127
FXCA20 KWBC 191915
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
315 PM EDT WED AUG 19 2026
FORECAST BULLETIN 19 AUGUST 2026 AT 1915 UTC:
PERSISTENT UPPER-LEVEL DYNAMIC SUPPORT AND HIGHLY ENHANCED
PRECIPITABLE WATER (PWAT) ACROSS EASTERN HONDURAS TO COSTA RICA
WILL SUSTAIN BROAD AREAS OF SIGNIFICANT RAINFALL.
THE TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) WILL ENHANCE HEAVY
RAINFALL OVER HISPANIOLA AND EASTERN CUBA ON THURSDAY AND CENTRAL
TO EASTERN CUBA ON FRIDAY.
LOW-LEVEL FORCING FEATURES WILL SUPPORT BROAD AREAS OF CONVECTIVE
PRECIPITATION ACROSS NORTHERN SOUTH AMERICAN.
MEXICO AND NORTHERN CENTRAL AMERICA . . .
AN UPPER-LEVEL LOW CENTERED OVER NORTHEASTERN MEXICO INTERACTS
WITH AN UPPER-LEVEL RIDGE EXTENDING OVER THE WEST TO CREATE
DIFFLUENCE CONDITIONS, WHILE A MID-LEVEL TROUGH WILL DEVELOP
ACROSS WESTERN AND SOUTHWESTERN MEXICO TODAY. THIS PATTERN ALOFT
WILL SUPPORT MODERATE LOWER-LEVEL MOISTURE CONVERGENCE BENEATH.
THE MOISTURE CONVERGENCE WILL EXTEND ALL ACROSS SIERRA MADRE
OCCIDENTAL, HOWEVER THE FAVORABLE DYNAMICS ALOFT TO THE SOUTHWEST
WILL LEAD TO HIGHER RAINFALL TOTALS TODAY OVER THIS REGION WITH
LOWER TOTALS ELSEWHERE. A COUPLE OF TROPICAL WAVES AND TOPOGRAPHY
WILL DRIVE RAIN ACCUMULATION UP TO 15-25 MM ACROSS ISTHMUS OF
TEHUANTEPEC REGION TODAY. THROUGHOUT THE NEXT FEW DAYS, THIS
PATTERN WILL TRACK WEST-NORWESTERWARD TO MAINTAIN HIGHER DAILY
RAIN ACCUMULATION ACROSS CENTRAL AND WESTERN AREAS. MESOSCALE
DYNAMIC FEATURES AND TOPOGRAPHIC FORCING WILL SUPPORT MODERATE
RAINFALL AROUND THE GULF OF HONDURAS AND AREAS OF GUATEMALA AND
HONDURAS THROUGH THE TIMEFRAME.
THE BAHAMAS AND CARIBBEAN . . .
A TROPICAL WAVE LOCATED OVER THE CENTRAL CARIBBEAN TODAY WILL MOVE
INTO THE WESTERN CARIBBEAN BY THURSDAY AND REACH THE YUCATAN
PENINSULA BY FRIDAY INCREASING DEEP CONVECTION SHOWERS WITH
RAINFALL MAXIMA OF 10 -15MM.
LIMITED MOISTURE ACCOMPANIES THIS WAVE WHILE AN UPPER-LEVEL TROUGH
WILL SUPPORT UPPER DIVERGENCE OVER HISPANIOLA TODAY AND THURSDAY
TO FAVOR ISOLATED DEEP CONVECTIVE SHOWERS WITH RAINFALL MAXIMA OF
15-30 MM.
THE ATLANTIC HIGH PRESSURE AREA NORTH OF THE CARIBBEAN BASIN WILL
DRIFT WESTWARD, FAVORING SAHARAN DUST ADVECTION INTO THE LESSER
ANTILLES TODAY. THE CONCENTRATION OF SAHARAN DUST WILL INCREASE
AND EXTEND FURTHER INTO THE CENTRAL CARIBBEAN AREA BY THURSDAY.
AN UPPER- AND LOWER-LEVEL TROUGH OVER FLORIDA WILL SUPPORT DEEP
CONVECTIVE DEVELOPMENT OVER THE NORTHERN BAHAMAS TODAY THROUGH
THURSDAY. THIS PATTERN WILL LEAD TO ISOLATED TO SCATTERED SHOWERS
AND LOCALIZED RAINFALL ACCUMULATION UP TO 15 MM.
NORTHERN SOUTH AMERICA AND SOUTHERN CENTRAL AMERICA . . .
AN UPPER-LEVEL ANTICYCLONIC CIRCULATION CENTERED NORTH OF HONDURAS
AND AN UPPER-LEVEL TROUGH EXTENDED FROM NORTHWESTERN VENEZUELA
INTO PANAMA INTERACT TO FAVOR UPPER DIVERGENCE ACROSS NICARAGUA TO
WESTERN PANAMA AND NORTHERN COLOMBIA. MODERATE TO STRONG LOW-LEVEL
MOISTURE CONVERGENCE IS PRESENT DUE TO THE MONSOON TROUGH AND A
TROPICAL WAVE ACROSS THE REGION. THIS PATTERN WILL LEAD TO DAILY
RAINFALL ACCUMULATION TOTALS OF 15-30 MM OVER NICARAGUA TO
EASTERN COSTA RICA AND ISOLATED AREAS IN NORTHERN COLOMBIA. A
LOW-LEVEL TROUGH OVER THE PANAMA BIGHT WILL FAVOR ISOLATED AREAS
OF HEAVY PRECIPITATION ACROSS WESTERN COLOMBIA TODAY. ABUNDANT
MOISTURE WILL BE PRESENT ACROSS ORINOQUIA, NORTHWEST AMAZON AND
WESTERN AMAZON BASIN THROUGH THE NEXT FEW DAYS DUE TO LOWER-LEVEL
ADVECTION. A SERIES OF LOW-LEVEL TROUGHS WILL TRIGGER RAINFALL
OVER THIS REGION THROUGH THE NEXT FEW DAYS WITH RAINFALL MAXIMA OF
20-40 MM ON FRIDAY ACROSS ORINOQUIA TO RORAIMA.
TROPICAL WAVES INITIALIZED AT 12 UTC:
TYP SOF INIT 20/00 20/12 21/00 21/12 22/00 22/12 23/00 23/12
TW 20N 37W 40W 44W 48W 51W 53W 56W 58W 62W
TW 20N 44W 48W 52W 55W 59W 62W 66W 70W 73W
TW 17N 71W 73W 75W 78W 82W 85W 88W 90W 93W
TW 16N 89W 93W 97W 101W 104W 107W 110W 111W 114W
TW 18N 94W 97W 100W 104W 107W 112W DISS --- ---
TW 11N 107W 109W 111W 113W 116W 119W EXITS --- ---
SANCHEZ-PEREZ...(WPC)
TINOCO-MORALES...(WPC)
LUCIANO...(MDC)
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