Meteorological Autumn Storm

000

FXUS61 KCAR 290124

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

924 PM EDT Mon Aug 28 2023

.SYNOPSIS...

High pressure will exit across the Maritimes overnight. A cold

front approaches Tuesday night, then crosses the region

Wednesday. High pressure then builds in and lasts through

Saturday.....

......SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...

There are a few features at play through the middle of the week

that will dictate the weather pattern across northern and

eastern Maine. There exist two tropical systems at the moment,

one being Hurricane Franklin which is currently moving north

well off the SE CONUS coast, and Tropical Storm Idalia which is

entering the southern Gulf of Mexico. Neither storm will

directly impact our forecast area. This is due to an upper level

longwave trough moving across northern New England through

mid-week, which will scoop up these systems and escort them out

into the middle of the Atlantic Ocean. That said, these tropical

systems will contribute to our weather in other ways. One of

which will be in the form of rip currents and increased swell

and wave heights from Hurricane Franklin, and more can be read

about this in the Tides/Coastal Flooding section below. The

other impact will be the increase in atmospheric moisture

available to the area.

As the longwave trough interacts with these tropical systems,

mid-level moisture will be pulled northwards into northern New

England. This increase in moisture will result in another

wetting rain day, especially across the Downeast region where

steady rain in excess of one to two inches of total rainfall are

expected. Though Downeast will likely see the highest rainfall

totals, northern areas will likely see around a half inch or

more of rainfall through the day on Wednesday.

Behind the trough of low pressure, high pressure will begin to

build into the area on Thursday. This high pressure will set up

a drier pattern for the area......

8:09 PM ADT Monday 28 August 2023

Rain at times heavy is forecast Tuesday night and Wednesday.

Total rainfall: 40 to 90 mm, with higher amounts possible.

Locations: Atlantic coast and eastern Nova Scotia.

Time span: Tuesday overnight into Thursday morning.

Potential impacts: Similar storms in the past have caused road shoulder erosion and washouts as well as elevated river levels. Winds are not expected to be impactful from this weather system over land.

Remarks: Heavy rain is possible, again. There remains a fair bit of uncertainty with regards to how this weather disturbance, which is unrelated to Hurricane Franklin, may interact with the hurricane as it is expected to pass well south of the province. As this information becomes clearer, timing and locations of the heaviest rain as well as expected rainfall amounts may change. Rainfall warnings may be required.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NSstorm@ec.gc.ca or tweet reports using #NSStorm.

2:52 PM ADT Monday 28 August 2023

Tropical Cyclone Information Statement (Franklin) in effect for:

Marine Zone

Maritime Waters

Laurentian Fan

Newfoundland Waters

Southeastern Grand Banks

Southwestern Grand Banks

Hurricane Franklin as of Monday afternoon was situated midway between the Bahamas and Bermuda and has intensified considerably to category 4 intensity. It may briefly reach category-5 while tracking well west then northwest of Bermuda.  

Latest computer models predict Franklin to move along or just inside the Canadian marine forecast district near category-2 or strong-category-1 intensity late Thursday into Friday.  Interests in the Southern Grand Banks should pay close attention to forecasts especially now that the storm has reached the upper categories of intensity.  It will take some time for the intensity to drop down before reaching the edge of the region.  

There is a possibility that some moisture from the hurricane could feed into an elongated low pressure system well to the north of it over Atlantic Canada beginning later Wednesday.  The details of this are not yet well understood but we will provide more discussion in later bulletins if required.  This bulletin is only valid for Laurentian Fan and the Southern Grand Banks so consult public forecast products issued by the Atlantic Storm Prediction Centre and the Newfoundland and Labrador Weather Office for details concerning rainfall.    

Large ocean swells will travel far north away from the hurricane and bring heavy surf conditions to parts of the Atlantic coast of Nova Scotia and southern Newfoundland beginning Wednesday. Indications are that swells near 2m (7 feet) will approach the shore on Thursday and could break up to 3m (10 feet).

After our assessments this morning, we have decided to commence with 6-hourly bulletins and track forecasts at 3 pm ADT Tuesday.

 

Forecaster: Fogarty

Please continue to monitor alerts issued by the Canadian Hurricane Centre and forecasts issued by Environment Canada.

Hazardous Weather Outlook

National Weather Service Caribou ME

334 AM EDT Mon Aug 28 2023

MEZ011-015>017-029-030-032-290745-

Central Penobscot-Southern Penobscot-Interior Hancock-

Central Washington-Coastal Hancock-Coastal Washington-

Northern Washington-

334 AM EDT Mon Aug 28 2023

This Hazardous Weather Outlook is for Coastal DownEast Maine, Far

Eastern Maine, Interior DownEast Maine and Penobscot Valley Maine.

.DAY ONE...Today and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Persistent south to southeast long period swells from Hurricane

Franklin Wednesday through Thursday will result in dangerous rip

currents and could also result in high surf and splashover along the

Downeast coast. Franklin is expected to track over 600 miles south

and east of eastern Maine in the open Atlantic Ocean.

Heavy rain is possible Wednesday with the approaching cold front and

tropical moisture from Franklin. Isolated flooding in urban areas

and small streams is possible especially across the Downeast into the

Greater Bangor area.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$