350
FXCA20 KWBC 101756
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
155 PM EDT THU SEP 10 2026
FORECAST BULLETIN 10 SEPTEMBER 2026 AT 1750 UTC:
SIGNIFICANT RAINFALL ACCUMULATION WILL PERSIST ACROSS SOUTHERN
CENTRAL AMERICA, WESTERN COLOMBIA, ORINOQUIA AND NORTHWESTERN
AMAZON.
EXPECT MODERATE TO LOCALLY HEAVY RAINFALL ALONG SIERRA MADRE
OCCIDENTAL, THE MEXICAN TRANSVOLCANIC BELT AND OVER THE GREATER
ANTILLES.
MEXICO AND NORTHERN CENTRAL AMERICA . . .
AN UPPER-LEVEL HIGH-PRESSURE SYSTEM CENTERED NORTH OF THE GULF OF
CALIFORNIA WILL INTERACT WITH A COUPLE OF UPPER-LEVEL LOW-PRESSURE
SYSTEMS THAT EXTEND FROM WESTERN MEXICO TO THE CENTRAL NORTH. THIS
PATTERN WILL FAVOR UPPER-LEVEL DIVERGENCE ACROSS SIERRA MADRE
OCCIDENTAL AND LLANURA COSTERA DEL PACIFICO TODAY THROUGH SATURDAY
WHILE THE CUT-OFF LOW OVER CENTRAL NORTHERN MEXICO MERGES WITH THE
SECONDARY SYSTEM TO THE SOUTHWEST. LOWER-LEVEL CIRCULATION WILL
SUPPORT MODERATE MOISTURE CONVERGENCE AND SLIGHTLY ABOVE NORMAL
PRECIPITABLE WATER (PWAT) ANOMALIES OVER SIERRA MADRE OCCIDENTAL
AND THE MEXICAN TRANSVOLCANIC BELT OVER THE NEXT THREE DAYS. RAIN
ACCUMULATION MAXIMA OF 15-35 MM ARE EXPECTED TODAY OVER
NORTHWESTERN MEXICO WITH MODERATE ACCUMULATIONS FURTHER SOUTH. BY
FRIDAY AND SATURDAY, MAIN AREAS OF PRECIPITATION WILL DEVELOP OVER
THE MEXICAN TRANSVOLCANIC BELT DUE TO THE UPPER-LEVEL DYNAMIC
REORGANIZATION. ON SATURDAY, STRONG LOW-LEVEL MOISTURE ADVECTION
AND TOPOGRAPHY WILL INCREASE DAILY RAINFALL TOTALS OVER NORTHERN
CENTRAL AMERICA, ESPECIALLY OVER BELIZE, EASTERN GUATEMALA AND
NORTHWESTERN HONDURAS.
THE BAHAMAS AND CARIBBEAN . . .
MODERATE TO LOCALLY HEAVY RAINFALL IS EXPECTED TO DEVELOP OVER
HISPANIOLA AND PORTIONS OF CUBA AND JAMAICA TODAY. THIS RAIN WILL
BE TRIGGERED BY A TROPICAL WAVE MOVING ACROSS THE REGION, WHICH
WILL ENHANCE LOW-LEVEL MOISTURE CONVERGENCE AND INTERACT WITH
LOCAL TOPOGRAPHY TO PRODUCE LOCALIZED HEAVY RAINFALL. AS THE
TROPICAL WAVE PROPAGATES WESTWARD ON FRIDAY TO EARLY SATURDAY, IT
WILL FIND BETTER STRUCTURED UPPER-LEVEL SUPPORT OVER CUBA, WHERE
RAINFALL ACCUMULATION MAXIMA OF 25-50 MM ARE FORECAST. IN THE TAIL
OF THE TROPICAL WAVE, A PLUME OF SAHARAN DUST WILL MOVE IN TO
SUPPRESS SHOWERS ACROSS THE EASTERN PORTION OF THE REGION.
NORTHERN SOUTH AMERICA AND SOUTHERN CENTRAL AMERICA . . .
STRONG, PERSISTENT LOW-LEVEL VORTICITY OVER SOUTHERN CENTRAL
AMERICA, COMBINED WITH HIGH PWAT ANOMALIES AND TROPICAL WAVE
PASSAGES, WILL SUSTAIN HEAVY RAINFALL OVER THE NEXT THREE DAYS.
TWO TROPICAL WAVES EXTENDING OVER CENTRAL COLOMBIA AND ORINOQUIA
TODAY, IN ADDITION TO SOME LOWER-LEVEL TROUGHS, WILL SUPPORT
MODERATE PRECIPITATION ACROSS THE REGION WHILE PROPAGATING
WESTWARD. DAILY RAINFALL MAXIMA OF 40-80 MM ARE EXPECTED OVER
COSTA RICA TO WESTERN COLOMBIA TODAY AND SATURDAY LINKED TO THE
PASSAGE OF THESE TWO TROPICAL WAVES. RAINFALL TOTALS WILL INCREASE
OVER TRINIDAD AND TOBAGO TO THE ORINOCO DELTA REGION DUE TO THE
INFLUENCE OF THE ITCZ.
TROPICAL WAVES INITIALIZED AT 12 UTC:
TYP SOF INIT 11/00 11/12 12/00 12/12 13/00 13/12 14/00 14/12
TW 21N 29W 31W 33W 35W 37W 40W 42W 45W 48W
TW 17N 35W 37W 39W 41W 43W 45W 47W 50W 53W
TW 12N 44W 46W 48W 51W 54W 57W 59W 61W 63W
TW 20N 71W 73W 76W 78W 80W 83W 86W 89W 92W
TW 17N 80W 82W 84W 86W 89W 92W 95W 97W 100W
TW 15N 94W 97W 100W 103W 107W ABS --- --- ---
TW 20N 108W 110W 111W 112W 113W 114W 115W 116W 117W
SANCHEZ-PEREZ...(WPC)
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