Winter Storm Warning 1, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST THU FEB 21 2013

.SYNOPSIS...
BREEZY AND GUSTY TRADE WINDS WITH PERIODS OF ENHANCED RAINFALL ARE
IN STORE FOR THE NEXT COUPLE OF DAYS. WHILE SHOWERS WILL BE CARRIED
TO LEEWARD SECTIONS AT TIMES...RAINFALL WILL BE FOCUSED ALONG
WINDWARD SLOPES...WITH THE GREATEST AMOUNT OF RAIN EXPECTED ON THE
BIG ISLAND AND MAUI WHERE FLOODING IS POSSIBLE. THE TRADES WILL
REMAIN RATHER STRONG THROUGH NEXT WEEK...WHILE A DRIER PATTERN OF
WINDWARD AND MAUKA SHOWERS DEVELOPS FROM WEST TO EAST DURING THE
WEEKEND.

&&

.DISCUSSION...
WET TRADE WIND WEATHER IS IN STORE FOR THE NEXT COUPLE OF DAYS...
WITH FLOODING RAINFALL LIKELY ON THE BIG ISLAND AND MAUI...MAINLY
WINDWARD. MID TO UPPER LEVEL TROUGHING EXTENDS JUST NORTH OF THE
STATE TODAY...CREATING MODERATELY UNSTABLE CONDITIONS. PRECIPITABLE
WATER /PW/ IS CURRENTLY NEAR NORMAL...ABOUT 1.1 INCHES ACCORDING TO
THE OVERNIGHT SOUNDINGS...BUT PW VALUES JUMP TO AROUND 1.5 INCHES
JUST EAST OF THE BIG ISLAND AND MAUI. THE UPPER TROUGH WILL SLOWLY
DROP SOUTHWARD TONIGHT...INCREASING INSTABILITY AS THE AREA EAST OF
THE STATE MOVES IN ON THE TRADE FLOW. AS A RESULT...EXPECT HEAVY
RAINFALL ALONG WINDWARD SLOPES OF ALL ISLANDS...WITH ABUNDANT
MOISTURE PROVIDING A FLOODING THREAT ON MAUI AND THE BIG ISLAND
THROUGH AT LEAST FRIDAY NIGHT. A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR THE BIG ISLAND AND MAUI FOR TONIGHT THROUGH FRIDAY NIGHT.

ALONG WITH THE FLOODING THREAT...HEAVY SNOWFALL IS EXPECTED ON THE
SUMMITS OF THE BIG ISLAND. ADVISORY LEVEL CONDITIONS ARE FORECAST
THERE FOR TODAY...AND A WINTER STORM WARNING HAS BEEN ISSUED FOR
TONIGHT AND FRIDAY. A WINTRY MIX IS POSSIBLE ON HALEAKALA
TONIGHT...BUT CONFIDENCE IS LOW.

THE GUSTY TRADE WINDS WILL CONTINUE THROUGH THE WEEK. A 1036 MB
HIGH CURRENTLY SITTING 1200 MILES NORTHEAST OF THE ISLANDS WILL
GRADUALLY WEAKEN OVER THE NEXT COUPLE OF DAYS...THOUGH LITTLE
CHANGE IN WINDS ARE EXPECTED. THE WIND ADVISORY FOR PORTIONS OF THE
BIG ISLAND HAS BEEN CANCELLED AS DECREASING STABILITY HAS LEAD TO
WEAKER GUSTS.

A DRIER TRADE WIND PATTERN WILL DEVELOP DURING THE WEEKEND FROM
WEST TO EAST. THE UPPER LEVEL TROUGH WILL SWING THROUGH...ALLOWING
INSTABILITY AND HEAVY SHOWERS CHANCES TO LINGER A BIT LONGER OVER
THE BIG ISLAND. BY SUNDAY...A TYPICAL TRADE WIND SHOWER PATTERN WILL
LIKELY DEVELOP.

&&

.MARINE...
GUSTY WINDS AND ELEVATED SEAS WILL PERSIST TODAY...CONTINUING TO
REQUIRE A SMALL CRAFT ADVISORY. WINDS WILL NOT CHANGE MUCH THROUGH
THE REST OF THE WEEK...SO THE ADVISORY LIKELY WILL BE EXTENDED
FURTHER.

THE HIGH SURF ADVISORY FOR TRADE WIND SWELL HAS BEEN EXTENDED INTO
FRIDAY MORNING...AND MAY NEED TO BE EXTENDED AGAIN.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 6 PM HST TODAY THROUGH 6 AM HST SATURDAY
FOR THE BIG ISLAND AND MAUI.

WINTER STORM WARNING FROM 6 PM HST TODAY THROUGH 6 PM HST FRIDAY
FOR BIG ISLAND SUMMITS.

WINTER WEATHER ADVISORY UNTIL 6 PM HST FRIDAY FOR BIG ISLAND
SUMMITS.

HIGH SURF ADVISORY UNTIL 6 AM HST FRIDAY FOR EAST-FACING SHORES OF
KAUAI...OAHU...MOLOKAI...MAUI...AND THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST FRIDAY FOR ALL HAWAIIAN
WATERS-

&&

WROE