| Track: https://www.nhc.noaa.gov/refresh/graphics_at1+shtml/?cone#contents Satellite: https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL312020 https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al312020 This could impact some of the same areas that got rain from Eta. It is forecast to be a little north of where Eta was in terms of landfall. NHC mentions the storm could stay just offshore too and be stronger than noted for the 4 and 5 day positions since it would then be over water. This could potentially be another powerful hurricane for Central America. (though rain alone can be extra dangerous for that region as we saw with Eta) Right now the GFS and Euro indicate the storm will make landfall in Central America and not emerge again like Eta did. GFS: https://www.tropicaltidbits.com/analysis/models/?model=gfs®ion=watl&pkg=mslp_uv850 Euro: https://www.tropicaltidbits.com/analysis/models/?model=ecmwf®ion=watl&pkg=mslp_uv850 Upcoming names: Iota Kappa Lambda Mu Nu Xi Omicron Pi Rho Sigma Tau Upsilon Phi Chi Psi Omega Tropical Depression Thirty-One Discussion Number 1...Corrected NWS National Hurricane Center Miami FL AL312020 1000 AM EST Fri Nov 13 2020 Corrected the time from EDT to EST Deep convection associated with the area of low pressure over the central Caribbean Sea has increased and become more concentrated since yesterday. One-minute GOES-16 visible satellite imagery shows that the circulation has also become better defined, with a westerly component seen in the low-cloud motion near the southwestern edge of the primary convective mass. Subjective Dvorak intensity estimates from both TAFB and SAB are T2.0, indicating that the convection has become sufficiently organized for the system to be classified as a tropical depression. The initial wind speed is set at 30 kt, in line with the Dvorak classifications. Environmental conditions of low vertical wind shear, warm sea surface temperatures, and a moist atmosphere favor intensification over the next few days. Given the current broad and sprawling structure of the system, strengthening may begin as gradual today, but once an inner core organizes, steady-to-rapid strengthening appears likely. While the SHIPS rapid intensification index does not show very high chances of rapid strengthening for any one 24-h period over the next few days, it does indicate a 50/50 chance (nearly 10 times the climatological mean) of a 65-kt increase in wind speed over the next 72 hours. As a result, the NHC forecast calls for significant strengthening during the 24 to 72 hour time period, and the system could approach the coast of Central America as a major hurricane in a few days. The NHC track forecast at days 4 and 5 shows the system weakening over land, however some of the track guidance keeps the system just off the coast on Honduras at that time. If a more northern track occurs, the system could be stronger at 96 and 120 h if it remains over water. The depression is moving west-southwestward at about 6 kt. A strong mid-level ridge that lies over Florida and the western Atlantic should steer the cyclone west-southwestward during the next 12 to 24 hours. After that time, the ridge is forecast to begin sliding eastward, and a westward to west-northwestward motion should begin. On the foreast track, the cyclone is expected to approach the coast of Central America in 60-72 h. The track guidance is in good agreement through the first couple of days, but there is increasing cross-track spread after that time. The HMON, HWRF, and GFS show a track near or north of the coast of Honduras after 72 hours, while the ECMWF and UKMET are farther south. For now, the NHC track is near the middle of the guidance envelope between the HFIP corrected consensus model and the TCVA multi-model consensus. Key Messages: 1. The depression is expected to strengthen to a hurricane while it approaches the coast of Central America, and there is a risk of dangerous wind, storm surge, and rainfall impacts across portions of Nicaragua and Honduras beginning Sunday night. Hurricane Watches will likely be issued for a portion of this area tonight. 2. Through Wednesday morning, heavy rainfall from Tropical Depression Thirty-One may lead to life-threatening flash flooding and river flooding across portions of Haiti, Jamaica and Central America. Flooding and landslides from heavy rainfall could be significant across Central America given recovery efforts underway after Hurricane Eta. FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 14.2N 74.3W 30 KT 35 MPH 12H 14/0000Z 14.0N 75.0W 35 KT 40 MPH 24H 14/1200Z 13.8N 76.0W 45 KT 50 MPH 36H 15/0000Z 13.9N 77.3W 60 KT 70 MPH 48H 15/1200Z 14.1N 79.0W 70 KT 80 MPH 60H 16/0000Z 14.5N 80.9W 85 KT 100 MPH 72H 16/1200Z 14.9N 82.7W 95 KT 110 MPH 96H 17/1200Z 15.2N 85.7W 50 KT 60 MPH...INLAND 120H 18/1200Z 14.7N 88.3W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown Tropical Depression Thirty-One Advisory Number 1...Corrected NWS National Hurricane Center Miami FL AL312020 1000 AM EST Fri Nov 13 2020 Corrected the time from EDT to EST ...NEW TROPICAL DEPRESSION FORMS IN THE CENTRAL CARIBBEAN SEA... ...EXPECTED TO STRENGTHEN AND APPROACH CENTRAL AMERICA AS A HURRICANE EARLY NEXT WEEK... SUMMARY OF 1000 AM EST...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...14.2N 74.3W ABOUT 310 MI...500 KM SSE OF KINGSTON JAMAICA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...WSW OR 250 DEGREES AT 7 MPH...11 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warning in effect. Interests in Nicaragua and Honduras should monitor the progress of this system. A Hurricane Watch may be required for a portion of that area tonight. DISCUSSION AND OUTLOOK ---------------------- At 1000 AM EST (1500 UTC), the center of Tropical Depression Thirty-One was located near latitude 14.2 North, longitude 74.3 West. The depression is moving toward the west-southwest near 7 mph (11 km/h) and this motion is expected to continue through early Saturday. A westward to west-northwestward motion at a slightly faster forward speed is expected to begin by late Saturday and continue through early Monday. On the forecast track, the system will move across the central Caribbean Sea during the next day or so, and approach the coasts of Nicaragua and northeastern Honduras late Sunday and Monday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. The depression is forecast to strengthen into a tropical storm later today or tonight. Additional strengthening is likely over the weekend, and the system could be near major hurricane strength when it approaches Central America. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- Rainfall: Through Wednesday morning, Tropical Depression Thirty-One is expected to produce 4 to 8 inches of rain, with local 12 inch totals, across portions of northern Columbia, Panama and Costa Rica. Across Jamaica and southern Haiti, 2 to 4 inches are expected, with local amounts up to 6 inches. Across remaining sections of Central America, the system has the potential to produce 20 to 30 inches of rain with a focus across northern Nicaragua and Honduras. This rainfall would lead to significant, life-threatening flash flooding and river flooding, along with landslides in areas of higher terrain. NEXT ADVISORY ------------- Next complete advisory at 400 PM EST. $$ Forecaster Brown |