*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********
...FRIDAY JULY 24 2020 5:53 PM EDT...
The following is a special update on Tropical Storm Hanna and the tropical wave of low pressure in the eastern tropical Atlantic to the southeast of the Republic of Cabo Verde Islands.
TROPICAL STORM HANNA...This special update is to increase the intensity forecast for Tropical Storm Hanna which has become better oragnized while the thunderstorm bands are moreso filling the north and west quardrants of the circulation while an eye type feature remains at the center of circulation. This indicates that the shortwave upper trough amplifying southward toward Hanna has not had a negative effect on the tropical storm. The 1200Z GFS model run shows the approaching shortwave upper trough fragment staying a bit further northeast of Hanna compared to this morning's 0600Z cycle...perhaps picking up on the impressive amount of thunderstorm latent heat release currently occuring with Hanna that may keep this cool core fragment pushed away. The National Hurricane Center has increased the intensity forecast to indicate Hanna will become a minimal category 1 hurricane with 75 mph maximum sustained winds just prior to landfall...thus issuing a hurricane warning for points just south of Matagorda Bay Texas. I have raised my intensity foreacst to a peak of 80 mph max winds given the current organization of the tropical storm. With these developments...there maybe a list minute rush to gather storm preparation supplies for power outages...wind damage...and coastal storm surge in the hurricane warned area before conditions detereorate tomorrow morning. If you must get supplies in a crowded setting...due to the COVID-19 virus emergency in the area...frequent sanitizing of your hands and wearing a face mask will be necessary to protect you and those around you from the virus. Sanitize the packaging of purchased supplies before use in your residence. In the event you may have to leave due to a concern such as storm surge...consider planning the use of a family/friend residence further inland or a hotel location further inland in case you may need it..as a crowded public shelter may not as ideal for controlling your exposure to COVID-19.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Jul 24)...50 mph maximum sustained wind tropical storm centered in the northwestern Gulf of Mexico at 27.3N-94.3W
IOH 24 Hr Forecast (1800Z Jul 25)...80 mph maximum sustained wind hurricane centered just southeast of Matagorda Bay Texas at 27.5N-95.8W
IOH 48 Hr Forecast (1800Z Jul 26)...45 mph maximum sustained wind tropical storm centered over southern Texas at 27N-98.8W
IOH 72 Hr Forecast (1800Z Jul 27)...Remnant low pressure over northern Mexico centered at 26N-102.3W
AREA OF INTEREST #1...Thunderstorm activity appears to be increasing in coverage and organization on the south side of a tropical wave of low pressure in the eastern tropical Atlantic. Therefore this special update is to raise my short-term 48 hour odds of tropical cyclone formation to a peak of 30%. If development does not occur in the short term...it appears the large size of its circulation will moreso draw in saharan dry air lying just to the north...therefore I drop odds of development in the middle of the 120-hour forecast period. I then raise odds a little during the end of the forecast period as the usually conservative ECMWF model insists on developing this wave as it approaches the Lesser Antilles by the end of the 120-hour forecast period.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z Jul 25)...30% chance of tropical cyclone formation (just southwest of the Republic of Cabo Verde Islands near 13N-25.5W)
IOH 48 Hr Outlook (1800Z Jul 26)...25% chance of tropical cyclone formation (tropical Atlantic near 13N-31.5W)
IOH 72 Hr Outlook (1800Z Jul 27)...5% chance of tropical cyclone formation (tropical Atlanic near 13N-37.6W)
IOH 96 Hr Outlook (1800Z Jul 28)...5% chance of tropical cyclone formation (tropical Atlanic near 13N-43.8W)
IOH 120 Hr Outlook (1800Z Jul 29)...15% chance of tropical cyclone formation (tropical Atlantic near 13N-51W)