Area Forecast Discussion
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000
FXPQ60 PGUM 032151
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
751 AM CHST WED MAY 4 2016

.SYNOPSIS...
PGUA DOPPLER WEATHER RADAR SHOWS A FEW SHOWERS MOVING THROUGH THE
MARIANAS WATERS. THE VAD WIND PROFILE REVEALS EAST-NORTHEAST WINDS
OF 7 TO 16 KNOTS THROUGH THE LOWEST 6 THOUSAND FEET OF THE AIR.
THE WEATHER BALLOON FROM LAST EVENING SHOWS THE WINDS CHANGE TO
WEST-SOUTHWEST AT 10 TO 20 KNOTS ABOVE 20 THOUSAND FEET.

&&

.DISCUSSION...
RATHER DRY TRADE-WIND PATTERN REMAINS ENTRENCHED. WHILE THIS COULD
INDEED BE THE TURNING POINT OF THE DROUGHT...IT WILL STILL BE
QUITE SOME TIME BEFORE THE DROUGHT CAN HONESTLY BE DECLARED MOSTLY
OVER. IT MIGHT EVEN TAKE UNTIL SOMETIME DURING JULY. LITTLE CHANGE
IN FORECAST PHILOSOPHY...JUST EXTENDED THE GRIDS AND REFRESHED THE
WAVES. WAVES WILL EDGE UP A LITTLE THIS EVENING...NOTHING TO GET
ALARMED ABOUT THOUGH. THEY WILL STAY AT THESE LEVELS THROUGH THE
WEEKEND THEN EDGE BACK DOWN NEXT WEEK. THEY MAY THEN DECREASE A
LITTLE MORE AROUND THE MIDDLE OF NEXT WEEK.

&&

.FIRE WEATHER...
WFO GUAM JUST MISSED A WETTING RAIN YESTERDAY WITH 0.19 INCHES.
THIS MAKES OUR LOCAL KEETCH-BYRAM DROUGHT INDEX 766. IT IS
POSSIBLE SOME AREAS GOT A WETTING RAIN YESTERDAY AND IT MIGHT
LOCALLY BE LOWER. OVERALL...THE DRIER WEATHER TODAY MEANS THE
MITIGATION OF FIRE DANGER WILL BE SHORT LIVED UNLESS WE GET
ANOTHER SHOT OF RAIN SOON.

&&

.EASTERN MICRONESIA...
LATEST ASCAT ANALYSIS REVEALS A NEAR-EQUATORIAL TROUGH EXTENDING
SOUTHEASTWARD FROM WESTERN MICRONESIA THRU 3N150E TO END SOUTH OF
KOSRAE AT EQ163E. MODERATE TRADE-WIND CONVERGENCE NORTH OF THIS
FEATURE MIGHT BE ENHANCED BY A MID-LEVEL TROUGH IN THE VICINITY TO
TRIGGER A FEW SHOWERS AND THUNDERSTORMS NEAR POHNPEI AND KOSRAE OVER
THE NEXT COUPLE OF DAYS.

THE LEADING EDGE OF A FRESH TRADE-WIND SURGE...IN THE FORM OF A
TRADE DISTURBANCE IS MOVING THRU THE MARSHALL ISLANDS THIS MORNING.
EXPECT SHOWERS AND THUNDERSTORMS TO CONTINUE NEAR MAJURO UNTIL LATER
THIS AFTERNOON. AFTER THE PASSAGE OF THIS DISTURBANCE BY TONIGHT...
SLIGHTLY DRIER TRADES SHOULD DECREASE SHOWER COVERAGE THERE. AS THIS
SAME DISTURBANCE GRADUALLY PULLS FARTHER WESTWARD...IT WILL INTERACT
WITH THE NEAR-EQUATORIAL TROUGH AND BRING MORE SHOWERS AND
THUNDERSTORMS TO KOSRAE AND POHNPEI TOWARD THIS WEEKEND. A SERIES OF
TRADE DISTURBANCES ARE VISIBLE UPSTREAM EAST OF THE DATE LINE. THESE
SYSTEMS MIGHT INTRODUCE MORE WET WEATHER TO MAJURO THIS WEEKEND.

&&

.WESTERN MICRONESIA...
A NEAR-EQUATORIAL TROUGH IS ANTICIPATED TO STAY NEAR 3N SOUTH OF ALL
MAJOR FORECAST POINTS FOR THE NEXT SEVERAL DAYS. THIS SHOULD ALLOW
MUCH DRIER MODERATE TRADES TO MAINTAIN FAIR CONDITIONS NEAR KOROR
AND YAP AT LEAST THRU THURSDAY NIGHT. THERE IS A CHANCE THAT MID-
LEVEL WINDS WILL SHIFT TO THE SOUTHEAST BY THIS WEEKEND. IF SO...
THEY MIGHT ADVECT MOISTURE NORTHWARD OVER BOTH LOCALES AND INCREASE
SHOWER ACTIVITY. FOR CHUUK...A TRADE-WIND DISTURBANCE HAS BEEN
TEAMING UP WITH DIVERGENT UPPER WINDS TO TRIGGER SPORADIC
CONVECTION. HOWEVER...LATEST SATELLITE LOOP INDICATES A WEAKENING
TREND ON THIS CONVECTION. THERE WAS NO EVIDENCE ON THE LATEST
SOUNDING YET BUT MODEL GUIDANCE IS SUGGESTING A DRY AIR INTRUSION
FROM THE NORTH. THEREFORE...HAVE TRIMMED BACK SHOWER COVERAGE BUT
KEPT THUNDERSTORMS IN THE CHUUK FORECAST UNTIL THURSDAY MORNING.
DURING THIS WEEKEND...ANOTHER TRADE DISTURBANCE CURRENTLY NEAR THE
MARSHALL ISLANDS COULD AFFECT CHUUK AS WELL.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...NONE.
&&

$$

STANKO/CHAN



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