Prognostic Meteorological Discussion
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FXCA20 KWBC 191832
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
232 PM EDT FRI SEP 19 2014

AT 15 UTC TS POLO CENTERED NEAR 17.3N 105.7W...WITH MAXIMUM
SUSTAINED WINDS OF 60KT AND CENTRAL PRESSURE OF 982 HPA...MOVING
TO THE WNW AT 6KT.

DISCUSSION FROM SEPTEMBER 19/00UTC: AT 250 HPA...A CLOSED HIGH
OVER CHIHUAHUA MEXICO ANCHORS A RIDGE OVER WESTERN PORTIONS OF THE
DOMAIN. THE RIDGE EXTENDS ON CONTINENTAL AREA TO THE NORTH OF 20N
AND WEST OF 90W. AT MID LEVELS...A RIDGE IS TO GRADUALLY BUILD
ACROSS NORTHERN MEXICO/WESTERN USA. RIDGE ALOFT IS TO VENT DIURNAL
CONVECTION ACROSS MEXICO...WITH ACTIVITY ALONG THE SIERRA MADRE TO
RESULT IN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM.
ON THE CENTRAL STATES OF MEXICO EXPECTING ACCUMULATION OF
10-15MM/DAY AND MAXIMA OF 20-30MM...WHILE ON THE SOUTHERN STATES
OF MEXICO EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM. THE BROAD RIDGE PATTERN OVER THE CONTINENT IS TO STEER TS
POLO WEST INTO THE PACIFIC. AS IT MEANDERS SOUTH OF THE BAJA
PENINSULA LATER ON SATURDAY...OUTER BAND CONVECTION IS LIKELY TO
AFFECT BAJA CALIFORNIA SUR...WITH RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-30MM.

BROAD MID/UPPER LEVEL RIDGE OVER THE WESTERN USA AND MEXICO
SUSTAINS THE SOUTHWARD AMPLIFICATION OF A TROUGH ACROSS THE
EASTERN USA-FLORIDA PENINSULA TO THE EASTERN GULF OF MEXICO. A
STRONG SHORT WAVE TROUGH OVER THE SOUTHEAST USA EARLY THIS MORNING
IS FORECAST TO ROUND THE BASE OF THE LONG WAVE LATER ON
TODAY/EARLY SATURDAY MORNING. THIS IS TO THEN INDUCE THE GRADUAL
AMPLIFICATION OF THE TROUGH TO THE WESTERN TIP OF CUBA/NORTHERN
YUCATAN LATER ON SATURDAY. AT LOW LEVELS THIS IS TO SUSTAIN A
TROUGH ACROSS SOUTHERN FLORIDA/NORTHWEST BAHAMAS TO THE NORTHERN
GULF OF MEXICO. AS UPPER TROUGH PATTERN DEEPENS THE SURFACE TROUGH
IS TO THEN ALIGN FROM NORTHEAST TO SOUTHWEST. OVER THE WESTERN
CARIBBEAN IS TO ALSO SUSTAIN AN INDUCED TROUGH THAT IS TO
RETROGRESS ACROSS BELIZE/QUINTANA ROO MEXICO TO THE YUCATAN.
ACROSS THE NORTHWEST BAHAMAS THIS IS TO FAVOR RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM. THROUGH DAY 03 THIS DECREASES
TO 05-10MM/DAY AND MAXIMA OF 15MM. OVER CUBA EXPECTING
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM IN SCATTERED
DIURNAL CONVECTION. OVER BELIZE-QUINTANA ROO/NORTHERN
GUATEMALA...THE MOST ACTIVE CONVECTION IS EXPECTED ON SATURDAY AND
SUNDAY...WHEN THE INVERTED TROUGH IS TO SUSTAIN RAINFALL AMOUNTS
OF 15-20MM/DAY AND MAXIMA OF 30-60MM.

A WANING TUTT LOW LIES TO THE SOUTH OF THE UPPER LEVEL LONG WAVE
AXIS...WITH CLOSED CIRCULATION SOUTH OF THE CAYMAN ISLES EXTENDING
A SHORT WAVE TROUGH TO NORTHEAST HONDURAS. UNDER INFLUENCE OF DEEP
MID/UPPER LEVEL TROUGH TO THE NORTH...THE TUTT IS TO SLOWLY LIFT
NORTH...WEAKENING ACROSS CENTRAL CUBA EARLY NEXT WEEK. ACROSS THE
CAYMAN ISLES THIS IS TO FAVOR ISOLATED TO SCATTERED CONVECTION
WITH ACCUMULATION OF 00-05MM/DAY AND MAXIMA OF 10MM. ACROSS
NORTHEAST HONDURAS/NICARAGUA EXPECTING ACCUMULATION OF 05-10MM/DAY
AND MAXIMA OF 15-25MM. ACROSS CUBA IT IS TO THEN FAVOR RAINFALL
AMOUNTS OF 10-15MM AND MAXIMA OF 20-40MM LATER ON SUNDAY TO MONDAY
MORNING.

AS THE TUTT WEAKENS...THE EASTERN PACIFIC ITCZ RETURNS TO ITS
CLIMATOLOGICAL POSITION OVER SOUTHERN CENTRAL AMERICA. THIS IS TO
THEN EXTENDS ACROSS COSTA RICA-PANAMA TO NORTHERN SOUTH AMERICA.
ACROSS COSTA RICA/SOUTHERN NICARAGUA TO PANAMA IT IS TO FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM. OVER
WESTERN-NORTHERN COLOMBIA INITIALLY EXPECTING RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 30-60MM. THIS DECREASES TO 10-15MM/DAY
AND MAXIMA OF 20-40MM THROUGH SUNDAY EVENING. FURTHERMORE...A LOW
FORMED ALONG THE CONVERGENCE ZONE NEAR 10N 90W. THIS IS TO MEANDER
WEST AS THE CYCLE PROGRESSES. EARLY IN THE CYCLE THIS IS TO
ENHANCE CONVECTIVE DEVELOPMENT ACROSS SOUTHERN HONDURAS-EL
SALVADOR...TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM. THROUGH SUNDAY ACTIVITY BUILDS WEST ACROSS SOUTHERN
GUATEMALA TO SOUTHERN CHIAPAS IN MEXICO...WITH RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 30-60MM.

ALSO AT 250 HPA...A WANING CELL OF THE SUBEQUATORIAL RIDGE EXTENDS
ACROSS THE CENTRAL-EASTERN CARIBBEAN. A TUTT TO THE EAST CENTERS
ON A CLOSED LOW OVER THE NORTHERN LEEWARD ISLANDS. A DEEPER/BETTER
ORGANIZED TUTT LOW CENTERS TO THE EAST NEAR 23N 48W. A BUILDING
CELL OF THE SUBTROPICAL RIDGE OVER THE WESTERN ATLANTIC WILL ALLOW
TUTT NORTH OF THE LEEWARDS TO RETROGRESS TO PUERTO RICO EARLY ON
SATURDAY...WHERE IT IS TO REMAIN THROUGH EARLY NEXT WEEK. THE
OTHER LOW MEANDERS WEST...AND IT IS TO MOVE NORTH OF THE ISLANDS
LATER ON MONDAY/TUESDAY. AT MID LEVELS...MODELS AGREE ON THEIR
FORECAST OF AN INVERTED TROUGH MEANDERING WEST ACROSS THE ISLAND
CHAIN EARLY ON SATURDAY MORNING...AND THROUGH SUNDAY MORNING
PULLING ACROSS PUERTO RICO TO THE MONA PASSAGE/DOMINICAN REPUBLIC.
THIS WILL COMBINE WITH TUTT PATTERN ALOFT TO HELP SUSTAIN
UNSETTLED WEATHER CONDITIONS ACROSS THE EASTERN CARIBBEAN ISLES.
ACROSS THE FRENCH/LEEWARD ISLANDS EXPECTING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-30MM...WHILE ACROSS PUERTO RICO
EXPECT ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-35MM. ACROSS
HISPANIOLA MOST ACTIVE CONVECTION IS EXPECTED ON SUNDAY...WHEN
UNDER INFLUENCE OF MID LEVEL TROUGH EXPECTING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-30MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
49W     51W    53W    56W    58W    61W    63W    65W     TW
67W     71W    73W    76W    78W    80W    82W    84W     TW

TROPICAL WAVE ALONG 49W MOVES NORTH OF THE GUIANAS LATER ON
FRIDAY/EARLY SATURDAY MORNING...WITH MOST ACTIVE CONVECTION
EXPECTED ALONG AND NORTH OF THE ITCZ TO THE NORTH. THE WAVE ENTERS
THE LESSER ANTILLES DURING LATE AFTERNOON ON SUNDAY/EARLY MONDAY
MORNING...WHERE IN INTERACTION WITH THE TUTT ALOFT IT IS TO
SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM.
ACROSS PUERTO RICO AND THE VIRGIN ISLES IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM.

TROPICAL WAVE ALONG 67W MOVES ACROSS HISPANIOLA THROUGH MID
MORNING ON SATURDAY...MEANWHILE FAVORING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM. IT ENTERS JAMAICA AROUND
NOONTIME ON SUNDAY...TO TRIGGER SCATTERED CONVECTION AND
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM. ACROSS
NORTHWEST VENEZUELA-NORTHERN COLOMBIA THIS IS TO SUSTAIN RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 30-60MM...WHILE OVER
PANAMA-COSTA RICA EXPECTING ACCUMULATION OF 10-15MM/DAY AND MAXIMA
OF 20-40MM.

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




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