Red Flag Warning 7, NWS Guam

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
801 AM CHST SUN MAY 8 2016

.SYNOPSIS...
PGUA DOPPLER WEATHER RADAR SHOWS ISOLATED TRADE-WIND SHOWERS
MOVING THROUGH THE MARIANAS WATERS. SHOWER COVERAGE UPSTREAM IS
SPARSE AND THIS DRIER WEATHER IS MOVING INTO THE ZONES. THE VAD
WIND PROFILE REVEALS EAST TO EAST-NORTHEAST WINDS OF 12 TO 22
KNOTS THROUGH THE LOWEST 10 THOUSAND FEET OF THE AIR. THE WEATHER
BALLOON FROM SATURDAY NIGHT REPORTED THAT WINDS BECAME VARIABLE
AROUND 10 KNOTS AT 20 THOUSAND FEET THEN BECAME WEST TO WEST-
SOUTHWEST AT 30 TO 50 KNOTS ABOVE 30 THOUSAND FEET.

&&

.DISCUSSION...
TROPICAL UPPER TROPOSPHERIC TROUGH WILL BE THE MAIN WEATHER
FEATURE FOR THE MARIANAS THIS WEEK. THE TUTT IS NOT PARTICULARLY
ACTIVE WITH RESPECT TO CONVECTION AT THIS TIME. MOSTLY IT IS
CAUSING A FIELD OF THICK AND JUICY CIRRUS TO LIFT NORTHWARD.
THEREFORE THE MAIN CHANGE TO THE FORECAST WAS TO MAKE TODAY PARTLY
SUNNY AND TONIGHT MOSTLY CLOUDY. LOWERED THE HIGH TEMPS TODAY BY 1
DEGREE DUE TO LESS INSOLATION.

&&

.FIRE WEATHER...
WINDS WILL BE THE MAIN FIRE WEATHER PROBLEM FOR TODAY. SHOULD BE
FAIRLY DRY AND THE DROUGHT INDEX IS NOW 770. THE NEXT FEW DAYS AT
LEAST ARE LOOKING PRETTY DRY...SO IT WILL INCREASE A BIT MORE AT
LEAST. IT COULD POSSIBLY EQUAL THE PEAK OF 779 IN 2010 AS EARLY AS
NEXT TUESDAY. WE HAVE A FIRE WEATHER WATCH OUT NOW...IF WINDS PICK
UP WE MAY NEED TO UPGRADE IT TO A RED FLAG WARNING.

&&

.EASTERN MICRONESIA...
TWO WEAK TRADE-WIND DISTURBANCES CAN BE SEEN ACROSS MICRONESIA
THIS MORNING...ONE DEPARTING CHUUK AND ANOTHER ONE APPROACHING
KOSRAE. RESIDUAL CONVERGENCE IN THE WAKE OF THE FIRST DISTURBANCE
WILL MAINTAIN A CHANCE OF THUNDERSTORMS NEAR CHUUK THRU THIS
EVENING. OTHERWISE...SURFACE RIDGING BETWEEN THESE TWO
DISTURBANCES SHOULD PROVIDE A BRIEF PERIOD OF FAIR WEATHER NEAR
BOTH CHUUK AND POHNPEI UNTIL MONDAY. FOR KOSRAE...THE SECOND
DISTURBANCE IS GOING TO TRIGGER OFF AND ON SHOWERS AND POSSIBLE
THUNDERSTORMS THRU TONIGHT.

FARTHER EAST...A TRADE-WIND CONVERGENCE ZONE PREVIOUSLY BETWEEN
3N AND 8N MEANDERING EASTWARD FROM 175E TO BEYOND 155W HAS BROKEN
UP INTO A SERIES OF WELL ORGANIZED TRADE DISTURBANCES. THE FIRST
ONE IS NEAR 177E AND SHOULD REACH THE MARSHALL ISLANDS LATE THIS
EVENING. THEREFORE EXPECT CONVECTION ASSOCIATED WITH THIS SYSTEM
TO SPREAD OVER MAJURO NEAR MIDNIGHT TONIGHT. AS THIS SYSTEM
GRADUALLY MOVES FARTHER WESTWARD...IT WILL TAKE ADVANTAGE OF
EXISTING DIVERGENT WINDS ALOFT TO TRIGGER MORE WET WEATHER FOR
KOSRAE AND POHNPEI ON MONDAY...CHUUK BY MONDAY EVENING. AT LEAST
THREE MORE TRADE DISTURBANCES FROM UPSTREAM EAST OF THE DATE LINE
WILL ALSO FOLLOW A SIMILAR PATH AND PROLONG UNSETTLED WEATHER
ACROSS ALL FOUR LOCATIONS THRU MIDWEEK.

&&

.WESTERN MICRONESIA...
REASONING FOR THE CHUUK FORECAST IS INCLUDED UNDER EASTERN
MICRONESIA ABOVE.

A SURFACE TROUGH EXTENDS NORTHWESTWARD FROM SOUTHWEST OF KOROR AT
EQ134E TO NEAR MINDANAO. CONVERGING TRADE WINDS EAST OF THIS
TROUGH ARE COMBINING WITH MOIST AIR AND DIVERGENT UPPER-LEVEL
WINDS TO FLARE UP SPORADIC CONVECTION JUST SOUTH OF KOROR AND YAP
THIS MORNING. DIVERGENT SOUTHERLY WINDS ALOFT WILL ADVECT THIS
CONVECTION NORTHWARD OVER KOROR BY THIS AFTERNOON...AND THEN YAP
THIS EVENING. THIS TREND IS ANTICIPATED TO CONTINUE THRU MONDAY
EVENING. AFTERWARD A FEW TRADE-WIND DISTURBANCES FROM THE EAST
WILL ARRIVE AND SUSTAIN LOCALLY HEAVY SHOWERS AND ISOLATED
THUNDERSTORMS FOR BOTH PLACES THRU MIDWEEK.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...FIRE WEATHER WATCH THROUGH MONDAY AFTERNOON FOR GUZ001.

MARIANAS WATERS...NONE.
&&

STANKO/CHAN