Flash Flood Warning 7, NWS Honolulu, HI

000 
WGHW70 PHFO 260203
FFSHI 
HIZ003-260400-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
358 PM HST SUN JAN 25 2004

...A FLASH FLOOD WARNING CONTINUES UNTIL 615 PM HST FOR MAUI...

AT 358 PM HST...WEATHER RADAR CONTINUED TO INDICATE VERY HEAVY 
RAINFALL NEAR HANA...KIHEI AND WINDWARD WEST SLOPES. THE HEAVY RAIN 
WAS SHOWING LITTLE MOVEMENT AND FLASH FLOODING IS EXPECTED TO 
CONTINUE IN THIS AREA.

WEATHER RADAR INDICATED THAT AS MUCH AS 4 INCHES OF RAIN MAY HAVE
FALLEN IN AND NEAR HANA WITHIN THE PAST 2 HOURS...WITH SLIGHTLY 
LESSER AMOUNTS ELSEWHERE.

REMINDER...A FLASH FLOOD WATCH ALSO REMAINS IN EFFECT FOR ALL 
HAWAIIAN ISLANDS.

STAY TUNED TO NOAA WEATHER RADIO...LOCAL TV OR RADIO FOR FURTHER
INFORMATION FROM THE NATIONAL WEATHER SERVICE.

$$
POWELL

000 
WGHW70 PHFO 260318
FFSHI 
HIZ003-260415-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
516 PM HST SUN JAN 25 2004

...THE FLASH FLOOD WARNING IS CANCELLED FOR MAUI...

WEATHER RADAR INDICATED THE HEAVY RAINFALL HAS ENDED ACROSS THE
WARNED AREA....AND THERE IS NO LONGER A THREAT FOR SERIOUS FLOODING.

RAINFALL WILL CONTINUE TO OCCUR OVER MAUI...AND RUNOFF WILL CONTINUE 
FOR THE NEXT FEW HOURS.

REMINDER...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL HAWAIIAN 
ISLANDS UNTIL 4 AM HST.

STAY TUNED TO NOAA WEATHER RADIO...LOCAL TV OR RADIO FOR FURTHER
INFORMATION FROM THE NATIONAL WEATHER SERVICE.

$$
POWELL

HAWAIIAN ISLANDS FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU
11 AM HST SUN JAN 25 2004

UPDATED TO INCLUDE KAUAI AND OAHU TO THE FLASH FLOOD WATCH AREA

.SYNOPSIS...
LINGERING INSTABILITY AND INCREASING MOISTURE WILL PROLONG THE
THREAT OF HEAVY SHOWERS AND THUNDERSTORMS INTO MONDAY AND POSSIBLY
TUESDAY. DRIER TRADE WIND WEATHER IS EXPECTED TO RETURN WEDNESDAY.

&&

.DISCUSSION...
AN UPPER TROUGH JUST WEST OF THE MAIN HAWAIIAN ISLANDS THIS MORNING
WILL MOVE SOUTHEASTWARD...DEEPEN...AND POSSIBLY CUT OFF INTO AN
UPPER LOW JUST SOUTHWEST OF OAHU OVER THE NEXT 48 HOURS. THIS WILL
KEEP THE AIRMASS OVER US UNSTABLE AND PLACE US BENEATH THE
UPLIFT...CONVECTION-INDUCING...PORTION OF THIS FEATURE. OVERNIGHT
SOUNDINGS SHOW THAT THE ATMOSPHERE IS ALREADY QUITE UNSTABLE...WITH
A LIFTED INDEX OF MINUS 9.2 NOTED AT HILO. MOISTURE IS ON THE
INCREASE AS WELL...WITH PRECIPITABLE WATER VALUES RISING AT BOTH
ENDS OF THE ISLAND CHAIN. ITS ALSO QUITE COLD ALOFT...WITH
TEMPERATURES OF MINUS 17 DEGREES C AT 500 MB ABOVE LIHUE. SATELLITE
LOOPS CORROBORATE THE INSTABILITY NOTED IN THE SOUNDING DATA...WITH
SHOWERY LOW CLOUDS AND ISOLATED THUNDERSTORMS SLOWLY WORKING THEIR
WAY WESTWARD ACROSS LOCAL WATERS EAST OF OAHU WITHIN SLUGGISH LOW
LEVEL FLOW. A COLD FRONT APPROACHING FROM THE NORTHWEST HAS A SECOND
AREA OF HEAVY SHOWERS AND THUNDERSTORMS WHICH WILL AFFECT THE
ISLANDS LATER THIS AFTERNOON AND OVERNIGHT TONIGHT. ANOTHER SURFACE
FEATURE IS A RIDGE OF HIGH PRESSURE WHICH EXTENDS WEST ALONG ABOUT
28N...INDUCING A STEEP ENOUGH PRESSURE GRADIENT TO PRODUCE THE WEAK
TRADES WHICH ARE BRINGING MOISTURE BACK INTO OUR WEATHER PICTURE.

IT IS THIS COMBINATION OF INSTABILITY AND INCREASING MOISTURE THAT
WILL LIKELY TRIGGER HEAVY SHOWERS AND THUNDERSTORMS ACROSS THE MAIN
ISLANDS LATER TODAY. THE ADDITIONAL FLOOD THREAT POSED BY THE
APPROACHING COLD FRONT PROMPTED AND EXPANSION OF THE FLOOD WATCH
AREA TO INCLUDE ALL OF THE MAIN HAWAIIAN ISLANDS AS OF 1045 AM HST.

BY WEDNESDAY...THE UPPER TROUGH WILL MOVE EAST OF THE BIG ISLAND AND
BEGIN TO FILL. THE SURFACE RIDGE WILL STRENGTHEN AT THE SAME
TIME...INDUCING DRIER MODERATE TRADE WIND FLOW.

&&

.SURF...
NO CHANGE IS EXPECTED IN THE SURF SITUATION WHERE THE SURF IS
EXPECTED TO REMAIN AT BORDERLINE ADVISORY LEVEL OF 15 FEET TODAY.

&&

.HNL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH......ALL HAWAIIAN ISLANDS
HIGH SURF ADVISORY.....NORTH AND WEST SHORES KAUAI OAHU MAUI
                       MOLOKAI AND LANAI
                       WEST FACING SHORES OF THE BIG ISLAND

&&

POWELL