431
FXCA20 KWBC 131602
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1201 PM EDT MON MAR 13 2023
FORECAST BULLETIN FROM 13 MAR 2023 AT 16 UTC: A WET MJO PULSE
CONTINUES PROPAGATING ACROSS THE AMERICAS/ATLANTIC INTO AFRICA.
ALTHOUGH THE BULK OF THIS PULSE IS ALREADY ENTERING
AFRICA...ENHANCED UPPER DIVERGENT CONDITIONS ARE EXPECTED TO
CONTINUE OVER THE CARIBBEAN...CENTRAL AMERICA AND SOUTH AMERICA
THROUGH THE FORECAST CYCLE. THIS WILL HIGHLIGHT REGIONS WHERE DEEP
CONVECTION AND PRECIPITATION DEVELOP.
IN AN ACTIVE PATTERN OF UPPER TROUGHS AND EXTRATROPICAL CYCLONES
PROPAGATING ACROSS THE USA INTO THE NORTH ATLANTIC...A SURFACE
FRONT IS LINGERING IN NORTHERN PORTIONS OF THE BASIN. ON MONDAY
EVENING THE BOUNDARY IS FORECAST ACROSS CENTRAL/SOUTHERN
FLORIDA...CENTRAL GULF OF MEXICO INTO SOUTHERN TAMAULIPAS. BY
TUESDAY EVENING...IT IS EXPECTED ACROSS THE CENTRAL
BAHAMAS...NORTHERN CUBA...CENTRAL GULF OF MEXICO INTO NORTHERN
TAMAULIPAS. A STRONG POLAR TROUGH AXIS PROPAGATING ACROSS THE
MISSISSIPPI VALLEY ON TUESDAY IS FORECAST TO ENTER IN PHASE WITH
THE POLAR TROUGH LONG THE EAST COAST OF THE USA/NORTH FLORIDA ON
WEDNESDAY. THIS WILL FAVOR A SURGE IN THE NORTHERLIES...WHICH WILL
RAPIDLY PUSH THE FRONT SOUTHWARD ACROSS THE ATLANTIC ON WEDNESDAY
AND THURSDAY. BY WEDNESDAY EVENING THE FRONT WILL EXTEND ACROSS
THE SOUTHEAST BAHAMAS/TURKS AND CAICOS...SOUTHEAST CUBA...INTO THE
EXTREME NORTHEAST YUCATAN PENINSULA. NOTE THAT THE FRONT IS
FORECAST TO ARRIVE IN HISPANIOLA ON THURSDAY AND IN PUERTO RICO
LATE ON THURSDAY/EARLY ON FRIDAY MORNING. A SHEAR LINE IS ALSO
FORECAST TO DEVELOP. BY WEDNESDAY EVENING IT IS EXPECTED INTO
NORTHERN HISPANIOLA. IN TERMS OF PRECIPITATION...ON MONDAY EXPECT
05-10MM/DAY AND MAXIMA OF 15-25MM IN EASTERN MEXICO WHERE THE
SIERRA MADRE ORIENTAL WILL PROVIDE TOPOGRAPHICAL ENHANCEMENT. IN
THE NORTHWEST BAHAMAS...FRONTAL CONVECTION WILL FAVOR 05-10MM/DAY
AND MAXIMA OF 15-30MM IN THUNDERSTORMS...AS THE FRONT INTERACTS
WITH A SHORT WAVE UPPER TROUGH. BY TUESDAY...EXPECT 10-15MM/DAY
AND MAXIMA OF 20-30MM IN THE CENTRAL AND NORTHWEST BAHAMAS AND
NORTHERN CUBA. IN TAMAULIPAS EXPECT 05-10MM/DAY AND MAXIMA OF
15-20MM. IN THE NORTHERN YUCATAN PENINSULA...PREFRONTAL CONVECTION
WILL FAVOR 10-15MM/DAY AND MAXIMA OF 20-35MM. ON
WEDNESDAY...FRONTAL CONVECTION IN SOUTHEAST CUBA WILL FAVOR
10-15MM/DAY AND MAXIMA OF 20-45MM. IN CENTRAL/NORTHERN CUBA AND
THE CENTRAL BAHAMAS EXPECT 05-10MM/DAY AND MAXIMA OF 15-30MM. IN
THE NORTHEAST YUCATAN PENINSULA EXPECT SIMILAR AMOUNTS. SHEAR LINE
CONVECTION WILL FAVOR 05-10MM/DAY AND MAXIMA OF 15-25MM IN
HISPANIOLA. ANOTHER AREAS PRONE TO UNSEASONABLY HIGH RAINFALL
TOTALS ARE JAMAICA AND PUERTO RICO BY MID-WEEK. A MOIST PLUME
REMNANT FROM LAST WEEK'S SURFACE FRONT WILL BE DRAWN NORTHWARD
INTO THE REGION. PRE-FRONTAL NORTHERLY WINDS WILL ENHANCE
LOW-LEVEL MOISTURE CONVERGENCE IN JAMAICA ON WEDNESDAY...TO FAVOR
05-10MM/DAY AND MAXIMA OF 15-25MM. IN PUERTO RICO...EXPECT
10-15MM/DAY AND MAXIMA OF 20-30MM ON TUESDAY...AND 05-10MM/DAY AND
MAXIMA OF 15-25MM ON WEDNESDAY.
ANOTHER SURFACE FRONT IS FORECAST TO ENTER EXTREME NORTHWEST
MEXICO ON WEDNESDAY. PRECIPITATION WILL START DEVELOPING ON
TUESDAY...WHEN EXPECT 05-10MM/DAY AND MAXIMA OF 15MM IN NORTHERN
BAJA CALIFORNIA. ON WEDNESDAY EXPECT 10-15MM/DAY AND MAXIMA OF
20-35MM.
A MOIST PLUME EXTENDS WEST OF COSTA RICA AS A BROAD SURFACE LOW
CONTINUES LINGERING OVER A REGION OF WARM SEA SURFACE
TEMPERATURES. THE CURRENT MJO PULSE CONTINUES TO SUSTAIN A
WEAKENING OF THE EASTERLY TRADES ACROSS CENTRAL AMERICA...WHICH IS
FAVORING AN UNUSUALLY WET SPELL IN THE PACIFIC BASIN OF SOUTHERN
CENTRAL AMERICA. THE MOIST PLUME IS FORECAST TO MEANDER NORTHWARD
INTO NICARAGUA ON MONDAY...AND HONDURAS/EL SALVADOR LATER. THIS
WILL ACTIVATE DIURNAL CONVECTION...FAVORING UNSEASONABLY HIGH
DAILY PRECIPITATION AMOUNTS THROUGH THE FORECAST CYCLE. ON
MONDAY...THE HEAVIEST PRECIPITATION IS EXPECTED IN THE PACIFIC
BASIN OF COSTA RICA...WHERE EXPECT 15-20MM/DAY AND MAXIMA OF
30-60MM MOSTLY IN MOUNTAINOUS AREAS. ELSEWHERE IN SOUTHERN COSTA
RICA AND IN MOST OF CENTRAL AND WESTERN NICARAGUA EXPECT
05-10MM/DAY AND MAXIMA OF 15-25MM. DIURNAL CONVECTION IN CENTRAL
GUATEMALA/NORTHERN CHIAPAS WILL FAVOR SIMILAR AMOUNTS...WHILE IN
THE MOUNTAINS OF GUATEMALA EXPECT MAXIMA OF 15MM. ON
TUESDAY...EXPECT 10-15MM/DAY AND MAXIMA OF 20-45MM IN COSTA RICA
AND IN NORTHERN NICARAGUA/CENTRAL AND SOUTHERN HONDURAS. IN
WESTERN HONDURAS...MOST OF GUATEMALA AND CHIAPAS/TABASCO EXPECT
10-15MM/DAY AND MAXIMA OF 20-35MM. IN SOUTHERN GUATEMALA/CHIAPAS
AND WESTERN EL SALVADOR EXPECT 05-10MM/DAY AND MAXIMA OF 15MM. ON
WEDNESDAY...EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM IN NORTHERN
NICARAGUA...MOST OF HONDURAS AND EASTERN AND NORTHERN EL SALVADOR.
IN BELIZE...GUATEMALA AND PORTIONS OF SOUTHEAST MEXICO EXPECT
05-10MM/DAY AND MAXIMA OF 15-25MM.
ACTIVE CONVECTION CONTINUES IN PORTIONS OF SOUTH AMERICA...AS AN
ENHANCED UPPER DIVERGENT PATTERN CONTINUES AND MOIST ONSHORE FLOW
FROM THE PACIFIC CONTINUES INTO ECUADOR AND PERU...IN A
PRECIPITABLE WATER POOL EXCEEDING 55MM. THE THREAT FOR HEAVY
RAINFALL WILL BE THE HIGHEST ON MONDAY...WHEN EXPECT 20-40MM/DAY
AND MAXIMA OF 75-125MM IN COASTAL ECUADOR AND PORTIONS OF NORTHERN
PERU. FROM SOUTHWEST COLOMBIA /NORTHWEST ECUADOR INTO SOUTHERN
ECUADOR AND AMAZONAS-PERU EXPECT 15-20MM/DAY AND MAXIMA OF
25-50MM. IN CENTRAL AND NORTHERN COLOMBIA...ENHANCED INSTABILITY
AND VENTILATION BY THE SUBEQUATORIAL RIDGE IN THE UPPER
TROPOSPHERE WILL FAVOR 10-15MM/DAY AND MAXIMA OF 20-40MM. ON
TUESDAY...EXPECT THE HEAVIEST IN NORTHERN COLOMBIA WHERE AMOUNTS
ARE FORECAST TO REACH 15-20MM/DAY AND MAXIMA OF 25-50MM. ELSEWHERE
IN ANDEAN COLOMBIA INTO MOST OF ECUADOR AND NORTHERN PERU EXPECT
10-15MM/DAY AND MAXIMA OF 20-40MM. ON WEDNESDAY...EXPECT THE
HEAVIEST IN COASTAL ECUADOR WHERE ITCZ CONVERGENCE WILL FAVOR
15-20MM/DAY AND MAXIMA OF 25-50MM. IN CENTRAL AND NORTHERN
COLOMBIA EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM. IN SOUTHERN
ANDEAN COLOMBIA AND THE EASTERN SLOPES OF ECUADOR EXPECT
05-10MM/DAY AND MAXIMA OF 15-25MM. NOTE A CONTINUED DRYING IN MOST
OF VENEZUELA...THE COLOMBIAN ORINOQUIA AND NORTHWEST BRASIL...AS
DRY AIR ADVECTION FROM THE CARIBBEAN/SOUTH ATLANTIC LEAD TO VERY
LOW AMOUNTS OF PRECIPITABLE WATER BY MID-WEEK. TO THE EAST...DRY
CONDITIONS ARE TO PREVAIL IN THE GUIANAS AS WELL. A GRADUAL
INCREASE IS EXPECTED FROM EAST TO WEST ON TUESDAY...AS MOISTURE
RETURNS ALONG THE ATLANTIC ITCZ. THIS WILL START TO FAVOR MAXIMA
OVER 25MM IN THUNDERSTORMS ON WEDNESDAY...IN PORTIONS OF EASTERN
FRENCH GUIANA.
GALVEZ/ACOSTA...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page