THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


CARIBBEAN FORECAST DISCUSSION




TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
218 PM EST TUE JAN 27 2015

DISCUSSION FROM JANUARY 27/00UTC: WEST OVER THE DOMAIN...A HIGH
NEAR COLIMA/NAYARIT IN SOUTHWEST MEXICO SUSTAINS A RIDGE FROM
NORTHERN CENTRAL AMERICA TO THE SOUTHWEST USA. STRONG MID/UPPER
LEVEL RIDGE PATTERN IS FORECAST TO PERSIST OVER THE NEXT COUPLE OF
DAYS...MEANWHILE FAVORING A STRONG CAP INVERSION. LATER ON
THURSDAY...HOWEVER...A TROUGH ON THE SOUTHERN STREAM IS TO MOVE TO
THE BAJA PENINSULA/NORTHWEST STATES OF MEXICO. DEEP TROUGH IS TO
THEN SUSTAIN A WARM/MOIST ADVECTIVE PATTERN ACROSS THE BAJA
PENINSULA TO SONORA-SINALOA-CHIHUAHUA IN NORTHWEST MEXICO. THROUGH
FRIDAY AFTERNOON THE INFLOW OF TROPOSPHERIC MOISTURE IS TO
INTENSIFY...WITH MODELS AGREEING ON POTENTIAL FOR MODERATE TO
HEAVY RAINS DURING THE DAY. ON THURSDAY EXPECTING RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15-20MM...WHILE ON FRIDAY EXPECT
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM. THERE IS A
RISK OF MODERATE TO HEAVY SNOWFALL AMOUNTS OVER THE HIGHER
MOUNTAIN PEAKS OVER WESTERN CHIHUAHUA.

AT MID/UPPER LEVELS...A DEEP TROUGH EXTENDS ACROSS THE EASTERN
USA/WESTERN ATLANTIC TO THE CARIBBEAN. HIGHLY AMPLIFIED POLAR
TROUGH PATTERN IS TO PERSIST DURING THE NEXT 36-48 HRS...THEN
RAPIDLY DEGRADE LATER IN THE WEEK AS SHORT WAVE ENERGY SHEARS EAST
AND NORTH...WITH TROUGH FORECAST TO PULL LATER IN THE WEEK.
MEANWHILE...THIS IS TO FOCUS SHORT WAVE ENERGY ACROSS THE ISLAND
OF HISPANIOLA. AT LOW LEVELS...THE TROUGH ALOFT SUSTAINS A BROAD
TROUGH ACROSS THE EASTERN USA/WESTERN ATLANTIC AND A POLAR FRONT
ACROSS THE SOUTHEAST BAHAMAS-EASTERN CUBA TO THE NORTHWEST
CARIBBEAN/GULF OF HONDURAS. LATER TODAY THE FRONT MOVES TO THE
TURKS AND CAICOS...TRAILING ACROSS EASTERN CUBA-JAMAICA TO
NORTHERN HONDURAS. FRONT IS TO THEN STALL OVER NORTHERN
HISPANIOLA-NORTHWEST CARIBBEAN THROUGH MIDDAY ON THURSDAY. LATER
IN THE DAY...TRAILING END OF THE FRONT LIFTS ACROSS THE CAYMAN
ISLES TO CUBA...WHERE IT IS TO REMAIN THROUGH THE END OF THE WEEK.
OVER THE SOUTHEAST BAHAMAS/TURKS AND EASTERN CUBA THIS IS TO FAVOR
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM. MOST INTENSE
IS EXPECTED ACROSS HISPANIOLA... WHERE THIS IS TO SUSTAIN RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM LATER ON WEDNESDAY
THROUGH FRIDAY MORNING. FURTHERMORE...FRONTAL NORTHERLIES OF
15-20KT OVER THE WESTERN CARIBBEAN ARE TO FAVOR SCATTERED
CONVECTION ALONG THE NORTH COAST OF HONDURAS/ISLAS DE LA BAHIA TO
NORTHEAST GUATEMALA...WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA
OF 15-25MM. THROUGH WEDNESDAY MORNING THIS DECREASES TO
05-10MM/DAY AND MAXIMA OF 15MM.

THE POLAR FRONT ALSO SUSTAINS A PREFRONTAL SHEAR LINE AND AN
INDUCED/ INVERTED TROUGH OVER THE CARIBBEAN. EARLY THIS MORNING
THE SHEAR LINE EXTENDED ACROSS HAITI TO WESTERN PANAMA...WITH
BOUNDARY LAYER WINDS OF 20-25KT OVER THE SOUTHERN
CARIBBEAN/EASTERN NICARAGUA. THROUGH WEDNESDAY MORNING THE SHEAR
LINE MOVES TO THE DOMINICAN REPUBLIC...TRAILING TO PANAMA/SOUTHERN
CARIBBEAN AS STRONG NORTHERLY TRADES PERSIST. THROUGH THURSDAY
MORNING THE SHEAR LINE MOVES TO PUERTO RICO...TRAILING TO THE
SOUTHERN CARIBBEAN/SOUTHERN CENTRAL AMERICA. THIS IS TO THEN
MEANDER BETWEEN PUERTO RICO AND THE VIRGIN ISLES OVER THE NEXT
COUPLE OF DAYS. THE INDUCED/INVERTED TROUGH...MEANWHILE...IS TO
GRADUALLY RELOCATE TO THE EASTERN CARIBBEAN DURING THE DAY ON
THURSDAY. UNDER INFLUENCE OF THIS TROUGH...AND A RIDGE TO THE
EAST...A MOIST SOUTHEASTERLY FLOW IS TO PERSIST ACROSS THE ISLAND
CHAIN...TO CONVERGE OVER HISPANIOLA/SOUTHWEST PUERTO RICO. OVER
HISPANIOLA THE SHEAR LINE IS TO FAVOR RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-40MM. AS IT MOVES ACROSS PUERTO RICO
AN THE VIRGIN ISLANDS EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-35MM. OVER THE SOUTHERN CARIBBEAN EXPECTING MOST
ACTIVE ACROSS WESTERN PANAMA-COSTA RICA ON WEDNESDAY TO
THURSDAY...WITH RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM.

FURTHERMORE...THE SURGING NORTHERLY TRADES ACROSS THE
CARIBBEAN/CENTRAL AMERICA WILL DRIVE THE EASTERN PACIFIC ITCZ
SOUTH TO ITS CLIMATOLOGICAL POSITION NEAR THE EQUATOR LATER
TODAY/EARLY ON THURSDAY MORNING. STRONG NORTHERLIES ACROSS
PANAMA/COSTA RICA ARE TO THEN FAVOR UPWELLING OF COLD WATER ALONG
THE COAST OF COLOMBIA/PANAMA-COSTA RICA...LEADING TO A GRADUAL
INCREASE IN CONVECTIVE STABILITY AND A DECREASE IN COASTAL
CONVECTION ON THE ANDEAN REGION AND WEST COAST OF COLOMBIA. AS A
RESULT EXPECTING RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF
10MM. MOST ACTIVE TO THE SOUTHWEST IS EXPECTED ON THURSDAY TO
FRIDAY WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM.

EAST OVER THE DOMAIN...RETROGRESSING TUTT/TUTT LOW IS TO MEANDER
OVER THE CENTRAL TROPICAL ATLANTIC...WITH AXIS TO MEANDER JUST
NORTH OF THE GUIANAS LATER TODAY THROUGH THURSDAY MORNING. THIS IS
TO THEN PROVIDE VENTILATION ALOFT TO CONVECTION ACROSS SURINAME
AND FRENCH GUIANA...WHERE WE EXPECT RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM THROUGH WEDNESDAY MORNING...AND
10-15MM/DAY AND MAXIMA OF 20-35MM THEREAFTER. CONVECTION IS TO
SPREAD WEST ALONG THE COAST LATER ON THURSDAY TO AFFECT
GUYANA...WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-20MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
NONE

JN BAPTISTE...MS (SAINT LUCIA)
NANDA...MDS (SURINAME)
DAVISON...WPC (USA)




Last Updated: 218 PM EST TUE JAN 27 2015