Henri Becomes Extratropical, Meanders Over Southern New England

731 

WTNT33 KWNH 240245

TCPAT3

BULLETIN

Post-Tropical Cyclone Henri Advisory Number  33

NWS Weather Prediction Center College Park MD   AL082021

1100 PM EDT Mon Aug 23 2021

...POST-TROPICAL CYCLONE HENRI MOVING EAST...

...HEAVY RAINFALL AND FLOODING EXPECTED TO CONTINUE ACROSS PORTIONS

OF SOUTHERN NEW ENGLAND THROUGH TONIGHT...

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

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

LOCATION...41.4N 72.0W

ABOUT 110 MI...175 KM ENE OF NEW YORK CITY

ABOUT 50 MI...80 KM SE OF HARTFORD CONNECTICUT

MAXIMUM SUSTAINED WINDS...25 MPH...35 KM/H

PRESENT MOVEMENT...E OR 80 DEGREES AT 13 MPH...20 KM/H

MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

WATCHES AND WARNINGS

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

Flood watches are in effect across portions of central New England.

DISCUSSION AND OUTLOOK

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

At 1100 PM EDT (0300 UTC), the center of Post-Tropical Cyclone Henri

was located near latitude 41.3 North, longitude 72.0 West. The

post-tropical cyclone is moving toward the east near 13 mph (20

km/h) and this motion is expected to continue.

Maximum sustained winds are near 25 mph (35 km/h) with higher gusts.

Little change in strength is forecast during the next 12 hours.

The estimated minimum central pressure is 1006 mb (29.71 inches).

HAZARDS AFFECTING LAND

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

RAINFALL: Remnant moisture from Henri is expected to produce 

additional rainfall 1 to 2 inches, with locally higher amounts 

possible, over southern to central New England through tonight. 

Heavy rainfall from Henri will continue to result in limited flash, 

urban, and small stream flooding impacts, along with isolated minor 

to moderate river flooding.

The flood risk associated with Henri is expected to diminish by

early Tuesday.

For the latest rainfall reports and wind gusts associated with Henri

at the following link:

https://www.wpc.ncep.noaa.gov/discussions/nfdscc3.html

SURF: Swells are expected to continue across much of the east

coast of the U.S. and Atlantic Canada through tonight. 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 Pagano

FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 41.3N  72.0W   20 KT  25 MPH...POST-TROPICAL/INLAND

 12H  24/1200Z 41.6N  69.7W   25 KT  30 MPH...POST-TROPICAL

 24H  25/0000Z...DISSIPATED

10:05 PM ADT Monday 23 August 2021

Special weather statement in effect for:

Fredericton and Southern York County

Significant rainfall is expected.

Total rainfall: 15 to 30 mm. Locally higher amounts possible.

Locations: western and northern New Brunswick.

Timespan: tonight until Tuesday morning.

Remarks: Rain is expected to begin later this evening over western New Brunswick and spread eastward through the night. Rain may become heavy at times tonight and taper off Tuesday morning.

While forecast guidance shows strong agreement regarding the timing of the rain, there is uncertainty in the area and extent of heaviest rain. General amounts of 15 to 30 mm are forecast with the potential for 40 to 50 possible locally.

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

000

FXUS61 KCAR 240124

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

924 PM EDT Mon Aug 23 2021

.SYNOPSIS...

The weak remnant low pressure of Henri will move east across

southern New England overnight and dissipate while tracking

across the Gulf of Maine Tuesday morning. High pressure will

build over the area Wednesday. Low pressure will track north of

the area on Thursday with a cold front moving across the region

Thursday evening. High pressure will build into the area into

the weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...

9:20 PM Update...Tonight`s satellite imagery shows a rather

complex array of shortwaves lifting up across the area. One

shortwave is over southern New England and a small but vigorous

little shortwave is to the east of that one pivoting north off

Cape Cod. Lift from the Cape Cod shortwave is likely enhancing

a corridor or rain which now extends from western Hancock County

north into northern Penobscot and southwestern Aroostook

County. Over an inch of rain has been reported so far in parts

of Hancock County. Raised rain amounts this evening, and also

increased pops and rain amounts in the northwest where another

corridor of rain has been lifting through. Temps look good so

far.

A weak meso low NE of the main remnant low of Henri along with

an upper lvl trof will be crossing the FA Ovrngt into erly Tue

morn with shwrs, rn, and isold tstms with elevated CAPE with

most models indicating the potential o significant rain over

Downeast and E Cntrl areas possibly reaching into the xtrm NE

with max QPF of 1.0 to 1.5 inches by 12z Tue and much lesser

amts N and W. In addition to weak upper jet stream dynamics,

Deep tropical air is in place as precip waters reach into the

1.50 - 2.00 inch range across our Rgn. Increased PoPs to near

100 percent alg our axis of heavier fcst QPF, but given the

relative narrowness and exact psn the rn band will take, fcst

confidence to how much actual QPF any ptn of the FA receives is

considered low for even the near term. Fog will again spread

nwrd from Downeast areas ovrngt, but will be most dense late

tngt ovr Downeast areas where a dense fog adv is once again

possible. Ovrngt lows will once again be well abv climo mean

values.

After exiting sct shwrs erly Tue morn, skies should become ptly

to msly cldy rather than solidly ovc by late Tue morn, allowing

for some sunshine and a return of warmer hi temps, but left ovr

llvl moisture and mid to upper lvl instabilty will result in

sct aftn tstms mainly across Nrn/Cntrl ptns of the FA erly to

mid aftn, with increasing capping alf with the apch of upper

lvl ridging likely keeping tstms fairly low topped and resulting

in lmtd rnfl and fairly rapid dissipation of activity after 5

pm with the loss of dytm htg.

&&

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

Tue Night will feature the departing upper level shortwave that

contains Henri remnants. Skies will clear overnight with some

patchy fog developing especially across Downeast areas. Temps

will fall back into the upper 50s across the North Woods, Low to

Mid 60s elsewhere in the FA. Wednesday will feature a weak

ridge over the area with west- northwest flow at the surface but

the flow will slowly shift south- southwest in the late

afternoon. Generally a mostly sunny day with some cumulus clouds

as high climb well into the 80s with some upper 80s possible in

the Highlands to Bangor area. In the afternoon a weak sea

breeze will develop and cool the coast so expect 70s in these

locations. An intially shortwave will washout to our west

during the evening so not expecting precipitation Wed Evening.

After midnight another trough will approach from the west and

here is where things get a little tricky into Thursday. But, a

chance of showers will develop across the North Woods and rest

of the Crown by daybreak as the trough approaches. Patchy fog

will exist given the semi-muggy and warmer lows in the low to

mid 60s.

The timing of the prefrontal trough and associated vort maxes

are differing between the Canadian, GFS and ECMWF but in better

agreement today. Early afternoon with strong daytime heating

sending highs into the low to mid 80s we will build enough CAPE

to support convection. Modeled soundings showing around

1000-1500j/kg SBCAPE with some models showing more, SFC- 3km

Lapse Rates looking nice for storms in the 7.8-8.5C/km range and

even 6C/km for 700-500mb. Shearing has come up a little but

still not very impressive with SFC-3km Shear around 25kts, Deep

Layer (LCL-EL) shear of around 40kts and EBWD 25-35kts. Current

helicity values are modeled at above 50-100m2s2 which suggests

enough to support rotating updrafts so potentially some stronger

storms but shear holds that back somewhat. Lastly, PWATs will

be running 1.5-1.7 inches which is around or slightly above the

90th percentile. Any stronger storms will pose the threat of

heavier downpours.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...

The front will clear the coast overnight bringing an end to

precipitation around midnight. Strong shortwave aloft will push

through the north and rest of the area into Friday. Slight

chance of POPs across the north before the much drier air pushes

into the area noted by the 20-25% 850-250mb RH values. Dew

Points Friday will be refreshing in the 40s to mid 50s from

north to south. Highs Friday with mostly sunny skies will be

cooler in the low 70s north to upper 70s south given downsloping

northwest winds. Speaking of the winds, cold air advection and

decent mixing we will see winds gusting 15-25mph at times. Fri

night into Saturday will be the coolest night with lows Sat AM

in the mid 40s across the North Woods. Upper 40s to low 50s in

the rest of the North with mid 50s at the coast. Saturday

ridging builds right overhead with associated surface high

pressure resulting in a mostly sunny day. Moisture will begin to

increase from the west so a slight chance of showers is

possible in the North Woods and Moosehead Lake region by sunset.

Highs once again below average in the low to mid 70s. Models

disagree significantly on what happens after this as high

pressure settles south of the Gulf of Maine. So, for now took

the national blend of models which shows chance of showers both

Sunday and Monday. Highs warming into the mid to upper 70s with

the return flow setting up. Lows will be running warmer into Mon

AM with mid to upper 50s.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...

NEAR TERM: Mon Eve...MVFR clgs/vsbys with sct shwrs. IFR

clgs/vsbys with patchy fog and advcng rnfl Downeast sites. Lgt

winds.

Mon Ovrngt - Erly Tue Morn...IFR - LIFR clgs/vsbys all TAF

sites in shwrs, rain, and fog. Isold tstms. Lgt winds.

Tue Late Morn and Aftn...Clgs and vsbys iimproving to Low VFR

clgs all TAF sites. Sct aftn shwrs/tstms Nrn TAF sitess with

brief MVFR vsbys possible. Lgt winds xcpt in and near tstms.

SHORT TERM: Wed...VFR. W-NW winds 5-10kts. A light SW wind

5-10kts will develop in the afternoon at BHB & BGR.

Thu...Generally VFR. TEMPO MVFR/IFR vsby & cigs with showers &

thunderstorms in the afternoon especially BGR northward. BCFG

possible especially at BHB & BGR in the morning. SW winds

5-15kts. Thu Night SW winds shift NW 5-15kts overnight as a

front passes.

Fri...VFR. NW winds 10-20kts with a few gusts to 25kts possible

especially at PQI, CAR & FVE.

Sat...VFR. N-NW winds 5-15kts.

&&

.MARINE...

NEAR TERM: Winds and seas just below SCA criteria Tngt into Tue

with left ovr swell from the remnant low of Henri, then seas

diminishing by late week as winds remain msly lgt. Kept close to

blended model wv guidance with wvs dominated by long pd swell

of 10 to 12 sec. Marine fog will dominate into Tue before winds

shift from offshore and begin to dissipate fog late in the day.

SHORT TERM: Winds/seas will be below SCA levels. Generally

southwest winds 5-15kts with some gusts to 20kts possible. Seas

2 to 4 feet Wednesday subsiding to 1 to 3 feet Thursday.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...

ME...None.

MARINE...None.

&&

$$

Near Term...VJN/MCB

Short Term...Sinko

Long Term...Sinko

Aviation...VJN/Sinko

Marine...VJN/Sinko

2:41 PM ADT Monday 23 August 2021

Tropical cyclone information statement for:

Nova Scotia

For Tropical Depression Henri.

THIS WILL BE THE FINAL STATEMENT FROM THE CHC ON TROPICAL DEPRESSION HENRI. THE SITUATION WILL NOW BE HANDLED BY LOCAL STORM PREDICTION CENTRES.

Tropical Depression Henri is still barely moving but is expected to slowly pick up speed and head east towards the Maritimes tonight and tomorrow.

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

LOCATION: NEAR 41.6 NORTH 73.8 WEST ABOUT 245 KM WEST-SOUTHWEST OF BOSTON.

MAXIMUM SUSTAINED WINDS: 50 KILOMETRES PER HOUR.

PRESENT MOVEMENT: EAST AT 9 KILOMETRES PER HOUR.

MINIMUM CENTRAL PRESSURE: 1006 MILLIBARS.

2. PUBLIC WEATHER IMPACTS.

Tropical Depression Henri is slowly making its way east toward the Maritimes tonight and tomorrow and should become post-tropical by Tuesday.

A rain band well ahead of Henri affecting the Maritimes today has already dropped near 10 millimetres of rain with higher amounts expected tonight. Rainfall amounts will continue to be variable but some regions in the Maritimes could see upwards of 50 millimetres by Tuesday evening.

No significant wind is expected over Maritimes land areas.

3. MARINE WEATHER IMPACTS.

Long period swells as high as 16 seconds were reported south of Nova Scotia early this morning. They will continue to subside by this evening.

There is a threat for rip tides along the Atlantic Coast of Nova Scotia this afternoon and evening, and caution should be observed.

Please check for updates regularly from the CHC at www.hurricanes.ca and our twitter feed @ECCC_CHC.

FORECASTER(S): MCARTHUR

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

For more comprehensive information about track tables and forecast rationale, please see the Technical Discussion

Hazardous Weather Outlook

National Weather Service Caribou ME

636 AM EDT Mon Aug 23 2021

MEZ002-005-006-011-015>017-032-241045-

Northeast Aroostook-Northern Penobscot-Southeast Aroostook-

Central Penobscot-Southern Penobscot-Interior Hancock-

Central Washington-Northern Washington-

636 AM EDT Mon Aug 23 2021

This Hazardous Weather Outlook is for Central Highlands Maine, Far

Eastern Maine, Far Northern Maine, Interior DownEast Maine and

Penobscot Valley Maine.

.DAY ONE...Today and tonight.

Isolated thunderstorms will develop this afternoon and continue

during the overnight hours. Storms will be capable of producing

torrential downpours tonight.

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

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$