Drought in Hawaii, July 21 to 31, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST TUE JUL 21 2015

.SYNOPSIS...
LIGHT WINDS ARE EXPECTED ACROSS THE STATE THROUGH
WEDNESDAY...ALLOWING LOCALIZED LAND AND SEA BREEZES. THE LIGHTER
WINDS WILL BRING A GREATER CHANCE OF AFTERNOON CLOUDS AND SHOWERS
OVER LEEWARD AND INTERIOR PORTIONS OF ALL ISLANDS. A DEVELOPING LOW
ALOFT JUST NORTHWEST OF THE ISLANDS MAY HELP TO ENHANCE SHOWERS OVER
THE AREA FOR THE NEXT COUPLE OF DAYS. TRADE WINDS WILL SLOWLY
STRENGTHEN DURING THE SECOND HALF OF THE WEEK...WITH SHOWERS ONCE
AGAIN FOCUSED OVER WINDWARD AREAS.

&&

.DISCUSSION...
TRADE WINDS CONTINUE TO BE ON THE DECLINE EARLY THIS MORNING...WITH
LIGHT LAND BREEZES DEVELOPED MAINLY OVER THE LEE AREAS OF THE
ISLANDS. GENERAL SYNOPTIC WIND FLOW APPEARED TO TURN A LITTLE MORE
SOUTHEAST...AND AS SUCH MOISTURE HUNG UP ALONG THE KOOLAUS EARLY
THIS MORNING. A PERSISTENT CELL HAS BEEN DUMPING QUITE A BIT OF RAIN
OVER MAUNAWILI AREA SINCE THE PAST COUPLE OF HOURS AND THERE IS NO
SIGN OF LETTING UP AT THIS TIME. THIS ON-GOING SITUATION NEEDS
CLOSE MONITORING...AS THE THREAT OF FLOODING FOR THAT GENERAL AREA
IS INCREASING. THE AIRMASS IN THE ISLAND VICINITY IS SLIGHTLY
UNSTABLE...AS AN UPPER LEVEL LOW DEVELOPS JUST NORTHWEST OF THE
ISLANDS
AND WILL PERSIST FOR THE NEXT COUPLE OF DAYS. WITH A BIT OF MOISTURE
PRESENT IN THE ISLAND VICINITY TODAY...EXPECT LOCALLY ENHANCED
SHOWERS TO AFFECT THE ISLANDS AT TIMES. MORE WIDESPREAD SEA BREEZES
ARE TO DEVELOP OVER THE ISLANDS LATER TODAY...WITH A SLIGHT CHANCE
OF AFTERNOON THUNDERSTORMS OVER THE BIG ISLAND...MAINLY OVER THE
WESTERN PORTION.

NOT MUCH CHANGES IN THE WEATHER SCENARIO IS EXPECTED WEDNESDAY...SO
THE ISLANDS CAN EXPECT TO SEE PRETTY MUCH A REPEAT OF TODAY
WEATHER...WITH MORE WIDESPREAD LAND AND SEA BREEZES AND AFTERNOON
CLOUDS AND SHOWERS. STILL EXPECT A SLIGHT CHANCE OF AFTERNOON
THUNDERSTORMS MAINLY OVER WESTERN PORTION OF THE BIG ISLAND.

BY THURSDAY...THE PRESSURE GRADIENT ACROSS THE STATE WILL
SLOWLY TIGHTEN. THE ISLANDS WILL SEE A RETURN OF STRONGER
TRADE WINDS BY LATE THURSDAY. AS THE WINDS STRENGTHEN...THE SHOWERS
WILL ONCE AGAIN BECOME FOCUSED OVER WINDWARD AND MAUKA AREAS.
THE LONG RANGE GUIDANCE CONTINUE TO HINT MOISTURE ASSOCIATED WITH
THE REMNANTS OF FORMER EAST PACIFIC TROPICAL CYCLONE ENRIQUE MAY
REACH THE ISLANDS DURING THE WEEKEND. IF SO...AN INCREASE IN SHOWERS
AS WELL AS HUMIDITY WITH A DECREASE OF TRADE WINDS MAY BE IN STORE
FOR THE STATE OVER THE WEEKEND.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT THE TERMINALS TODAY. HOWEVER...CLOUD
COVER EXPECTED TO INCREASE ACROSS MOUNTAINOUS TERRAIN LATER TODAY
MAY PRODUCE LOCAL AND BRIEF MVFR OR LOWER CONDITIONS LATER AS IT
SLOUGHS OFF ACROSS ADJACENT WATERS. AIRMET SIERRA FOR MOUNTAIN
OBSCURATION IN EFFECT FOR MAUI AND THE BIG ISLAND WILL LIKELY BE
CANCELLED LATER THIS MORNING.

&&

.MARINE...
WINDS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY /SCA/
CRITERIA THROUGH THURSDAY. AS THE TRADES STRENGTHEN BY LATE
THURSDAY...SCA WIND CONDITIONS MAY OCCUR OVER THE TYPICAL WINDIER
LOCATIONS NEAR MAUI AND THE BIG ISLAND.

SURF ALONG EAST FACING SHORES WILL REMAIN ELEVATED THROUGH
THURSDAY...PEAKING WEDNESDAY...AS A NEW NE SWELL ARRIVES WHILE THE
EXISTING EAST SWELLS CONTINUE. SURF FOR EAST FACING SHORES IS
EXPECTED TO INCREASE TO JUST BELOW ADVISORY LEVELS THROUGH WEDNESDAY.

A PERSISTENT STORM SYSTEM IN THE SOUTH PACIFIC EAST OF NEW ZEALAND
DEVELOPED A COUPLE OF DAYS AGO HAS BEEN GENERATING LARGE SWELL
TOWARD HAWAII. THIS SWELL IS ANTICIPATED TO ARRIVE IN HAWAII FRIDAY
AND WILL LIKELY BE LARGE ENOUGH TO BRING ADVISORY LEVEL SURF HEIGHTS
ALONG SOUTH FACING SHORES THIS WEEKEND. PLEASE REFER TO THE SURF
DISCUSSION /SRDHFO/ DISCUSSION FOR MORE DETAILS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

DISCUSSION/MARINE...HUI
AVIATION...POWELL