The Ghost Of Fred Moves Away As TS Henri Approaches

57 

WTNT33 KNHC 200255

TCPAT3

BULLETIN

Tropical Storm Henri Advisory Number  17

NWS National Hurricane Center Miami FL       AL082021

1100 PM EDT Thu Aug 19 2021

...HENRI HOLDING ON AGAINST SHEAR AND MAINTAINING 65-MPH WINDS...

...INTERESTS IN THE NORTHEASTERN U.S. SHOULD MONITOR ITS PROGRESS...

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

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

LOCATION...29.8N 72.3W

ABOUT 415 MI...670 KM SSE OF CAPE HATTERAS NORTH CAROLINA

ABOUT 800 MI...1285 KM S OF NANTUCKET MASSACHUSETTS

MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H

PRESENT MOVEMENT...WNW OR 285 DEGREES AT 8 MPH...13 KM/H

MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES

WATCHES AND WARNINGS

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

There are no coastal watches or warnings in effect.

Interests in the northeastern U.S. and Atlantic Canada should

monitor the progress of Henri.  Watches will likely be required for

a portion of this area early Friday.

DISCUSSION AND OUTLOOK

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

At 1100 PM EDT (0300 UTC), the center of Tropical Storm Henri was 

located near latitude 29.8 North, longitude 72.3 West. Henri is 

moving toward the west-northwest near 8 mph (13 km/h). A sharp turn 

to the northwest and north is anticipated on Friday, followed by an 

acceleration to the north and north-northeast on Saturday and 

Sunday. On the forecast track, the center of Henri will remain well 

offshore of the east coast of the United States over the next couple 

of days, but it is forecast to be near or over southern New England 

on Sunday and Monday.

Maximum sustained winds remain near 65 mph (100 km/h) with higher 

gusts.  Little change in strength is expected during the next 12 

hours, but Henri is forecast to intensify into a hurricane by Friday 

night with additional strengthening expected this weekend. 

Tropical-storm-force winds extend outward up to 90 miles (150 km)

from the center.

The estimated minimum central pressure is 997 mb (29.44 inches).

HAZARDS AFFECTING LAND

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

RAINFALL: Henri may produce rainfall amounts of 2 to 5 inches over

southeastern New England Sunday into Monday, with isolated maximum

totals near 8 inches. Heavy rainfall from Henri may result in areas

of flash, urban, and small stream flooding.

SURF:  Swells generated by Henri should continue to affect Bermuda

during the next day or so.  Swells are expected to increase across

much of the east coast of the U.S. and Atlantic Canada on Friday and

into the weekend.  These swells could 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 Papin/Beven

879 

WTNT43 KNHC 200259

TCDAT3

Tropical Storm Henri Discussion Number  17

NWS National Hurricane Center Miami FL       AL082021

1100 PM EDT Thu Aug 19 2021

The satellite presentation on Henri this evening continues to 

exhibit a persistent bursting pattern, with the center estimated to 

be just to the north and west of the coldest cloud tops which 

occasionally have been below -80 C in the overshooting tops. This 

current satellite presentation is primarily due to continued 

moderate to strong northerly vertical wind shear, which is forcing 

the convection underneath the cirrus canopy down-shear of the 

low-level center, as seen on a 2230 UTC SSMIS microwave pass.  While 

the mid-level vortex with the convection also remains tilted 

down-shear of the low-level center, it has not completely separated 

due to the persistent convection, preventing the low-level center 

from escaping poleward in more shallow low-level steering. 

Tonight's subjective Dvorak estimates from SAB/TAFB are in 

agreement with T3.5/55 kt and given that this value is near what 

the earlier Air Force Reconnaissance mission found, the latest 

intensity is being maintained at 55 kt for this advisory.

There is a bit of uncertainty determining if Henri has begun a more 

poleward motion since the center remains under the convective cirrus 

plume, but my best guess is now 285/9 kt. Over the next 12-24 hours, 

the mid- to upper-level ridging that has dominated the synoptic 

steering pattern for Henri the last few days will quickly break 

down, as a shortwave trough drops in from the Great Lakes into the 

Mid-Atlantic and cuts off. This feature is now forecast to continue 

digging in to the west of Henri. To the east, a new mid-level ridge 

is also forecast to build in to the right of Henri. This synoptic 

pattern should draw the cyclone poleward with an acceleration to the 

north-northeast in the 24-48 h period. Afterwards, the 

aforementioned trough takes on a negative tilt to the southwest of 

Henri, helping to reorient the mid- to upper-level flow out of the 

south-southeast, and this flow could result in a slight leftward 

bend in the track between 48-72 h. The majority of guidance this 

cycle now is forecasting the mid-level ridge east of Henri to build 

poleward with the storm, blocking an easy path for the storm to stay 

on a more northeast heading out to sea. Consequently, the latest NHC 

forecast track now explicitly shows landfall in southeast 

Massachusetts at 72 h. The track guidance this cycle has come into 

better agreement, though there remain some leftward (UKMET) and 

rightward (ECMWF) outliers. The latest forecast track lies very 

close to the HFIP corrected consensus approach (HCCA) guidance, 

which is also very near the latest GFS forecast track.  

Data from the NOAA G-IV synoptic mission around Henri shows that 

just north of the tropical cyclone there remains some very dry 

mid-latitude air, which is being advected into the storm by 20-25 

kt of northerly vertical wind shear. Over the next 24-36 hours, 

this shear is forecast to gradual subside, as Henri moves near the 

center of an upper-level ridge axis. By 36-48 hours, the vertical 

wind shear is forecast to be under 10-kt by both the GFS- and 

ECWMF-based SHIPS guidance, while the storm is also traversing 

28-29 C sea-surface temperatures (SSTs). Thus, the latest NHC 

intensity forecast still calls for strengthening beginning after 12 

hours, and the rate of strengthening could be a bit quicker as the 

storm moves over the warm gulf stream waters between 36-48 hours. 

Thereafter, Henri will cross a very sharp SST gradient with 

sea-surface temperatures down below 23 C near the New England coast 

to the east of Long Island. Henri is forecast to begin weakening 

after 48 hours, but the storm could still be near hurricane 

intensity by the time Henri is forecast to be near the Northeast 

coastline. Transition to a post-tropical storm is expected to begin 

shortly thereafter which should be sometime in the 96-h to 120-h 

points as deep convection ceases over the storm over cold SSTs

As noted previously, the wind field of Henri is expected to expand, 

especially as it interacts with a mid-latitude trough located to its 

west. Therefore, users are reminded to not focus on the exact 

forecast points as impacts will extend far from the center.

Key Messages:

1. Henri is forecast to be near the northeast coast of the U.S.

on Sunday and Monday, and the risks of storm surge, wind, and rain

impacts in portions of southern New England and eastern Long Island

are increasing.  Watches will likely be required for portions of

this area early Friday.

2. Swells from Henri will begin to reach much of the east coast of

the U.S. and Atlantic Canada by the end of the week and continue

through the weekend. These swells could cause life-threatening surf

and rip currents.

3. Heavy rainfall may lead to flash, urban, and small stream

flooding over portions of southeastern New England Sunday into

Monday.

FORECAST POSITIONS AND MAX WINDS

INIT  20/0300Z 29.8N  72.3W   55 KT  65 MPH

 12H  20/1200Z 30.3N  73.2W   55 KT  65 MPH

 24H  21/0000Z 31.8N  73.3W   60 KT  70 MPH

 36H  21/1200Z 34.4N  72.2W   65 KT  75 MPH

 48H  22/0000Z 37.6N  71.0W   80 KT  90 MPH

 60H  22/1200Z 40.1N  70.6W   75 KT  85 MPH

 72H  23/0000Z 41.7N  70.8W   60 KT  70 MPH...INLAND

 96H  24/0000Z 42.5N  70.1W   40 KT  45 MPH...OVER WATER

120H  25/0000Z 43.7N  65.4W   35 KT  40 MPH...POST-TROPICAL

$$

Forecaster Papin/Brown

000

FXUS61 KCAR 200114

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

914 PM EDT Thu Aug 19 2021

.SYNOPSIS...

The remnants of Fred will approach overnight and track along

the Maine coast into Friday morning. High pressure will build

over the area Saturday. Tropical Storm Henri will approach the

area later Sunday and may impact the region on Monday, and pull

away from the area by Tuesday.....

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

Now comes the interesting part. Tropical Storm Henri could be

making an impact on the New England region as it head northward

from the western Atlc. Most of the long range guidance

including the Canadian Global show Henri strengthening to near

or at Hurricane strength as it heads toward the New England

coast Sunday night into Monday. This storm could very well have

a big impact from LI, MA up into ME, depending on what track

this storm takes. The ECMWF and Canadian bring the system to

Cape Cod and slow it before it weakens and becomes extra-

tropical. The GFS however, brings the system to near Cape Cod

and then swings it ne through the Gulf of Maine just off the

Maine coast. This track would bring at least tropical storm

conditions to the coast and interior Downeast. As of 3 PM, the

official NHC track brings the storm to the Cape Cod and then

pushes it to the ne keeping it over the outer Gulf of Maine

waters. For now, decided to go w/40% pops into Monday evening.

In the wake of this storm, the upper trof is forecast to swing

across the region on Tuesday w/the sfc cold front. The threat

for showers and possible tstms increases during the day w/some

cooling aloft allowing for destabilization. The cold front is

shown to move through by late Wednesday night and then stall

across central areas on Wednesday. A weak disturbance moving

across the region in the westerly zonal flow aloft coupled w/the

stalled front could be focus for some showers/tstms during the

afternoon. Attm, stayed w/20% pops for Wednesday. Another cold

front expected for later Thursday and another threat for showers

and tstms. Temps during this timeframe will be AOA normal.......

2:59 PM ADT Thursday 19 August 2021

Tropical cyclone information statement for:

Nova Scotia

For Tropical Storm Henri.

THE NEXT INFORMATION STATEMENT IS SCHEDULED FOR 09:00 A.M. ADT FRIDAY.

1. SUMMARY OF BASIC INFORMATION AT 03:00 P.M. ADT.

LOCATION: NEAR 29.5 NORTH 70.8 WEST.

MAXIMUM SUSTAINED WINDS: 110 KILOMETRES PER HOUR.

PRESENT MOVEMENT: WEST AT 17 KILOMETRES PER HOUR.

MINIMUM CENTRAL PRESSURE: 995 MILLIBARS.

2. SUMMARY.

Henri is forecast to move slowly northward this weekend and could strengthen to a Category-2 hurricane quite far north, while east of Virginia. Normally these storms track at an increasing speed when they move north but Henri is expected to slow down as it nears Cape Cod. Also once it moves over colder water it will weaken at a particularly quick pace then move slowly east or northeastward. This storm will likely behave in several non-traditional ways and could track in a manner similar to Hurricane Edouard in 1996. https://www.ec.gc.ca/ouragans-hurricanes/default.asp?lang=en&n=8CC1EF90-1. That storm did bring strong winds and very heavy rainfall, and that scenario is also possible for Henri.

The storm will probably not affect our weather directly until Monday and/or Tuesday, and depending on the intensity and size, may simply bring moderate wind and rain. Larger than normal surf conditions will develop on the Atlantic Coast of Nova Scotia this weekend. The timing/track of course will change over the next several days as usual, so please check for updates regularly from the CHC at www.hurricanes.ca and our twitter feed @ECCC_CHC.

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

528 AM EDT Thu Aug 19 2021

MEZ001>006-010-011-015>017-029>032-201200-

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-

528 AM EDT Thu Aug 19 2021

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...Today and tonight.

Tonight, heavy rainfall is likely across Southern Piscataquis,

central and southern Penobscot, Hancock and Washington Counties.

Rainfall totals 1.50 to 2.00 inches will be common in these areas,

with locally greater totals expected. Rainfall totals will rapidly

decrease across northern areas. Widespread flooding is not expected

at this time, but ponding may occur in areas with poor drainage.

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

Monday into Tuesday, there is a possibility of Tropical Storm

Henri, currently southwest of Bermuda, crossing the Gulf of Maine.

This could bring heavy rainfall and strong winds to the Downeast

coast, but most likely significant swell and potential high surf

along the shoreline. There is a lot of uncertainty in the exact track

and intensity of this system, so keep up to date on the forecast for

the latest.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$