Prognostic Meteorological Discussion
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
221 PM EDT WED MAY 25 2016

TROPICAL DISCUSSION FROM MAY 25/12UTC: DEEP MID/UPPER LEVEL TROUGH
ENTERED THE WESTERN USA/NORTHWESTERN MEXICO. AS IT PUSHES
EAST...THE TROUGH IS PRESSING AGAINST A BROAD RIDGE TO THE SOUTH.
AT 500 HPA THE RIDGE EXTENDS NORTH FROM A CLOSED HIGH OVER CENTRAL
MEXICO TO THE CENTRAL USA AND EAST INTO CENTRAL AMERICA. THROUGH
FRIDAY EVENING THE RIDGE IS TO FLATTEN TO THE NORTH OF 20N AS THE
TROUGH SLOWLY MOVES EAST INTO THE CENTRAL USA. AS THE RIDGE
WEAKENS THE CAP INVERSION IS TO GRADUALLY RELAX ITS FOOTHOLD...
ALLOWING FOR DEEPER MOISTURE/CONVECTION TO DEVELOP. EARLY IN THE
CYCLE CONVECTION IS TO CLUSTER ALONG THE SIERRA MADRE ORIENTAL
OVER EASTERN MEXICO...TO RESULT IN RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-35MM. ALONG THE CONTINENTAL DIVIDE TO THE
SOUTH...DIURNAL ACTIVITY IS TO BUILD BETWEEN SOUTHERN CHIAPAS TO
NORTHWEST NICARAGUA. THROUGH THURSDAY AND FRIDAY THIS WILL
INCREASE TO 05-10MM/DAY AND MAXIMA OF 15-20MM/DAY.

EAST OF THE RIDGE...A DEEP/HIGH AMPLITUDE TROUGH LIES OVER THE
WESTERN ATLANTIC TO THE CENTRAL CARIBBEAN. THE RIDGE TO THE WEST
IS DIVERTING SHORT WAVE VORTICES ACROSS THE SOUTHEAST USA INTO THE
TROUGH TO THE EAST. THE INFLOW OF SHORT WAVE ENERGY WILL SUSTAIN
GRADUAL GENERATION OF A MID LEVEL LOW TO THE NORTH OF THE BAHAMAS
LATER TODAY/EARLY ON THURSDAY MORNING. BROAD TROUGH IS TO THEN
PERSIST THROUGH AT LEAST SATURDAY MORNING. AT LOW LEVELS...UNDER
THE INFLUENCE OF THE DEEP TROUGH...AN INDUCED/INVERTED TROUGH
EXTENDS NORTH ACROSS THE CENTRAL CARIBBEAN-HAITI/EASTERN CUBA TO
THE WESTERN ATLANTIC. ALONG THE BASE OF THIS TROUGH THE GFS IS
FORECASTING A LOW TO FORM LATER IN THE WEEK...WITH THE NHC
MONITORING THIS AREA FOR POSSIBLE SUBTROPICAL CYCLONE GENERATION.
THE LOW LEVEL TROUGH IS ENHANCING MOISTURE TRANSPORT AND
CONVERGENCE ACROSS THE CENTRAL CARIBBEAN. THROUGHOUT THE FORECAST
PERIOD THE ENVIRONMENTAL CONDITIONS WILL REMAIN FAVORABLE AND
CONDUCIVE TO ORGANIZED/LONG LASTING CONVECTION TO DEVELOP. ACROSS
CUBA AND THE BAHAMAS EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 25-50MM. THROUGH THURSDAY THIS WILL DECREASE TO
10-15MM/DAY AND MAXIMA OF 20-30MM. OVER HISPANIOLA AND JAMAICA
EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-40MM...WITH LOCALLY HIGHER AMOUNTS HIGHLY LIKELY. THROUGH
FRIDAY THE DAILY MAXIMA DECREASES TO 20-30MM. THE DEEP/HIGH
AMPLITUDE TROUGH IS TO ALSO INTERACT WITH THE ITCZ OVER COSTA
RICA-PANAMA-NORTHWEST COLOMBIA. ACROSS PANAMA-COSTA RICA/NORTHWEST
COLOMBIA EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM.

A MID LEVEL SHORT WAVE RIDGE TO THE EAST DOMINATES THE EASTERN
CARIBBEAN/ISLAND CHAIN...WHERE IT SUSTAINS A FAIRLY STRONG CAP
INVERSION. THIS RIDGE IS EXPECTED TO HOLD THROUGH FRIDAY
MORNING...THEN CRUMBLE UNDER PRESSURE FROM THE TROUGH TO THE WEST.
AS THE RIDGE WEAKENS EXPECTING CAP INVERSION TO SLACKEN...WITH
PWAT CONTENT TO GRADUALLY INCREASE. MEANWHILE...EXPECTING FAIR
WEATHER CONDITIONS ACROSS PUERTO RICO AND THE LESSER ANTILLES. ON
FRIDAY...SCATTERED SHOWERS ARE FORECAST TO DEVELOP...TRIGGERING
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM. OVER
VENEZUELA...CONVECTION ALONG THE NEAR EQUATORIAL TROUGH IS TO
CLUSTER TO THE SOUTH OF 07N...TO RESULT IN RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC.
INITIAL    24    36    48    60    72    84    96         TYPE
57W       61W   65W   68W   71W   74W   77W   80W         TW
78W       79W   80W   81W   DISSIPATES                    TW

A TROPICAL WAVE ALONG 57W AND SOUTH OF 10N MOVES ACROSS GUYANA TO
EASTERN VENEZUELA EARLY ON THURSDAY...WHERE IT IS TO SUSTAIN
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. OVER
CENTRAL VENEZUELA THIS IS TO INTERACT WITH THE NEAR EQUATORIAL
TROUGH TO TRIGGER RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM. LATER IN THE DAY ACTIVITY WILL SPREAD ACROSS WESTERN
VENEZUELA TO EASTERN COLOMBIA. AS IT PULLS ACROSS COLOMBIA
EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM.

TROPICAL WAVE ALONG 78W AND SOUTH OF 15N IS TO INTERACT WITH THE
INDUCED TROUGH OVER THE CENTRAL CARIBBEAN. THROUGH FRIDAY MORNING
THE WAVE BECOMES ILL DEFINED AS IT MERGES WITH THE LOW LEVEL
TROUGH TO THE NORTH. MEANWHILE...AS IT PULLS ACROSS WESTERN
COLOMBIA TO PANAMA THIS WILL FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 35-70MM.

CARDOS...SMN (MEXICO)
CABANERIT...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)

$$





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