TROPICAL STORM MATTHEW FORECAST SYNOPSIS…ISSUED SEP. 28, 2016…4:00 P.M. EDT

TROPICAL CYCLONE FORMATION:  T.S. MATTHEW

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(T. F. “Storm” Walsh III)

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CURRENT 2016 ATLANTIC TROPICAL CYCLONE TOTALS:

TOTAL STORMS: 13
HURRICANES: 4
MAJOR HURRICANES: 1
U.S.LANDFALLS: 4

StormW’s Seasonal Hurricane Forecast:
TOTAL STORMS: 13-15
HURRICANES: 6-7
INTENSE HURRICANES: 3-4

Here is some updated information regarding Matthew for the 5:00 p.m. advisory from the NHC:

5:00 PM AST Wed Sep 28
Location: 13.8°N 62.0°W
Moving: W at 18 mph
Min pressure: 1008 mb / 29.77 in
Max sustained: 60 mph

TROPICAL STORM MATTHEW HURREVAC NHC TRACKING MAPS
hurrevac-matthew-error
hurrevac-matthew-wnd

WATCHES AND WARNINGS

CHANGES WITH THIS ADVISORY:
The government of the Netherlands has issued a Tropical Storm Watch for Bonaire. The government of Curacao has issued a Tropical Storm Watch for Curacao and the government of Aruba has issued a Tropical Storm Watch for Aruba.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for… * Guadeloupe and Martinique * St. Lucia * Dominica, Barbados, St. Vincent, and the Grenadine Islands A Tropical Storm Watch is in effect for… * Bonaire, Curacao, and Aruba A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next 36 to 48 hours. Interests along the coast of Venezuela and Colombia should monitor the progress of Matthew. For storm information specific to your area, please monitor products issued by your national meteorological service. 

HAZARDS AFFECTING LAND

WIND: Tropical storm conditions will continue through this evening over the southern Leeward Islands and northern Windward Islands within the warning. Tropical storm conditions are possible in Bonaire, Curacao, and Aruba, beginning late Thursday.

RAINFALL: Matthew is expected to produce total rainfall accumulations of 4 to 8 inches across the Windward Islands and southern portions of the Leeward Islands through Thursday. These rains may produce life-threatening flash floods and mud slides. Rainfall totals of 1 to 2 inches are expected farther to the north into the northern Leeward Islands, including the United States and British Virgin Islands and Puerto Rico. Rainfall totals of 1 to 3 inches are expected over Aruba, Bonaire, and Curacao through Friday.

NHC INTENSITY FORECAST

INIT 28/2100Z 13.8N 62.0W 50 KT 60 MPH
12H 29/0600Z 14.1N 64.4W 50 KT 60 MPH
24H 29/1800Z 14.4N 67.1W 55 KT 65 MPH
36H 30/0600Z 14.4N 69.5W 65 KT 75 MPH
48H 30/1800Z 14.1N 71.3W 70 KT 80 MPH
72H 01/1800Z 14.2N 73.5W 80 KT 90 MPH
96H 02/1800Z 15.8N 75.0W 90 KT 105 MPH
120H 03/1800Z 19.0N 76.0W 90 KT 105 MPH

Looking quickly at current wind shear for this advisory, the upper level anticyclone has collapsed, which may be temporary, and some 20 knots of shear is over the storm at the moment.  However, the forecast pattern still indicates very favorable conditions for the central Caribbean for further development, and I cannot rule out RI at this time.

CURRENT WIND SHEAR PRODUCT FROM CIMSS
wg8shr

Good day everyone!

INVEST 97L was finally able to close off a low level circulation (LLC), and was upgraded to Tropical Storm Matthew at 11:00 a.m.  As of the 2:00 p.m. intermediate advisory, the following was available on Matthew:

2:00 PM AST Wed Sep 28
Location: 13.6°N 61.3°W
Moving: W at 20 mph
Min pressure: 1008 mb / 29.77 in
Max sustained: 60 mph

As of the intermediate advisory, the following WATCHES and WARNINGS were in effect from the NHC:

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for… * Guadeloupe and Martinique * St. Lucia * Dominica, Barbados, St. Vincent, and the Grenadine Islands

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning.

Interests in Bonaire, Curacao, Aruba, and elsewhere in the Lesser Antilles should monitor the progress of Matthew. For storm information specific to your area, please monitor products issued by your national meteorological service.

HAZARDS AFFECTING LAND 

WIND: Tropical storm conditions will continue to spread over the southern Leeward Islands and northern Windward Islands within the warning area this afternoon and continue into this evening.

RAINFALL: Matthew is expected to produce total rainfall accumulations of 4 to 8 inches across the Windward Islands and southern portions of the Leeward Islands through Thursday. These rains may produce life-threatening flash floods and mud slides. Rainfall totals of 1 to 2 inches are expected farther to the north into the northern Leeward Islands, including the United States and British Virgin Islands and Puerto Rico.

HURREVAC MATTHEW NHC TRACKING MAPS
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hurrevac-matthew-wnd

MATTHEW FLOATER SATELLITE LOOP IMAGERY
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rgb0-lalo-97l

Based on my analysis of the current wind shear pattern, and current upper level pattern, conditions over Matthew have improved since my analysis this morning.  The upper level anticyclone that has been forecast, has developed and is positioned over the center of the storm.  Once in the central Caribbean, this upper feature is forecast to become better established, indicating a very favorable upper level environment.   Looking at the forecast projection of this, I’m not going to list all the other parameters, however ALL forecast parameters favor quicker development, and given the high OHC, I still cannot rule out the possibility of RI either in the central Caribbean, or once over the Bahamas after recovering from land interaction with Cuba.  This system will still have the potential to become a major hurricane.  At the moment, the majority of the intensity modeling in the current run, bring this to a strong CAT 2 hurricane.  While I concur with the NHC intensity forecast right now,  It is my opinion however, if all the favorable forecast parameters hold true, Matthew should strengthen quicker, and we could very well see a major hurricane.

GFS WIND SHEAR / 200 MB STREAMLINE FORECAST
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gfs_dl_shear_carib_17
gfs_dl_shear_carib_25
OCEAN HEAT CONTENT
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ATCF 18Z MATTHEW INTENSITY GUIDANCE
97l-18z-dynamic

Upon analysis of the global models, and ensemble members from the GFS and ECMWF, it appears we may have a clearer picture, and some semblance of agreement, albeit with variations, in the track guidance with Matthew.  Again, if it remains weaker and slows down, it will have the tendency to move further to the west, and track most likely per the ECMWF.  A stronger, and slightly faster system (as in its average speed over the past few days) will more likely tend to follow what the GFS is proposing.  Right now, even though the ECMWF ensemble members have shifted right, it has been the more steady of the modeling, in that the shifts we have seen in comparison to the GFS operational model have been fairly small in comparison.  It is also noted, the GFS has been back and forth over the past 3 days, but has seemed to have been a little more consistent in the past 2 runs, with a slight right shift in track from having gone into the Tidewater area, to just offshore the Tidewater area.  Out of respect for the ECMWF which nailed Joaquin last season, beating out not only the other global models, but the dynamic track guidance modeling, I am inclined right now to lean toward the ECMWF solution at the moment from the 12Z run, which shows slower moving system, to just north of the Bahamas in 10 days, vice the GFS showing it all the way into Nova Scotia by day 10. The NHC forecast track is a blend of the GFS and ECMWF, and I concur with the overall track,  however I feel the turn may occur a little further west.  The GGEM and NAVGEM sort of follow this, however bring the storm on more of a northward,  almost skirting the U.S. east coast.  In any case, it now appears after analysis again this afternoon of the 500 mb anomaly pattern, the proposed sharp northward turn should occur.  However, as I have noticed the models continued shifting of the ridge/trof pattern, and varying strengths and position of the U.S ridge by day 7-10, it is not fully known at the moment how close Matthew could actually come to the U.S. east coast.  I will continue to monitor Matthew and the overall pattern for any significant changes during the remainder of the week.  Depending on what we have over the next few days, I may try to update after I get home from work,, especially next week.  If not, I will most likely do a special update late on Saturday.

ECMWF EPS 00Z RUN
eps_al97_2016092800
ECMWF SOLUTION 198 HOURS
ecmwf_z500_norm_east3_34

ECMWF 240 HOURS
ecmwf_z500_norm_east3_41

GFS SOLUTION 198 HOURS
gfs_z500_norm_conus_34

GFS 240 HOURS
gfs_z500_norm_conus_41

CMC GGEM SOLUTION 144 / 240 HOURS
cmc_mslp_uv10m_east_25

 

 

 

 

 

 

 

 

 

cmc_mslp_uv10m_east_41

NAVGEM SOLUTION 144 HOURS
nav_precip_mslp_east_25

Elsewhere, Tropical Storm formation is not expected during the next 5-7 days.

Have a blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
CoCoRAHS OBSERVER

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