Prognostic Meteorological Discussion
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FXCA20 KWBC 261830
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT TUE AUG 26 2014

AT 15UTC...HURRICANE CRISTOBAL CENTERED NEAR 27.2N 71.7W...WITH
CENTRAL PRESSURE OF 988 HPA AND MAXIMUM SUSTAINED WINDS OF 65KT.
SEE NHC BULLETIN FOR OFFICIAL FORECAST.

DISCUSSION FROM AUGUST 26/00UTC: UPPER LEVEL ANALYSIS SHOWS A TUTT
WITH AXIS NORTH-NORTHEAST ACROSS SOUTHWEST STATES OF MEXICO TO THE
GULF COAST OF TEXAS. THIS SPLITS THE SUBTROPICAL RIDGE IN TWO
CELLS...WITH WESTERNMOST DOMINATING THE NORTHERN STATES OF
MEXICO/BAJA PENINSULA WHILE THE EASTERNMOST ENVELOPS THE
GULF-CENTRAL/SOUTHERN STATES OF MEXICO-CUBA AND MOST OF CENTRAL
AMERICA. UNDER INFLUENCE OF AN AMPLIFYING TROUGH OVER THE WESTERN
USA THIS PATTERN IS TO RAPIDLY EVOLVE. THROUGH THURSDAY AFTERNOON
THE TROUGH IS TO DEEPEN ACROSS NEW MEXICO TO NORTHERN
SONORA/CHIHUAHUA. AS IT PRESSES AGAINST THE RIDGE TO THE
SOUTH...THE RIDGE IS FORECAST TO GRADUALLY WEAKEN. RIDGE PATTERN
OVER THE GULF-CENTRAL AMERICA WILL BE MORE RESILIENT...AND AS THE
TROUGH DEEPENS TO THE WEST THIS WILL ALLOW THE RIDGE TO BUILD
NORTHWARD ACROSS THE SOUTHEAST USA. AS UPPER RIDGE PATTERN
EVOLVES...TUTT IS TO SPLIT IN TWO. NORTHERN HALF IS TO REMAIN OVER
EAST TEXAS-NORTHEAST MEXICO...WHILE THE SOUTHERN HALF QUICKLY
PULLS WEST INTO THE EASTERN TROPICAL PACIFIC. OVER NORTHWEST
MEXICO...AS UPPER LEVEL RIDGE WEAKENS...GUIDANCE SHOWING A
DECREASE IN DIURNAL CONVECTION ACROSS SONORA-SINALOA-CHIHUAHUA.
EARLY IN THE CYCLE EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-40MM. THROUGH THURSDAY THIS DECREASES TO 05-10MM/DAY
AND MAXIMA OF 15-25MM. ACROSS CENTRAL MEXICO EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM. OVER SOUTHERN MEXICO
MOST ACTIVE CONVECTION IS EXPECTED ALONG THE PACIFIC COAST AS
ENHANCED BY A SURFACE TROUGH. THIS IS TO ALSO SUSTAIN COASTAL
CONVECTION ACROSS SOUTHERN GUATEMALA-EL SALVADOR/ SOUTHERN
HONDURAS TO NORTHWEST NICARAGUA...WITH RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY THIS INCREASES
TO 15-20MM/DAY AND MAXIMA OF 35-70MM.

A NORTH-TO-SOUTH MID/UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN
FRINGES OF THE SUBTROPICAL RIDGE...WITH AXIS ALONG 72W/73W.
ANOTHER RIDGE LIES TO THE EAST OF THIS TROUGH...ENVELOPING THE
ATLANTIC BASIN WHILE ANCHORING ON A CLOSED HIGH NEAR 30N 56W.
HURRICANE CRISTOBAL IS FORECAST TO LIFT NORTH BETWEEN THESE
SYSTEMS. AS IT PULLS AWAY...EXPECTING A DECREASE IN ASSOCIATED
CONVECTION ACROSS THE SOUTHEAST BAHAMAS-TURKS AND CAICOS.
MEANWHILE...IT IS TO FAVOR ADDITIONAL RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM IN SCATTERED DEEP CONVECTION.

DEEP MID LEVEL TROUGH PATTERN OVER THE WESTERN ATLANTIC SUSTAINS
AN INDUCED INVERTED TROUGH OVER THE CARIBBEAN...WITH AXIS NORTH
FROM GULF OF URABA/ EASTERN PANAMA TO JAMAICA/EASTERN CUBA. TROUGH
IS FORECAST TO MEANDER WESTWARD ACROSS THE CENTRAL CARIBBEAN AS
DISPLACED BY PREVAILING EASTERLY TRADES...MOVING TO CENTRAL
AMERICA EARLY ON THURSDAY MORNING. AS IT MEANDERS OVER THE CENTRAL
CARIBBEAN IT IS TO INTERACT WITH THE EASTERN PACIFIC ITCZ AND THE
NEAR EQUATORIAL TROUGH. OVER NORTHWEST COLOMBIA-EASTERN PANAMA
THIS IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM. THROUGH THURSDAY THIS DECREASES TO 10-15MM/DAY AND MAXIMA
OF 20-40MM. ACROSS WESTERN PANAMA-COSTA RICA INITIALLY EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM...INCREASING
TO MAXIMA OF 25-50MM ON WEDNESDAY-THURSDAY. AS THE TROUGH MEANDERS
WEST INTO NICARAGUA/NORTHEAST HONDURAS IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THE TROUGH
IS TO ALSO ENHANCE CONVECTION ACROSS JAMAICA-EASTERN CUBA EARLY IN
THE CYCLE...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM. AS MOISTURE POOLS ACROSS CUBA MAXIMA INCREASES TO 25-50MM
ON WEDNESDAY AFTERNOON.

ALSO AT UPPER LEVELS...A TUTT EXTENDS NORTH ACROSS WESTERN
VENEZUELA TO THE EASTERN CARIBBEAN. THROUGH THIS EVENING THIS IS
TO MEANDER WEST INTO EASTERN COLOMBIA-SOUTHERN
HISPANIOLA...REACHING THE CENTRAL CARIBBEAN/GULF OF URABA LATER ON
WEDNESDAY. AS IT IS TO REMAIN CUT OFF FROM THE FLOW...THIS IS TO
THEN WEAKEN WHILE MEANDERING FARTHER WEST. EARLY IN THE CYCLE IT
IS TO ENHANCE CONVECTION ACROSS PUERTO RICO AND THE DOMINICAN
REPUBLIC...TO FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM. MOST ACTIVE TO THE SOUTH IS EXPECTED IN INTERACTION WITH
THE NEAR EQUATORIAL TROUGH OVER VENEZUELA AND COLOMBIA...WHERE IT
IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM.

ANOTHER TUTT IS TO RETROGRESS ACROSS THE ATLANTIC...WITH CLOSED
LOW MOVING NORTH OF PUERTO RICO BY MIDDAY ON THURSDAY. IT IS TO
THEN MEANDER NORTH OF THE FORECAST AREA THROUGH THE END OF THE
WEEK. AT MID LEVELS IT IS TO REFLECT AS AN INVERTED TROUGH OVER
THE LEEWARD ISLES BY MIDDAY ON THURSDAY. THIS MEANDERS WEST ACROSS
THE VIRGIN ISLES TO PUERTO RICO LATER IN THE DAY. POSITIVE
INTERACTION WITH A TROPICAL WAVE ENTERING THE BASIN IS
LIKELY...SEE BELOW FOR DETAILS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
41W     45W    49W    52W    55W    58W    60W     62W     TW
50W     54W    58W    62W    65W    69W    73W     76W     TW

A TROPICAL WAVE ALONG 41W REACHES FRENCH GUIANA LATER ON
WEDNESDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY
AND MAXIMA OF 10MM. THIS IS TO ENTER THE FRENCH/LEEWARD ISLES
EARLY ON FRIDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. IN INTERACTION WITH A TUTT IT
IS TO THEN SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM.

A TROPICAL WAVE ALONG 50W AND SOUTH OF 15N MOVES ACROSS THE
GUIANAS EARLY IN THE CYCLE...TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM. OVER NORTHEAST VENEZUELA AND
THE WINDWARD ISLES EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-30MM. OVER THE EASTERN CARIBBEAN MOST ACTIVE
CONVECTION IS EXPECTED TO THE SOUTH OF 15N/16N...WHILE OVER
VENEZUELA IN INTERACTION WITH THE NET IT IS TO SUSTAIN RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY IT
DECREASES TO 05-10MM/DAY AND MAXIMA OF 15-20MM AS IT ENTERS
COLOMBIA.

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




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