915  
FXCA20 KWBC 061930  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
229 PM EST MON NOV 06 2017  
 
TROPICAL DISCUSSION FROM NOV 06/12 UTC: BROAD MID/UPPER LEVEL  
RIDGE EXTENDS ACROSS MEXICO-THE GULF TO THE SOUTHERN USA...WITH  
AXIS ANCHORING AT 500 HPA ON A CLOSED HIGH OVER MEXICO NEAR 23N  
100W. STRONG RIDGE PATTERN ALOFT IS TO HOLD THROUGH WEDNESDAY  
MORNING. LATER IN THE DAY...AS A POLAR TROUGH DEEPEN ACROSS THE  
TEXAS...THE RIDGE TO THE SOUTH IS TO RAPIDLY WEAKEN.  
MEANWHILE...MID LEVEL RIDGE PATTERN IS TO SUSTAIN A SUBSIDENCE  
INVERSION ACROSS MEXICO THAT IS TO INHIBIT ORGANIZED DEEP  
CONVECTION. AT LOW LEVELS THIS SUSTAINS A CLOSED HIGH OVER THE  
NORTHWEST GULF OF MEXICO. THE LOW LEVEL HIGH PRESSURE RIDGE FAVORS  
A LIGHT NORTHEASTERLY FLOW ACROSS CUBA TO THE WESTERN CARIBBEAN.  
THIS IS CONVERGING ALONG THE COAST OF HONDURAS WHERE WE EXPECT  
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.  
 
THE POLAR TROUGH WILL SUSTAIN A SURFACE FRONT THAT MOVES ACROSS  
TEXAS ON TUESDAY...INTO NORTHEAST MEXICO ON WEDNESDAY...WHERE IT  
IS EXPECTED TO STALL. PREFRONTAL CONVECTION WITH THIS SYSTEM IS  
EXPECTED ACROSS NORTHERN VERACRUZ ON WEDNESDAY-THURSDAY...TO  
TRIGGER RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM IN  
SHALLOW CONVECTION.  
 
A TUTT TO THE EAST OF THE UPPER LEVEL RIDGE EXTENDS TO THE  
SOUTHWEST ACROSS THE NORTHWEST BAHAMAS-CENTRAL CUBA TO THE  
NORTHWEST CARIBBEAN. THROUGH TUESDAY EVENING THE TROUGH IS TO  
RELOCATE TO THE SOUTHEAST BAHAMAS/TURKS-EASTERN CUBA-CENTRAL  
CARIBBEAN...WHERE IT IS TO STALL WHILE PRESSING AGAINST A CELL OF  
THE SUBEQUATORIAL RIDGE TO THE EAST. AS THE RIDGE TO THE WEST  
WEAKENS ON WEDNESDAY/THURSDAY...THE MID/UPPER LEVEL TROUGH IS  
FORECAST TO ALSO WEAKEN AS SHORT WAVE ENERGY LIFTS OVER THE  
SUBEQUATORIAL RIDGE TO THE EAST. THE BAHAMAS-CUBA AND JAMAICA WILL  
LIE ON THE CONVERGENT/SUBSIDENT SIDE OF THE UPPER LEVEL TROUGH.  
HISPANIOLA-PUERTO RICO AND THE VIRGIN ISLES WILL REMAIN ON THE  
DIVERGENT SIDE OF THE UPPER LEVEL AXIS...A PATTERN THAT IS TO HOLD  
DURING THE NEXT FEW DAYS. AT LOW LEVELS...UNDER INFLUENCE OF A  
RIDGE OVER THE WESTERN ATLANTIC AND AN INVERTED TROUGH OVER THE  
CENTRAL CARIBBEAN...A MOIST SOUTHEASTERLY FLOW DOMINATES THE  
EASTERN CARIBBEAN ISLES. THIS SUSTAINS A PWAT CONTENT OF AROUND  
50MM...THAT IS EXPECTED TO PERSIST DURING THE NEXT THREE DAYS.  
ACROSS THE LEEWARD ISLANDS EXPECTING SCATTERED CONVECTION ON  
TUESDAY TO TRIGGER AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM.  
ACROSS PUERTO RICO AND THE DOMINICAN REPUBLIC THIS WILL ENHANCE  
DIURNAL CONVECTION/SEA BREEZE RELATED CONVERGENCE...TO SUSTAIN  
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM. THROUGH  
WEDNESDAY THIS INCREASES TO 15-20MM/DAY AND MAXIMA OF 30-60MM.  
 
AS THE MID LEVEL TROUGH MEANDERS ACROSS THE SOUTHERN  
CARIBBEAN...THIS WILL INTERACT WITH THE ITCZ OVER PANAMA-NORTHERN  
COLOMBIA. ACROSS PANAMA-COSTA RICA EXPECTING RAINFALL AMOUNTS OF  
05-10MM/DAY AND MAXIMA OF 15-25MM/DAY. OVER NORTHERN-WESTERN  
COLOMBIA/ANDEAN REGION THIS IS TO INITIALLY FAVOR RAINFALL AMOUNTS  
OF 05-10MM/DAY AND MAXIMA OF 15-20MM. ON TUESDAY...AS A WESTERLY  
FLOW ESTABLISHES ACROSS THE EASTERN PACIFIC...THIS INCREASES TO  
10-15MM/DAY AND MAXIMA OF 20-45MM. ON WEDNESDAY EXPECTING RAINFALL  
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 35-70MM. ON  
THURSDAY...AS THE TROUGH ALOFT WEAKENS...THIS DECREASES TO  
15-20MM/DAY AND MAXIMA OF 25-50MM.  
 
CELL OF THE SUBEQUATORIAL RIDGE OVER THE EASTERN  
CARIBBEAN/NORTHERN SOUTH AMERICA IS TO VENT NEAR EQUATORIAL TROUGH  
RELATED CONVERGENCE ACROSS VENEZUELA AND ITCZ RELATED CONVECTION  
ACROSS THE GUIANAS. ACROSS VENEZUELA EXPECTING RAINFALL AMOUNTS OF  
05-10MM/DAY AND MAXIMA OF 15-20MM. THROUGH WEDNESDAY THIS  
INCREASES TO 10-15MM/DAY AND MAXIMA OF 20-35MM. ACROSS THE GUIANAS  
EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM.  
THROUGH THURSDAY THIS DECREASES TO 05-10MM/DAY AND MAXIMA OF  
15-30MM.  
 
TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC:  
INITIAL 24 36 48 60 72 84 96 TYPE SOF  
55W 57W 59W 62W 65W 67W 69W 71W TW 19N  
72W 73W 74W 75W 75W 76W 77W 78W TUTT INDCD 22N  
81W 83W 85W 87W DISSIPATES EW 17N  
 
TROPICAL WAVE ALONG 55W AND SOUTH OF 19N IS TO INTERACT WITH THE  
ITCZ OVER SURINAME-GUYANA TO TRIGGER RAINFALL AMOUNTS OF  
10-15MM/DAY AND MAXIMA OF 20-40MM THROUGH TUESDAY MORNING...WITH  
SIMILAR AMOUNTS ACROSS THE WINDWARD ISLES/NORTHEAST VENEZUELA  
EARLY ON TUESDAY...WHILE ON THE FRENCH-LEEWARD ISLES EXPECTING  
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15MM. ACROSS VENEZUELA  
THIS IS TO INTERACT WITH THE NEAR EQUATORIAL TROUGH TO SUSTAIN  
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM ON  
WEDNESDAY.  
 
REMNANTS OF A TUTT INDUCED TROUGH EXTENDS NORTH ALONG 72W TO 22N.  
AS IT PHASES WITH TUTT ALOFT OVER THE CENTRAL CARIBBEAN THE LOW  
LEVEL TROUGH IS TO STRENGTHEN...WITH A CLOSED CIRCULATION FORMING  
OVER THE GULF OF URABA. THIS WILL THEN FAVOR A MOIST WESTERLY FLOW  
ACROSS COLOMBIA TO ENHANCE CONVECTIVE DEVELOPMENT ON THE WESTERN  
COASTAL PLAINS AND THE ANDEAN REGION. IT IS TO ALSO DRAW A PLUME  
OF MOISTURE NORTH ACROSS THE CENTRAL CARIBBEAN TO HAITI ON  
WEDNESDAY...TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA  
OF 20-45MM. MOIST PLUME REACHES JAMAICA LATER ON THURSDAY...WITH  
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-40MM.  
 
AN ILL ORGANIZED EASTERLY WAVE EXTENDS ALONG 81W TO 17N. AS IT  
ENTERS THE CONVERGENT SIDE OF MID LEVEL RIDGE ENVELOPING MOST OF  
CENTRAL AMERICA THE WAVE IS FORECAST TO DISSIPATE LATER ON  
TUESDAY/EARLY WEDNESDAY MORNING. MEANWHILE...ACROSS WESTERN  
PANAMA/COSTA RICA TO SOUTHERN NICARAGUA EXPECTING RAINFALL AMOUNTS  
OF 05-10MM/DAY AND MAXIMA OF 15-25MM.  
 
GUY...NMS (BELIZE)  
PECK...MS (JAMAICA)  
RIVAS...SENAMHI (PERU)  
DAVISON...WPC (USA)  
 

 
 
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