Meteorological Autumn Storm Update One

000

FXUS61 KCAR 300245

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

1045 PM EDT Tue Aug 29 2023

.SYNOPSIS...

A cold front crosses the region late Wednesday. High pressure

then builds in and lasts through the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

Update...

Have issued a Dense Fog Advisory for coastal portions of

Hancock and Washington counties through 8 AM with this update.

A cold front approaches northwest Maine late tonight while low

pressure moves along the front. Aloft, a disturbance approaches

late tonight in advance of a trof crossing the Great Lakes.

Moisture increases tonight, with precipitable water values

increasing to around 1.50 inches across northern areas, to

around 2.00 inches Downeast. Rain chances increase overnight,

with the greater chances across Downeast areas. Fog will move

inland across Downeast areas from the Gulf of Maine. Patchy fog

will develop late across the remainder of the region. Low

temperatures will range from around 60 to the lower 60s across

the forecast area. Have updated to adjust for current conditions

along with expected overnight temperatures, clouds and rain

chances.

Previous Discussion...

Tonight...

Moisture continues to increase from the south as the upper

trough and cold front approach. Also, deeper moisture begins to

move in from the S/SW as an atmospheric river sets up with

moisture tapped from both Franklin and Idalia. Rainfall totals

don`t look too heavy (yet) with the heavier activity generally

waiting until during the day Wednesday.

Wednesday...

Very high precipitable water values of 1.5-2 inches (highest

Downeast) with deep tropical moisture over the area. Forcing

will be from an approaching shortwave trough and cold front.

Concern for locally heavy rain, but concern not quite high

enough to do a flash flood watch. Also, very low confidence on

what part of the area will get the heaviest rain, or what part

of the day will feature the heaviest rain. Generally looking

for over 0.5 inch, though can`t rule out locally up to or a

little over 2 inches. If this happens in a couple hours, could

be some local flooding concerns. Cold front moves into Northern

Maine just before sunset, with rain tapering off behind the cold

front.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...

The cold front will cross the Gulf of Maine by late Wednesday

night, bringing gusty NW winds behind the front. The air mass

behind the front will be drier, so showers should taper off

quickly Wednesday night. The main concern for Wednesday night

and Thursday will be high surf associated with Hurricane

Franklin, which is well offshore. With sunny conditions Thursday

morning, this could be problematic with folks venturing to the

coast to see the swells. Recommend staying away from shorelines

with hazardous conditions expected. More details follow in the

Tides/Coastal Flooding section below.

Otherwise, Thursday through Friday will be dry and slightly

cooler behind the cold front. Should the atmosphere decouple,

there is a possibility of frost on Wednesday night in the far

North Woods, but right now conditions look to be dynamic enough

to prevent this from happening. By Thursday night/Friday

morning, the air mass will have warmed slightly so frost is less

likely......

Hazardous Weather Outlook

National Weather Service Caribou ME

1027 PM EDT Tue Aug 29 2023

MEZ001>006-010-011-015>017-031-032-301200-

Northwest Aroostook-Northeast Aroostook-Northern Somerset-

Northern Piscataquis-Northern Penobscot-Southeast Aroostook-

Central Piscataquis-Central Penobscot-Southern Penobscot-

Interior Hancock-Central Washington-Southern Piscataquis-

Northern Washington-

1027 PM EDT Tue Aug 29 2023

This Hazardous Weather Outlook is for Central Highlands Maine, Far

Eastern Maine, Far Northern Maine, Interior DownEast Maine, North

Woods Maine and Penobscot Valley Maine.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Locally heavy rain is expected Wednesday with the approaching cold

front. Isolated flooding in urban areas and small streams is

possible.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$

URGENT - WEATHER MESSAGE

National Weather Service Caribou ME

944 PM EDT Tue Aug 29 2023

MEZ029-030-301200-

/O.NEW.KCAR.FG.Y.0029.230830T0144Z-230830T1200Z/

Coastal Hancock-Coastal Washington-

Including the cities of Ellsworth, Bar Harbor, Bucksport, Orland,

Castine, Eastport, Perry, Machias, and Cherryfield

944 PM EDT Tue Aug 29 2023

...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM EDT WEDNESDAY...

* WHAT...Visibility one quarter mile or less in dense fog.

* WHERE...Coastal Hancock and Coastal Washington Counties.

* WHEN...Until 8 AM EDT Wednesday.

* IMPACTS...Hazardous driving conditions due to low visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of

distance ahead of you.

&&

$$

Norcross

Coastal Hazard Message

National Weather Service Gray ME

842 PM EDT Tue Aug 29 2023

MEZ023-024-NHZ014-301000-

/O.CON.KGYX.RP.S.0001.230830T1200Z-230901T0000Z/

Coastal York-Coastal Cumberland-Coastal Rockingham-

842 PM EDT Tue Aug 29 2023

...HIGH RIP CURRENT RISK REMAINS IN EFFECT FROM 8 AM EDT

WEDNESDAY THROUGH THURSDAY EVENING...

* WHAT...Dangerous rip currents expected.

* WHERE...In Maine, Coastal York and Coastal Cumberland

  Counties. In New Hampshire, Coastal Rockingham County.

* WHEN...From Wednesday morning through Thursday evening.

* IMPACTS...Rip currents can sweep even the best swimmers away

  from shore into deeper water.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Swim near a lifeguard. If caught in a rip current, relax and

float. Don`t swim against the current. If able, swim in a

direction following the shoreline. If unable to escape, face the

shore and call or wave for help.

&&

$$

8:21 PM ADT Tuesday 29 August 2023

Rain at times heavy is expected Wednesday.

Total rainfall: 30 to 50 mm, with locally higher amounts possible.

Locations: Prince Edward Island.

Time span: beginning early Wednesday morning, ending from west to east by late Wednesday night.

Remarks: Periods of rain with embedded downpours or thunderstorms is expected again on Wednesday. There remains a fair bit of uncertainty with regards to how this weather disturbance, which is unrelated to Hurricane Franklin, will evolve as it tracks across 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.

Potential impacts: Similar storms in the past have caused water pooling on road surfaces, road shoulder erosion and washouts as well as elevated river levels.

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

8:21 PM ADT Tuesday 29 August 2023

Rain at times heavy is expected overnight tonight and Wednesday.

Total rainfall: 30 to 50 mm, with locally higher amounts likely.

Locations: southern and central New Brunswick.

Time span: overnight tonight and Wednesday, ending from west to east by late Wednesday night.

Remarks: Periods of rain with embedded downpours or thunderstorms is expected again overnight tonight and Wednesday. There remains a fair bit of uncertainty with regards to how this weather disturbance, which is unrelated to Hurricane Franklin, will evolve as it tracks across 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.

Potential impacts: Similar storms in the past have caused water pooling on road surfaces, road shoulder erosion and washouts as well as elevated river levels. Keep storm drains clear of debris to help with drainage.

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

8:19 PM ADT Tuesday 29 August 2023

Rain at times heavy is expected overnight tonight and Wednesday.

Total rainfall: 40 to 80 mm, with locally higher amounts possible.

Locations: Nova Scotia.

Time span: overnight tonight and Wednesday, ending from west to east by late Wednesday night.

Remarks: Rain with embedded downpours or thunderstorms is expected again overnight tonight and Wednesday. There remains a fair bit of uncertainty with regards to how this weather disturbance, which is unrelated to Hurricane Franklin passing well to the south, will evolve as it tracks across the province. As this information becomes clearer, timing and locations of the heaviest rain as well as expected rainfall amounts may change.

Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible.

Watch for possible washouts near rivers, creeks and culverts.

Rainfall warnings are issued when significant rainfall is expected.

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.