TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1134 AM EDT FRI JUL 09 2021

AT 18 UTC TROPICAL STORM ELSA CENTERED NEAR 25.4N 83.0W WITH
MAXIMUM SUSTAINED WINDS OF 60KT AND MINIMUM CENTRAL PRESSURE OF
1000 HPA. THE STORM IS MOVING NORTH AT 08KT. SEE NHC ADVISORY FOR
DETAILS.

TROPICAL DISCUSSION FROM JUL 06/19 UTC: WEST OVER THE DOMAIN...AT
250 HPA...A RIDGE OVER THE WESTERN USA BRANCHES TO THE NORTHWEST
STATES OF MEXICO/BAJA CALIFORNIA...WITH A DEEP MID/UPPER LEVEL
TROUGH TO THE EAST DOMINATING THE CENTRAL USA. UNDER THE INFLUENCE
OF THE RIDGE TO THE WEST...THE TROUGH IS TO GRADUALLY AMPLIFY
ACROSS TEXAS TO NORTHEAST STATES OF MEXICO...WHERE IT IS TO LINGER
THROUGH THE END OF THE WEEK. UNDER THE INFLUENCE OF THIS TROUGH
CONDITIONS ARE TO BECOME FAVORABLE FOR A HEAVY RAINFALL PRODUCING
MCS TO FORM OVER NORTHEAST MEXICO EARLY ON WEDNESDAY
MORNING...WITH REGENERATION LIKELY ON THURSDAY. THIS WILL LEAD TO
HEAVY RAINFALL AMOUNTS WITH ACCUMULATION OF 20-35MM/DAY AND MAXIMA
OF 75-125MM/DAY THROUGH THURSDAY MORNING...WHILE ON THURSDAY TO
FRIDAY IT WEAKENS TO 20-30MM/DAY AND MAXIMA OF 40-80MM. ON THE
CENTRAL STATES OF MEXICO/SIERRA MADRE DEL SUR EXPECTING LESSER
AMOUNTS...WITH ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF
20-35MM/DAY. THROUGH THURSDAY THIS WEAKENS TO 05-10MM/DAY AND
MAXIMA OF 15-25MM.

A WANING MID/UPPER LEVEL TROUGH OVER THE GULF MEANDERS ALONG 90W
TO THE YUCATAN/CAMPECHE SOUND. AS IT REMAINS CUT OFF FROM THE
FLOW...THE TROUGH IS EXPECTED TO GRADUALLY FILL. AT LOW
LEVELS...TROPICAL STORM ELSA TO THE EAST IS INDUCING A LOW LEVEL
TROUGH ACROSS THE WESTERN GULF TO THE YUCATAN. THIS COMBINES WITH
THE UPPER LEVEL TROUGH IN SUPPORT OF SCATTERED CONVECTION ACROSS
SOUTHERN MEXICO-THE YUCATAN/NORTHERN CENTRAL AMERICA. ACROSS
CHIAPAS TO SOUTHERN GUATEMALA THIS IS TO SUSTAIN MODERATE RAINFALL
AMOUNTS WITH ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF
20-35MM...WHILE OVER NORTHERN GUATEMALA-THE YUCATAN EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. ON
WEDNESDAY-THURSDAY THIS WEAKENS TO 05-10MM/DAY AND MAXIMA OF
15-25MM OVER SOUTHERN GUATEMALA/CHIAPAS WHILE ACROSS THE YUCATAN
IT WEAKENS TO 00-05MM/DAY AND MAXIMA OF 10MM.

OTHER CONVECTION IS EXPECTED ACROSS CUBA AND THE BAHAMAS. OVER
WESTERN CUBA EXPECTING ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF
20-35MM EARLY IN THE CYCLE...WHILE ACROSS EASTERN CUBA AND JAMAICA
EXPECTING ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-20MM. ON
WEDNESDAY ACTIVITY ACROSS CUBA WEAKENS TO 05-10MM/DAY AND MAXIMA
OF 15MM...WHILE OVER JAMAICA IT DECREASES TO 00-05MM/DAY AND
MAXIMA OF 10MM. OVER THE CENTRAL AND THE NORTHWEST
BAHAMAS...MEANWHILE...EXPECTING A SLIGHT INCREASE...WITH
ACCUMULATION OF 00-05MM/DAY AND MAXIMA OF 10MM EARLY IN THE CYCLE
INCREASING TO 05-10MM/DAY AND MAXIMA OF 15MM ON WEDNESDAY.

FARTHER EAST...A TUTT LOW TO THE NORTH/NORTHEAST OF PUERTO RICO
EXTENDS A SHORT WAVE TROUGH TO THE EASTERN CARIBBEAN. THE TUTT LOW
IS TO MEANDER WEST WHILE REMAINING NORTH OF THE GREATER
ANTILLES...WITH CLOSED LOW NEARING THE TURKS LATER ON FRIDAY.
ACROSS PUERTO RICO EXPECTING SLIGHT ENHANCEMENT TO DIURNAL
CONVECTION TODAY...WITH BETTER CHANCE FOR DEVELOPMENT ON WEDNESDAY
AS AN INDUCED PERTURBATION IN THE EASTERLY TRADES MEANDERS ACROSS
THE ISLANDS. HIGHER AMOUNTS ARE EXPECTED TO THE SOUTHO OVER THE
ORINOCO DELTA REGION IN VENEZUELA/TRINIDAD AND TOBAGO...WITH
ACCUMULATION OF 20-30MM/DAY AND MAXIMA OF 40-80MM. OVER WESTERN
VENEZUELA TO COLOMBIA IT GRADUALLY INCREASE FROM 05-10MM/DAY AND
MAXIMA OF 15-25MM EARLY IN THE CYCLE TO 10-15MM/DAY AND MAXIMA OF
20-45MM LATER ON THURSDAY...WITH MOST INTENSE ACROSS WESTERN
COLOMBIA TO SOUTHERN CENTRAL AMERICA.

TROPICAL WAVES/TUTT INDUCED PERTURBATIONS/TRADE WIND SURGES
INITIALIZED AT 12 UTC.
TYPE INIT  07/00 07/12 08/00 08/12 09/00 09/12 10/00 SOF
TW   28W   34W   38W   42W   46W  50W   55W  60W   18N
TW   52W   55W   60W   63W  69W   72W   76W  80W   11N
TI     65W   69W   73W DISSIPATES                  25N
TW   97W   99W   102W  104W  105W 106W  108W 1009W 17N

A TROPICAL WAVE ALONG 43W AND SOUTH OF 11N ENTERS FRENCH GUIANA ON
WEDNESDAY MORNING TO SUSTAIN RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-25MM. HIGHER AMOUNTS ARE EXPECTED ACROSS NORTHERN
GUYANA TO NORTHEAST VENEZUELA-TRINIDAD/THE GRENADINES...WITH
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-35MM. ON WEDNESDAY
THIS DECREASES TO 05-10MM/DAY AND MAXIMA OF 15-25MM AS IT SPREADS
ACROSS NORTHERN VENEZUELA...WHILE OVER AMAZONIA TO THE SOUTH INTO
EASTERN COLOMBIA EXPECTING ACCUMULATION OF 10-15MM/DAY AND MAXIMA
OF 20-35MM.

TUTT LOW NORTH OF PUERTO RICO SUSTAINS AN INDUCED PERTURBATION ON
THE MID LEVEL EASTERLIES. OVER THE FRENCH AND LEEWARD ISLANDS THIS
IS TO SUSTAIN RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM
EARLY IN THE CYCLE...WHILE OVER THE GRENADINES-TRINIDAD/NORTHEAST
VENEZUELA EXPECTING ACCUMULATION OF 20-30MM/DAY AND MAXIMA OF
40-80MM AS IT INDUCES THE NORTHWARD MODULATION OF THE ITCZ. ACROSS
PUERTO RICO AND THE DOMINICAN REPUBLIC IT WILL SUSTAIN
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM ON WEDNESDAY
BEFORE DISSIPATING EARLY ON THURSDAY.

TROPICAL WAVE ALONG 94W AND SOUTH OF 17N IS TO ENHANCE COASTAL
CONVECTION ACROSS SOUTHERN GUERRERO...WITH ACCUMULATION OF
20-30MM/DAY AND MAXIMA OF 40-80MM. ON WEDNESDAY EXPECTING
ADDITIONAL RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-45MM...WHILE OVER CENTRAL MEXICO IT WILL FAVOR RAINFALL AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-45MM. ON THURSDAY THIS WEAKENS TO
05-10MM/DAY AND MAXIMA OF 15-25MM.

DAVISON...WPC (USA)