513
FXCA20 KWBC 061502
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1102 AM EDT THU APR 06 2023
NOTE: SEVERE RAINFALL EVENT CONTINUES UNRAVELING IN ECUADOR AND
NORTHERN PERU ON THURSDAY. A POTENT TROPOSPHERIC KELVIN WAVE IS
COUPLING WITH AN ECHO TRAINING EVENT ALONG THE ITCS INTO SOUTHWEST
ECUADOR. THIS WILL FAVOR RAINFALL TOTALS OF 100-200MM/DAY AS
MAXIMA THROUGH FRIDAY MORNING. GENERALIZED ONSHORE FLOW AND
VENTILATION WILL FAVOR MAXIMA OF 75-125MM IN THE REST OF THE
PACIFIC BASIN FROM SOUTHWEST COLOMBIA INTO PIURA PERU. THE THREAT
SHOULD SETTLE ON FRIDAY LEADING TO DRIER CONDITIONS INTO THE
WEEKEND.
FORECAST BULLETIN FROM 06 APR 2023 AT 1500 UTC: A STATIONARY FRONT
EXTENDS FROM SOUTHWEST LOUISIANA AND OFF THE TEXAS COAST INTO
EXTREME NORTHERN VERACRUZ AND CENTRAL MEXICO. THIS IS FAVORING
ISENTROPIC LIFT AS MOIST SOUTHEASTERLY TRADES FROM THE GULF OF
MEXICO ASCENT OVER THE BOUNDARY. THIS IS ALSO INTERACTING WITH A
SHORT WAVE UPPER TROUGH AND UPPER JETS COUPLED ON THEIR DIVERGENT
SIDE. UNDER THIS PATTERN... EXPECT AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM. APPROPIATE VERTICAL WIND SHEAR WILL FAVOR
SEVERE CONVECTION IN NORTHERN TAMAULIPAS AND NUEVO LEON WITH THIS
SYSTEM. FURTHER SOUTH...EXPECT 15-20MM/DAY AND MAXIMA OF 25-50MM
AS THE SYSTEM INTERACTS WITH THE SIERRA MADR ORIENTAL IN NORTHERN
VERACRUZ/HIDALGO/SAN LUIS POTOSI. FURTHER NORTH EXPECT 10-15MM/DAY
AND ISOLATED MAXIMA OF 20-40MM. ON FRIDAY...THE FRONT WILL START
TO WEAKEN WHILE UPPER DYNAMICAL FORCING DECREASES. THIS WILL FAVOR
05-10MM/DAY AND MAXIMA OF 15-25MM. REMAINING ONSHORE FLOW INTO THE
CENTRAL SIERRA MADRE ORIENTAL WILL FAVOR 10-15MM/DAY AND MAXIMA OF
20-35MM. ACTIVITY DECREASE AFTER. ALSO IN MEXICO...DIURNAL
CONVECTION IS EXPECTED TO REMAIN ACTIVE ALONG THE SOUTHERN SIERRA
MADRE ORIENTAL ON A DAILY BASIS. EXPECT MAXIMA OF 10MM ON
THURSDAY...INCREASING TO AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM IN THURNDERSTORMS THEREAFTER.
ANOTHER REGION OF INTEREST IS THE NORTHEAST CARIBBEAN. A POTENT
UPPER TROUGH IS FAVORING SCATTERED STRONG CONVECTION ACROSS THE
LEEWARD ISLANDS AND PARTS OF PUERTO RICO. THE UPPER TROUGH CENTERS
TO THE NORTH OF THE DOMINICAN REPUBLIC AND IS FORECAST TO REMAIN
QUASI-STATIONARY IN THIS POSITION...WHILE THE MOIST PLUME TO ITS
SOUTHEAST MEANDERS NORTHWESTWARD. ON THURSDAY...THE POTENTIAL FOR
LOCALLY HEAVY RAINFALL CONTINUES IN PUERTO RICO...WHERE EXPECT
15-20MM/DAY AND MAXIMA OF 30-60MM ESPECIALLY IN THE VI AND EASTERN
PUERTO RICO. NOTE THAT THE RISK FOR SQUALLY WEATHER
CONTINUES...AND ISOLATED OCURRENCES OF HAIL CAQNNOT BE RULED OUT.
IN WESTERN PUERTO RICO INTO MOST OF THE DOMINICAN REPUBLIC EXPECT
10-15MM/DAY AND MAXIMA OF 20-40MM. ON FRIDAY...EXPECT A DECREASE
IN PUERTO RICO/VI TO 10-15MM/DAY AND MAXIMA OF 20-35MM...WHILE IN
THE DOMINICAN REPUBLIC EXPECT 10-15MM/DAY AND MAXIMA OF 20-45MM.
ON SATURDAY...EXPECT 05-10MM/DAY AND MAXIMA OF 15-25MM IN THE
DOMINICAN REPUBLIC WHILE MUCH LOWER AMOUNTS ARE EXPECTED IN
PUERETO RICO.
NORTHERN SOUTH AMERICA IS ANOTHER REGION OF CONCERN. SATELLITE
IMAGERY SHOWS A FORMIDABLE OUTFLOW...PARTIALLY ENHANCED BY THE
TROPOSPHERIC KELVIN AS IT HIGHLIGHTS VENTILATION IN THE SYNOPTIC
SCALE. THE PACIFIC ITCZ IS VERY ACTIVE AND IS IMPACTING THE WEST
COAST OF SOUTH AMERICA IN NORTHERN PERU/SOUTHERN ECUADOR AND IN
SOUTHERN COLOMBIA. THE LARGEST AMOUNTS ARE EXPECTED IN THESE
REGIONS...WHERE INTERMITENT HEAVY RAINFALL WILL FAVOR 20-40MM/DAY
AND MAXIMA OF 75-125MM THROUGH FRIDAY MORNING...ALTHOUGH ECHO
TRAINING ALONG THE ITCZ WILL FAVOR 25-50MM/DAY AND MAXIMA OF
100-200MM IN SOUTHWEST ECUADOR. VERY ACTIVE CONDITIONS ARE ALSO
EXPECTED IN MOST OF WESTERN AND CENTRAL COLOMBIA ON
THURSDAY...WHERE AMOUNTS ARE FORECAST TO RE3ACH 15-20MM/DAY AND
MAXIMA OF 30-60MM. IN THE WESTERN AMAXON...FROM AMAZONAS-BRASIL
INTO THE ORIENTE ECUATORIANO AND NORTHERN PERU EXPECT 15-20MM/DAY
AND MAXIMA OF 25-50MM. ON FRIDAY...EXPECT A SHARP DECREASE IN
PRECIPITATION ALONG THE WEST COAST OF TROPICAL SOUTH
AMERICA...WHERE EXPECT SCATTERED DIURNAL CONVECTION AND MAXIMA OF
15-25MM. IN MOST OF ANDEAN AND CENTRAL COLOMBIA...INTO THE LAKE
MARACAIBO REGION AND MAGDALENA BAJO EXPECT 10-15MM/DAY AND MAXIMA
OF 20-45MM. IN SOUTHEAST COLOMBIA AND NORTHERN PERU/AMAZONAS
BRASIL EXPECT CONTINUED ACTIVE CONDITIONS TO FAVOR 15-20MM/DAY AND
MAXIMA OF 30-60MM...FAVORED BY MOIST POOL/PRECIPITABLE WATER OVER
60MM...THE KELVIN WAVE AND THE NET. IN NORTHWEST VENEZUELA ANDTHE
COLOMBIAN ORINOQUIA/NORTHERN VENEZUELAN AMAZON EXPECT 05-10MM/DAY
AND MAXIMA OF 15-25MM. ON SATURDAY...EXPECT THE HEAVIEST
PRECIPITATION TO CLUSTER FROM AMAZONAS-BRASIL INTO NORTHERN
PERU/ORIENTE ECUATORIANO AND MOST OF THE COLOMBIAN AMAZON AND
SOUTHERN ORINOQUIA. IN THESE REGIONS EXPECT 15-20MM/DAY AND MAXIMA
OF 35-70MM WITH A RISK FOR MCS FORMATION. IN THE NORTHERN
COLOMBIAN ORINOQUIA INTO SOUTHERN AND WESTERN VENEZUELA ESPECT
10-15MM/DAY AND MAXIMA OF 20-35MM. IN ANDEAN COLOMBIA...THE
INFLUENCE OF A DRIER AIR MASS ENTERING FROM THE EASTERN PACIFIC ON
SATURDAY WILL FAVOR A CONTINUED DRYING TREND...TO LIMIT
ACCUMULATIONS TO 05-10MM/DAY AND MAXIMA OF 15-20MM.
GALVEZ/ALAMO/ACOSTA...WPC (USA)
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