Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans: Select a text product: Hawaiian Islands Synoptic Discussion and Guidance Hawaiian Islands Short Term Forecast Hawaiian Islands 7-day Zone Forecast Hydrologic Outlook Flash Flood Warning Flash Flood Watch Flash Flood Statement Tornado Warning Severe Weather Statement Severe Thunderstorm Warning Special Weather Statement Winter Storm Warnings/Watches/Advisories Urgent Weather Message Marine Weather Statement/High Surf Advisory/Warning Special Marine Warning Radar Message Special Messages Unknown Terminal Aerodome Foreasts (TAFS) Area Forecast for Hawaii and Adjacent Coastal Waters Upper-level Winds and Temperature Forecast for the 4 Major Hawaii AP AIRMETs for IFR Conditions, Turbulence, and Icing Thunderstorm SIGMETs Hawaiian Islands Satellite Interpetation Message Central/North Pacific Tropical Weather Outlook Central/North Pacific Tropical Weather Summary Central Pacific Tropical Cyclone Summary South Pacific Tropical Cyclone Summary Tropical Cyclone SIGMETs Buoy Winds and Wave Forecast Oahu Surf Observation and Forecast/Coastal Forecast for Hawaiian Waters Offshore Forecast for Hawaiian Waters North Pacific High Seas Forecast South Pacific High Seas Forecast Hawaiian Islands Automated Surface Observation System Hourly Weather Roundup Hawaiian Islands Wind Data Hawaiian Islands Rainfall Summary Hawaii Temperature and Precipitation Summary Daily Hawaii Cooperative Observations Honolulu AP Climate Summary Lihue AP Climate Summary Kahului AP Climate Summary Hilo AP Climate Summary Atlantic Tropical Cyclone Discussion Atlantic Tropical Weather Outlook East Pacific Tropical Cyclone Discussion East Pacific Tropical Weather Outlook Central Pacific Tropical Cyclone Discussion Central Pacific Tropical Weather Outlook West Pacific Tropical Cyclone Discussion West Pacific Tropical Weather Outlook 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 668 FXHW60 PHFO 191958 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST SUN MAY 19 2013 .SYNOPSIS... A SURFACE TROUGH WILL PRODUCE LIGHT WINDS AND A CHANCE OF LOCALLY HEAVY SHOWERS FROM OAHU TO THE BIG ISLAND TODAY. A WEAK FRONT WILL BRING NORTH WINDS AND SOME CLOUDS AND SHOWERS TO KAUAI TODAY...AND TO OAHU TONIGHT. THE TROUGH WILL GRADUALLY WEAKEN AS IT LINGERS NEAR THE ISLANDS THROUGH MID-WEEK. AS HIGH PRESSURE BUILDS NORTHEAST OF THE AREA...TRADE WINDS WILL SPREAD BACK OVER THE ISLANDS BY NEXT WEEKEND. HIGH SURF WILL CONTINUE ALONG THE SOUTH SHORES INTO MONDAY AND WILL REMAIN ELEVATED THROUGH MID-WEEK. && .DISCUSSION... A COMPLICATED WEATHER PATTERN PERSISTS OVER THE CENTRAL NORTH PACIFIC. WATER VAPOR IMAGERY A SHOWS LOW ALOFT NORTH OF THE ISLANDS. A NEARLY STATIONARY SURFACE TROUGH EXTENDS FROM NORTH NORTHEAST TO SOUTH SOUTHWEST OVER MAUI. A WEAK COLD FRONT JUST NORTH OF KAUAI IS MOVING SOUTH AT 10 TO 15 MPH. CLOUDS ARE ISOLATED OVER MOST AREAS FROM KAUAI TO LANAI THIS MORNING EXCEPT FOR BROKEN CLOUDS AND ISOLATED SHOWERS OVER THE NORTH SHORE OF KAUAI. CLOUDS HAVE INCREASED RAPIDLY OVER THE SLOPES OF MAUI AND THE BIG ISLAND SINCE THIS MORNING AND MOST AREAS ARE NOW CLOUDY. THERE ARE SCATTERED MODERATE SHOWERS OVER WATER NORTH AND SOUTH OF MAUI COUNTY AND OVERCAST CLOUDS AND NUMEROUS SHOWERS JUST SOUTHEAST OF THE BIG ISLAND. THE SHOWERS EAST OF MAUI ARE MOVING FROM THE SOUTH WHILE SHOWERS NEAR KAUAI ARE MOVING FROM THE NORTH. THE ATMOSPHERE OVER THE ISLAND REMAINS UNSTABLE BECAUSE OF THE LOW ALOFT. BALLOON SOUNDINGS FROM 200 AM SHOWED WEAK TEMPERATURE INVERSIONS AT 10000 FT AT LIHUE AND 14000 FT AT HILO...WITH PRECIPITABLE WATER VALUES OF 1.16 INCHES AT LIHUE AND 1.53 INCHES AT HILO. THE TROUGH NEAR MAUI WILL ALLOW SEA BREEZES TO FORM OVER THE ISLANDS FROM THE BIG ISLAND TO OAHU LATER TODAY...AND THERE WILL BE ENOUGH INSTABILITY FOR LOCALLY HEAVY SHOWERS ON THOSE ISLANDS. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS ON THE BIG ISLAND. THE WEATHER ON KAUAI WILL BE DIFFERENT. THE WEAK FRONT WILL MOVE OVER KAUAI...BRINGING SOME CLOUDS AND SHOWERS BUT THE COOL NORTHERLY FLOW BEHIND THE FRONT WILL MAKE THE ATMOSPHERE MORE STABLE AND PREVENT THE SHOWERS FROM BECOMING HEAVY. THE WEAKENING FRONT WILL BRING CLOUDS AND SHOWERS TO OAHU TONIGHT BEFORE DISSIPATING NEAR MOLOKAI MONDAY MORNING. THE SURFACE TROUGH WILL LINGER NEAR THE ISLANDS THROUGH MID-WEEK ALLOWING DAYTIME SEA BREEZES AND NIGHTTIME LAND BREEZES TO PREVAIL. THIS PATTERN WILL PRODUCE MOSTLY CLOUDY AFTERNOONS AND EVENINGS WITH SHOWERS CONCENTRATED OVER INTERIOR AREAS AND PARTLY CLEARING DURING THE OVERNIGHT HOURS. MODELS REMAIN IN GOOD AGREEMENT SHOWING THE TRADE WINDS BECOMING WELL-ESTABLISHED BY FRIDAY. THE CONVECTIVE PATTERN WILL END AND THE TRADES WILL BRING SHOWERS TO WINDWARD AND MAUKA AREAS. && .AVIATION... THE LIGHT WINDS WILL ALLOW WIDESPREAD SEA BREEZES TO DEVELOP FROM THE BIG ISLAND TO OAHU THIS AFTERNOON...WITH CLOUDS AND +SHRA OVER INTERIOR AND LEEWARD AREAS LEADING TO AREAS OF MVFR VIS/CIG. ISOL IFR CONDITIONS ARE ALSO POSSIBLE IN AREAS OF +SHRA...AND IN ISOL +TSRA OVER BIG ISLAND SLOPES THIS AFTERNOON. A WEAK COLD FRONT WILL BRING TEMPO MVFR CONDITIONS TO THE N SIDE OF KAUAI. && .MARINE... WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS STATEWIDE THIS WEEK. A SERIES OF SWELLS WILL KEEP ELEVATED SURF ALONG SOUTH FACING SHORES THROUGH MOST OF THE WEEK. SURF IS EXPECTED TO REMAIN ABOVE THE ADVISORY THRESHOLD THROUGH AT LEAST EARLY MONDAY MORNING. A MARINE WEATHER STATEMENT REMAINS POSTED FOR WAVES BREAKING NEAR CHANNEL ENTRANCES AND POSSIBLE HARBOR SURGES. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 6 AM HST MONDAY FOR SOUTH FACING SHORES OF ALL ISLANDS. && $$ DONALDSON 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