068
FXCA20 KWBC 151736
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
135 PM EDT MON MAY 15 2023
NOTE: THE RISK FOR HEAVY RAINFALL IN EXTREME NORTHEAST MEXICO
CONTINUES. UNDER THE INFLUENCE OF A NEGATIVELY TILTED UPPER
TROUGH...A MOIST LOW-LEVEL JET AND AN APPROACHING KELVIN
WAVE...EXPECT ROUNDS OF HEAVY RAIN PRODUCING THUNDERSTORMS ON
FRIDAY AND ESPECIALLY SATURDAY AFTERNOON. THROUGH MONDAY
MORNING...THERE IS A RISK FOR TOTAL ACCUMULATION OF 150-250MM IN 3
DAYS.
FORECAST BULLETIN FROM 12 MAY 2023 AT 1720 UTC: A BROAD MID-UPPER
TROUGH IN THE WESTERN US IS DEVELOPING SHORT WAVE VORTICES THAT
ARE ROTATING ALONG ITS PERIPHERY. ONE OF THESE VORTICES EXTENDS
INTO CHIHUAHUA/DURANGO ON FRIDAY. AS IT PROPAGATES TOWARDS THE RIO
BRAVO REGION...IT WILL FAVOR ENHANCED UPPER DIVERGENCE IN A REGION
OF PRECIPITABLE WATER OVER 45MM AND MOISTURE CONVERGENCE IN THE
CYCLONIC TIER OF A LOW-LEVEL JET. THIS WILL FAVOR 15-20MM/DAY AND
MAXIMA OF 40-80MM WITH A RISK FOR SEVERITY. ON SATURDAY...EXPECT A
PEAK IN THE EVENT...WHEN ACCUMULATIONS ARE LIKELY TO REACH 25-50MM
AND MAXIMA 75-125MM WITH A RISK FOR SEVERITY AND HEAVY RAIN RATES.
THE EVENT IS EXPECTED TO WIND DOWN AFTER.
ELSEWHERE IN MEXICO...THE ARRIVAL OF A KELVIN WAVE AND THE
AFOREMENTIONED UPPER TROUGH ARE FAVORING A RAPID MOISTENING AND
DESTABILIZATION. MOISTURE INFLOW FROM THE GULF OF MEXICO IS
EXPECTED TO GRADUALLY ACTIVATE DIURNAL CONVECTION IN PORTIONS OF
NORTHWEST AND CENTRAL/SOUTHWEST MEXICO. STILL...THE LARGEST
AMOUNTS ARE EXPECTED ALONG/NEAR THE SIERRA MADRE ORIENTAL WHERE
THE LARGEST AMOUNTS OF PRECIPITABLE WATER ARE EXPECTED. ON
FRIDAY...EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM ALONG THE SIERRA
MADRE ORIENTAL AND EJLE VOLCANICO CENTRAL. ON SATURDAY...EXPECT
15-20MM/DAY AND AMXIMA OF 30-60MM FROM NORTHERN VERACRUZ INTO SAN
LUIS POTOSI/CENTRLA TAMAULIPAS/NUEVO LEON. FROM OAXACA INTO
CENTRAL MEXICO EXPECT 05-10MM/DAY AND MAXIMA OF 15-25MM. ON
SUNDAY...EXPECT MODERATE AMOUNTS DEVELOPING IN
CHIHUAHUA/DURANGO/WESTERN COAHUILA AS A NEGATIVELY TILTED UPPER
TROUGH INTERACTS WITH A MOIST PLUME. THIS WILL FAVOR 10-15MM/DAY
AND MAXIMA OF 20-45MM. TO THE EAST...EXPECT 10-15MM/DAY AND MAXIMA
OF 20-35MM FROM THE RIO BRAVO INTO NORTHERN PUEBLA/HIDALGO. HIGHER
AMOUNTS ARE EXPECTED IN SOUTHERN MEXICO FROM CHIAPAS INTO
VERACRUZ/CENTRLA PUEBLA AS THE FIRST TROPICAL WAVES ENTERS THE
REGION. EXPECT 15-20MM/DAY AND MAXIMA OF 35-70MM.
AN CLOSED UPPER LOW IS ORGANIZING OVER THE EASTERN GULF OF
MEXICO...AND IS FORECAST TO MEANDER VERY SLOWLY TOWARDS THE
FLORIDA STRAIT THROUGH THE FORECAST CYCLE. COLD TEMPERATURES IN
THE MID-UPPER TROPOSPHERE WILL FAVOR ROUNDS OF SEVERE CONVECTION
IN CUBA AND SQUALLY WEATHER IN THE BAHAMAS...ESPECIALLY ON FRIDAY
AND SATURDAY. ON FRIDAY EXPECT 05-10MM/DAY AND MAXIMA OF 15-30MM
IN CENTRAL AND WESTERN CUBA...WITH A RISK FOR SEVERITY. IN THE
BAHAMAS EXPECT 05-10MM/DAY AND MAXIMA OF 15-25MM STIMULATED AS
WELL BY A FRONTAL BOUNDARY ACROSS THE CENTRAL BAHAMAS. ON
SATURDAY...EXPECT ONCE AGAIN RISK FOR SEVERE CONVECTION IN CENTRAL
CUBA...WHERE AMOUNTS WILL REACH 10-15MM/DAY AND MAXIMA OF 20-45MM.
IN EASTERN CUBA AND THE CENTRAL BAHAMAS...EXPECT 10-15MM/DAY AND
MAXIMA OF 20-35MM WITH A RISK FOR SQUALLY WEATHER. ON
SUNDAY...EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM IN CENTRAL CUBA
AND IN MOST OF THE CENTRAL AND SOUTHEAST BAHAMAS.
ALSO IN THE CARIBBEAN...A MOIST PLUME IS PROPAGATING ACROSS THE
LEEWARD ISLANDS INTO PUERTO RICO ON FRIDAY. SHORT WAVE
PERTURBATIONS EMBEDDED IN THE MID/UPPER TROPOSPHERIC WESTERLIES
WILL AID WITH THE STIMULATION OF DIURNAL CONVECTION IN SOUTHEAST
CUBA...HISPANIOLA AND PUERTO RICO...ESPECIALLY WHEN INTERACTING
WITH THE MOIST PLUME. ON FRIDAY...EXPECT 10-15MM/DAY AND MAXIMA OF
20-45MM IN SOUTHEAST CUBA AND HISPANIOLA...WHILE IN PUERTO RICO
AND THE VI EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM. ON SATURDAY
EXPECT ISOLATED MAXIMA OF 25-50MM IN NORTHWEST PUERTO RICO AND THE
NORTHERN DOMINICAN REPUBLIC...WHILE IN JAMAICA AND THE REST OF
HISPANIOLA EXPECT ISOLATED MAXIMA OF 15-20MM. ON SUNDAY EXPECT
ISOLATED MAXIMA OF 25-50MM IN NORTHERN HISPANIOLA AND IN SOUTHEAST
CUBA...WHILE IN JAMAICA EXPECT ISOLATED MAXIMA OF 15-20MM.
IN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA...ACTIVITY IS
ORGANIZING PRIMARILY WITH WAVES IN TRADES. IN CENTRAL
AMERICA...EXPECT GENERALLY HIGHER AMOUNTS IN NORTHERN PORTIONS AS
THE REGION HAS LARGER AMOUNTS ON INSTABILITY AND ASCENT STIMULATED
BY MID-UPPER TROUGHS. IN SOUTH AMERICA...THE NET WILL ALSO BE A
SYSTEM THAT WILL ENHANCE CONVECTION LOCALLY. WESTERLY FLOW IN THE
UPPPER LEVELS OF NORTHERN SOUTH AMERICA WILL ALSO PLAY A ROLE IN
STIMULATING CONVECTION. SHORT WAVE PERTURBATIONS ARE EXPECTED TO
PROVIDE LOCAL ENHANCEMENT IN NORTHERN COLOMBIA AND NORTHWEST
VENEZUELA. THE MOST PROMINENT PERTURBATION IS FORECAST TO AMPLIFY
ON SATURDAY AND SUNDAY...TO FAVOR HEAVY RAIN PRODUCING
THUNDERSTORMS. SEE BELOW FOR WAVE POSITIONS AND ASSOCIATED
ACCUMULATIONS IN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 16/00 16/12 17/00 17/12 18/00 18/12 19/00
TW 11N 57W 60W 64W 67W 71W 74W 78W 80W
EW 20N 78W 81W 84W 87W 91W 94W 97W 100W
TW 17N 98W 103W 107W 111W 114W 118W 122W 126W
A TROPICAL WAVE IS INITIALIZED AT 57W AND SOUTH OF 11N. THE WAVE
IS LOCATED BETWEEN GUYANA AND VENEZUELA BY MONDAY EVENING AND WILL
FAVOR MAXIMA OF 30-60MM OVER MOST OF GUYANA INTO SOUTHERN
VENEZUELA AND RORAIMA ON MONDAY. ON TUESDAY...THE WAVE IS FORECAST
OVER CENTRAL VENEZUELA BY THE EVENING...FAVORING MAXIMAS OF
25-50MM OVER SOUTH-CENTRAL VENEZUELA...RORAIMA...AND NORTHERN
AMAZONAS-BRASIL. BY WEDNESDAY...
AN EASTERLY WAVE IS INITIALIZED AT 78W AND SOUTH OF 20N AND IT IS
FORECAST FROM THE CAYMAN ISLANDS AND INTO CENTRAL PANAMA BY MONDAY
EVENING. THE AFOREMENTIONED AREAS ARE FORECAST FOR MAXIMA OF
15-30MM ON MONDAY.
A TROPICAL WAVE IS INITIALIZED AT 98W AND TO THE SOUTH OF 17N AND
IS FORECAST TO CONTINUE MOVEMENT OVER THE PACIFIC OCEAN IN AN
EASTWARD POSITION FROM MONDAY EVENING AND ONWARD. ON MONDAY...
GALVEZ/ACOSTA...WPC (USA)
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