003
FXCA20 KWBC 281618
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1217 PM EDT FRI JUL 28 2023
FORECAST BULLETIN FROM 28 JUL 2023 AT 1630 UTC: WEST IN
MEXICO...DIURNAL CONVECTION IS EXPECTED ON A DAILY BASIS ALONG THE
SIERRA MADRE OCCIDENTAL. MODELS ARE GENERALLY UNDERESTIMATING THE
POTENTIAL ACCUMULATIONS. EXPECT MAXIMA IN THE 15-35MM/DAY RANGE
FROM SINALOA/WEST DURANGO INTO SONORA. NOTE THAT ISOLATED HIGHER
ACCUMULATIONS ARE POSSIBLE WHERE SHORT-LIVED ORGANIZED CONVECTION
DEVELOPS. ELSEWHERE IN MEXICO THE MOST REMARKABLE ACTIVITY IS WITH
A TROPICAL WAVE FORECAST TO ENTER CHIAPAS/TABASCO/CAMPECHE ON
SATURDAY AND RAPIDLY MOVE INTO GUERRERO BY SUNDAY (SEE WAVE
SECTION BELOW FOR RAINFALL AMOUNTS).
TO THE EAST...A TUTT LOW IS PROPAGATING FROM THE SOUTHEAST BAHAMAS
ON FRIDAY THROUGH EAST CUBA BY SUNDAY...AND CENTRAL/WEST CUBA BY
MONDAY. ALTHOUGH IT WILL PROVIDE VENTILATION AND ENHANCED
INSTABILITY...THE AIR MASS IN THE NORTHERN CARIBBEAN IS NOT AS
MOIST AS TO SUSTAIN SCATTERED HEAVY RAIN. ACCORDINGLY...EXPECT
ISOLATED ENHANCEMENT WHERE DIURNAL CONVECTION DEVELOPS. ON FRIDAY
EXPECT THE HEAVIEST IN WEST CUBA AS TRAILING MOISTURE BEHIND A
TROPICAL WAVE FAVORS MAXIMA OF 20-35MM. IN NORTHERN
HISPANIOLA...EAST CUBA AND NORTHWEST PUERTO RICO EXPECT MAXIMA OF
15-25MM. ON SATURDAY...EXPECT MAXIMA OF 20-45MM IN EAST CUBA AND
MAXIMA OF 15-30MM IN THE DOMINICAN REPUBLIC AND NORTHWEST PUERTO
RICO. ON SUNDAY...EXPECT MAXIMA OF 15-20MM IN JAMAICA AND IN MOST
OF CUBA...ALTHOUGH ISOLATED HIGHER AMOUNTS ARE EXPECTED IN THE
STRONGEST THUNDERSTORMS DUE TO ENHANCEMENT BY THE TUTT.
IN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA...ACTIVITY IS
ORGANIZING WITH THE ITCZ AND WAVES IN THE TRADES. THE LARGEST
AMOUNTS ARE EXPECTED IN NORTHERN CENTRAL AMERICA WITH THE TROPICAL
WAVE CURRENTLY ENTERING EASTERN NICARAGUA/HONDURAS (SEE BELOW FOR
AMOUNTS). OTHERWISE...EXPECT LOCALLY STRONG NOCTURNAL CONVECTION
IN PORTIONS OF NORTHWEST COLOMBIA/MAGDALENA BAJO ON
FRIDAY-SATURDAY MORNING...WHERE MAXIMA OF 25-50MM CAN BE EXPECTED.
ON SATURDAY THE FOCUS SHIFTS EAST INGO EAST VENEZUELA/GUYANA DUE
TO A LOW-LEVEL TROUGH AND ENHANCED VENTILATION SOUTH OF AN UPPER
RIDGE. THIS WILL FAVOR MAXIMA OF 25-50MM. THIS REPEATS ON SUNDAY
IN EAST AND NORTHEAST VENEZUELA...WHILE A TROPICAL WAVE AND
LOW-LEVEL WESTERLIES IN THE PACIFIC FAVOR MAXIMA OF 25-50MM IN
WEST COLOMBIA. OTHERWISE...EXPECT GENERALLY MAXIMA IN THE 15-45MM
RANGE.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 29/00 29/12 30/00 30/12 31/00 31/12 01/00 01/12
TW 20N 39W 44W 49W 53W 57W 60W 63W 66W 69W
TW 10N 58W 61W 65W 69W 73W 77W 81W 84W 87W
TW 21N 79W 85W 88W 92W 96W 99W 102W 106W 109W
A TROPICAL WAVE IS INITIALIZED AT 39W AND SOUTH OF 20N. THIS WAVE
IS SLANTED FROM SOUTHWEST TO NORTHEAST...AND ASSOCIATES WITH A
PERTURBATION THAT IS BEING MONITORED BY THE NHC. NOTE THAT CURRENT
FORECASTS SUGGEST THAT IF THE DISTURBANCE ORGANIZES...IT WILL
LIKELY RECURVE NORTHWARD MISSING THE CARIBBEAN BASIN. STILL...THE
ASSOCIATED TROPICAL WAVE IS FORECAST TO APPROACH THE GUIANAS ON
SATURDAY...TO FAVOR MAXIMA OF 20-35MM IN SURINAME/SOUTH
GUYANA...AND MAXIMA OF 25-50MM IN NORTHWEST GUYANA AND EASTERN
VENEZUELA. ON SUNDAY...IT WILL FAVOR MAXIMA OF 30-60MM IN EAST
VENEZUELA...AND MAXIMA OF 15-20MM IN THE WINDWARD ISLANDS.
A TROPICAL WAVE IS INITIALIZED AT 58W AND SOUTH OF 10N. THIS WAVE
IS NARROW AND IT'S ASSOCIATED MOIST PLUME IS NOT ROBUST.
THUS...ENHANCEMENT OF CONVECTION WILL BE MINOR. ON FRIDAY IT WILL
FAVOR MAXIMA OF 15MM IN THE LESSER ANTILLES AND 20-45MM IN GUYANA
AND EAST VENEZUELA. ON SATURDAY IT WILL FAVOR MAXIMA OF 15-30MM IN
NORTHWEST PUERTO RICO AND IN THE DOMININCAN REPUBLIC...AND SIMILAR
AMOUNTS IN WEST VENEZUELA. ON SUNDAY IT WILL FAVOR MAXIMA OF
15-20MM IN EAST CUBA AND JAMAICA...WHILE IN WEST AND NORTHWEST
COLOMBIA IT FAVORS MAXIMA OF 25-50MM.
A TROPICAL WAVE IS INITIALIZED AT 79W AND SOUTH OF 21N. IT IS
ACCOMPANIED BY A ROBUST POOL OF PRECIPITABLE WATER EXCEEDING
60MM...AS WELL AS WINDS NEAR 25KT. IT WILL FAVOR HEAVY RAINFALL IN
NORTHERN CENTRAL AMERICA ON FRIDAY AND SATURDAY. ON
FRIDAY...EXPECT MAXIMA OF 75-125MM IN EAST HONDURAS/NORTHEAST
NICARAGUA AMD MAXIMA OF 40-80MM IN ISLAS DE LA BAHIA AND CENTRAL
HONDURAS...WITH A RISK FOR MCS FORMATION. WEST ACROSS SOUTHERN
BELIZE/EAST GUATEMALA AND THE GULF OF FONSECA REGION EXPECT MAXIMA
OF 25-50MM...GIVEN A LIMITATION OF POTENTIALLY HIGHER AMOUNTS DUE
TO ADIABATIC COMPRESSION OF STRONG NORTHEASTERLY LOW-LEVEL WINDS.
ON SATURDAY...EXPECT MAXIMA OF 75-125MM IN GUATEMALA/WESTERN
HONDURAS/NORTHWEST EL SALVADOR AND CHIAPAS WITH A RISK FOR MCS
FORMATION. IN SOUTHEAST MEXICO FROM SOUTHERN VERACRUZ TO CAMPECHE
IT WILL FAVOR MAXIMA OF 25-50MM. ON SUNDAY IT WILL FAVOR MAXIMA OF
30-60MM IN NORTHERN OAXACA/CENTRAL AND SOUTHERN VERACRUZ DUE TO
ONSHORE FLOW...AND SIMILAR AMOUNTS IN WESTERN OAXACA/GUERRERO.
GALVEZ/ACOSTA...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page