Wednesday Morning update for September 4, 2019
In this update:
- Latest on Dorian, Fernand, TD8 and Invest 92-L
- The very dangerous threat that Dorian has on the Tri-Counties for the weekend…
1. Latest on the Tropics:
- Dorian: ABOUT 105 MI...175 KM E OF DAYTONA BEACH FLORIDA
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NNW OR 340 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...961 MB...28.38 INCHES
Dorian continues to weaken and move ever so slowly, and is expected to near the Florida/Georgia border later tonight, then make a very near landfall in the Carolinas Tomorrow, and then gather steam and head for us next by the weekend.
- Fernand:ABOUT 90 MI...145 KM SE OF LA PESCA MEXICO
ABOUT 95 MI...150 KM NE OF TAMPICO MEXICO
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES
Tropical Storm Fernand is a weak Tropical Storm, that is currently bringing Tropical Storm conditions to the coast of Mexico, Fernand is Moving West at 6 km/h with max wind speeds of 50 mph or 85 km/h. Fernand is expected to make landfall very late tonight in Mexico and then weaken to a Tropical Depression afterwards through the day tomorrow and be ripped apart from mountains on Friday.
- Tropical Depression # 8: ABOUT 615 MI...995 KM WNW OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES
Tropical Depression # 8 is expected to become Tropical Storm Gabrielle later today, as it heads for the open waters of the Mid Atlantic, This storm could pose a possible threat to our neck of the woods by middle of next week.
PS: Latest data as of 5:30am, as I am writing this… shows that TD8 is Now TS Gabrielle, next update from the NHC should confirm that!
- Invest 92-L: A trough of low pressure, located just east of Bermuda, is producing
disorganized showers and thunderstorms. Some development of this
disturbance is possible, and a tropical depression could form during
the next couple of days as the disturbance moves northeastward, away
from Bermuda. Afterward, upper-level winds are forecast to become
less favorable for tropical cyclone formation. Interests in Bermuda
should monitor the progress of this system, and areas of heavy
rainfall are likely.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.
- Invest 94-L: A tropical wave is forecast to emerge over the far eastern tropical
Atlantic between Africa and the Cabo Verde Islands later today.
Environmental conditions are forecast to be conducive for
development, and a tropical depression is likely to form late this
week or over the weekend while the system moves westward to
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...high...70 percent.
We have been monitoring Dorian for quite sometime now, and for much of the time the models have been pretty consistent, and they still are! There is some disagreement on timing, strength and a slight difference in track.. But there is a few things we know!
- We know that Dorian WILL have a big impact on the province.
- We know the timing will be very early Saturday morning or afternoon.
- We know that Dorian will spread very heavy rain and Tropical Storm force winds to the Tri-Counties.
Dorian will arrive near the Tri-Counties on Early Saturday, and most of the Global models have it very close, so close in fact that it is still debatable if we will see Hurricane Force Conditions! Which are winds of 120km/h or greater.
There are 4 top Hurricane weather models, the ECMWF, GFS, HMON & UKMO.
The ECMWF being the most reliable and accurate model in the world, followed by the GFS.. The ECMWF,HMON, ICON models show a very close pass to the south of Shelburne by Saturday morning, close enough to bring Hurricane conditions. Meanwhile, the GFS, UKMO, GEM, ACCESS-G and APREGE models puts it still further out, however close enough to bring Tropical Storm conditions.
Dorian is currently being steered by 2 Big ridges of High pressure, one over the Atlantic, and another in the Southern states. Meanwhile, there is a cold front that is over the Great lakes that is heading Eastward and is the same cold front that will bring us some rain for later tonight into Thursday.. This front could play a role in where Dorian goes, if the front can stall a little then maybe it could be just in time to grab Dorian and push it further out, just enough to give us a break from the Strongest winds. We will have to still deal with flooding rain, and Tropical Storm wind Gusts but the Hurricane force will be far enough offshore.
If the front passes sooner than expected and is moving faster than Dorian, Dorian will miss it, and eventually will come up farther north and much closer that thought which will lead to Hurricane conditions.
In my honest opinion, It is looking very likely that the worst case scenario will happen.. The cold front will be to quick, and Dorian won’t have time to catch up to it because she is simply just to slow! Along with the fact that models continue to trend Westward, and the ECMWF is on board with it, for this update the TCWS will be following the track and conditions close to what the ECMWF and ICON model consensus are predicting.
So let’s start with Rainfall! With the timing first.
Saturday 3am: Drizzle or showers starts in the Very southern tip of Shelburne, ( Clarks Harbor, Barrington, etc)
Saturday 6am: Rain spreads into the entire county of Yarmouth & Shelburne as some light to moderate rain, Extreme southern tip of Digby starts seeing some Drizzle.
Saturday 9am: Moderate rain arrives in Yarmouth and Shelburne, light rain spreads into the rest of Digby.
Saturday Noon: Rain becomes heavier in all 3 Tri-Counties.
Saturday 3pm: Getting near the center! Rain becomes a bit more heavier, rain rates of 15-20mm/3hrs.
Saturday 6pm: Dorian unleashes her Tropical drenching downpours, this is the very heavy rain!! rain rates now in Shelburne at this hour would be 30 to 50mm/3hr, a little less in Yarmouth and Digby at 15-20mm/3hr
Saturday 9pm: Heaviest rain arrives! Shelburne being hardest hit, with 60-70mm per 3 hrs! or 20mm per hour! Still heavy rain rates in Yarmouth and Digby.
Sunday 12am: Heaviest rain moves out, but still raining fairly heavy.
Sunday 3am: Rain becomes lighter, almost like a light to moderate rainfall.
Sunday 6am: Tapers to light showers and drizzle
Sunday 9am: Clears out.
So the rain lasts for a long time! And very heavy too.. and this being a big Tropical System, it is no doubt that we will get a lot! So how much?
Digby County: 80 to 100mm
Yarmouth County: 90-110mm, However for towns near West Pubnico and East of there that is close to the border of Shelburne, rainfall amounts of 130-160mm is very likely.
Shelburne: 115-160mm, heaviest in town of Shelburne, clark’s Harbour and Barrington.
Now the rain is big, but the winds will be the worst of them all! Very damaging winds…
Starting us off at 9am on Saturday: Sustained winds of 30 to 40 on the coast, 15-25 inland, Gusts of 50-70km/h on the coast and 30-40 inland.
Saturday @ Noon: Sustained winds at the coast clock 60 km/h, nearing tropical Storm force, Inland areas between 20-30km/h. Gusts on the coast reach 70 to 90 km/h, easily Tropical Storm force.
Saturday @ 3pm: Sustained winds at the coast now exceeding tropical Storm force at 70-90km/h, the threshold for damage.. Inland, sustained winds are at 40km/h. Gusts at the coast are between 100 and 120 km/h, nearing Hurricane Strength, while Inland Gusts are 80 to 100km/h, enough to cause damage..
Saturday @ 6pm: Winds now reach 40-60km/h sustained inland, while the coast now have sustained wind speeds of 80 to 110 km/h! Strong tropical Storm force, these winds are past damage criteria, the Gusts will be much higher as the storm nears. Gusts on the coast at this hour, 130 to 160km/h! Hurricane force. Inland Gusts will be 100 to 120km/h.
Saturday @ 9pm: This is when Dorian is just near the doorsteps of Shelburne! This is the worst of the storm for rain, wind and storm surge! Winds Sustained on the coast are now at 100+km/h, Inland sustained winds are over 60km/h, Tropical Storm conditions. Gusts will be at there strongest. Coastal Gusts at this hour will be 140 to 170km/h, Inland Gusts will be exceeding 140km/h as well and these are Category 1 hurricane force winds.
So With winds Sustained near 100 on the coast and Gusts as high as 150km/h inland and the coast… what kind of Damage can we expect?
This storm when at it’s nearest approach will likely still be a Category 1 Hurricane with 80 M.P.H winds, some of that wind field may enter Shelburne county. However,Hurricane Wind Gusts can be felt far inland into Yarmouth county at near 150km/h.
What will be worst is the 100+ winds will persist for 6+ hours.
Types of Damage Due to Hurricane Winds
Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
157 mph or higher
137 kt or higher
252 km/h or higher
Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
Next Update is at noon! Which will have more on the rain tonight and your full forecast! Along with updates on the Tropics!