Storm Summary for Tropical Storm Flossie
Monday, July 29, 2013 at 2 AM HST
(Output from Hurrevac, based on Central Pacific Hurricane Center Forecast Advisory # 18A) Flossie is currently a tropical storm on the Saffir-Simpson Hurricane Wind Scale, with maximum sustained winds of 50 mph (43 kts), moving northwest at 16 mph. The estimated minimum central pressure is 1000 mb. Tropical storm-force winds extend outward up to 140 miles (220 km) from the storm center. Certain coastal locations are under Tropical Storm Warning and Tropical Storm Watch as illustrated in the map below. The geographic extents of these watches and warnings are detailed in the advisory text at the end of this report.

Wind Analysis for Maui, HI

(Based upon Tropical Storm Flossie Advisory #18A)

Wind Probabilities

LANAI CITY, the closest reporting location, has within the 5-day forecast period of this advisory, a 14%

chance of at least tropical storm-force (34kt/39mph) winds.

Peak Wind*

Winds in Maui, HI are projected to peak at 36kt/41mph around 2:00 PM on Monday, July 29, 2013

Wind Arrival and Duration*

Tropical storm-force winds (34kt/39mph) are forecast to begin in Maui, HI on Monday, July 29, 2013 at

12:00 PM. Winds of this magnitude or higher are forecast to continue for 8 hours.

50kt/58mph winds are not forecast for Maui, HI.

64kt/74mph winds are not forecast for Maui, HI.

* These wind estimations are limited to the first 72 hours (3 days) following advisory issuance, and are

subject to considerable forecast uncertainty and generalization, especially if the storm is distant.

Maximum sustained winds (the highest surface wind maintained over a 1 minute period) are reported

here. Wind gusts and winds at higher elevations will be greater.

Storm Summary for Tropical Storm Flossie #18A – Page 2

WTPA31 PHFO 291154

TCPCP1

BULLETIN

TROPICAL STORM FLOSSIE INTERMEDIATE ADVISORY NUMBER 18A

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062013

200 AM HST MON JUL 29 2013

…FLOSSIE CONTINUES TO BEAR DOWN ON THE MAIN HAWAIIAN ISLANDS…

SUMMARY OF 200 AM HST…1200 UTC…INFORMATION

———————————————-

LOCATION…19.6N 152.5W

ABOUT 165 MI…320 KM E OF HILO HAWAII

ABOUT 370 MI…650 KM ESE OF HONOLULU HAWAII

MAXIMUM SUSTAINED WINDS…50 MPH…85 KM/H

PRESENT MOVEMENT…W OR 280 DEGREES AT 16 MPH…26 KM/H

MINIMUM CENTRAL PRESSURE…1000 MB…29.53 INCHES

WATCHES AND WARNINGS

——————–

CHANGES WITH THIS ADVISORY…

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT…

A TROPICAL STORM WARNING IS IN EFFECT FOR…

*HAWAII COUNTY

*MAUI COUNTY…INCLUDING THE ISLANDS OF MAUI…MOLOKAI…LANAI AND

KAHOOLAWE

*OAHU

A TROPICAL STORM WATCH IS IN EFFECT FOR

*KAUAI AND NIIHAU

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE

EXPECTED WITHIN THE WARNING AREA WITHIN 36 HOURS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE

POSSIBLE WITHIN THE WATCH AREA WITHIN 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA…PLEASE MONITOR

PRODUCTS ISSUED THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN

HONOLULU.

DISCUSSION AND 48-HOUR OUTLOOK

——————————

AT 200 AM HST…THE CENTER OF TROPICAL STORM FLOSSIE WAS LOCATED

NEAR LATITUDE 19.6 NORTH…LONGITUDE 152.5 WEST. FLOSSIE IS

MOVING TOWARD THE WEST NEAR 16 MPH…28 KM/H. THIS MOTION IS

EXPECTED TO CONTINUE FOR NEXT 12 HOURS WITH A SLIGHT TURN TO THE

WEST NORTHWEST AFTER THAT.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH…85 KM/H…WITH HIGHER

GUSTS. SOME WEAKENING IS FORECAST DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 100 MILES…160 KM

Storm Summary for Tropical Storm Flossie #18A – Page 3

FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB…29.53 INCHES.

HAZARDS AFFECTING LAND

———————-

WIND…TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE BIG

ISLAND THIS MORNING…MAUI COUNTY BY LATE MORNING AND OAHU TONIGHT.

TROPICAL STORM CONDITIONS ARE POSSIBLE ON KAUAI AND NIIHAU

TONIGHT.

RAINFALL…HEAVY RAINFALL IS EXPECTED TO BEGIN THIS MORNING OVER

HAWAII COUNTY AND THIS AFTERNOON OVER MAUI COUNTY…WITH HEAVY RAIN

SPREADING TO OAHU TONIGHT. FLOSSIE IS EXPECTED TO PRODUCE TOTAL

RAINFALL AMOUNTS OF 6 TO 10 INCHES OVER THE BIG ISLAND AND MAUI

COUNTY…WITH ISOLATED MAXIMUM AMOUNTS OF 15 INCHES POSSIBLE…

MAINLY WINDWARD. RAINFALL AMOUNTS OF 4 TO 8 INCHES ARE POSSIBLE

OVER OAHU…WITH ISOLATED MAXIMUM AMOUNTS OF 12 INCHES POSSIBLE…

MAINLY WINDWARD. THIS RAINFALL COULD CAUSE LIFE-THREATENING FLASH

FLOODS AND MUD SLIDES…ESPECIALLY IN THE MOUNTAINS.

SURF…DANGEROUSLY HIGH SURF IS HAMMERING EAST FACING SHORES OF THE

BIG ISLAND. SURF WILL CONTINUE TO BUILD THIS MORNING WITH THE

LARGEST SURF CONTINUING INTO TUESDAY. THE BIG SURF MAY CAUSE

COASTAL ROAD CLOSURES…EVEN BEFORE THE STORM ARRIVES. PLEASE SEE

THE LATEST HURRICANE LOCAL STATEMENT FOR INFORMATION SPECIFIC TO

YOUR AREA.

NEXT ADVISORY

————-

NEXT COMPLETE ADVISORY…500 AM HST.

$$

FORECASTER DONALDSON

WTPA41 PHFO 290904

TCDCP1

TROPICAL STORM FLOSSIE DISCUSSION NUMBER 18

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062013

1100 PM HST SUN JUL 28 2013

SUBJECTIVE DVORAK ANALYSIS FROM PHFO…JTWC AND SAB ALL HAD FINAL

T-NUMBERS OF 2.5 AND CURRENT INTENSITIES OF 3.0. GOES SATELLITE

IMAGERY OVER THE PAST 6 HOURS HAS SHOWN A STEADY DECREASE IN COLD

CLOUD TOPS NEAR THE CENTER OF FLOSSIE. THIS TREND HAS CONTINUED

SINCE 0600 UTC AND THE LATEST IMAGERY SEEMS TO BE SHOWING AN EXPOSED

LOW LEVEL CIRCULATION CENTER EMERGING SOUTH OF THE REMAINING COLD

CLOUD TOPS. IT APPEARS THE CENTER MAY BE SOUTHWEST OF THE POSITIONS

FROM THE SYNOPTIC TIME DVORAK FIXES AND THE 0600 UTC BULLETIN

POSITIONS REFLECT THIS.

Storm Summary for Tropical Storm Flossie #18A – Page 4

FLOSSIE CONTINUES TO MOVE INTO AN UNFAVORABLE ENVIRONMENT…WITH DRY

AIR ALOFT AND NORTHERLY SHEAR ASSOCIATED WITH AN ANTICYCLONE ALOFT

NORTHWEST OF THE SYSTEM. WITH NO DEEP CONVECTION PERSISTING NEAR THE

CENTER OF THE SYSTEM…CONTINUED WEAKENING IS EXPECTED.

TRACK GUIDANCE REMAINS TIGHTLY CLUSTERED IN THE SHORT TERM…SHOWING

FLOSSIE NEAR THE BIG ISLAND MONDAY MORNING. GUIDANCE THEN SHOWS THE

TRACK SHIFTING TOWARD THE WEST NORTHWEST AS THE ANTICYCLONE ALOFT

SHIFTS EAST AND THE STEERING FLOW SHIFTS OUT OF THE EAST SOUTHEAST.

ONE FACTOR WHICH REMAINS UNCERTAIN IS THE IMPACT OF FLOSSIE MOVING

NEAR…OR PERHAPS DIRECTLY OVER…THE HIGH TERRAIN OF THE BIG ISLAND

OF HAWAII. HOWEVER…WE EXPECT FLOSSIE TO BE A MUCH WEAKER SYSTEM AT

THAT POINT.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 19.2N 152.1W 45 KT 50 MPH

12H 29/1800Z 19.4N 154.4W 40 KT 45 MPH

24H 30/0600Z 20.0N 158.0W 35 KT 40 MPH

36H 30/1800Z 20.2N 161.5W 30 KT 35 MPH

48H 31/0600Z 20.5N 164.5W 25 KT 30 MPH

72H 01/0600Z 22.0N 171.0W 25 KT 30 MPH

96H 02/0600Z 22.5N 176.0W 20 KT 25 MPH…POST-TROP/REMNT LOW

120H 03/0600Z…DISSIPATED

$$

FORECASTER DONALDSON

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