889
AXPQ20 PGUM 010050
TWDPQ
TROPICAL WEATHER DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1050 AM CHST MON DEC 1 2025
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 TROPICAL DISTURBANCE, INVEST 93W, REMAINS AN OPEN TROUGH AT THE
SURFACE, WITH A MID-LEVEL ROTATION EVIDENT. LATEST LOCATION
PLACES THE DISTURBANCE NEAR 15N141E, WEST OF THE MARIANAS.
CONVECTION REMAINS UNORGANIZED WITH FLAREUPS OF CONVECTION ALONG
THE NORTHERN PORTION OF THE DISTURBANCE. ALTHOUGH SIGNIFICANT
DEVELOPMENT IS NOT EXPECTED AT THIS TIME, IT MAY START TO DEVELOP
A BROAD, LOW-LEVEL CIRCULATION AS IT MOVES WEST-NORTHWEST AND
PASSES NORTH OF YAP OVERNIGHT AND TUESDAY MORNING.
..OTHER WEATHER SYSTEMS
NEAR EQUATORIAL TROUGH...
THE NET STILL REMAINS ACROSS THE SOUTHERN HALF OF WESTERN
MICRONESIA, ENTERING THE REGION NEAR 5N130E TO A WEAK, ELONGATED
CIRCULATION ROUGHLY LOCATED NEAR 5N139E, THEN EXTENDS SOUTHEAST TO
MEET THE EQUATOR AT 154E. PATCHY, MODERATE CONVECTION IS FOUND
ACROSS THE WESTERN AND SOUTHERN PORTIONS OF THE NET, BUT INCREASES
TO SCATTERED TO NUMEROUS SHOWERS ON ITS NORTHEASTERN EDGE WHERE
IT COLLIDES WITH THE TRADE-WIND PATTERN AND WITH INVEST 93W TO THE
NORTH, ACROSS SOUTHERN AND WESTERN CHUUK STATE AND EASTERN YAP
STATE. THE NET COULD SEE A SLIGHT NORTHWARD BEND AS 93W MOVES
NORTH OF YAP AND PALAU OVER THE NEXT COUPLE DAYS.
TRADE-WIND TROUGHS...
A TRADE-WIND TROUGH EXTENDS NORTH FROM 93W, PASSING NEAR THE
WEST OF GUAM AND THE SOUTHERN CNMI TO END NEAR 26N146E, NEAR MAUG
IN THE FAR NORTHERN MARIANAS. THIS GENERATING SCATTERED TO
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE MARIANAS
AND OPEN WATERS TO THE WEST. THIS IS EXPECTED TO CONTINUE MOVE
WEST-NORTHWEST IN THE COMING DAYS, IN TANDEM WITH 93W.
ANOTHER TRADE-WIND TROUGH IS EMBEDDED IN THE ITCZ PATTERN, LOCATED
FROM 2N162E TO 6N179E. THIS IS HELPING TO SPREAD SHOWERS SOUTHWARD
ACROSS SOUTHERN KOSRAE STATE. THIS TROUGH IS EXPECTED TO PROPAGATE
WESTWARD INTO CENTRAL MICRONESIA IN THE NEXT COUPLE DAYS.
OTHER SYSTEMS...
A FRONTAL SYSTEM IS DRAPED ACROSS THE NORTHERN EXTENT OF OUR
REGION, EXTENDING AS A COLD FRONT FROM 23N180E, THEN TRANSITIONS
INTO A WEAK, STATIONARY FRONT AT 19N168E, NEAR WAKE, CURVES
NORTHWESTWARD TO 24N143E, NEAR IWO TO, WHERE IT CONTINUES AS A
WEAKENING SHEAR LINE TO 20N130E. WIDESPREAD CLOUDINESS AND
SCATTERED SHOWERS ARE FOUND WITHIN 200 MILES NORTH OF THE
BOUNDARY, WITH A FEW THUNDERSTORMS AT THE TAIL-END OF THE SHEAR
LINE. IN THE COMING DAYS THE SHEAR LINE WEST OF IWO TO LOOKS TO
WEAKEN FURTHER, BUT AS A HIGH PRESSURE SYSTEM PASSES TO THE
DISTANT NORTH, THE PRESSURE GRADIENT LOOKS TO DEEPEN BEHIND THE
FRONTAL BOUNDARY BETWEEN 150E AND 180.
..ITCZ
THE ITCZ EXTENDS INTO THE REGION AT 7N180, PASSING THROUGH MAJURO,
THEN EXTENDS WEST-SOUTHWEST TO KOSRAE, NEAR 5N162E. ANOTHER ITCZ
FRAGMENT IS ALSO BRINGING SHOWERS TO POHNPEI, FROM 7N161E TO
7N154E. THIS IS GENERATING SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS ACROSS MUCH OF EASTERN MICRONESIA. WITH A
BROADENING HIGH PRESSURE SYSTEM TO THE DISTANT NORTH IN THE COMING
DAYS, THE DEEPENING PRESSURE GRADIENT WILL ENHANCE THE TRADE-WIND
REGIME, BUT THE ITCZ IS EXPECTED TO RETREAT SOUTHWARD AND
BECOME FRAGMENTED.
IC
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