Tropical Storm Philippe Heads Our Way Update One

000

FXCA62 TJSJ 050255

AFDSJU

Area Forecast Discussion

National Weather Service San Juan PR

1055 PM AST Wed Oct 4 2023

...New UPDATE, AVIATION, MARINE...

.UPDATE...

Issued at 1024 PM AST Wed Oct 4 2023

Philippe will move northward over the Atlantic Ocean, lifting

moisture from the Caribbean Sea over the region away from the

islands. Showers will affect the U.S. Virgin Islands and the

southern and eastern sections of Puerto Rico, including Vieques

and Culebra. Rivers are across the eastern third of Puerto Rico

are running high. Soils are already saturated, and additional

rains may result in mudslides or landslides across steep terrains.

Unstable weather conditions will last through at least Friday.

&&

.AVIATION...

(00Z TAFS)

Issued at 1024 PM AST Wed Oct 4 2023

Light SHRAs will persist, especially across the eastern third of

PR and the USVI overnight. -SHRA/SHRA will move over JSJ/IST/ISX

under a southerly wind flow between 5 and 15 knots. The potential

for TSRA will persist through the the fcst period especially

between 05/15-22z. JSJ/IST/ISX may be impacted by the afternoon

convection tomorrow, reducing VIS between 1-3 SM at times.

&&

.MARINE...

Issued at 1024 PM AST Wed Oct 4 2023

Mariners expect hazardous marine conditions due to choppy seas up

to 7 feet across the Atlantic Offshore Waters and up to 6

elsewhere. Philippe induces a southerly wind flow between 15 and

20 knots, but gusty winds up to 30 kts are possible, especially

near showers and thunderstorms. A Small Craft Advisory is in

effect for the Atlantic Offshore Waters. Elsewhere, please

exercise caution.

&&

.SYNOPSIS...Cloudy skies prevailed across the local islands

throughout the day with numerous showers and isolated thunderstorms

noted early in the morning across south central and southeast

Puerto Rico as well as the outlying islands. Showery conditions

will maintain an elevated risk for urban and small stream flooding

as well as isolated flash flooding through at least Friday.

Weather conditions are expected to improve during the upcoming

weekend.

&&

.SHORT TERM...Tonight thru Friday...

Upper level trough across the western Atlantic and Tropical Storm

Philippe now located 225 miles north northwest of Saint Thomas, will

continue to promote moisture advection across the local islands

through at least Friday. As a result, wet conditions will continue

to prevail with periods of showers and thunderstorms mainly across

the east and south sections of Puerto Rico, Vieques, Culebra and the

US Virgin Islands. With these showers and thunderstorms, additional

rainfall amounts are expected to range between 2 and 4 inches...

with isolated higher amounts possible. Therefore, the main hazard

is still the risk of urban and small stream flooding as well as

isolated flash flooding and mudslides.

Locally induced afternoon showers across the northern slopes of

Puerto Rico cant be ruled out on Thursday and Friday, but it will be

highly depended on the cloud cover across the area. Overall, the

weather conditions are expected to improve by the upcoming weekend

with PW values dropping below 2.0 inches by Sunday.

Preliminary rainfall totals...from 800 AM AST yesterday through 2

PM AST this afternoon...are ranging between 2 to 4 inches across

the southern slopes of Puerto Rico, Vieques, Culebra and the US

Virgin Islands with isolated higher amounts up to 8 inches in

Saint John.

&&

.LONG TERM...FROM PREV DISC.../428 AM AST Wed Oct 4 2023/

Saturday through Wednesday...

As Tropical Storm Philippe continues to move northward into the

western Atlantic, a southerly wind flow will continue across the

surface to lower levels, becoming more southeasterly Sunday onward.

Lingering moisture is expected on Saturday. By Sunday, surface

ridge begins to establish east- northeast of the northern Lesser

Antilles bringing drier air into the area. This will significantly

reduce rain activity compared to what was experience the days

prior. However each afternoon, thunderstorms are likely to form

across the interior to northwestern section of Puerto Rico. Then

on Tuesday, the possible arrival of a band of moisture may enhance

the day`s rainfall amounts, followed by drier air on Wednesday.

During this long term period, southerly to southeasterly surface

winds will cause hot afternoon conditions across the islands,

especially northern coastal sections of Puerto Rico. Expect heat

indices to reach above 107F in some areas each afternoon.......

000

WTNT32 KNHC 050238

TCPAT2

BULLETIN

Tropical Storm Philippe Advisory Number  47

NWS National Hurricane Center Miami FL       AL172023

1100 PM AST Wed Oct 04 2023

...PHILIPPE STILL PRODUCING RAINS IN PUERTO RICO AND THE VIRGIN 

ISLANDS...

...TROPICAL STORM CONDITIONS EXPECTED ON BERMUDA THURSDAY NIGHT

AND FRIDAY...

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

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

LOCATION...23.8N 66.1W

ABOUT 380 MI...610 KM N OF ST. THOMAS

ABOUT 590 MI...955 KM S OF BERMUDA

MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H

PRESENT MOVEMENT...N OR 350 DEGREES AT 13 MPH...20 KM/H

MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES

WATCHES AND WARNINGS

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

CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...

* Bermuda

A Tropical Storm Warning means that tropical storm conditions are

expected somewhere within the warning area within 36 hours.

Interests in eastern New England and Atlantic Canada should monitor

the progress of Philippe.

For storm information specific to your area, please monitor

products issued by your national meteorological service.

DISCUSSION AND OUTLOOK

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

At 1100 PM AST (0300 UTC), the center of Tropical Storm Philippe was

located near latitude 23.8 North, longitude 66.1 West. Philippe is

moving toward the north near 13 mph (20 km/h). This general motion

with an increase in forward speed is expected through Saturday.  On

the forecast track, the center of Philippe will pass near Bermuda 

on Friday, and approach eastern New England and Atlantic Canada on 

Saturday.

Maximum sustained winds are near 40 mph (65 km/h) with higher 

gusts. Gradual strengthening is forecast during the next few days.

Tropical-storm-force winds extend outward up to 205 miles (335 km)

from the center.

The estimated minimum central pressure is 1004 mb (29.65 inches).

HAZARDS AFFECTING LAND

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

Key messages for Philippe can be found in the Tropical Cyclone

Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 KNHC

and on the web at hurricanes.gov/text/MIATCDAT2.shtml

RAINFALL:  Rainfall will begin to affect Bermuda on Thursday with 

rainfall totals of 3 to 5 inches expected through Friday.

These rainfall amounts could result in scattered flash flooding.

Rainfall across Puerto Rico and the U.S. and British Virgin Islands 

should diminish on Thursday.

WIND:  Tropical storm conditions are possible on Bermuda beginning

Thursday night.

SURF:  Swells generated by Philippe will affect portions of the

Atlantic coasts of the northern Leeward Islands, the Virgin Islands,

and Puerto Rico for another day or so.  Large swells are already

affecting Bermuda from another weather system but will begin to

increase further on Thursday as Philippe approaches the island.

These conditions are likely to cause life-threatening surf and rip

currents. Please consult products from your local weather office.

NEXT ADVISORY

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

Next intermediate advisory at 200 AM AST.

Next complete advisory at 500 AM AST.

$$

Forecaster Cangialosi

000

WTNT42 KNHC 050242

TCDAT2

Tropical Storm Philippe Discussion Number  47

NWS National Hurricane Center Miami FL       AL172023

1100 PM AST Wed Oct 04 2023

Philippe has generally changed little during the past several hours. 

The storm still resembles an elongated trough in satellite images 

with a north-south oriented area of deep convection extending a 

couple of hundred north and several hundred miles south of the 

center.  Areas of heavy rain continue to linger near Puerto Rico and 

the Virgin Islands.  Since the system appears to be steady in 

strength, the initial intensity is held at 35 kt based on the 

earlier aicraft data.  This wind speed estimate is also in line with 

the latest satellite intensity estimates.

The storm is moving northward at 11 kt in the flow between a ridge 

over the central Atlantic and a mid- to upper-level low off the 

Florida coast.  This northward motion with an increase in forward 

speed is expected during the next few days, taking the center 

of the system across Bermuda in 36-48 hours.  Philippe will likely 

turn northwestward into Maine and Atlantic Canada this weekend when 

another trough cuts off over the northeastern U.S.  The NHC track 

forecast is similar to the previous one and near the middle of the 

guidance envelope.

Nearly all of the models show slow strengthening during the next 2 

or 3 days, which seems to be due to baroclinic influences from the 

trough/low currently east of Florida.  The mid- to upper-level 

trough/low will likely merge with Philippe in 48-60 hours, which 

should cause the system to develop frontal features and become 

extratropical after it passes Bermuda.  The post-tropical cyclone 

is expected to weaken once it moves inland over Maine and Atlantic 

Canada.  The NHC intensity forecast also lies near the middle of 

the guidance envelope.

KEY MESSAGES:

1. Tropical storm conditions are expected on Bermuda beginning

Thursday night, and a Tropical Storm Warning is in effect. Heavy 

rainfall will begin to affect the island on Thursday.

2. Philippe is likely to move over portions of Atlantic Canada and

eastern New England, likely as a post-tropical cyclone, this

weekend.  Regardless of Philippe's intensity or structure, interests

in those areas should monitor the storm's progress and be prepared

for the possibility of strong winds and heavy rainfall.

FORECAST POSITIONS AND MAX WINDS

INIT  05/0300Z 23.8N  66.1W   35 KT  40 MPH

 12H  05/1200Z 25.4N  66.3W   35 KT  40 MPH

 24H  06/0000Z 28.4N  66.0W   40 KT  45 MPH

 36H  06/1200Z 31.9N  65.9W   40 KT  45 MPH

 48H  07/0000Z 35.3N  66.4W   45 KT  50 MPH

 60H  07/1200Z 39.0N  66.7W   50 KT  60 MPH

 72H  08/0000Z 43.3N  67.1W   50 KT  60 MPH...POST-TROP/EXTRATROP

 96H  09/0000Z 51.6N  73.2W   35 KT  40 MPH...POST-TROP/EXTRATROP

120H  10/0000Z...DISSIPATED

$$

Forecaster Cangialosi