Prognostic Meteorological Discussion
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FXCA20 KWBC 261831
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT THU MAY 26 2016

TROPICAL DISCUSSION FROM MAY 25/12UTC: A DEEP MID/UPPER LEVEL
TROUGH PUSHES ACROSS THE WESTERN TO THE CENTRAL USA THROUGH
SATURDAY EVENING. AS IT MIGRATES ACROSS THE USA THE TROUGH WILL
PRESS AGAINST A RIDGE TO THE SOUTH. THIS IS TO THEN FAVOR GRADUAL
EROSION OF THE RIDGE PATTERN. EARLY IN THE CYCLE THE RIDGE IS TO
ENVELOP CENTRAL-SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. BY
THE END OF THE WEEK IT WILL CONFINE TO SOUTHERN-SOUTHWEST MEXICO.
AS THE RIDGE ERODES...THE CAP INVERSION IS TO ALSO WEAKEN.
MEANWHILE...THE INVERSION WILL BE STRONG ENOUGH TO DELAY ONSET OF
DIURNAL CONVECTION...BUT NOT STRONG ENOUGH TO SUPPRESS IT. AS A
RESULT...CONVECTION ALONG THE SIERRA MADRE ORIENTAL OF MEXICO WILL
RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM.
THROUGH SATURDAY THIS WILL INCREASE TO 10-15MM/DAY AND MAXIMA OF
20-30MM. OTHER CONVECTION IS TO CLUSTER ALONG THE CONTINENTAL
DIVIDE BETWEEN SOUTHERN MEXICO AND NORTHWEST NICARAGUA...WITH
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. THROUGH
SATURDAY THIS INCREASES TO 10-15MM/DAY AND MAXIMA OF 15-20MM. OVER
THE GULF OF FONSECA...ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE
FOR GENERATION OF MESO SCALE CONVECTIVE SYSTEMS...SO LOCALLY
HIGHER AMOUNTS ARE HIGHLY PROBABLE.

IN A SINUSOIDAL PATTERN...A DEEP MID/UPPER LEVEL TROUGH LIES TO
THE EAST...WITH AXIS SOUTH ALONG A CLOSED LOW OVER THE
BAHAMAS-CUBA TO THE CENTRAL CARIBBEAN/SOUTHERN CENTRAL AMERICA.
THIS TROUGH IS TO PERSIST OVER THE NEXT FEW DAYS. AT LOW LEVELS
THIS SUSTAINS AN INDUCED/INVERTED TROUGH OVER THE CENTRAL
CARIBBEAN-CUBA-THE BAHAMAS. ALONG THIS AXIS THE NHC IS FORECASTING
A WARM CORE LOW TO DEVELOP TO THE EAST-NORTHEAST OF THE BAHAMAS.
MEANWHILE...THE TROUGH WILL ENHANCE MOISTURE TRANSPORT ACROSS THE
CENTRAL TO NORTHERN 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 10-15MM/DAY AND MAXIMA OF
20-40MM. ON SATURDAY RAINFALL AMOUNTS ACROSS CUBA WILL DECREASE TO
10-15MM/DAY AND MAXIMA OF 20-30MM...WHILE OVER THE BAHAMAS
EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER
HISPANIOLA EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM THROUGH SATURDAY...WHILE OVER JAMAICA EXPECTING RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. 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. ON SATURDAY THIS WILL DECREASE TO 15-20MM/DAY AND MAXIMA
OF 30-60MM.

DOWNSTREAM FROM THIS TROUGH...AT UPPER LEVELS...A SHORT WAVE RIDGE
EXTENDS OVER THE EASTERN CARIBBEAN ISLES ALONG 60W TO 30N. AT 500
HPA IT ANCHORS ON A CLOSED HIGH WEST OF THE FRENCH ISLES. THIS
HIGH/RIDGE FAVORS A MID CONVERGENT PATTERN THAT IS INHIBITING
ORGANIZED CONVECTION THROUGH FRIDAY EVENING THE RIDGE IS FORECAST
TO COLLAPSE UNDER PRESSURE FROM BROAD TROUGH TO THE WEST. AT LOW
LEVELS...WINDS OVER THE EASTERN CARIBBEAN WILL VEER TO THE
SOUTHEAST EARLY IN THE CYCLE...TO FAVOR A MOIST ADVECTIVE PATTERN.
IN RESPONSE OF WEAKENING CAP INVERSION AND MOIST ADVECTION THE
PWAT CONTENT WILL INCREASE TO 50MM. THIS IS TO THEN FEED
CONVECTIVE DEVELOPMENT. ON FRIDAY...SCATTERED SHOWERS ARE FORECAST
TO DEVELOP...TRIGGERING RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA
OF 10MM. ON SATURDAY TO SUNDAY THIS BECOMES BETTER
ORGANIZED...WITH RAINFALL AMOUNTS OVER PUERTO RICO OF 10-15MM/DAY
AND MAXIMA OF 20-35MM. ON THE FRENCH AND LEEWARD ISLES EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM ON SATURDAY.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC.
INITIAL    24    36    48    60    72    84    96         TYPE
40W        42W   44W   47W   49W   52W   55W   57W        EW
66W        69W   72W   74W   77W   DISSIPATES             TW
80W        81W   83W   DISSIPATES                         TW

A WEAK WAVE IN THE EASTERLY TRADES IS INITIALIZED ALONG 40W. THIS
REACHES FRENCH GUIANA ON SATURDAY EVENING...TO FAVOR LIGHT TO
MODERATE CONVECTION WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF
15-20MM.

A TROPICAL WAVE ALONG 66W AND SOUTH OF 12N MOVES ACROSS CENTRAL TO
WESTERN VENEZUELA/EASTERN COLOMBIA LATER TODAY...TO FAVOR RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM IN INTERACTION WITH
THE NEAR EQUATORIAL TROUGH. ACROSS COLOMBIA IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM. ON SATURDAY
THE WAVE DISSIPATES AS IT INTERACTS WITH THE CENTRAL CARIBBEAN
TROUGH.

TROPICAL WAVE ALONG 80W AND SOUTH OF 15N IS TO GRADUALLY WEAKEN AS
IT INTERACTS WITH THE INDUCED TROUGH. MEANWHILE...ACROSS WESTERN
PANAMA-COSTA RICA THIS IS TO 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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