411
FXCA20 KWBC 101611
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1211 PM EDT THU AUG 10 2023
FORECAST BULLETIN FROM 10 AUG 2023 AT 1830 UTC: NORTHWEST OVER
MEXICO...THE NORTH AMERICAN MONSOON DIURNAL CONVECTION WILL REMAIN
SEASONALLY ACTIVE THROUGHT HE FORECAST CYCLE IN ASSCOAITION WITH
WARM SST IN THE GULF OF CALIFORNIA AND A TROPICAL WAVE.
VENTILATION WILL BE FAVORABLE FOR STRONG THUNDERSTORMS...AS THE
SIERRA MADRE OCCIDENTAL WILL LIKE UNDER SOUTHERLY DIFFLUENT FLOW
BETWEEN THE SUBTROPICAL UPPER RIDGE OVER THE GULF OF MEXICO...AND
A QUASI-STATIONARY UPPER TROUGH JUST WEST OF THE BAJA CALIFORNIA
PENINSULA. EXPECT MAXIMA GENERALLY IN THE 25-50MM/DAY
RANGE...INCLUDING A RISK COR MCS FORMATION ON THURSDAY. ALSO OF
RELEVANCE...A MOIST PLUME IS MOVING ACROSS GUATEMALA/CHIAPAS ON
THURSDAY...AND OAXACA/GUERRERO/MICHOACAN ON FRIDAY. AS THIS
INTERACTS WITH A TUTT LOW THAT IS RETROGRADING ACROSS NORTHERN
CENTRAL AMERICA ON THURSDAY...AND SOUTH-CENTRLA MEXICO ON
FRIDAY...EXPECT STRONG CONVECTION AND LOCALLY HEAVY RAINFALL. ON
THURSDAY THIS WILL FAVOR MAXIMA OF 30-60MM IN CHIAPAS/WEST
GUATEMALA WITH A RISK FOR MCS. ON FRIDAY THIS WILL FAVOR SIMILAR
CONDITIONS FRMO WESTERN OAXACA/MORELOS INTO MICHOACAN.
OTHERWISE...DIURNAL CONVECTION WILL FAVOR MAXIMA OF 15-35MM IN
MOST OF SOUTH-CENTRAL AND SOUTHWEST MEXICO ON A DAILY BASIS.
A LARGE TUTT LOW CENTERING EAST OF THE LEEWARD ISLANDS ON THURSDAY
IS FORECAST TO RETROGRADE RAPIDLY WEST-SOUTHWESTWARD TO CENTER
NEAR 15N 70W OR SOUTH OF THE DOMINICAN REPUBLIC BY SATURDAY
EVENING. THE TUTT IS LARGE IN EXTENSION...BUT ITS RAPID MOVEMENT
AND LIMITED AVAILABLE MOISTURE IN THE EASTERN CARIBBEAN WILL LIMIT
SOME ITS POTENTIAL ENHANCEMENT. STILL...IT WILL START STIMULATING
CONVECTION IN TRINIDAD AND TOBAGO AND NORTHEASTE VENEZUELA ON
FRIDAY...WHERE IT WILL FAVOR MAXIMA OF 15-30MM. ON
SATURDAY...EXPECT ENHANCEMENT IN CENTRAL AND SOUTHERN
HISPANIOLA...WHERE EXPECT 05-10MM/DAY AND MAXIMA OF 15-30MM WITH A
SLIGHT RISK FOR SEVERE CONVECTION...GIVEN 500 HPA TEMPERATURES <
-7C. IN SOUTHWEST PUERTO RICO THIS WILL FAVOR MAXIMA OF
15-20MM...WHILE IN NORTHWEST VENEZUELA/NORTHERN COLOMBIA THIS
FAVORS MAXIMA OF 20-35MM.
OTHER THAN THESE FEATURES AND THE INFLUENCE OF TROPICAL WAVES (SEE
BELOW)...AN EVOLUTION OF INTEREST IS THE STRENGTHENING OF THE
PANAMANIAN LOW ON SATURDAY AND SUNDAY. THIS ARRIVES ACCOMPANIED BY
STRONG EASTERLY TRADES IN THE CARIBBEAN NORTH OF 13N...WHICH WILL
HIGHLIGHT MOISTURE CONVERGENCE IN EASTERN HONDURAS/NICARAGUA TO
FAVOR MAXIMA OF 30-60MM FROM SATURDAY INTO EARLY SUNDAY. SOUTH OF
PANAMA...ENHANCED LOW-LEVEL WESTERLIES WILL ENHANCE MOISTURE
CONVERGENCE IN WESTERN COLOMBIA TO TRIGGER 20-40MM/DAY AND MAXIMA
OF 75-125MM. IN NORTHWEST COLOMBIA...PANAMA AND SOUTHERN COSTA
RICA EXPECT MAXIMA OF 25-50MM. AS THIS SYSTEM MOVES WESTWARD ON
SUNDAY...EXPECT THE POTENTIAL FOR HEAVY RANFALL TO FOCUS ON THE
PACIFIC BASINS OF WEST PANAMA AND COSTA RICA.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 11/00 11/12 12/00 12/12 13/00 13/12 14/00 14/12
TW 18N 67W 70W 74W 78W 82W 84W 87W 90W 93W
TW 21N 73W 75W 78W 80W ABSORBED
TW 17N 96W 100W 102W 105W DISS
TW 23N 104W 108W 110W 113W 116W EXITS
A TROPICAL WAVE IS INITIALIZED AT 67W AND SOUTH OF 18N. IT IS
MOVING RAPIDLY WHILE ACCOMPANIED BY STRONG EAST-SOUTHEASTERLY
TRADES BEHIND THE WAVE AXIS. ON THURSDAY...IT WILL FAVOR MAXIMA OF
20-35MM IN PUERTO RICO/EASTERN DOMINICAN REPUBLIC IN SQUALLY
CONVECTION. IN CENTRAL AND WEST HISPANIOLA IT WILL FAVOR MAXIMA OF
35-70MM. IN CENTRAL AND WESTERN VENEZUELA/EASTERN COLOMBIA IT WILL
FAVOR MAXIMA OF 20-35MM...WHILE IN THE LAKE MARACAIBO REGION AND
NORTHERN COLOMBIA IT FAVORS MAXIMA OF 35-70MM IN EVENING
CONVECTION. ON FRIDAY...IT WILL FAVOR MAXIMA OF 25-50MM IN EAST
AND CENTRAL CUBA. IN WESTERN AND NORTHERN COLOMBIA EXPECT SIMILAR
AMOUNTS...WHILE IN PANAMA EXPECT MAXIMA OF 20-35MM. ON
SATURDAY...THE WAVE IS EXPECTED TO MERGE WITH A WEAKENING TROPICAL
WAVE LOCATED JUST TO ITS WEST. GIVEN PARTICULARLY HIGH LEVELS OF
PRECIPITABLE WATER THIS WILL FAVOR MAXIMA OF 30-50MM IN WEST CUBA
AND IN EASTERN HONDURAS/EAST NICARAGUA AND NORTHERN COSTA RICA. IN
SOUTHERN COSTA RICA AND WEST PANAMA THIS WILL FAVOR MAXIMA OF
25-50MM.
A TROPICAL WAVE IS INITIALIZED AT 73W AND SOUTH OF 21N. IT IS
FORECAST TO BECOME ABSORBED BY A MORE SIGNIFICANT TROPICAL WAVE
TRAILING BEHIND BY SATURDAY MORNING. IN THE MEAN TIME...IT WILL
FAVOR MAXIMA OF 25-50MM IN EAST CUBA ON THURSDAY. ALSO ON
THURSDAY...IT WILL FAVOR MAXIMA OF 35-70MM IN NORTHERN AND WESTERN
COLOMBIA...AND MAXIMA OF 20-35MM IN JAMAICA AND THE HAITIAN
PENINSULA. IN THE CENTRAL AND SOUTHEAST BAHAMAS EXPECT MAXIMA OF
15-25MM. ON FRIDAY IT WILL FAVOR MAXIMA OF 25-50MM IN CENTRAL CUBA.
A WEAK TROPICAL WAVE IS INITIALIZED NEAR 100W AND SOUTH OF
17N...AND WILL HAVE LIMITED EFFECTS IN CONTINENTAL CONVECTION AND
PRECIPITATION.
A TROPICAL WAVE IS INTIALIZED NEAR 104W AND SOUTH OF 23N. ON
THURSDAY IT WILL FAVOR MAXIMA OF 25-50MM FROM NAYARIT/NORTHERN
JALISCO INTO WESTERN CHIHUAHUA/SOUTHEAST SONORA. IT THEN EXITS THE
REGION...YET ENHANCED AVAILABLE MOISTURE WILL MAINTAIN THE NORTH
AMERICAN MONSOON CONVECTION ACTIVE THROUGH AT LEAST SATURDAY.
GALVEZ...WPC (USA)
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