Good day everyone!
Well, SURPRISE! SURPRISE!…Tropical Storm HUMBERTO spun up rather quickly over the weekend…I must say, I am impressed!
Based on the 8:00 a.m. EDT Intermediate advisory from the NHC, the following information was available on HUMBERTO, and is posted in the tracking map:
HUMBERTO developed rather quickly from Tropical Depression NINE yesterday.
Currently, HUMBERTO is moving toward the west at around 12 mph. HUMBERTO is currently south of a fairly strong subtropical ridge in the EATL. Analysis of the current steering layer mean and forecast steering layers maps from the PSU e-WALL site, I expect this westward to WNW motion to continue for the next 60-72 hours. Beyond that, the steering layers forecast indicates an approaching trof of low pressure will come in from over the Canary Islands, in addition to a slight weakness developing near 50W Longitude, which should induce a sharp turn toward the NW. This motion should continue for about 48 hours, before the ridge is forecast to rebuild north of the storm, pulling back toward the WNW. Based on this analysis, and analysis of the current Dynamic Model Guidance, I concur with the NHC forecast track.
Based on the current and forecast wind shear maps, HUMBERTO has an impressive upper level anticyclone overhead, and this feature could remain over the system for the next 72-96 hours. Albeit I do agree with the NHC intensity forecast, should upper level winds remain as favorable as forecast by ALL of the models (8 knots) I cannot rule out HUMBERTO trying to make a run at Major Hurricane status prior to entering cooler waters and increasing shear. Based on the shear forecast, HUMBERTO may lose upper air support in about 5-6 days. Based on the stair step track, I will continue to monitor HUMBERTO for any significant changes over the next 5-7 days.
NHC INTENSITY FORECAST
FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 13.4N 22.8W 35 KT 40 MPH 12H 09/1800Z 13.6N 24.3W 45 KT 50 MPH 24H 10/0600Z 14.1N 26.2W 55 KT 65 MPH 36H 10/1800Z 14.9N 27.8W 60 KT 70 MPH 48H 11/0600Z 16.2N 28.7W 70 KT 80 MPH 72H 12/0600Z 20.0N 29.5W 80 KT 90 MPH 96H 13/0600Z 23.5N 30.5W 70 KT 80 MPH 120H 14/0600Z 25.2N 33.4W 60 KT 70 MPH
Elsewhere, I am still monitoring the remnant of GABRIELLE for possible regeneration. Albeit the NHC gives this area only a 20% chance, based on forecast motion, and current wind shear forecast, upper level winds are forecast to become more conducive for development as this disturbed weather continues moving toward the NNE over the next few days.
I will be monitoring a cluster of thunderstorms near the Gulf of Honduras today, as they have become more consolidated over the past 6 hours, and satellite loop imagery indicates the presence of some overshooting cloud tops. Analysis of the upper level divergence and lower level convergence values indicate while still fairly low, these values have increased over the past 3 hours. Upper level winds are forecast to remain marginal, however based on current and forecast steering, this could possibly enter the BOC, where upper level winds are forecast to become conducive for development in about 72 hours.
I will also be monitoring cloudiness over the Africa continent for any development as these areas move into the Atlantic over the next few days.
We could see some spin up in the BOC over the next 5-6 days, as 2 of the Global models indicate a weak close low, while the others indicate lowering of pressure. The GFS develops a Tropical system around the 23rd, in the Caribbean near Honduras, and pulls it to south of western Cuba 2-3 days afterward.
The 500 mb anomaly departure maps indicate this as well, and the NCEP MULTI MODEL and Ensemble guidance indicates a strong probability of development in the BOC within the time specified.
Tropical Storm formation is not expected through the next 48 hours.
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)