279
FXPQ50 PGUM 030815
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
615 PM CHST WED JUN 3 2020
MARIANAS SYNOPSIS
PARTLY CLOUDY SKIES, ISOLATED SHOWERS AND MODERATE TRADE WINDS ARE
PRESENT ACROSS THE MARIANAS. SEAS OF 2 TO 4 FEET ARE INDICATED AT THE
BUOYS.
DISCUSSION
MODELS HAVE CHANGED VERY LITTLE THE LAST COUPLE OF RUNS, AND SO THE
FORECAST IS UNCHANGED AS WELL. GFS STILL GRAZES GUAM WITH SCATTERED
SHOWERS ASSOCIATED WITH A TROUGH PASSING SOUTH OF GUAM ON SATURDAY,
AND ISOLATED THUNDERSTORMS ARE STILL POSSIBLE FOR THE MARIANAS
FRI-SAT. OTHERWISE, ONLY ISOLATED SHOWERS ARE EXPECTED OVER THE
NEXT WEEK, WITH LITTLE CHANGE IN WINDS.
MARINE
MODERATE TRADE WINDS AND 3-4 FT SEAS ARE EXPECTED TO CHANGE LITTLE
OVER THE NEXT WEEK, WITH A MODERATE RIP RISK REMAINING FOR EAST
FACING REEFS. AS NOTED ABOVE, ISOLATED THUNDERSTORMS ARE EXPECTED
FRI-SAT, WITH SCATTERED SHOWERS SATURDAY FOR GUAM WATERS.
EASTERN MICRONESIA AND CHUUK
GENTLE TO MODERATE TRADE WINDS ARE SEEN ACROSS THE REGION. A SURFACE
TROUGH IS ACROSS CHUUK STATE NEAR 152E AND A TRADE-WIND DISTURBANCE
IS APPROACHING KOSRAE FROM 165E. AT THE UPPER LEVELS, A LOW IS NEAR
SAIPAN AT 15N148E AND A HIGH IS EAST OF POHNPEI AT 8N160E. THESE
SYSTEMS WILL SUSTAIN DIVERGENT FLOW ACROSS CHUUK AND POHNPEI OVER THE
NEXT FEW DAYS.
THE SURFACE TROUGH WILL CONTINUE TO COUPLE WITH SOUTHERLY DIVERGENT
FLOW ALOFT TO TRIGGER SPORADIC CONVECTION NEAR CHUUK THRU THURSDAY
NIGHT. FARTHER EAST, THE TRADE DISTURBANCE SHOULD PROLONG PATCHY
SHOWERS AND A FEW THUNDERSTORMS NEAR POHNPEI THRU FRIDAY, AND KOSRAE
UNTIL THURSDAY EVENING. THIS SAME DISTURBANCE WILL ALSO SUSTAIN
INSTABILITY NEAR CHUUK THRU FRIDAY NIGHT. AFTER THE PASSAGE OF THESE
SYSTEMS, DRIER TRADE WINDS WILL USHER IN FAIR CONDITIONS FOR CHUUK
AND POHNPEI BY THIS WEEKEND, AND KOSRAE BY THURSDAY EVENING. THESE
SAME DRIER TRADES SHOULD CONTINUE TO DOMINATE MAJURO THRU SATURDAY.
THE ONLY EXCEPTION WILL BE FROM LATER TONIGHT THRU THURSDAY NIGHT IN
WHICH A WEAK SURFACE IMPULSE CAN SPARK A FEW SHOWERS. A BAND OF
CONVERGENT TRADE WINDS CAN BE SEEN BETWEEN 3N AND 5N FROM NEAR TARAWA
AND BUTARITARI ATOLLS AT 170E EASTWARD TO THE DATE LINE. THIS FEATURE
IS EXPECTED TO GRADUALLY SHIFT NORTHWESTWARD STARTING THIS WEEKEND
WHICH WILL BRING MORE SHOWERS TO MAJURO AND KOSRAE AROUND SUNDAY.
A MODERATE TRADE-WIND SWELL WILL MAINTAIN SEAS AT 4 TO 5 FEET ACROSS
THE ENTIRE REGION INTO EARLY NEXT WEEK.
WESTERN MICRONESIA FOR YAP AND KOROR
MAINLY GENTLE WINDS ARE SEEN ACROSS FAR WESTERN MICRONESIA THIS
AFTERNOON. A COUPLE OF WEAK IMPULSES ARE SEEN NEAR YAP AT 138E AND
FARTHER EAST AT 144E. AN UPPER-LEVEL TROUGH EXTENDS NORTHEASTWARD
FROM SOUTHWEST OF PALAU AT 4N130E ACROSS KOROR AND YAP TO BEYOND A
LOW NEAR SAIPAN AT 15N148E.
DESPITE THE PRESENCE OF MODEST DIVERGENCE ALOFT RELATED TO THE UPPER
FEATURES AND WEAK SURFACE IMPULSES, MUCH DRIER AIR ABOVE 650MB SHOULD
SUSTAIN PARTLY CLOUDY SKIES ABOVE YAP THRU THURSDAY NIGHT. FOR KOROR,
THE LACK OF DRIER AIR WILL ALLOW PERIODIC SHOWERS AND A FEW
THUNDERSTORMS TO FLARE UP THRU THURSDAY EVENING. MOST MODEL GUIDANCE
IS FORMING A NEAR-EQUATORIAL TROUGH SOUTH OF KOROR AND YAP NEAR 6N
LATE THURSDAY NIGHT AND FRIDAY, THEN GRADUALLY LIFTING NORTHWARD THRU
THE WEEKEND. UNDER THIS SCENARIO, SHOWER COVERAGE WILL INCREASE NEAR
KOROR STARTING THURSDAY NIGHT, AND YAP BY FRIDAY AFTERNOON. UNSTABLE
WEATHER IS GOING TO CONTINUE AT LEAST THRU EARLY NEXT WEEK. GENTLE TO
OCCASIONALLY MODERATE WINDS AND BENIGN SEAS ARE ANTICIPATED ACROSS
FAR WESTERN MICRONESIA INTO NEXT WEEK.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MARIANAS WATERS...NONE.
MIDDLEBROOKE/CHAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page