TROPICAL CYCLONE FORMATION: MAJOR HURRICANE MATTHEW
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(T. F. “Storm” Walsh III)
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CURRENT 2016 ATLANTIC TROPICAL CYCLONE TOTALS:
TOTAL STORMS: 13
MAJOR HURRICANES: 2
StormW’s Seasonal Hurricane Forecast:
TOTAL STORMS: 13-15
INTENSE HURRICANES: 3-4
Good evening everyone!
Hurricane MATTHEW still remains a MAJOR HURRICANE this evening. During the day, he weakened slightly, however remains a CATEGORY 4 Hurricane on the Saffir-Simpson scale, with maximum sustained winds of 145 mph. As of the 5:00 p.m. advisory, the following was available on MATTHEW:
5:00 PM EDT Sun Oct 2
Location: 14.6°N 74.8°W
Moving: NW at 5 mph
Min pressure: 945 mb / 27.90 in
Max sustained: 145 mph
Based on current I.K.E (Integrated Kinetic Energy) calculations, MATTHEW has a SDP (Surge Destructive Potential) at the moment of 3.208 The Surge Destructive Potential Rating based on a scale of zero to 6. SDP is interpreted similar to the Saffir Simpson scale in that the most destructive storms are rated above 5 and the least destructive storms < 1.
MATTHEW’S structure today had become somewhat a little less prominent as far as the inner core, however recent satellite loop imagery indicates the hurricane has improved in overall structure this evening, with the core appearing somewhat tighter, and excellent banding, with an improved CDO in the recent loop imagery.
The brief disruption was attributed to some wind shear and a little dry air intrusion. The shear had been caused by the orientation of the upper level anticyclone being WSW of the center. The most recent wind shear profile indicates that the upper level anticyclone has come closer toward the center, and the upper level pattern has once again improved since early this afternoon.
Based on my analysis of the current wind shear forecast and 200 mb streamline pattern, the GFS indicates very favorable upper level winds to remain in place during at least the next 96 hours, as the storm begins to exit the Bahamas area. Up until that point, there should be only slight weakening as MATTHEW recovers from land interaction. At around 120 hours, or shortly after the 96 hour time frame, all models seem to be in agreement of vertical wind shear increasing over MATTHEW, and the hurricane should begin a weakening trend, albeit most likely slow. The NHC had mentioned in the previous discussion, that the lower OHC once he entered the Atlantic, along with the increase in shear, would provide a little weakening. This appears to be the case once it gets north of the Bahamas. However the current OHC map indicates the Gulfstream to have some fairly high OCH. While I concur with the NHC intensity forecast, I am not willing to rule out a slightly stronger CAT 3 hurricane through the Bahamas, with weakening occurring in step with the NHC forecast. This will also depend on any fluctuations caused by any EWRC’s (EyeWall Replacement Cycles).
NHC INTENSITY FORECAST
INIT 02/2100Z 14.6N 74.8W 125 KT 145 MPH
12H 03/0600Z 15.4N 74.9W 125 KT 145 MPH
24H 03/1800Z 16.7N 74.9W 125 KT 145 MPH
36H 04/0600Z 18.3N 74.7W 115 KT 130 MPH
48H 04/1800Z 20.1N 74.5W 110 KT 125 MPH…INLAND
72H 05/1800Z 23.6N 75.1W 100 KT 115 MPH
96H 06/1800Z 26.8N 76.1W 95 KT 110 MPH
120H 07/1800Z 30.0N 76.5W 90 KT 105 MPH
MATTHEW had spent a short few hours moving toward the west earlier, however has resumed a NW track. I expect this motion to continue for the next few hours, quite possibly until later this evening, before eventually turning more toward the north. Now, the EXACT timing of this is unknown, and very complicated at the moment. Based on the last 2 frames in the satellite loop imagery, the eye of MATTHEW appears to have taken a slight jog west. Whether this is significant or not, is unknown at the moment. The eye is at the point currently, where the hurricane is now supposed to be heading north, per the NHC track. However, the problem we’ve had today is, with MATTHEW weakening, the storm is being affected by the next steering layer down in the atmosphere…from the 200-700 mb layer, down to the 200-850 mb layer. It does appear MATTHEW could be a little stronger, and could be being influenced by a blend of the layers…regardless, both layers pretty much indicated a flow to the NW to NNW. Given the strength of MATTHEW, he may be modifying the steering by somewhat reinforcing the ridge, albeit this works better on a major hurricane positioned more toward the ridge axis, vice the western periphery of the ridge. Based on satellite loop imagery, and the fact the hurricane is currently slightly west of the forecast points. should this W or NW motion continue during the next few hours, I believe the forecast track may be adjusted a little to the left, which would shift the path a little to the west. How far of a shift will remain to be seen, if any shift is done by the NHC.
For all intents and purposes, based on my analysis of the ECMWF and GFS Ensemble members, and the operational portion of the global models, the models as of the afternoon runs, were in good agreement of now following a NNW track toward the U.S., and then keeping it offshore and curving it off the the NE by day 6-7. The GFS seems to bring it the closest to the U.S., and the ECMWF a little further east, but stalling it briefly south of the OBX by day 7, and then kicking it out to sea by day 9. Right now, I prefer a blend of the GFS/ECMWF forecast, however should the continued movement to the NW continue, the hurricane could move closer to the U.S. east coast. Right now, I do not believe a direct hit is in order, however the hurricane is going to have to be monitored closely, as models have still shifted back and forth slightly during the day. Based on this somewhat uncertainty, I concur pretty much with the NHC forecast track, however I feel track my be a little left of that forecast. Once MATTHEW enters the Bahamas, I should have better clarity as to future track.
In any event, residents within the WATCH and WARNING areas should be quickly completing preparations, and residents of the central and western Bahamas should be prepared to deal with a CATEGORY 3 Hurricane.
The following is a summary of WATCHES and WARNINGS in effect for MATTHEW as of 5:00 p.m.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Hurricane Warning is in effect for…
* Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma, and Las Tunas.
A Hurricane Watch is in effect for…
* Cuban province of Camaguey
* Southeastern Bahamas, including the Inaguas, Mayaguana, Acklins, Crooked Island, Long Cay, and Ragged Island
* Turks and Caicos Islands
A Tropical Storm Warning is in effect for…
* Dominican Republic from Barahona westward to the border with Haiti
A Tropical Storm Watch is in effect for… * Dominican Republic from Puerto Plata westward to the border with Haiti
Interests elsewhere in Hispaniola and in the Bahamas should monitor the progress of Matthew.
A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm- force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion.
A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.
A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.
A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area, please monitor products issued by your national meteorological service.
HAZARDS AFFECTING LAND
WIND: Hurricane conditions are expected to reach Jamaica and Haiti on Monday, and eastern Cuba Monday night. Tropical storm conditions are expected to first reach Jamaica and Haiti tonight, and eastern Cuba early Monday, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. Tropical storm conditions are expected along the southern coast of the Dominican Republic within the warning area by tonight. Hurricane conditions are possible in the hurricane watch areas by late Tuesday with tropical storm conditions possible by early Tuesday. Tropical storm conditions are also possible in the tropical storm watch area in the Dominican Republic by late Monday.
RAINFALL: Matthew is expected to produce total rain accumulations of 15 to 25 inches of southern Haiti and the southwestern portion of the Dominican republic, with possible isolated amounts of 40 inches. Across eastern Cuba and western Haiti total rain accumulations of 8 to 12 inches are expected, with possible isolated maximum amounts of 20 inches. Across eastern Jamaica total rainfall of 5 to 10 inches is expected, with isolated maximum amounts of 15 inches possible. This rainfall will likely produce life-threatening flash floods and mud slides. Matthew is expected to produce total rain accumulations of 8 to 12 inches over the southeastern Bahamas, with isolated maximum amounts of 15 inches. Matthew is expected to produce total rain accumulations of 2 to 5 inches, with isolated maximum amounts of 8 inches over the Turks and Caicos Islands. Lower amounts are expected across the northeastern section of Haiti and the Dominican Republic, with amounts ranging from 1 to 3 inches with isolated amounts around 5 inches. Rain amounts of 1 to 2 inches are expected over western Jamaica. Additional rainfall of 1 to 2 inches is expected over northern Colombia through Sunday.
STORM SURGE: The combination of a dangerous storm surge and large and destructive waves could raise water levels by as much as the following amounts above normal tide levels… Southern Coast of Cuba east of Cabo Cruz…7 to 11 feet South Coast of Haiti…7 to 10 feet Northern Coast of Cuba east of Camaguey…4 to 6 feet Jamaica…3 to 5 feet Gulf of Gonave in Haiti…3 to 5 feet Southern coast of the Dominican Republic…1 to 3 feet
Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. Large waves generated by Matthew will cause water rises to occur well in advance of and well away from the track of the center.
SURF: Swells generated by Matthew will continue to affect portions of the coasts of Puerto Rico, Hispaniola, Jamaica, Aruba, Bonaire, Curacao, Venezuela, Colombia, eastern Cuba, and the Caribbean coastline of Central America during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.
The following graphic is from SLOSH model data, indicating potential storm surge values. The margin of error for the SLOSH model output is plus or minus 20%:
The following graphics are from the NHC and indicate tropical storm force wind probabilities, and hurricane force wind probabilities:
Have a blessed evening!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS