FXCA20 KWBC 051817 PMDCA Tropical Discussion - International Desks NWS Weather Prediction Center College Park MD 217 PM EDT Wed Aug 05 2026 Forecast Bulletin 5 August 2026 at 1820 UTC: Numerous areas of rainfall will remain present across the region, with higher and wider regions of rainfall accumulations across western to southwestern Mexico, southern Central America, western Colombia and Orinoquia for the next three days. At upper levels, a pair of upper lows and embedded troughs will promote broad ascent across the region. An upper ridge extends from Baja California to northeastern Mexico, while a trough anchors over the northern Gulf into the southern US. The upstream side in between these systems will support upward motion over central northern areas of Mexico that will displace westward though the day. Over the mid southern Mexico a low pressure system sustains upward motions from the western to eastern Mexican region and across the southwestern. A wider low pressure system is centered over Greater Antilles and its associated troughs extend northward over The Bahamas and southwestward over central America. A ridge is extended over Lesser Antilles limiting convection. Over the next three days, the trough over the Gulf will dig in north and the northwestern Gulf into northeastern Mexico to become enclosed by Friday, pushing favorable conditions further southwest over the western and southwestern region. The low over southern Mexico will move west southwestward decreasing the aloft dynamical support over the region. The system over the Caribbean region will move westward and it�s expected to last along the next three days, while the ridge over the Lesser Antilles will follow it to allow the entrance of a second upper level low in the region on Friday. At mid levels, four main troughs are present across the region. One extends over Baja California and northwestern Mexico, a second one over the Isthmus of Tehuantepec, one is extended over Panama into the Caribbean sea, and one over western Cuba into southeastern US. Mid level pressure anomalies remain near neutral across much of the area, with the most pronounced positive anomaly over Mexico and portions of The Bahamas, while the most significant negative anomalies are located from northwestern Colombia to eastern Panama. Throughout the next three days these troughs will remain present and will shift westward displacing the areas of turbulence associated to the west of each area of influence. The one over Central America will have the slowest movement, and will support significant convection along the next three days. At lower levels, significant levels of humidity are present mainly over portions of western Mexican coast, across central America to Colombia regions and from Yucatan Peninsula to The Bahamas region. More significant rainfall will occur over eastern Nicaragua to areas of Colombia. Areas along the Sierra Madre Occidental and, across northern Central America, Cuba and Hispaniola, will be affected by locally convective rain. Throughout the next three days, no major changes are expected besides the shift to the west of these areas of precipitation and less rainy conditions over southern Central America. Over the Northern South America, the Orinoquia region will experience the highest amount of precipitation associated to the low level humidity advection in interaction with low level troughs and tropical waves moving around the region. Tropical Waves Initialized at 12 UTC: Typ SOF INIT 06/00 06/12 07/00 07/12 08/00 08/12 09/00 09/12 TW 14N 27W 30W 34W 39W 44W 48W 52W 55W 58W TW 21N 43W 46W 50W 54W 57W 61W 64W 67W 71W EW 13N 49W 53W 57W 61W 65W 69W 72W 75W 78W TW 14N 79W 81W 83W 85W 87W 89W 91W 94W 97W TW 13N 106W 109W 112W 115W 117W EXIT - - - Sanchez-Perez...(WPC) $$