Flash Flood Warning 58, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST MON MAR 13 2006

.SYNOPSIS...A WETTER PATTERN WITH A THREAT OF HEAVY RAINFALL
 BEGINNING TONIGHT AND LASTING THROUGH MOST OF THE WEEK.
 TRADE WINDS TO WEAKEN AND TURN SOUTHEAST LATER TONIGHT.

&&

.DISCUSSION...SURFACE PRESSURES BEGAN DROPPING EARLIER THIS MORNING
 AND ARE NOW ONE TO TWO MILLIBARS LOWER THAN THEY WERE 24 HOURS AGO.
 THIS TREND SUPPORTS THE NOTION OF A DEEPENING SURFACE TROUGH TO THE
 WEST OF THE STATE MOVING OUR WAY. THE TROUGH IS EXPECTED TO BE
 REINFORCED BY LOW PRESSURE IMPULSES...OR TROUGHS...IN THE UPPER
 LEVELS AS THEY ALSO MOVE TOWARD THE ISLANDS. AS MENTIONED EARLIER
 THE FIRST IS EXPECTED TO PASS CLOSE TO THE ISLANDS TONIGHT. THIS
 WEAK ONE SHOULD BE FOLLOWED BY A SECOND DURING THE MIDDLE OF THIS
 WEEK AND A THIRD NEXT WEEKEND. ALSO THE APPROACHING SURFACE TROUGH
 SHOULD WEAKEN OUR TRADE WINDS AND TURN THEM MORE SOUTHEASTERLY.
 IT IS THIS DIRECTION THAT WOULD MAKE THE WINDWARD SIDE OF OAHU
 THE MOST VULNERABLE TO HEAVIER SHOWERS LATER TONIGHT. HOWEVER THE
 SOUTHEAST SIDE OF THE BIG ISLAND WILL LIKELY RECEIVE THEIR HEAVIEST
 RAINS UNTIL LATER IN THE WEEK WHEN THERE IS GREATER UPPER LEVEL
 ENHANCEMENT. SHORT TERM EASING IS EXPECTED AROUND FRIDAY BEFORE THE
 THE ARRIVAL OF THE THIRD UPPER TROUGH NEXT WEEKEND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
 FLASH FLOOD WATCH...ALL ISLANDS THRU THURSDAY.
 SMALL CRAFT ADVISORY...CANCELLED AT 4 PM TODAY.

&&

MATSUDA