Prognostic Meteorological Discussion
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FXCA20 KWBC 241855
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 PM EDT THU APR 24 2014

DISCUSSION FROM APRIL 24/00UTC: DYNAMIC PATTERN IS DOMINATING THE
UNITED STATES WITH SEVERAL UPPER TROUGHS AND RIDGES PROGRESSING
EASTWARD THROUGH THE CYCLE. ALTHOUGH THESE WILL NOT DIG TOO FAR
SOUTH...THEY WILL STILL MODULATE ACTIVITY ACROSS MEXICO AND THE
NORTHERN CARIBBEAN AS THEY WILL ENHANCE/LIMIT UPPER DIVERGENCE.
ACROSS MEXICO...MOST ACTIVITY WILL BE TRIGGERED BY DIURNAL
BREEZES. THIS WILL LEAD TO LARGEST AMOUNTS ACROSS THE SIERRA MADRE
ORIENTAL AND SOUTHERN MEXICO. ISOLATED DIURNAL CONVECTION WILL
PRODUCE ACCUMULATIONS OF 05-10MM/DAY AND MAXIMA OF
15-25MM...INCREASING SLIGHTLY TOWARDS SUNDAY.

IN THE NORTHERN CARIBBEAN...MOST ACTIVE WILL PERSIST IN HISPANIOLA
WHERE MODERATE CONVECTIVE INSTABILITY WILL PERSIST IN THE REMNANTS
OF A SURFACE FRONT TO THE NORTHEAST. CONVECTIVE INSTABILITY WILL
FEED DIURNAL STORMS ALLOWING FOR ACCUMULATIONS IN THE ORDER OF
15-20MM/DAY AND MAXIMA OF 25-50MM THROUGH EARLY FRIDAY. THESE ARE
TO DECREASE GRADUALLY THROUGH THE CYCLE TO PRODUCE 10-15MM/DAY AND
MAXIMA OF 20-30MM BY SUNDAY. MODERATE RAINFALL AMOUNTS ARE ALSO
EXPECTED IN EXTREME SOUTHEASTERN CUBA BUT THESE WILL LIMIT TO
ISOLATED MAXIMA OF 15-20MM. NEW TROUGH ARRIVING FROM THE UNITED
STATES WILL LEAD TO MARGINAL DESTABILIZATION ACROSS THE BAHAMAS ON
DAY 02. THIS WILL LEAD TO SCATTERED SHOWERS WITH ACCUMULATIONS OF
05-10MM/DAY AND MAXIMA OF 15MM.

IN CENTRAL AMERICA...DIURNAL CONVECTION IS ACTIVATING ACROSS
GUATEMALA/WESTERN HONDURAS AND EL SALVADOR. MODELS CONTINUE
CONFIDENT ABOUT MODERATE CONVECTIVE INSTABILITY BUILDING TOWARDS
THE AFTERNOON ESPECIALLY IN HIGHER LOCATIONS. THIS...TOGETHER WITH
THE DIURNAL CONVERGENCE OF BREEZES...SHOULD STIMULATE THE
DEVELOPMENT OF SHORT-LIVED AFTERNOON-EVENING THUNDERSTORMS WITH
ACCUMULATIONS OF 05-10MM/DAY AND ISOLATED MAXIMA IN THE 15-30MM
RANGE.

TO THE SOUTH...PERTURBATIONS IN THE TRADES ARE STARTING TO
ACTIVATE. ONE IS AMPLIFYING ACROSS COLOMBIA...AIDED BY WEAK
MID-LEVEL TROUGH EXTENDING OVER THE CENTRAL CARIBBEAN. THIS
PERTURBATION HAS A VERY GOOD SIGNATURE IN CONVECTIVE INSTABILITY
AND CAN EASILY BE FOLLOWED BY LOOKING AT THE GALVEZ-DAVISON INDEX
OR GDI. THE PERTURBATION WILL ENHANCE ACTIVITY ACROSS COLOMBIA
THROUGH EARLY FRIDAY TO PRODUCE MAXIMA OF 35-70MM ACROSS THE
ANDEAN REGION INTO MOST OF WESTERN AND NORTHWESTERN COLOMBIA. AS
PERTURBATION GRADUALLY MIGRATES TO THE WEST...IT WILL START
AFFECTING EASTERN PANAMA ON FRIDAY INTO SATURDAY...LEADING TO
MAXIMA OF 20-35MM/DAY. DURING THE SAME PERIOD...STRONGEST
CONVECTION IN COLOMBIA WILL CONCENTRATE OVER THE WESTERN ANDES
INTO THE CHOCO PRODUCING MAXIMA OF 25-50MM/DAY. DURING SATURDAY
INTO SUNDAY...STRONGEST ACTIVITY WILL CONCENTRATE OVER SOUTHERN
COSTA RICA AND WESTERN PANAMA PRODUCING MAXIMA OF 25-50MM/DAY. IN
COLOMBIA...LARGEST AMOUNTS ARE EXPECTED ALONG THE WESTERN ANDES
WITH MAXIMA OF 25-50MM/DAY.

GARCIA...SMN (MEXICO)
FIGUEROA...MARN (EL SALVADOR)
GALVEZ...WPC (USA)
$$





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