Prognostic Meteorological Discussion
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FXCA20 KWBC 191844
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
243 PM EDT TUE AUG 19 2014

DISCUSSION FROM AUGUST 19/00UTC: MID-UPPER RIDGE CENTERS OVER
SOUTHERN CHIHUAHUA/SOUTHERN SONORA/BAJA CALIFORNIA SUR IN MEXICO.
IN THE MEAN TIME...TUTT LOW CENTERS OFF THE COAST OF TAMAULIPAS.
RIDGE IS TO HOLD THROUGH THE CYCLE WHILE TUTT LOW PRESSES AGAINST
IT...RETROGRESSING INTO GUANAJUATO/SAN LUIS POTOSI THROUGH FRIDAY.
CONVECTIVE INSTABILITY WILL REMAIN HIGH ACROSS CENTRAL AND WESTERN
MEXICO...WHERE DIURNAL CONVECTION WILL CONTINUE SEASONALLY ACTIVE.
EXPECTING AN ACTIVATING TREND THROUGH THE CYCLE ACROSS THE SIERRA
MADRE OCCIDENTAL...WHERE MAXIMA WILL INCREASE FROM 20-40MM/DAY ON
TUESDAY-EARLY WEDNESDAY...TO 40-80MM/DAY ON THURSDAY-FRIDAY
ESPECIALLY IN NORTHERN SINALOA/WESTERN DURANGO/WESTERN CHIHUAHUA.
ELSEWHERE ACROSS CENTRAL AND SOUTHERN MEXICO...EXPECTING ISOLATED
TO SCATTERED MAXIMA OF 20-50MM/DAY IN DIURNAL CONVECTION.

A TRAIN OF TUTTS AND UPPER RIDGES DOMINATES THE CARIBBEAN BASIN.
ONE OF THE TUTTS CENTERS TO THE SOUTHWEST OF JAMAICA AND WILL
RETROGRESS INTO THE GULF OF HONDURAS REGION...TO CENTER OVER THE
ISLANDS OF NORTHERN HONDURAS BY THURSDAY AND THEN MEANDER IN THE
REGION. THE TUTT IS INTERACTING WITH A TROPICAL WAVE IN THE TRADES
TO AFFECT COSTA RICA AND NICARAGUA ON TUESDAY. AS WAVE PROGRESSES
WESTWARD IN PHASE WITH TUTT...EXPECTING WIDESPREAD THUNDERSTORMS
TO AFFECT BOTH COUNTRIES WITH ACCUMULATIONS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM. ON WEDNESDAY...EXPECTING STRONGEST CONVECTION
TO AFFECT EL SALVADOR/SOUTHERN GUATEMALA WITH SIMILAR AMOUNTS.
OVER COSTA RICA AND NICARAGUA EXPECTING A DECREASE TO MAXIMA OF
20-40MM. BY THURSDAY-EARLY FRIDAY...MODELS LIKE TO ORGANIZE A
BROAD CYCLONE ALONG THE TROPICAL WAVE AS IT MOVES OVER THE EASTERN
PACIFIC. THIS WILL STIMULATE MOISTURE TRANSPORT AND CONVERGENCE
ACROSS THE COASTS OF WESTERN EL SALVADOR/SOUTHERN GUATEMALA INTO
CHIAPAS/OAXACA IN MEXICO. EXPECTING ACCUMULATIONS INCREASING TO
15-20MM/DAY AND MAXIMA OF 25-50MM.

A RIDGE CENTERS OVER THE EXTREME NORTHWESTERN BAHAMAS AND WILL
HOLD WHILE SLOWLY MEANDERING TOWARDS THE NORTHEASTERN GULF OF
MEXICO BY THURSDAY MORNING. AT LOW-LEVELS...A REGION OF WEAK TRADE
WIND CONVERGENCE AND ENHANCED CONVECTIVE INSTABILITY IS LINGERING
OVER THE NORTHERN BAHAMAS AND THE FLORIDA STRAIGHT. THIS IS
LEADING TO SCATTERED THUNDERSTORMS THAT ARE FORECAST TO CONTINUE
THROUGH WEDNESDAY-THURSDAY. EXPECTING THESE TO PRODUCE
ACCUMULATIONS OF 10-15MM/DAY AND MAXIMA OF 20-35MM...DECREASING
GRADUALLY THROUGH WEDNESDAY AND RAPIDLY AFTERWARDS. ACTIVITY WILL
RETROGRESS SLOWLY...WHICH WILL MOVE THE FOCUS OF THE MOST
WIDESPREAD ACTIVITY FROM THE BAHAMAS INTO CUBA BY THURSDAY-FRIDAY.
EXPECTING ACCUMULATIONS INCREASING TO 05-10MM/DAY AND MAXIMA OF
15-25MM/DAY ACROSS CUBA...WITH A DECREASING TREND OVER THE BAHAMAS
BY THEN.

A LARGE TUTT IS APPROACHING THE NORTHEASTERN CARIBBEAN WITH
CIRCULATION TO THE NORTHEAST OF THE LEEWARD ISLANDS. TUTT WILL
RETROGRESS AND EXTEND ACROSS PUERTO RICO/USVI/LEEWARDS INTO
WEDNESDAY MORNING...HISPANIOLA/SOUTHEASTERN CUBA INTO THURSDAY
MORNING TO THEN EXIT INTO JAMAICA/CAYMAN ISLANDS. TUTT WILL
ENHANCE ACCUMULATIONS...LEADING TO MAXIMA OF 15-25M/DAY ACROSS
PUERTO RICO/DOMINICAN REPUBLIC. ON WEDNESDAY INTO
THURSDAY...EXPECTING A SIMILAR DISTRIBUTION OF PRECIPITATION WITH
AN INCREASE TO MAXIMA OF 20-35MM/DAY EXTENDING INTO PARTS OF
HAITI. ON THURSDAY-FRIDAY EXPECTING ISOLATED MAXIMA OF 20-35MM/DAY
ALSO IN PUERTO RICO...DOMINICAN REPUBLIC AND ALSO IN SOUTHEASTERN
CUBA/JAMAICA.

NEXT SYSTEMS OF INTEREST ARE TROPICAL WAVES ARRIVING IN THE BASIN.
THE FIRST WAVE WILL ENHANCE CONVECTION MOSTLY ACROSS NORTHERN
SOUTH AMERICA. ON TUESDAY...IT WILL LEAD TO MAXIMA OF 15-20MM/DAY
ACROSS THE GUIANAS. ON WEDNESDAY-EARLY THURSDAY...IT WILL PRODUCE
ACCUMULATIONS OF 20-30MM/DAY FROM THE SOUTHERN WINDWARD ISLANDS
INTO NORTHEASTERN VENEZUELA. ON THURSDAY-FRIDAY...EXPECTING A
FURTHER INCREASE...WITH MAXIMA OF 25-50MM/DAY ACROSS NORTHEASTERN
VENEZUELA/CENTRAL LESSER ANTILLES...AND 20-40MM/DAY IN THE
WINDWARD ISLANDS.

FURTHER WEST ACROSS COLOMBIA...ACTIVE DIURNAL CONVECTION WILL
PERSIST ACROSS THE NORTHWESTERN PORTION OF THE COUNTRY. EXPECTING
MAXIMA OF 20-40MM/DAY. IN THE MEANTIME...EXPECTING AN INCREASE IN
WESTERN VENEZUELA/NORTHEASTERN COLOMBIA DURING FRIDAY TO MAXIMA OF
15-25MM/DAY.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
41W      42W    44W    47W    50W    54W    57W    59W     TW
47W      50W    52W    55W    58W    61W    63W    66W     TW
84W      86W    89W    92W    95W    98W   100W   102W     TW

A TROPICAL WAVE ALONG 41W IS TO REACH FRENCH GUIANA LATER ON
WEDNESDAY...THEN QUICKLY MOVE ACROSS SURINAME TO GUYANA THROUGH
THURSDAY AFTERNOON.

A WAVE AT 47W IS REACHING FRENCH GUIANA ON TUESDAY. IT WILL THEN
PULL ACROSS SURINAME/GUYANA TO THE WINDWARD ISLANDS ON
WEDNESDAY...AND CENTRAL VENEZUELA ON THURSDAY.

TROPICAL WAVE ALONG 84W IS ENTERING CENTRAL AMERICA. ACROSS COSTA
RICA/NICARAGUA IT IS TO SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 30-60MM THROUGH WEDNESDAY MORNING. OVER SOUTHERN
HONDURAS-EL SALVADOR-SOUTHERN GUATEMALA EXPECTING SIMILAR
ACCUMULATIONS ON WEDNESDAY-THURSDAY. OVER GUATEMALA-SOUTHERN
MEXICO IT IS TO THEN TRIGGER RAINFALL AMOUNTS 15-20MM/DAY AND
MAXIMA OF 25-50MM ON WEDNESDAY. ACROSS SOUTHERN MEXICO EXPECT
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 25-50MM.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)
GALVEZ...WPC(USA)

$$





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