Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans: Select a text product: Narrow the Menu List Select Time Limit: 12 hours | 24 hours | 48 hours | 72 hours | No time limit Select Product Type: All | Routine Bulletins/FCSTS | Warnings/Watches/Advisories | HAWN Weather | Tropical | Marine | Aviation | Daily Obs | Special Hawaiian Islands Synoptic Discussion and Guidance 709 FXHW60 PHFO 200116 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 PM HST WED JUN 19 2013 .SYNOPSIS... A SURFACE RIDGE SEVERAL HUNDRED MILES NORTH OF THE STATE WILL DRIVE MODERATE TO LOCALLY BREEZY TRADE WINDS THROUGH THE WEEK. A TYPICAL SUMMERTIME RAINFALL PATTERN WILL FOCUS MODEST RAINFALL OVER WINDWARD SLOPES OF ALL ISLANDS...WHILE LEEWARD BIG ISLAND SLOPES SEE A FEW AFTERNOON SHOWERS. && .DISCUSSION... MODERATE TRADE WINDS WILL HOLD DURING THE NEXT COUPLE OF DAYS... WITH LOCALLY BREEZY WINDS SETTLING IN FOR THE WEEKEND. A NEARLY STATIONARY SURFACE RIDGE ABOUT 550 MILES NORTH OF THE ISLANDS IS DRIVING THE TRADE WIND FLOW. A COLD FRONT APPROACHING FROM THE NORTHWEST IS WEAKENING THE RIDGE SLIGHTLY...AND THE PRESSURE GRADIENT BETWEEN BUOYS 51101 AND 51003 REMAINS DOWN ABOUT 1 MB SINCE YESTERDAY. THE FRONT WILL PASS TO THE NORTH OVER THE NEXT COUPLE OF DAYS...WEAKENING THE PRESSURE GRADIENT OVER THE STATE A LITTLE MORE AND CAUSING TRADES TO DECLINE JUST A NOTCH. THE RIDGE WILL STRENGTHEN ON FRIDAY INTO THE WEEKEND...CAUSING WINDS TO BECOME LOCALLY BREEZY AGAIN. EXPECT A RATHER TYPICAL...TRADE WIND RAINFALL PATTERN TO CONTINUE TO FOCUS MODEST SHOWERS OVER WINDWARD SLOPES. AFTERNOON SOUNDINGS... AS WELL AS RECENT AIRCRAFT DATA...SHOW LOW TO MID LEVEL RIDGING MAINTAINING STABLE CONDITIONS WITH AN INVERSION IN THE 6500 TO 7500 FOOT RANGE AND PRECIPITABLE WATER VALUES AROUND THE JUNE AVERAGE. MODELS HINT AT LITTLE CHANGE DURING THE NEXT COUPLE OF DAYS. AN UPPER LEVEL TROUGH OVERHEAD IS NOT STRONG ENOUGH TO PRODUCE ANY LOW LEVEL INSTABILITY OVER THE ISLANDS...BUT IT WILL CONTINUE TO PRODUCE HIGH CLOUDS SKIRTING JUST EAST OF THE STATE. RIDGING ALOFT WILL BUILD IN FROM THE EAST DURING THE WEEKEND...POSSIBLY DECREASING POPS. IN ADDITION...AS THE UPPER TROUGH DEPARTS TO THE WEST...WE COULD SEE PERIODS OF HIGH CLOUDS SPREADING OVER THE ISLANDS. IN THE EXTENDED...TRADES ARE EXPECTED TO DROP SLIGHTLY DURING THE FIRST HALF OF THE NEW WORK WEEK AS A DEEPENING LOW IN THE FAR NORTHEAST PACIFIC WEAKENS THE RIDGE TO OUR NORTH. THE FRONT ASSOCIATED WITH THE LOW WILL DISSIPATE WELL BEFORE REACHING THE ISLANDS...BUT MODELS ARE HINTING THAT REMNANT MOISTURE COULD STALL NEAR KAUAI ON WEDNESDAY. WE ARE NOT CONFIDENT IN ANY SIGNIFICANT INCREASE IN SHOWERS. && .AVIATION... VFR WILL PREVAIL ACROSS MOST OF THE STATE. EXPECT ISOL MVFR CIGS OVER WINDWARD SLOPES AND POSSIBLY PHTO...MAINLY AT NIGHT. && .MARINE... WITH WINDS DOWN A NOTCH...THE SMALL CRAFT ADVISORY...SCA...HAS BEEN DROPPED...BUT IT WON/T STAY DOWN FOR LONG. BORDERLINE CONDITIONS WILL PREVAIL OVER THE TYPICALLY WINDY WATERS AROUND THE BIG ISLAND AND MAUI THROUGH THURSDAY AND POSSIBLY INTO FRIDAY. THE SCA FLAG WILL BE HOISTED AGAIN FOR THESE WATERS ON FRIDAY OR SATURDAY AS TRADES REBUILD FOR THE WEEKEND. NO SIGNIFICANT SWELLS ARE IN STORE. MODERATE AND ROUGH SURF WILL PERSIST ALONG WINDWARD SHORES. SMALL BACKGROUND SOUTH SWELLS WILL HOLD FOR THE NEXT FEW DAYS...FOLLOWED BY A MODERATE SOUTHEAST SWELL FOR SUNDAY INTO EARLY NEXT WEEK. A MODERATE SOUTH SOUTHWEST SWELL IS POSSIBLE BY THE MIDDLE OF NEXT WEEK. NORTH FACING SHORES SHOULD ALSO SEE A SMALL NORTHWEST SWELL MONDAY THROUGH WEDNESDAY. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WROE Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students. It was last modified on: Tue, Sep 21 2010 - 2314 UTC Send comments to: Ryan Lyman