356
AXPQ20 PGUM 220059
TWDPQ
TROPICAL WEATHER DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1059 AM CHST FRI MAY 22 2026
TROPICAL WEATHER DISCUSSION FOR THE WESTERN NORTH PACIFIC BETWEEN
THE EQUATOR AND 25N FROM 130E TO 180. THE FOLLOWING INFORMATION IS
BASED ON RECENT SATELLITE IMAGERY/DATA, WEATHER OBSERVATIONS, RADAR,
AND METEOROLOGICAL ANALYSIS.
..SPECIAL FEATURES
TROPICAL AND MONSOON DISTURBANCES...
A FAIRLY TIGHT CIRCULATION JUST SOUTHWEST OF KOROR NEAR 6N133E.
CONVECTION CONTINUES TO FLARE UP ON THE WESTERN FLANK AND APPEARS
TO BE ELEVATED WITH A SLIGHTLY ELEVATED VORTICITY CENTER. A
SIMILAR CONVECTIVE BEHAVIOR IS ANTICIPATED THE NEXT FEW DAYS AS
THIS DISTURBANCE SLOWLY HEADS WEST.
THEN WE HAVE INVEST 99W (CURRENTLY RATED "SUB-LOW" BY JTWC) NEAR
7N148E, WHICH IS LOCATED NEAR PIKELOT, WITH A SLIGHT ELEVATED
VORTICITY CENTER ASSOCIATED WITH IT JUST WEST OF ONOUN. INVEST 99W
IS EXPECTED TO CONTINUE HEADING WEST NORTHWEST OVER THE NEXT FEW
DAYS WITH MINIMAL SURFACE CONVECTION CURRENTLY (FAIRLY ROBUST BUT
DISPLACED NORTHEAST OF THE LLCC/NORTH OF THE ELEVATED CENTER),
EXPECTED TO BECOME MORE ROBUST AND TIED TO THE LLCC DURING THE
NEXT 48 TO 96 HOURS SOMEWHERE BETWEEN GUAM AND YAP.
TO ADD TO THE MIX, WE HAVE NEWLY-FORMED/DESIGNATED INVEST 90W
LOCATED SOUTH OF KWAJALEIN NEAR 3N169E. FAIRLY DEEP CONVECTION
(AIDED BY AN ELEVATED CENTER JUST EAST OF THE LLCC) IS FOUND
AROUND THE LLCC. THIS SYSTEM IS ALSO EXPECTED TO DEVELOP AS IT
HEADS WEST-NORTHWEST TOWARDS THE MARIANAS EARLY NEXT WEEK.
..OTHER WEATHER SYSTEMS
NEAR-EQUATORIAL TROUGH...
THE NET ENTERS GUAM'S AOR AT 6N130E AND EXTENDS EASTWARD TO THE
LLCC SOUTHWEST OF KOROR. IT THEN CONTINUES EAST TO INVEST 99W WEST
OF CHUUK NEAR PIKELOT, TURNING SOUTHEAST AND PASSING THROUGH A
COL, SOUTHWEST OF POHNPEI NEAR NUKUORO, THEN CONTINUING TO INVEST
90W SOUTH OF KWAJALEIN/SOUTHEAST OF EBON, BEFORE ENDING AT EQ170E.
SPORADIC CONVECTION IS FOUND NEAR AND SOUTH OF THE NET WITH
VARYING DEGREES OF CONVECTIVE COVERAGE AND STRENGTH. OVERALL, THE
NET LOOKS TO BECOME MORE CONVECTIVELY ACTIVE IN THE NEXT FEW DAYS.
TRADE-WIND TROUGHS...
A TROUGH IN THE TRADES EXTENDS NORTH FROM INVEST 99W, ENDING EAST
OF GUAM NEAR 13N149E. SCATTERED SHOWERS, SOME LOCALLY INTENSE AS
EVIDENT BY CLOUD TOP TEMPERATURES SURPASSING -80 DEG.C, IS
ACCOMPANYING THIS FEATURE, WHICH LOOKS TO MOVE WEST AND BRING THE
MARIANAS AT LEAST SCATTERED SHOWERS OVER THE WEEKEND, WITH SOME
GUSTY WINDS PROBABLE AS WELL.
ANOTHER TROUGH EXTENDS NORTH FROM INVEST 90W TO ALINGLAPLAP, WITH
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUING TO DEVELOP.
THIS WILL CONTINUE TO BE THE CASE THROUGH EARLY NEXT WEEK AS THIS
TROUGH AND 0-W MOVE WEST-NORTHWEST.
..ITCZ
THE ITCZ IS WELL-ESTABLISHED NEAR 5N AND EXTENDS FROM THE TROUGH
AT 169E, EASTWARD TO THE DATE LINE AND BEYOND. WE EXPECT THE ITCZ
TO REMAIN CONVECTIVELY ACTIVE WITH FAIRLY ROBUST CONVECTION, AS
IT SPREADS WEST THROUGH EARLY NEXT WEEK.
DOLL
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