Debby Now A Tropical Depression Finally Heads Northward

723 

WTNT34 KWNH 090242

TCPAT4

BULLETIN

Tropical Depression Debby Advisory Number  27

NWS Weather Prediction Center College Park MD   AL042024

1100 PM EDT Thu Aug 08 2024

...MAJOR FLOOD THREAT CONTINUES FOR PORTIONS OF WESTERN VIRGINIA...

SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION

-----------------------------------------------

LOCATION...36.2N 80.2W

ABOUT 80 MI...135 KM NNE OF CHARLOTTE NORTH CAROLINA

ABOUT 90 MI...140 KM WNW OF RALEIGH NORTH CAROLINA

MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H

PRESENT MOVEMENT...NNE OR 20 DEGREES AT 26 MPH...43 KM/H

MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES

WATCHES AND WARNINGS

--------------------

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

Flood Watches and Warnings are in effect for portions of....

* South Carolina

* North Carolina

* Virginia

* Eastern West Virginia

* Maryland

* Pennsylvania

A Flood Watch is in effect for portions of...

* Upstate New York

* Northern Vermont

* Northern New Hampshire

A Tornado Watch is in effect for portions of...

* Eastern North Carolina

* Northern and Eastern Virginia

* Maryland

* District of Columbia

* Eastern West Virginia

Coastal Flood Advisories are in effect for portions of...

* Eastern North Carolina

* Areas surrounding the Chesapeake Bay and Potomac River

* Central New Jersey Coast

A Gale Watch is in effect the coastal waters of...

* Rhode Island

* Southeastern Massachusetts up through Cape Cod

Wind Advisories are in effect for portions of...

* Western Virginia

* Eastern Maryland

* Delaware

* Eastern Pennsylvania

* New Jersey

* Southern New York

* Southern Connecticut

DISCUSSION AND OUTLOOK

----------------------

At 1100 PM EDT (0300 UTC), the center of Tropical Depression Debby

was located near latitude 36.2 North, longitude 80.2 West. The

depression is moving toward the north-northeast near 26 mph (43

km/h) and this motion is expected to slowly increase and shift to 

the northeast over the next day.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.

Little change in strength is forecast during the next 48 hours. 

The estimated minimum central pressure is 1001 mb (29.56 inches).

HAZARDS AFFECTING LAND

----------------------

Key messages for Debby can be found in the Tropical Cyclone

Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC.

RAINFALL: Debby is expected to produce an additional 3 to 6 inches

of rainfall with locally higher amounts, across portions of

southeastern North Carolina leading to maximum storm total amounts

as high as 15 inches.  Additional rainfall of 1 to 3 inches over

portions of eastern South Carolina will bring maximum storm total

amounts as high as 20 to 25 inches. Considerable flooding is

expected across portions of eastern South Carolina and southeast

North Carolina through Friday.

From central North Carolina northward across portions of Virginia, 3

to 7 inches with local amounts to 10 inches, are expected through

Friday. This rainfall will likely result in areas of considerable to

locally catastrophic flash and urban flooding, especially in the

terrain of western Virginia, with river flooding also possible.

From portions of Maryland north through Upstate New York and

Vermont, 2 to 4 inches, with local amounts to 6 inches, are expected

through Friday night. This will likely result in areas of

considerable flash and urban flooding as well as river flooding.

For the remainder of northern New England, 1 to 3 inches, with

local amounts to 4 inches, are expected into Saturday.  Scattered

instances of flash flooding are possible.

For a complete depiction of forecast rainfall and flash flooding

associated with  Debby, please see the National Weather Service

Storm Total Rainfall Graphic, available at

hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk

graphic at hurricanes.gov/graphics_at4.shtml?ero.  For a list of

rainfall observations (and wind reports) associated this storm, see

the companion storm summary at WBCSCCNS4 with the WMO header ACUS44

KWBC or at the following link:

www.wpc.ncep.noaa.gov/discussions/nfdscc4.html.

TORNADOES: A few tornadoes may occur tonight from eastern North

Carolina into Virginia and Maryland. The threat for tornadoes will

shift northward into parts of New Jersey, eastern Pennsylvania and

southeast New York on Friday.

SURF:  Large swells will continue to affect the Southeast and the

Mid Atlantic coast for another day or so. These conditions are

likely to cause life-threatening surf and rip current conditions.

Please consult products from your local weather office.

NEXT ADVISORY

-------------

Next complete advisory at 500 AM EDT.

$$

Forecaster Pereira/Gallina/Chenard

253

FXUS61 KCAR 090153

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

953 PM EDT Thu Aug 8 2024

.SYNOPSIS...

A warm front will lift northeast over the area on Friday with

the remnants of Debby tracking northeast into Quebec by Saturday

as a cold front swings through the state. A secondary cold

front crosses the area Sunday night into Monday. Another cold

front crosses the area Monday night into Tuesday.

&&

.NEAR TERM /THROUGH FRIDAY/...

630 pm update...Increased PoPs this evening as light rain is

falling out of mid clouds in western portions of the forecast

area. Also increased cloud cover through Friday morning. Low

temp forecast still looks reasonable with the greater cloud

cover.

Previous discussion...

Sfc high has built into Atlantic Canada this afternoon with moisture

advection beginning over New England. As hipres builds east this

evening, expect dwpts to start climbing with pw values beginning to

increase after 00z. Given clouds moving in fairly quickly after

midnight have boosted temps up by several degrees.

H8 warm front will be lifting thru the region during the overnight

hours with scattered showers entering the Central Highlands toward

daybreak, which is a good 3-6 hrs faster than prior fcst. Have

brought categorical pops from Central Highlands into sern Aroostook

by 12z and lifting north into nrn Aroostook by 18z, leaving

scattered showers behind late afternoon/early evening.

Elevated instability expected to move in beginning 15z Friday with

temps cooling aloft. This likely to coincide with 850 front moving

north into the area with isold storms along and behind it in the

afternoon and continuing after 00z Saturday.

With pw values climbing to well above the 90th percentile tomorrow

afternoon and forcing with the warm front, coupled with LLJ

increasing to between 30-40 kts late in the afternoon, cannot rule

out locally heavy rainfall. The most likely area for this looks to

be in the North Woods during the day tomorrow. QPF amounts during

the day likely to be right around an inch along the NW Aroostook and

Quebec border with locations north of Baxter SP over to the NB

border expecting between 0.5-0.75 inches.

As the H8 front lifts north into Canada tomorrow, there will likely

be a break over central and southern areas, before remnants of Debby

move up from the southwest scraping along the international border.

Max temps will be well below normal with locations struggling to

crack into the middle 60s acrs the region.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...

Faster trend in models for remnants of Debby continues into

Friday night and Saturday, and adjusted forecast accordingly.

Center of Debby likely to pass just north of us late Friday

night. Our area will be under the warm sector Friday night, with

the cold front south of the center of remnants of Debby passing

through from west to east around midday Saturday with rapid

drying behind it.

Friday early evening, a bit of a lull in the heavier rain

should continue from late Friday afternoon, in between the warm

front passage and the increasing moisture ahead of the

approaching cold front. Adjusted PoPs accordingly. Temperatures

will be mild and rising through the night as the warmer,

juicier, very high precipitable water air continues to move in

from the south. Later in the night, band of moderate to locally

rain with perhaps a few embedded storms moves through from west

to east. Many areas will see a bit of a lull in between the two

rounds of rain, and the rain Friday night doesn`t look terribly

heavy either, so expecting any flooding that does occur to be

minor and limited to smaller streams. Not expecting any severe

storms later Friday night, though any heavier pockets of rain or

isolated storms could help mix down some stronger winds.

Speaking of winds, they are a bit of a concern especially later

Friday night into Saturday morning. A strong low level southerly

jet (by August standards) moves over the area. The strongest

winds aloft may actually be over Northern Maine closer to the

center of Debby passing just to our north. Not expecting the

full force of the winds aloft to mix down, but should be enough

wind gusts of 35-40 mph to perhaps lead to isolated power

outages, especially considering wet soils and leaves on the

trees which makes tree damage easier to occur. Tentatively

expecting the stronger wind in the far north as well as along

the coast, but isolated power outages are possible anywhere.

Rain rapidly tapers off from west to east Saturday behind the

cold front. Could see a few storms fire Saturday afternoon over

Eastern Maine especially toward the NB border just ahead of the

front, but not too big of a deal.

Saturday night and Sunday looking generally dry with just a

small chance of Sunday afternoon mainly North Woods.

Temperatures close to average Sunday afternoon with drier air

behind the cold front.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...

An upper level trough moves through Monday, with could bring a

better shot at showers and storms in the afternoon, especially

over the north. With cold air aloft, setup could be favorable

for small hail. Instability is pretty marginal though, so not

expecting severe storms.

Fairly quiet weather pattern Tuesday through Thursday with fairly

light NW flow. Models are in good agreement on the overall

pattern though there is uncertainty in timing of any potential

subtle shortwaves in the broad NW flow. Just enough instability

and moisture for a few afternoon showers and perhaps storms each

day, though Monday looks like the more active day thanks to a

better defined trough passage that day.

Temperatures will be a bit cooler than average Monday, but then

rebound to a bit warmer than average Tuesday to Thursday.

Dewpoints should be in the mid 50s to low 60s Monday through

Thursday, lowest in the north, which is about average for this

time of year......

10:30 PM ADT Thursday 8 August 2024

Heavy rainfall is possible.

Total rainfall: 30 to 40 mm. Locally higher amounts possible.

Locations: New Brunswick, except for eastern areas.

Time span: Friday morning until late Saturday.

Remarks: areas of heavy rain associated with the remnants of Tropical Storm Debby will affect parts of New Brunswick Friday into Saturday. Embedded thundershowers are also possible that could enhance rainfall amounts in some areas.

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.

In effect for:

Fredericton and Southern York County

000

WTNT34 KNHC 082031

TCPAT4

BULLETIN

Tropical Depression Debby Advisory Number  26

NWS National Hurricane Center Miami FL       AL042024

500 PM EDT Thu Aug 08 2024

...MAJOR FLOOD THREAT CONTINUES FOR PORTIONS OF THE CAROLINAS AND

WESTERN VIRGINIA...

...FUTURE ADVISORIES WILL BE ISSUED BY THE WEATHER PREDICTION

CENTER...

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION

----------------------------------------------

LOCATION...35.1N 80.2W

ABOUT 45 MI...75 KM E OF CHARLOTTE NORTH CAROLINA

ABOUT 95 MI...155 KM WSW OF RALEIGH NORTH CAROLINA

MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H

PRESENT MOVEMENT...NNW OR 345 DEGREES AT 10 MPH...17 KM/H

MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES

WATCHES AND WARNINGS

--------------------

CHANGES WITH THIS ADVISORY:

All Tropical Storm Warnings have been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

There are no coastal watches or warnings in effect.

DISCUSSION AND OUTLOOK

----------------------

At 500 PM EDT (2100 UTC), the center of Tropical Depression Debby

was located inland near latitude 35.1 North, longitude 80.2 West. 

The depression is moving toward the north-northwest near 10 mph (17

km/h).  A faster northward or north-northeastward motion is 

expected during the next day or two.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.

Little change in strength is forecast during the next couple of 

days, but Debby is expected to become a post-tropical cyclone on 

Friday.

The estimated minimum central pressure based on surface 

observations is 998 mb (29.47 inches).

HAZARDS AFFECTING LAND

----------------------

Key messages for Debby can be found in the Tropical Cyclone

Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC.

WIND: Wind gusts to tropical-storm-force could occur for a few more

hours along portions of the North Carolina coast.

STORM SURGE: Coastal flooding is possible in the Cape Fear, Neuse, 

and Pamlico Rivers...1 to 3 ft.

For a complete depiction of areas at risk of storm surge inundation,

please see the National Weather Service Peak Storm Surge Graphic,

available at hurricanes.gov/graphics_at4.shtml?peakSurge.

RAINFALL: Debby is expected to produce an additional 3 to 6 inches 

of rainfall with locally higher amounts, across portions of 

southeastern North Carolina leading to maximum storm total amounts 

as high as 15 inches.  Additional rainfall of 1 to 3 inches over 

portions of eastern South Carolina will bring maximum storm total 

amounts as high as 20 to 25 inches. Considerable flooding is 

expected across portions of eastern South Carolina and southeast 

North Carolina through Friday.

From central North Carolina northward across portions of Virginia, 3 

to 7 inches with local amounts to 10 inches, are expected through 

Friday. This rainfall will likely result in areas of considerable to 

locally catastrophic flash and urban flooding, especially in the 

terrain of western Virginia, with river flooding also possible.

From portions of Maryland north through Upstate New York and 

Vermont, 2 to 4 inches, with local amounts to 6 inches, are expected 

through Friday night. This will likely result in areas of 

considerable flash and urban flooding as well as river flooding.

For the remainder of northern New England, 1 to 3 inches, with 

local amounts to 4 inches, are expected into Saturday.  Scattered 

instances of flash flooding are possible.

For a complete depiction of forecast rainfall and flash flooding 

associated with  Debby, please see the National Weather Service 

Storm Total Rainfall Graphic, available at 

hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk 

graphic at hurricanes.gov/graphics_at4.shtml?ero.  For a list of 

rainfall observations (and wind reports) associated this storm, see 

the companion storm summary at WBCSCCNS4 with the WMO header ACUS44 

KWBC or at the following link:

www.wpc.ncep.noaa.gov/discussions/nfdscc4.html. 

TORNADOES: A few tornadoes may occur through tonight from central

and eastern North Carolina into central and southeast Virginia.  

The threat for tornadoes will shift northward into parts of New 

Jersey and eastern Pennsylvania on Friday.

SURF:  Large swells will continue to affect the Southeast U.S.

coast for another day or so. These conditions are likely to

cause life-threatening surf and rip current conditions. Please

consult products from your local weather office.

NEXT ADVISORY

-------------

This is the last public advisory issued by the National Hurricane

Center on Debby.  Future information on this system can be 

found in Public Advisories issued by the Weather Prediction Center 

beginning at 1100 PM EDT, under AWIPS header TCPAT4, WMO 

header WTNT34 KWNH, and on the web at www.hurricanes.gov.

Rainfall forecasts for the United States can always be found at 

https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml 

and outlooks of flash flood risks can be found at 

https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php

.

$$

Forecaster Cangialosi

000

WTNT44 KNHC 082032

TCDAT4

Tropical Depression Debby Discussion Number  26

NWS National Hurricane Center Miami FL       AL042024

500 PM EDT Thu Aug 08 2024

Debby continues to move farther inland and the center is now

located over south-central North Carolina.  The storm continues to

produce heavy rains across portions of the Carolinas and Virginia,

with the major flood threat continuing in those areas. Surface

observations indicate that winds along the North Carolina coast and

offshore have decreased, and based on that data, the initial

intensity is lowered to 30 kt, making Debby a tropical depression.  

Although the sustained winds have decreased, there could still be 

some gusts to tropical-storm-force along portions of the North 

Carolina coast for a few more hours.

The system is moving north-northwestward at 9 kt.  A turn to the

north or north-northeast and a significant increase in forward

speed are expected.  This motion will take Debby, or its

remnants, across the Mid-Atlantic and Northeast States during the

next day or so.  Debby is likely to complete extratropical

transition tonight or on Friday and dissipate in a couple of days.

This is the last tropical cyclone discussion issued by the

National Hurricane Center on Debby.  Future information on

this system can be found in discussions issued by the Weather

Prediction Center beginning at 1100 PM EDT, under AWIPS header

TCDAT4, WMO header WTNT44 KWNH, and on the web at

www.hurricanes.gov.

Rainfall forecasts for the United States can always be found at

https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml

and outlooks of flash flood risks can be found at

https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php

Key Messages:

1. Heavy rainfall across portions of the Carolinas is expected to

persist through today along with areas of considerable flooding.

Heavy rainfall will also result in considerable to locally

catastrophic flooding impacts across portions of the Mid-Atlantic

States and Northeast through Saturday morning.

FORECAST POSITIONS AND MAX WINDS

INIT  08/2100Z 35.1N  80.2W   30 KT  35 MPH...INLAND

 12H  09/0600Z 37.1N  79.5W   30 KT  35 MPH...INLAND

 24H  09/1800Z 41.2N  76.7W   30 KT  35 MPH...POST-TROP/EXTRATROP

 36H  10/0600Z 45.7N  71.1W   30 KT  35 MPH...POST-TROP/EXTRATROP

 48H  10/1800Z 48.9N  62.8W   30 KT  35 MPH...POST-TROP/EXTRATROP

 60H  11/0600Z...DISSIPATED

$$

Forecaster Cangialosi

Hazardous Weather Outlook

National Weather Service Caribou ME

252 PM EDT Thu Aug 8 2024

MEZ001>006-010-011-015>017-029>032-091900-

Northwest Aroostook-Northeast Aroostook-Northern Somerset-

Northern Piscataquis-Northern Penobscot-Southeast Aroostook-

Central Piscataquis-Central Penobscot-Southern Penobscot-

Interior Hancock-Central Washington-Coastal Hancock-

Coastal Washington-Southern Piscataquis-Northern Washington-

252 PM EDT Thu Aug 8 2024

This Hazardous Weather Outlook is for Central Highlands Maine,

Coastal DownEast Maine, Far Eastern Maine, Far Northern Maine,

Interior DownEast Maine, North Woods Maine and Penobscot Valley

Maine.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday into Saturday morning, a frontal system combined with deep

tropical moisture associated with the remnants of Debby will bring

heavy rainfall and the risk of minor flooding to the area. Winds

gusting as high as 35 to 40 mph could lead to isolated power outages.

Along the coast, high surf is possible Saturday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$