519
FXCA20 KWBC 261820
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
219 PM EDT FRI APR 26 2024
FORECAST BULLETIN 26 APR 2024 AT 1900 UTC: AS THE UPPER TROUGH IN
THE WESTERN USA PROPAGATES EASTWARD...IT WILL FAVOR A POTENTIAL OF
SEVERE CONVECTION IN PORTIONS OF THE PLAINS OF THE USA.
HOWEVER...DYNAMICAL FORCING WILL BE SUFFICIENT TO SUSTAIN A SLIGHT
POTENTIAL FOR SEVERE CONVECTION IN NORTHERN COAHUILA ON
FRIDAY...PRODUCING VERY ISOLATED MAXIMA. ALSO IN MEXICO...EXPECT
ISOLATED DIURNAL CONVECTION ALONG SOUTHERN PORTIONS OF THE SIERRA
MADRE ORIENTAL.
A FRONT HAS STARTED TO PROPAGATE SOUTHEASTWARD AGAIN ACROSS THE
SOUTHEAST BAHAMAS/SOUTHEAST CUBA. ON SATURDAY...ITS TAIL IS
FORECAST TO BECOME STATIONARY ONCE AGAIN ACROSS SOUTHEAST CUBA. BY
SUNDAY EVENING...EXPECT THE FRONT BECOMING STATIONARY JUST TO THE
NORTH OF PUERTO RICO AND ALONG NORTHERN HISPANIOLA. NOTE THAT AN
ILL-DEFINED SHEAR LINE IS ALSO EXPECTED WITH THIS SYSTEM...BUT IT
WILL HAVE LIMITED EFFECTS ON PRECIPITATION AS IT INTERACTS WITH A
MID-LEVEL RIDGE SITTING OVER THE LEEWARD ISLANDS. IN TERMS OF
PRECIPITATION...EXPECT MODERATE AMOUNTS IN PUERTO RICO AND
HISPANIOLA ON FRIDAY IN ASSOCIATION WITH THE MOIST PLUME AHEAD OF
THE FRONT. VERTICAL WIND SHEAR MIGHT BE TOO LARGE TO SUSTAIN HEAVY
AMOUNTS. HOWEVER...COOL MID-LEVELS...SHEAR AND MOISTURE GRADIENTS
IN THE MID-TROPOSPHERE MIGHT FAVOR A MARGINAL RISK FOR SEVERE
CONVECTION IN HISPANIOLA ON FRIDAY AND SATURDAY. IN TERMS OF
AMOUNTS...ON FRIDAY EXPECT MAXIMA OF 20-45MM IN HISPANIOLA AND
MAXIMA OF 20-35MM IN PUERTO RICO. ON SATURDAY...EXPECT MAXIMA OF
20-35MM IN NORTHEAST HISPANIOLA AND PUERTO RICO...WHILE IN HAITI
EXPECT MAXIMA OF 15-20MM. NORTHEASTERLY TRADES WILL ALSO STIMULATE
MOISTURE CONVERGENCE IN NORTHEAST JAMAICA TO FAVOR MAXIMA OF
20-35MM...WHILE FRONTAL CONVECTION AND ONSHORE FLOW FAVORS MAXIMA
OF 20-35MM IN SOUTHEAST CUBA.
IN CENTRAL AMERICA...DIURNAL CONVECTION IS EXPECTED ON A DAILY
BASIS IN EL SALVADOR AND SOUTHERN GUATEMALA. HOWEVER...DRY
MID-LEVELS WILL COUTERACT THE ENHANCEMENT PRODUCED BY THE UPPER
TROUGH PRESENT IN THE WESTERN CARIBBEAN. HIGHER AMOUNTS ARE
EXPECTED IN SOUTHERN CENTRAL AMERICA AND IN WESTERN/NORTHWEST
COLOMBIA. ON FRIDAY...A MOIST PLUME AND ASSOCIATED TROUGH IS
PROPAGATING WESTWARD ACROSS PANAMA/EASTERN COSTA RICA...AND IS
BEING ENHANCED BY THE INTERACTION WITH THE UPPER TROUGH TO THE
NORTH. PRECIPITABLE WATER VALUES ARE EXCEEDING 65MM...AND
EXCESSIVE RAINFALL HAS BEEN REPORTED IN EXTENSIVE AREAS OF CENTRAL
PANAMA. THIS WILL CONTINUE TO FAVOR LOCALLY HEAVY RAINFALL AS IT
PROPAGATES WESTWARD INTO COSTA RICA. ON FRIDAY EXPECT MAXIMA OF
30-60MM IN EAST COSTA RICA AND WEST PANAMA. EXPECT MAXIMA OF
40-80MM IN EASTERN PANAMA AND NORTHWEST COLOMBIA. ON
SATURDAY...EXPECT A NORTHWARD MIGRATION OF THE ITCZ TO CONTINUE
INTO SOUTHERN COSTA RICA/WESTERN PANAMA...AS IT IS AIDED BY THE
UPPER TROUGH TO THE NORTH. THIS WILL FAVOR MAXIMA OF 50-100MM FROM
SOUTHERN COSTA RICA INTO THE AZUERO PENINSULA.
AN EASTERLY WAVE IS PROPAGATING ACROSS THE REGION. AS THE WAVE
PROPAGATES ACROSS CENTRAL COLOMBIA ON FRIDAY...IT WILL FAVOR
MAXIMA OF 40-80MM. ON SATURDAY IT IS EXPECTED TO PROPAGATE ACROSS
WESTERN COLOMBIA/EAST PANAMA...TO FAVOR MAXIMA OF 35-70MM. BY
SUNDAY EXPECT THE FOCUS OF THE PRECIPITATION IN SOUTHERN COSTA
RICA AND SOUTHWEST PANAMA.
GALVEZ/CLARKE/LEDESMA/ACOSTA...WPC (USA)
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