Prognostic Meteorological Discussion
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FXCA20 KWBC 221832
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
232 PM EDT MON SEP 22 2014

DISCUSSION FROM SEPTEMBER 22/00UTC: BROAD CELL OF THE SUBTROPICAL
RIDGE DOMINATES MEXICO-WESTERN/CENTRAL USA...AS IT ANCHORS ON A
250 HPA HIGH THAT MEANDERS OVER SOUTHERN CHIHUAHUA/SONORA IN
NORTHWEST MEXICO. UPPER RIDGE PATTERN IS TO REMAIN NEARLY
UNCHANGED THROUGH WEDNESDAY MORNING. IT IS TO THEN CRUMBLE AS A
TROUGH AMPLIFIES ACROSS THE CENTRAL-WESTERN USA TO THE NORTHERN
STATES OF MEXICO LATER IN THE DAY. AS A RESULT...DIURNAL
CONVECTION IS TO DOMINATE ACROSS MEXICO OVER THE NEXT TWO DAY.
ALONG THE SIERRA MADRE OCCIDENTAL EXPECTING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM. BUT AS THE TROUGH AMPLIFIES TO
NORTHERN MEXICO...THIS WILL INCREASE TO 10-15MM/DAY AND MAXIMA OF
20-40MM. ALONG THE SIERRA MADRE ORIENTAL/NORTHEAST MEXICO
EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 30-60MM.
THE MOST INTENSE IS EXPECTED BETWEEN TAMAULIPAS AND VERACRUZ.
ALTHOUGH A SLIGHT DECREASE IS EXPECTED ON DAY 02...AMPLIFYING
TROUGH ON WEDNESDAY IS TO ONCE AGAIN FAVOR A SURGE IN ACTIVITY
ACROSS COAHUILA-TAMAULIPAS TO NORTHERN VERACRUZ. ON THE SIERRA
MADRE DEL SUR AND CENTRAL STATES OF MEXICO... INITIALLY EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM. BUT AS A
LOW ALONG THE ITCZ TO THE SOUTH BECOMES BETTER ORGANIZED... THIS
WILL INCREASE TO 15-20MM/DAY AND MAXIMA OF 30-60MM.

A LONG WAVE TROUGH BOUNDS THE EASTERN FRINGES OF THE SUBTROPICAL
RIDGE...AS IT EXTENDS AT 250 HPA ACROSS THE EASTERN USA TO THE
YUCATAN PENINSULA. BUT AS THE RIDGE WEAKENS TO THE WEST...TROUGH
IS TO GRADUALLY WEAKEN AS THE CYCLE PROGRESSES. THROUGH THURSDAY
EVENING THE TROUGH IS THEN FORECAST TO PULL. AT LOW LEVELS...THIS
SUSTAINS A BROAD TROUGH ACROSS THE EASTERN USA/WESTERN
ATLANTIC...AND AN INDUCED INVERTED TROUGH OVER THE EASTERN GULF OF
MEXICO/FLORIDA PENINSULA. THIS IS ENHANCING LOW LEVEL MOISTURE
CONVERGENCE FROM WESTERN CUBA TO THE NORTHWEST BAHAMAS. ACROSS THE
NORTHWEST-CENTRAL BAHAMAS EXPECTING SCATTERED CONVECTION TO
SUSTAIN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM...WHILE OVER CUBA EXPECT 10-15MM/DAY AND MAXIMA OF
20-40MM. THE TROUGH ALOFT IS TO ENHANCE SEA BREEZE CONVERGENCE
ACROSS BELIZE-YUCATAN PENINSULA THROUGH TUESDAY EVENING...WITH
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM. OTHER
CONVECTIVE ENHANCEMENT TO THE SOUTH IS EXPECTED FROM SOUTHERN
CHIAPAS TO SOUTHERN GUATEMALA...WHERE THIS IS TO FAVOR RAINFALL
AMOUNTS OF 15-20MM/DAY OF 40-80MM. ON TUESDAY TO WEDNESDAY THE
MAXIMA DECREASES TO 25-50MM.

THERE IS ALSO A TUTT LOW OVER THE WESTERN CARIBBEAN. THIS IS TO
CONTINUE WEAKENING AS IT INTERACTS WITH HIGH AMPLITUDE TROUGH TO
THE WEST...WITH SHORT WAVE ENERGY GRADUALLY SHREDDING ACROSS THE
CAYMAN ISLES-CUBA. THROUGH TUESDAY EVENING THE TROUGH IS FORECAST
TO MEANDER NORTH ACROSS CUBA. MEANWHILE...ACROSS JAMAICA IT IS TO
FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.
ACROSS CENTRAL-EASTERN CUBA...AS IT INTERACTS WITH A TROPICAL
WAVE...EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM.

FARTHER EAST...SHORT WAVE RIDGE EXTENDS ACROSS THE CENTRAL
CARIBBEAN TO NORTHERN COLOMBIA/SOUTHERN CENTRAL AMERICA...WITH
AXIS ANCHORING AT 250 HPA ON A CLOSED HIGH OVER LA GUAJIRA
PENINSULA. SHORT WAVE RIDGE PATTERN IS TO PERSIST NEARLY UNCHANGED
THROUGH THURSDAY MORNING. MEANWHILE...THIS IS TO VENT DEEP
CONVECTION ACROSS NORTHWEST VENEZUELA/NORTHERN-WESTERN COLOMBIA...
WHERE WE EXPECT RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM. THIS DECREASES TO MAXIMA OF 25-50MM LATER ON
TUESDAY-WEDNESDAY. ACROSS COSTA RICA-PANAMA TO SOUTHERN NICARAGUA
EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM.

ANOTHER RIDGE LIES NORTH OF THE GREATER ANTILLES...WITH AXIS AT
250 HPA ENVELOPING AREA BETWEEN 72W-57W AND 20N-35N. AN ILL
ORGANIZED TUTT LOW LIES TO THE SOUTHEAST OF THIS AXIS...CENTERING
OVER THE NORTHERN LEEWARD ISLANDS. A DEEPER/BETTER ORGANIZED TUTT
LOW LIES TO THE EAST...WITH CLOSED CIRCULATION NEAR 25N 52W. UNDER
INFLUENCE OF THE RIDGE TO THE NORTH...BROAD TUTT IS TO RETROGRESS
TOWARDS THE NORTHEAST CARIBBEAN. AS IT NEARS THE ISLANDS...IT IS
TO RAPIDLY ABSORB THE WANING LOW OVER THE NORTHERN LEEWARD ISLES.
LATER ON WEDNESDAY/EARLY THURSDAY MORNING THE DEEP LOW MOVES NORTH
OF PUERTO RICO...WHILE EXTENDING A TROUGH INTO THE EASTERN
CARIBBEAN. THIS REFLECTS QUITE WELL AT MID LEVELS...AND AS A
RESULT IT WILL SUSTAIN ENVIRONMENTAL CONDITIONS FAVORABLE AND
CONDUCIVE TO ORGANIZED DEEP CONVECTION. INITIALLY...MOST ACTIVE
CONVECTION IS EXPECTED OVER THE FRENCH-LEEWARD ISLES...WITH
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM THROUGH
TUESDAY MORNING...AND MAXIMA OF 30-60MM ON TUESDAY TO WEDNESDAY.
ACROSS PUERTO RICO EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM ON TUESDAY THROUGH THURSDAY...WITH SIMILAR
AMOUNTS ACROSS HISPANIOLA.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
47W     48W    50W    52W    54W    56W    58W    60W   TUTT
INDCD.
63W     65W    68W    70W    72W    74W    76W    78W     TW
81W     82W    83W    84W    85W    86W    88W    89W     TW

THE DEEP TUTT SUSTAINS AN INDUCED TROUGH IN THE EASTERLY
TRADES...WITH AXIS NORTH ALONG 47W. MOST ACTIVE CONVECTION WITH
THIS FEATURE IS EXPECTED TO THE NORTH OF 15N...AND IT IS TO AFFECT
THE FRENCH/LEEWARD ISLES LATER ON DAY 04 WITH RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-40MM.

TROPICAL WAVE ALONG 63W IS TO INTERACT WITH TUTT LOW OVER THE
LEEWARD ISLES TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-45MM. ACROSS PUERTO RICO IT IS TO THEN FAVOR RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 30-60MM...WITH MOST ACTIVE
ACROSS EASTERN PORTIONS OF THE ISLAND. OVER THE WINDWARD
ISLES-NORTHEAST VENEZUELA IT IS TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. AS THE WAVE MOVES ACROSS
HISPANIOLA IT IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 25-50MM ON TUESDAY-WEDNESDAY. OVER NORTHWEST
VENEZUELA-NORTHERN COLOMBIA...IN INTERACTION WITH THE
NET...EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM.

TROPICAL WAVE ALONG 81W IS TO INTERACT WITH TUTT TO SUSTAIN
SCATTERED CONVECTION ACROSS JAMAICA WITH ACCUMULATION OF
05-10MM/DAY AND MAXIMA OF 15-25MM. ACROSS THE CAYMAN ISLANDS IT IS
TO THEN FAVOR RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM. OVER COSTA RICA TO NICARAGUA EXPECTING RAINFALL AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-45MM...WHILE OVER HONDURAS/EL
SALVADOR IT IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA
OF 25-50MM...WHILE OVER GUATEMALA/BELIZE IT IS TO ALSO SUSTAIN
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM.

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




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