FNUS70 PHFO 131908
FWSHFO

SPOT FORECAST FOR PRESIDENTS DAY
NATIONAL WEATHER SERVICE HONOLULU HI
908 AM HST FRI MAR 13 2009

IF CONDITIONS BECOME UNREPRESENTATIVE...PLEASE CONTACT
THE NATIONAL WEATHER SERVICE.

.DISCUSSION...LOW PRESSURE WELL NORTH OF THE AREA IS HAS WEAKENED
PRESSURE GRADIENTS IN THE VICINITY OF THE BIG ISLAND. THIS WILL ALLOW
FOR LIGHT WINDS AND SEA BREEZES ALONG THE SOUTHEAST COAST TODAY
AND LAND BREEZES DEVELOPING TONIGHT. WITH DRAINAGE WINDS...CLEARING
SKIES AND LIGHT WINDS...A NOCTURNAL INVERSION WILL LIKELY
DEVELOP TRAPPING HIGHER CONCENTRATIONS OF THE VOG NEAR THE
SURFACE FOR SOME AREAS EARLY...WHICH WILL LIKELY IMPROVE BY MID
MORNING AS DAYTIME MIXING BEGINS. OVERNIGHT INTO SATURDAY...THE
LOW WILL BEGIN TO MOVE WESTWARD ALLOWING FOR SOUTH WINDS TO
INCREASE...BUT STILL REMAIN GENERALLY ON THE LIGHTER SIDE
POTENTIALLY CARRYING VOG TO SOME OF THE MORE POPULATED AREAS
NORTH OF THE VOLCANO. THERE IS SUBSTANTIAL UNCERTAINTY REGARDING THE
ONSET AND INTENSITY OF THE SOUTHERLY FLOW AT THIS TIME.


.TODAY...
SKY/WEATHER.........PARTLY SUNNY. ISOLATED SHOWERS.
MAX TEMPERATURE.....AROUND 60.
MIN HUMIDITY........65 PERCENT.
20-FOOT WINDS.......VARIABLE WIND LESS THAN 6 MPH UNTIL 1 PM...THEN
                    SOUTHEAST AROUND 6 MPH.
MIXING HEIGHT.......3500 FT AGL.
TRANSPORT WINDS.....WEST 5 TO 10 MPH.

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY. ISOLATED SHOWERS.
MIN TEMPERATURE.....AROUND 46.
MAX HUMIDITY........100 PERCENT.
20-FOOT WINDS.......SOUTHWEST AROUND 6 MPH UNTIL MIDNIGHT...THEN NORTH
                    AROUND 7 MPH.
MIXING HEIGHT.......3500 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 5 TO 10 MPH.

.SATURDAY...
SKY/WEATHER.........PARTLY SUNNY. SCATTERED SHOWERS.
MAX TEMPERATURE.....AROUND 63.
MIN HUMIDITY........55 PERCENT.
20-FOOT WINDS.......SOUTH 8 TO 12 MPH.
MIXING HEIGHT.......3500 FT AGL.
TRANSPORT WINDS.....SOUTHWEST AROUND 20 MPH.


$$

FORECASTER...DEJESUS
REQUESTED BY...NPS
REASON FOR REQUEST...VOLCANIC EMISSIONS