Drought in Hawaii, November 8 to 30, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST TUE NOV 8 2011

.SYNOPSIS...
AN UPPER LEVEL LOW NEAR THE STATE WILL KEEP UNSETTLED WEATHER
THROUGH SATURDAY. SHOWERS WILL BE FOCUSED ACROSS WINDWARD AND MAUKA
AREAS... BUT WILL ALSO SPREAD LEEWARD AT TIMES. A STRONG HIGH
PRESSURE SYSTEM WILL PASS TO THE FAR TO THE NORTH WEDNESDAY
STRENGTHENING WINDS AT THAT TIME.

&&

.DISCUSSION...
AN UPPER LEVEL LOW LIES OVER THE EASTERN HALF OF THE HAWAIIAN
ISLANDS THIS MORNING. THE TROUGH IS EXPECTED TO REMAIN NEAR THE AREA
THROUGH SATURDAY AND WILL BE THE FOCUS OF THE UNSETTLED WEATHER
ACROSS STATE UNTIL THEN.

LATEST BALLOON SOUNDING SHOW MID-LEVEL INVERSIONS ON BOTH THE LIHUE
AND HILO PROFILES AT AROUND 7 TO 8 KFT. LIHUE IS DRY ALOFT AS IT IS
ON THE BACK SIDE OF THE TROUGH...WHILE THE HILO SOUNDING SHOWS SOME
MID-LEVEL MOISTURE NEAR THE LOW CORE INDICATIVE OF THE CURRENT CLOUD
COVER ACROSS THE BIG ISLAND THIS MORNING. BOTH SOUNDINGS SHOW STEEP
MID-LEVEL LAPSE RATES DUE IN PART TO UNSEASONABLY COLD MID-LEVEL
TEMPERATURES ASSOCIATED WITH THE UPPER LOW. THE 500MB TEMPERATURE
AT HILO WAS -14C AND AT LIHUE WAS -10C. PRECIPITABLE WATER /PW/
VALUES ARE AVERAGE AT LEAST AT THE LOW LEVELS WHICH...ALONG WITH
THE MID-LEVEL INVERSION...ARE THE REASON SHOWERS HAVE BEEN FAIRLY
LIGHT OVERNIGHT.

CLOUDS AND SHOWERS ARE EXPECTED TO REMAIN LIGHT THIS
MORNING...BREAKING UP SOMEWHAT AS CLOUD TOPS WARM AND HUMIDITIES
DECREASE. HIGHER PW...CLOUDS AND SHOWERS ALL ASSOCIATED FROM A
MID-LEVEL DISTURBANCE CROSSING THE BIG ISLAND AND MAUI WILL IMPACT
WINDWARD AREAS LATER THIS AFTERNOON AND EVENING. THE MOISTURE WILL
THEN SPREAD TO THE OTHER ISLANDS BY TONIGHT AND WEDNESDAY...BUT MAUI
AND THE BIG ISLAND WILL GET THE WORST BECAUSE THE INVERSION WILL
ERODE WITH THE PASSING DISTURBANCE. A SLIGHT CHANCE FOR
THUNDERSTORMS IS ALSO IN THE FORECAST TONIGHT AND WEDNESDAY MORNING
AS A RESULT.

ON WEDNESDAY...MODELS SHOW A PIECE OF ENERGY FROM THE NORTHERN
STREAM DIGGING DOWN THE BACKSIDE OF THE UPPER LOW...CAUSING IT TO
BUILD WESTWARD THROUGH FRIDAY. THIS TROUGH WILL ALSO BRING ANOTHER
SURGE OF COLDER MID-LEVEL TEMPERATURES...DESTABILIZING THE AIRMASS
ACROSS THE WESTERN SIDE OF THE STATE AGAIN. A BRIEF DRYING PERIOD
NEAR THE SURFACE COULD BRING A LULL IN SHOWER ACTIVITY WEDNESDAY
NIGHT AND THURSDAY FOR THE WESTERN HALF OF THE STATE...BUT OTHERWISE
PW VALUES WILL REMAIN A BIT ABOVE AVERAGE AFTER THAT FIRST PULSE
MOVES THROUGH TONIGHT AND WEDNESDAY. THE GFS AND ECMWF BOTH SHOW A
SURGE IN MOISTURE CENTERED AROUND THURSDAY NIGHT THROUGH SATURDAY
ASSOCIATED WITH THE REMAINS OF A DISSIPATED FRONT AND WILL BE
EXPECTING A GENERALLY WET PATTERN DURING THAT TIME.

AT THE SURFACE...WINDS WILL REMAIN FRESH TO LOCALLY STRONG TODAY.
HIGH PRESSURE FAR EAST NORTHEAST OF THE STATE WILL GIVE WAY TO A
STRONGER HIGH BUILDING IN FAR NORTH OF THE STATE TOMORROW. WINDS
ARE EXPECTED TO INCREASE ON WEDNESDAY AS A RESULT AND REMAIN STRONG
INTO FRIDAY...EVENTUALLY WEAKENING OVER THE WEEKEND. THE STRONGER
WINDS WILL RESULT IN MORE PASSING LEEWARD SHOWERS THE SECOND HALF OF
THE WEEK...ESPECIALLY THURSDAY NIGHT AND FRIDAY AS SURFACE MOISTURE
REMAINS HIGH.

&&

.AVIATION...
AIRMET TANGO REMAINS IN PLACE FOR LOW LEVEL TURBULENCE BLW 080 TO
THE S AND W OF THE TERRAIN ON ALL ISLANDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY /SCA/ DUE TO STRONG WINDS IS IN EFFECT FOR
THE TYPICALLY WINDIER WATERS NEAR MAUI COUNTY AND THE BIG ISLAND.
BEGINNING AT 600 PM HST ALL HAWAIIAN CHANNELS WILL BE UNDER THE SCA
AS TRADE WINDS GRADUALLY STRENGTHEN...AND WILL LIKELY INCLUDE ALL
COASTAL WATERS BY WEDNESDAY MORNING. A HIGH SURF ADVISORY MAY ALSO
BE NEEDED ALONG EAST FACING SHORES FOR ROUGH AND CHOPPY SURF LATE IN
THE WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST WEDNESDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM HST
WEDNESDAY FOR KAUAI CHANNEL-KAIWI CHANNEL.

&&

FOSTER