902
FXCA20 KWBC 181932
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
232 PM EST THU JAN 18 2024
FORECAST BULLETIN 18 JAN 2024 AT 1930 UTC: THE POLAR OUTBREAK
ACROSS NORTH AMERICA CONTINUES. ANOTHER UPPER TROUGH IS ORGANIZING
A SURFACE FRONT ACROSS THE SOUTHERN USA ON THURSDAY. THE FRONT IS
FORECAST TO RAPIDLY MOVE SOUTHWARD ENTERING MEXICO LATE ON
THURSDAY EVENING. BY FRIDAY EVENING THE FRONT IS EXPECTED ACROSS
THE FAR NORTHWEST BAHAMAS...SOUTH FLORIDA...CENTRAL GULF OF MEXICO
NEAR 23N 90W...NORTH VERACRUZ...NORTHERN DURANGO...NORTHWEST
CHIHUAHUA. BY SATURDAY EVENING EXPECT THE BOUNDARY ACROSS THE
CENTRAL BAHAMAS...NORTH-CENTRAL CUBA...THE CENTRAL YUCATAN
PENINSULA...NROTHERN OAXACA INTO THE CENTRAL MEXICAN PLATEAU. A
SHEAR LINE IS ALSO FORECAST TO ORGANIZE ON FRIDAY. BY FRIDAY
EVENING EXPECT THE SHEAR LINE ACROSS SOUTHEAST CUBA...JUST SOUTH
OF THE CAYMAN ISLANDS...NORTHEAST HONDURAS. BY SATURDAY EVENING
EXPECT IT ACROSS THE SOUTHEAST BAHAMAS...SOUTHEAST CUBA...CAYMAN
ISLANDS...ISLAS DE LA BAHIA/NORTHERN HONDURAS.
INITIALLY THE FRONT WILL PRODUCE LIMITED RAINFALL AMOUNTS GIVEN
VERY LIMITED MOISTURE AVAILABILITY IN THE REGION. BY FRIDAY
THROUGH SATURDAY MORNING EXPECT 05-10MM/DAY AND ISOLATED MAXIMA OF
15MM IN NORTH VERACRUZ/HIDALGO...WHILE IN THE NORTHWEST BAHAMAS
EXPECT MAXIMA UNDER 10MM/DAY. HOWEVER...HIGHER AMOUNTS ARE
EXPECTED IN SOUTHERN MEXICO AS THE NORTHERLY WINDS INTERACT WITH
OROGRAPHY. EXPECT MAXIMA OF 20-35MM FROM SOUTHERN VERACRUZ/NORTH
OAXACA INTO NORTH GUATEMALA/CAMPECHE. ELSEWHERE IN THE YUCATAN
PENINSULA AND NORTH BELIZE EXPECT MAXIMA OF 15MM IN
THUNDERSTORMS...AIDED BY A PREFRONTAL TROUGH STRUCTURE. THE SHEAR
LINE WILL FAVOR MAXIMA OF 15MM IN NORTHEAST HONDURAS. BY
SATURDAY...A POTENT UPPER TROUGH IS FORECAST TO ENTER MEXICO FROM
THE WEST. THIS WILL INTERACT WITH A BRANCH OF THE SUBTROPICAL JET
LOCATED DOWNSTREAM...TO RESULT IN ENHANCED UPPER DIVERGENCE ACROSS
MOST OF SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. THE
DYNAMICALLY INDUCED ASCENT WILL FAVOR HIGHER RAINFALL TOTALS FROM
SATURDAY INTO EARLY SUNDAY. ONSHORE FLOW ACROSS MOST OF VERACRYZ
INTO CHIAPAS/TABASCO WILL FAVOR 15-20MM/DAY AND MAXIMA OF
25-50MM. IN NORTHWEN HONDURAS/ISLAS DE LA BAHIA...EAST GUATEMALA
AND SOUTHERN BELIZE...THE SHEAR LINE AND ENHANCED ONSHORE FLOW
WILL FAVOR 15-20MM/DAY AND MAXIMA FO 30-60MM. THE UPPER TROUGH
WILL ALSO STIMULATE CONVECTION IN CENTRAL MEXICO WHERE EXPECT
05-10MM/DAY AND MAXIMA OF 15MM IN THUNDERSTORMS. ISOLATED
PRECIPITATION IS EXPECTED ALSO ALONG THE SIERRA MADRE OCCIDENTAL
AND SIERRA SAN PEDRO MARTIR IN MEXICO. TO THE EAST...EXPECT
05-10MM/DAY AND MAXIMA OF 15-25MM IN THE YUCATAN PENINSULA WHILE
IN WEST CUBA AND THE CENTRAL/NORTHWEST BAHAMAS EXPECT MAXIMA OF
15MM WITH THE FRONT. IN THE CAYMAN ISLANDS EXPECT MAXIMA OF 10MM
WITH THE SHEAR LINE.
IN AREAS SOUTH...THE UPPER CONVERGENT MJO...WESTERLY FLOW IN THE
UPPER TROPOSPHERE AND THE MID-LEVEL RIDGE WILL COMBINE TO SUSTAIN
LIMITED PRECIPITATION AMOUNTS. EXCEPTIONS WILL BE THE REGIONS OF
ITCZ CONVERGENCE IN THE PACIFIC AND ATLANTIC. IN ECUADOR THIS WILL
FAVOR 10-15MM/DAY AND MAXIMA OF 20-45M INCREASING GRADUALLY TO
15-30MM/DAY AND MAXIMA OF 40-80MM. IN WEST COLOMBIA EXPECT MORE
CONSERVATIVE AMOUNTS GIVEN UNFAVORABLE CONDITION IN THE UPPER
TROPOSPHERE. IN THE GUIANAS...THE MOST ACTIVE IS EXPECTED IN
AMAPA/FRENCH GUIANA WHERE EXPECT VERY ISOLATED MAXIMA OF
25-50MM/DAY ON THURSDAY DECREASING TO ISOLATED MAXIMA OF 20-35MM
THEREAFTER.
GALVEZ...WPC (USA)
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