000Z 15.9N 128.8W 65 KT 75 MPH

96H 04/0000Z 16.4N 132.0W 55 KT 65 MPH

120H 05/0000Z 16.5N 135.5W 45 KT 50 MPH

$$

FORECASTER STEWART

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