TROPICAL CYCLONE FORMATION: POST-TROPICAL CYCLONE MATTHEW / TROPICAL STORM NICOLE
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(T. F. “Storm” Walsh III)
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CURRENT 2016 ATLANTIC TROPICAL CYCLONE TOTALS:
TOTAL STORMS: 14
MAJOR HURRICANES: 2
StormW’s Seasonal Hurricane Forecast:
TOTAL STORMS: 13-15
INTENSE HURRICANES: 3-4
Good evening everyone!
After a couple days off to shake off the cobwebs…back in the saddle again!
Matthew made landfall Southeast of McClellanville, SC. around 11:00 a.m. Sat. morning, Oct. 08, 2016 as a Category 1 hurricane. Matthew has since been downgraded to a post-tropical cyclone, having had a cold front wrap into the SW portion of the system, and is now deemed extra-tropical.
As of the 5:00 p.m. the NHC issued its last advisory, and the following was available on Matthew:
5:00 PM EDT Sun Oct 9
Location: 35.4°N 72.0°W
Moving: ENE at 15 mph
Min pressure: 988 mb / 29.18 in
Max sustained: 75 mph
Matthew should now continue to gradually weaken during the next 24-36 hours, and should become fully absorbed by the front within 48 hours, and I concur with the NHC intensity forecast.
NHC INTENSITY FORECAST
INIT 09/2100Z 35.4N 72.0W 65 KT 75 MPH…POST-TROP/EXTRATROP
12H 10/0600Z 36.4N 69.2W 55 KT 65 MPH…POST-TROP/EXTRATROP
24H 10/1800Z…ABSORBED BY FRONT
Matthew is moving to the East, and based on forecast steering layers maps, and current dynamic track guidance, I expect this motion to continue during the next 24-36 hours. Soon thereafter, a turn toward the ENE or NE appears to be in order. Based on this, I have no reason to disagree with the NHC forecast track on Matthew.
Elsewhere, Tropical Storm Nicole (once hurricane Nicole) remains almost stationary, 575 miles S. of Bermuda.
As of the 5:00 p.m. advisory from the NHC, the following was available on Nicole:
5:00 PM AST Sun Oct 9
Location: 24.2°N 65.3°W
Moving: Nearly stationary
Min pressure: 989 mb / 29.20 in
Max sustained: 65 mph
Satellite loop imagery indicates Nicole’s presentation has improved over the past few hours, with the LLC becoming positioned closer to the convective cloud cover. Nicole has been under some pretty moderate northerly winds shear, but looking at the improved structure may indicate shear could be in the process of diminishing somewhat. The latest wind shear product from CIMSS indicated northerly shear on the order of around 20-30 knots. This flow and shear was indicated on the 12Z run of the GFS.
Based on analysis of forecast steering maps, and dynamic model track guidance, Nicole should begin to track on an average, slow northerly motion by Monday, and continue this general motion through to Wed., then turning more to the NNE. This motion would bring the western side of the storm very close to the East side of Bermuda. At the moment, I have to concur with the NHC forecast track.
Based on my analysis of the most current wind shear products, Nicole should improve in structure, slowly over the next 24 hours, while still experiencing a slow decrease in northerly shear. In about 36 hours from 12Z forecast this a.m., wind shear is forecast to subside, and upper level winds are forecast to become favorable for strengthening…This window of favorable upper level winds should remain from the forecast period of 36-96 hours from 12Z this morning. Based on this analysis, I concur with the NHC intensity forecast, and Nicole could once again become a hurricane. After the 96 point, shear is once again forecast to increase, and should prevent any strengthening from that point. It is noted however, that by this time in the period, Nicole could show some strengthening due to baroclinic processes, in which shear would actually aid the system.
NHC INTENSITY FORECAST
INIT 09/2100Z 24.2N 65.3W 55 KT 65 MPH
12H 10/0600Z 25.0N 65.2W 60 KT 70 MPH
24H 10/1800Z 25.9N 65.3W 65 KT 75 MPH
36H 11/0600Z 26.6N 65.5W 70 KT 80 MPH
48H 11/1800Z 27.2N 65.9W 75 KT 85 MPH
72H 12/1800Z 28.4N 66.4W 80 KT 90 MPH
96H 13/1800Z 31.3N 65.0W 80 KT 90 MPH
120H 14/1800Z 35.4N 59.0W 75 KT 85 MPH
Residents of the Island of Bermuda should closely monitor the future progress of Nicole, and review their hurricane preparedness plans, as well as monitoring local weather service office statements.
Elsewhere, based on my analysis of both the GFS and ECMWF 500 mb height anomaly maps (I will be analyzing these for continuity over the next couple of days), we may have to watch the W. Caribbean / GOMEX areas within the next 7-10 days. Analysis of both of these global models indicates a very powerful trof / cutoff low in the North Central Atlantic, which appears to be associated with Nicole, and the 500 mb deep layer trof that eventually picks her up, begins to back toward the SW, eventually causing a strong trof split in about 7-8 days. By days 9-10, this low completes the trof split, and sends a large piece into the Caribbean / GOMEX area, indicating a significant lowering of pressure heights, and appears to close off a 500 mb low at the moment. Again, the pattern of the ridge building north of the GOMEX, would support this setup…what is affectionately stated by Joe Bastardi as “the ridge over troubled water”. This setup is not unlike what brought Matthew, Hermine, etc. As I’ve stated before, when you have a strong enough ridge build over the NE U.S. or North of the GOMEX far enough (roughly in these invites), and conditions are favorable, you can get development, as pressures south of the ridge, naturally lower. This is part of the PGF (Pressure Gradient Force). Now, this is mainly for those in the weather groups I post in on Facebook…PLEASE do not bombard me with questions such as, will it become a hurricane, or where I think it’s going to go. Those questions are moot at the moment, until we see if anything actually does develop out of the pattern.
I will continue to monitor everything, and intend to update M-W.
Elsewhere, Tropical Storm formation is not expected during the next 7-10 days.
Have a blessed evening!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS