818
FXCA20 KWBC 011839
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
239 PM EDT THU JUN 01 2023
FORECAST BULLETIN FROM 01 JUN 2023 AT 1830 UTC: THE MODEL GUIDANCE
HAS BACKED OFF CONSIDERABLY FOR THE SHOWER ACTIVITY ACROSS
NORTHERN SOUTH AMERICA OVER THE NEXT COUPLE OF DAYS. THERE IS
HOWEVER A SIGNIFICANT RAINFALL EVENT HAPPENING ACROSS
HISPANIOLA...CUBA AND THE BAHAMAS LATER TODAY AND THROUGH THE
WEEKEND. THE 3-DAY RAINFALL TOTAL COULD RANGE BETWEEN 75 AND 150MM
IN MANY SECTORS OF SOUTHERN HAITI...EASTERN BAHAMAS...AND THE
EASTERN SECTIONS OF CUBA. HOWEVER...ISOLATED SECTIONS OF
SOUTHEASTERN CUBA AND SOUTHWESTERN HAITI MAY OBSERVE UP TO 20MM
OVER THE 3-DAY PERIOD. THIS IS DUE TO A SURFACE LOW ACROSS THE
GULF OF MEXICO AND ANOTHER SURFACE LOW DEVELOPING NEAR
BERMUDA...PULLING DEEP TROPICAL MOISTURE FROM THE SOUTH. THIS
INCREASE IN MOISTURE WILL THEN INTERACT WITH STRONG MID LEVEL AND
UPPER LEVEL TROUGHS. THE UNSTABLE ATMOSPHERE WILL CAUSE SHOWERS
AND THUNDERSTORMS TO PERSIST ACROSS THESE SECTORS BEFORE THE
TROUGHS WEAKEN LATE SUNDAY. OVER THIS AREA...THE EGDI ALGORITHM IS
VERY BULLISH IN ITS SOLUTION...SUGGESTING SCATTERED THUNDERSTORMS
AND HEAVY RAIN. HOWEVER...IS IT SHY IN THE SEVERITY AND HAIL
POTENTIAL ALGORITHM. THIS MAY BE BECAUSE THE MID LEVEL
TEMPERATURES ARE ABOVE NORMAL...AND THEREFORE NOT COLD ENOUGH TO
CAUSE SEVERE HAIL ACROSS THE AREA. NEVERTHELESS...PERSISTENT
MODERATE TO HEAVY RAIN IS TO BE EXPECTED ACROSS THE AREA FOR THE
REST OF TODAY AND THROUGH THE WEEKEND.
ELSEWHERE...THERE ARE A NUMBER OF SURFACE TROUGHS OVER THE
ATLANTIC BASIN AND TWO EASTERLY WAVES ACROSS THE LOWER LATITUDES
OF THE TROPICS...MAINLY CROSSING NORTHERN SOUTH AMERICA.
HOWEVER...THE LACK OF UPPER LEVEL DYNAMICS MAY BE THE REASON WHY
THE MODEL GUIDANCE HAS NOW ADJUSTED THE RAINFALL SOLUTION AND IT
SUGGESTS MUCH LESS RAINFALL THAN IT DID A FEW DAYS AGO. THERE ARE
HOWEVER A FEW ISOLATED AREAS WITH SIGNIFICANT RAINFALL...BUT THESE
ARE VERY ISOLATED AND POSSIBLY INFLUENCED BY LOCAL EFFECTS...SUCH
AS THE WEST COAST OF ECUADOR HAVING SOME SEA BREEZE CONVERGENCE.
OVERALL...MOST OF MEXICO CONTINUES HAVING A LOW CHANCE OF
SIGNIFICANT RAINFALL OVER THE NEXT FEW DAYS...EXCEPT A FEW
SECTIONS OF SOUTHERN AND EASTERN MEXICO...WHERE A FEW AREAS CAN
OBSERVE MAXIMAS BETWEEN 15-25MM. THE LATEST GFS AND ECMWF MODEL
GUIDANCE IS NOW SUGGESTING DAILY RAINFALL MAXIMA OF 15-25MM ACROSS
CENTRAL AND NORTHERN SOUTH AMERICA TODAY AND SATURDAY...WITH A FEW
AREAS RECEIVING MAXIMA OF 20-45MM ON SUNDAY. HOWEVER...THE WEST
COAST OF ECUADOR MAY OBSERVE MAXIMA OF UP TO 50MM TODAY AND
SATURDAY. COSTA RICA AND PANAMA STILL LOOK RELATIVELY RAINY...WITH
MAXIMAS RAINING FROM 15MM TO UP TO 50MM ACROSS ISOLATED AREAS.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 02/00 02/12 03/00 03/12 04/00 04/12 05/00
TW 13N 52W 55W 59W 61W 64W 67W 70W 73W
TW 14N 61W 64W 66W 68W 70W DISS --- ---
A TROPICAL WAVE IS INITIALIZED AT 52W AND 13N. THE WAVE IS
FORECAST TO BE OVER THE SURINAME/GUYANA BORDER AND MAY EXPECT
SIMILAR AMOUNTS THROUGH TODAY. BY FRIDAY EVENING...THE TROPICAL
WAVE REACHES EASTERN VENEZUELA. EAST VENEZUELA IS FORECAST A
MAXIMA OF 15-25MM. ON SATURDAY...THE TROPICAL WAVE MOVES OVER
WESTERN VENEZUELA/EAST COLOMBIA...WHERE EXPECT MAXIMA OF 15-25MM.
A TROPICAL WAVE IS INITIALIZED AT 61W AND SOUTH OF 14N. FOR THE
REST OF TODAY INTO EARLY FRIDAY...EXPECT MAXIMA OF 15-25MM ACROSS
VENEZUELA THIS EVENING INTO EARLY FRIDAY. BY FRIDAY EVENING...THE
WAVE REACHES WEST CENTRAL VENEZUELA...WHERE A RAINFALL MAXIMA OF
15-25MM IS FORECAST. THE WAVE LOSES DEFINITION THEREAFTER AND IS
EXPECTED TO DISSIPATE.
ALAMO/ACOSTA...WPC (USA)
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