961
FXCA20 KWBC 191924
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
323 PM EDT TUE MAY 19 2026
FORECAST BULLETIN 19 MAY 2026 AT 1930 UTC:
MEXICO AND NORTHERN CENTRAL AMERICA
A MID TO UPPER LEVEL RIDGE EXTENDS FROM THE EAST PACIFIC OCEAN
INTO MEXICO AND CENTRAL AMERICA, REACHING THE SOUTHERN UNITED
STATES ON TUESDAY MORNING. THIS RIDGE IS FAVORING SUBSIDENCE OVER
MUCH OF THE REGION, ACCOMPANIED BY DRY AIR IN THE MID-LEVELS, AND
INVERSION CAPS INHIBITING DEEP CONVECTION ON TUESDAY. TO THE
NORTHWEST, A DEEP MID TO UPPER LEVEL TROUGH EXTENDS OVER THE
SOUTHWEST UNITED STATES INTO THE NORTH BAJA CALIFORNIA PENINSULA,
INTERACTING WITH THE POTENT RIDGE OVER MEXICO. THIS WILL ENHANCE
SHORT WAVE TROUGHS ALONG THE PERIPHERY OF THE RIDGE IN THE MID
LEVELS, FAVORING LOWER PRESSURES IN THE LOW LEVELS OF THE
ATMOSPHERE AND ACTIVATING THE NORTH AMERICAN LOW LEVEL JET (LLJ)
ALONG THE EASTERN COAST OF MEXICO INTO SOUTHERN TEXAS. THIS INFLUX
OF TROPICAL MOISTURE WILL FAVOR INSTABILITY OVER COAHUILA AND
NUEVO LEON, AND MODERATE PRECIPITATION TOTALS WITH A RISK OF
SEVERE WEATHER ARE EXPECTED ON TUESDAY. SIMILAR CONDITIONS ARE
EXPECTED ALONG THE SIERRA MADRE ORIENTAL, EXTENDING INTO SOUTHERN
OAXACA, WHERE LIGHT TO MODERATE PRECIPITATION TOTALS ARE EXPECTED.
BY WEDNESDAY, A WEAKENING OF THE MID TO UPPER LEVEL RIDGE OVER
MEXICO AND CENTRAL AMERICA WILL WEAKEN THE TRADE WIND INVERSIONS
AND THE SUBSIDENCE OVER THE REGION. THIS WILL ALLOW FOR THE
MOISTURE IN THE LOW LEVELS TO DEVELOP INTO DEEPER CONVECTION OVER
CENTRAL AMERICA AND MEXICO, WHICH HAVE BEEN SEEING HIGH SURFACE
TEMPERATURES. ALONG THE SIERRA MADRE ORIENTAL, EXPECT MODERATE
PRECIPITATION MAXIMA FOR WEDNESDAY. INTO CENTRAL AMERICA, THE
DIURNAL CYCLE WILL FAVOR LIGHT TO LOCALLY MODERATE TOTAL
PRECIPITATION ON WEDNESDAY. BY THURSDAY, THE UPPER LEVEL TROUGH
OVER THE SOUTHWEST UNITED STATES WILL EXTEND A TROUGH AXIS INTO
THE MEXICAN PLATEAU BY THE EVENING HOURS. INCREASING THE
INSTABILITY IN THE REGION, EXPECT A SLIGHT RISK OF SEVERE WEATHER
IN THE NORTHERN SECTORS OF COAHUILA, NUEVO LEON, AND TAMAULIPAS.
EXPECT LOCALLY MODERATE TO HEAVY PRECIPITATION IN THE REGION.
REGIONS OF EL SALVADOR AND SOUTH GUATEMALA CAN EXPECT THE EFFECTS
OF A TROPICAL WAVE THAT IS EXTENDING INTO THE REGION THURSDAY. DUE
TO THE LACK OF AVAILABLE MOISTURE, EXPECT LIGHT TO MODERATE
PRECIPITATION TOTALS FOR THURSDAY.
CARIBBEAN AND THE BAHAMAS
OVER THE NEXT FEW DAYS, A RETROGRADING, NEGATIVELY TILTED TROPICAL
TROPOSPHERIC UPPER TROUGH (TUTT) IS LOCATED OVER THE BAHAMAS AND
TURKS AND CAICOS, FAVORING INSTABILITY FOR THE FORECAST PERIOD.
EVEN WITH THIS CONDITION, THE GENERALIZED LOW AMOUNTS OF AVAILABLE
MOISTURE IN THE REGION WILL LIMIT HEAVY PRECIPITATION, WITH THE
EXCEPTION OF LOCALLY HIGHER TOTALS. THE AREAS THAT CAN EXPECT
LIGHT TO MODERATE TOTALS ON TUESDAY ARE EXPECTED OVER THE BAHAMAS,
TURKS AND CAICOS, CUBA, AND HISPANIOLA. TRACE TO LIGHT
PRECIPITATION TOTALS COULD BE SEEN IN PUERTO RICO/VI AND THE
LESSER ANTILLES. THE PRESENCE OF A MID TO UPPER LEVEL RIDGE
EXPANDING OVER THE CARIBBEAN WILL FAVOR DRY CONDITIONS AND
SUBSIDENCE OVER MUCH OF THE EASTERN CARIBBEAN ON WEDNESDAY. THE
TUTT WILL PERSIST OVER THE BAHAMAS AND RETROGRADE INTO
FLORIDA-UNITED STATES, EXTENDING INTO CUBA AND HISPANIOLA. SIMILAR
PRECIPITATION TOTALS ARE EXPECTED ON WEDNESDAY. THE MID TO UPPER
LEVEL RIDGE PERSISTS INTO THURSDAY OVER THE CARIBBEAN, MEANDERING
INTO THE WEST, FAVORING LESS PRECIPITATION INTO HISPANIOLA ON
THURSDAY. AT THE SAME TIME, THE TUTT REMAINS IN THE SAME REGION AS
WEDNESDAY, FAVORING MODERATE TO LOCALLY HEAVY RAINFALL FOR THE
BAHAMAS, AND LIGHT TO MODERATE TOTALS FOR CUBA, TURKS AND CAICOS
AND HAITI ON THURSDAY.
SOUTHERN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA
THE REGION OF SOUTHERN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA
IS SEEING THE PASSAGE OF VARIOUS TROPICAL WAVES OVER THE FORECAST
PERIOD. A WAVE OVER COSTA RICA AND PANAMA WILL FAVOR MAXIMA
LOCALLY REACHING 50MM OR HIGHER TOTALS IN EASTERN COSTA RICA AND
PORTIONS OF NORTHWEST PANAMA, LIGHT TO MODERATE TOTALS COULD BE
EXPECTED FROM THE OSA PENINSULA THROUGH THE AZUERO PENINSULA. IN
WESTERN COLOMBIA, ENHANCED MOIST ONSHORE FROM A TROUGH ENTERING
THE GULF OF PANAMA WILL FAVOR HEAVY PRECIPITATION ON TUESDAY. ON
WEDNESDAY, THE TROPICAL WAVE IS EXPECTED IN WESTERN NICARAGUA,
FUELING MOIST ONSHORE FLOW INTO EASTERN NICARAGUA AND PORTIONS OF
COASTAL COSTA RICA AND PORTIONS OF THE AZUERO PENINSULA. THE
TROUGHING OVER THE GULF OF PANAMA WILL CONTINUE TO FAVOR HEAVY
PRECIPITATION IN WESTERN COLOMBIA WITH THE UPPER LEVEL SUPPORT OF
TWO INTERACTING UPPER LEVEL HIGH PRESSURE SYSTEMS. THE CONDITIONS
ARE EXPECTED TO CONTINUE INTO THURSDAY IN WESTERN COLOMBIA, WHILE
THE REST OF SOUTHERN CENTRAL AMERICA CAN EXPECT LIGHT TO MODERATE
PRECIPITATION.
ANOTHER TROPICAL WAVE IS LOCATED OVER THE GUIANAS ON TUESDAY AND
EXPECTED TO MOVE INTO VENEZUELA ON WEDNESDAY. THE REGION CAN
EXPECT ENHANCED DEEP CONVECTION ON TUESDAY AND WEDNESDAY, WHILE
TOTAL PRECIPITATION BETWEEN THE TWO DAYS IS EXPECTED TO BE
MODERATE TO HEAVY, WITH LOCALLY HIGHER TOTALS POSSIBLE. ON
THURSDAY, THE WAVE IS EXPECTED OVER EAST COLOMBIA, WHERE MODERATE
TO LOCALLY HEAVY PRECIPITATION TOTALS ARE EXPECTED.
A TROPICAL WAVE CURRENTLY LOCATED OVER THE ATLANTIC OCEAN WILL
ARRIVE INTO THE GUIANAS AND THE AMAZON DELTA BY THE EVENING HOURS
OF THURSDAY. EXPECT THIS TO FAVOR MODERATE PRECIPITATION INTO THE
REGION.
TYP SOF INIT 20/00 20/12 21/00 21/12 22/00 22/12 23/00 23/12
TW 07N 33W 37W 40W 44W 48W 51W 54W 55W 58W
TW 10N 58W 60W 62W 65W 68W 70W 72W 74W 76W
TW 13N 79W 81W 83W 85W 87W 89W 91W 93W 96W
TW 13N 101W 105W 108W 113W 115W -- --
CASTELLANOS..(WPC)
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