958
FXCA20 KWBC 091631
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1230 PM EDT THU MAY 09 2024

FORECAST BULLETIN 09 MAY 2024 AT 1700 UTC:

A LARGE MID-UPPER TROUGH IS DEEPENING ACROSS THE WESTERN USA. THE
INFLUENCE OF A ROBUST MID-LEVEL RIDGE EXTENDING ACROSS SOUTHWEST
MEXICO INTO SOUTH FLORIDA IS LIMITING THE PROGRESSION OF THIS
UPPER TROUGH INTO PORTIONS OF NORTHERN MEXICO. HOWEVER...THE RIDGE
IS FORECAST TO START MEANDERING EASTWARD LATE DURING THE
WEEKEND...WHICH WILL ALLOW FOR A SLOW PROGRESSION OF THE UPPER
TROUGH AND SLIGHTLY WETTER CONDITIONS IN NORTHEAST MEXICO
DEVELOPING DURING THE WEEKEND. A SURFACE FRONT WILL ALSO PLAY A
ROLE. THE FRONT IS FORECAST TO REACH NORTHERN COAHUILA BY FRIDAY
EVENING...TO THEN BECOME STATIONARY JUST TO THE NORTH OF
BROWNSVILLE BY SATURDAY. THIS WILL HIGHLIGHT MOISTURE CONVERGENCE
TO FAVOR 05-10MM/DAY AND MAXIMA OF 15-25MM ON FRIDAY AND SATURDAY.

THE WET SPELL IN THE CENTRAL AND NORTHEAST CARIBBEAN THIS WEEK IS
STARTING TO WANE...AS A DRIER AIR MASS IN THE MID/UPPER LEVELS
MOVES IN FROM THE NORTHEAST. HOWEVER...THE UPPER TROUGH PATTERN IS
FORECAST TO HOLD ACROSS PUERTO RICO AND THE LEEWARD ISLANDS
THROUGH SATURDAY...WHICH WILL FAVOR AN ENHANCEMENT OF DEEP-LAYER
INSTABILITY. FURTHERMORE...LIMITED CLOUD COVER WILL PLAY A ROLE IN
ENHANCING DIURNAL HEATING. IN A 50MM+ PRECIPITABLE WATER
ENVIRONMENT...EXPECT STRONG AFTERNOON THUNDERSTORMS ON THURSDAY
AND FRIDAY. ON THURSDAY...EXPECT MAXIMA OF 25-50MM IN INTERIOR
PORTIONS OF PUERTO RICO...WHILE IN EASTERN HISPANIOLA EXPECT
MAXIMA OF 20-45MM. ON FRIDAY...EXPECT MAXIMA OF 20-40MM IN PUERTO
RICO. AMOUNTS DECREASE THEREAFTER.

SEASONALLY ACTIVE CONVECTION IS EXPECTED IN NORTHERN SOUTH AMERICA
AND SOUTHERN CENTRAL AMERICA. THE KEY ENHANCING FACTORS WILL BE
ACTIVE EASTERLY WAVES...WHICH ARE PROPAGATING ALONG THE NET. THE
BASE OF A MID-LEVEL TROUGH EXTENDING ACROSS THE EASTERN CARIBBEAN
INTO NORTHERN VENEZUELA WILL PROVIDE ADDITIONAL LOCAL ENHANCEMENT.
ON THURSDAY...THE HEAVIEST PRECIPITATION IS EXPECTED IN EASTERN
COLOMBIA AND SOUTHWEST VENEZUELA AS AN EASTERLY WAVE AND THE NET
INTERACT IN A MOIST POOL OF 60+MM OF PRECIPITABLE WATER. ALSO ON
THURSDAY...VENTILATION ALONG THE SOUTHERN FRINGES OF A CELL OF THE
SUBEQUATORIAL RIDGE WILL FAVOR HIGH ACCUMULATION FROM FRENCH
GUIANA/AMAPA INTO SOUTHEAST VENEZUELA. EXPECT MAXIMA OF 75-125MM
WITH AN EASTERLY COASTAL AREAS DUE TO ITCZ CONVERGENCE AND AN
EASTERLY WAVE...AND MAXIMA GENERALLY IN THE 30-60MM/DAY RANGE IN
AREAS WEST. ON FRIDAY...EXPECT THE HEAVIEST IN NORTHERN COLOMBIA
AND NORTHWEST VENEZUELA...WHERE MAXIMA IS LIKELY TO REACH 40-80MM.
ON SATURDAY...ENHANCED MOIST ONSHORE FLOW ALONG THE ATLANTIC ITCZ
AND INCREASED CYCLONIC VORTICITY IN THE LOWER TROPOSPHERE WILL
LIKELY FAVOR AN INCREASE IN MAXIMA TO 35-70MM. ENHANCED MOISTURE
CONVERGENCE WILL FAVOR SIMILAR AMOUNTS IN WEST SURINAME AND
CENTRAL/SOUTHERN GUYANA...ALSO AIDED BY AN EASTERLY WAVE.

GALVEZ...WPC (USA)
























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