Tropical Depression Forms in the Atlantic

As mentioned here earlier this week, the tropical wave southwest of the Cape Verde Islands has developed into a Tropical Depression and is expected to become the 4th named storm of the season. The system, now with a well defined central circulation and organized deep convection, is slowly increasing in strength despite the dry air in the area.

Tropical Satellite

The depression, located at 10.5 North and 35.9 West, has maximum sustained winds of 35 mph with gusts over 40 mph.   The system is moving to the west at 13 mph but is expected to turn slightly north as a weakness in the ridge of high pressure develops.  That weakness is only temporary though and a turn back toward the west is expected.  The tropical depression currently has a central pressure of 1009 millibars.  The anticipated maximum sustained winds are located below.  As you can see on the map, we anticipate this system to reach hurricane strength sometime on Thursday. The current model forecasts bring the system up to Category 2 status by the beginning of next week as conditions remain favorable for additional strengthening and development for the next few days.

tracking map

The tropical depression is expected to become a Tropical Storm over the next day or 2, and a projection of the area of possible Tropical Storm winds is here.

depression 4

This system is expected to be closing in the the Lesser Antilles by the end of this weekend. Interests here in the United States should expect the approach of this system late next week and should continue to monitor this system accordingly.

Forecaster Robert Millette

Atlantic Basin Tropical Weather Outlook

Atlantic Tropics

While the tropics have remained quiet with the only 3 named storms not reaching Hurricane strength, we are reaching peak Hurricane season and at least one tropical wave is starting to show signs of becoming the next tropical system of the Atlantic.

Currently located several hundred miles Southwest of the Cape Verde Islands, a strengthening system of low pressure associated with a vorticity maximum in the upper levels of the atmosphere continues to produce areas of convective showers and thunderstorms.

two_atl_2d0

Satellite imagery shows increasing organization within the system and the region around the tropical wave is conducive to tropical development with weak shear profiles and plenty of moisture due to the monsoonal trough located in the area.  Ocean temperatures in this region are warm and are actually running above normal for this time of year.

cdas-sflux_sst_global_1

cdas-sflux_ssta_global_1

Current long range forecasts bring this system toward the north of the Carribean Sea close to the Bahamas where very warm waters could be very conducive to a strengthening tropical system.  Anyone with interests along the Atlantic Coast should should monitor the development of this system over the coming week.

Two other Tropical waves located in the Atlantic basin, one directly in front of the system mentioned above and one over the Island of Hispanola, do not show  signs of impending tropical development at this time.

Forecaster Robert Millette

Severe Storms give way to hot and humid conditions for the Northeast

Storms Northeast 2

In what continues to be an eventful Severe Weather season in the Northeast, several reports of wind damage occurred from Eastern New York through Massachusetts and New Hampshire as a cluster of strong to severe thunderstorms moved through the region.  Here are a couple of photos from yesterday’s action with the top being near Haverhill (credit Roger Doucette) and the bottom being Manchester NH (credit Jennifer Brooks)

Northeast Storms

Storms Northeast 2

The storms have now given way to clearing skies and for the Northeast, skies will be generally clear for the next several days as a high pressure system moves south of the area.  The High will begin to move out over the Atlantic on Tuesday.  A low pressure system will make its way into the Great Lakes region  and move North toward Hudson Bay Wednesday into Thursday.  The cold front associated with that low will push across the Northeast Thursday into Friday.

Temperatures through out the region will be hot as day time highs will reach into the upper 80’s and lower 90’s with dew points in the 60’s for the next several days bringing beautiful beach weather up and down the coast.  The cold front will bring a quick break to start the weekend, but temperatures will stay warm in the mid to upper 80’s.

Northeast Temperatures

Hawaiian Tropical Storm Watches cancelled

Tropical Storm Watches have been cancelled for Hawaii.  Tropical Storm Hilda, with maximum sustained winds of 45 mph,  is now 250 miles Southeast of Hilo Hawaii and continuing to stay far enough South of the islands that Tropical Storm impacts are not expected at this time.  The Tropical Storm conditions will likely diminish in the next 24 hours as Hilda continues to weaken into a Tropical Depression.   Currently located at 17.2 North 152.4 West, the center of circulation has begun moving to the Southwest according to visible satellite.  While convective activity continues to pop up near the center of circulation, strong wind shear is continuing to keep this convection in a highly disorganized state as Hilda transitions from a Tropical system into a Remnant Low.

Forecast map

The center of Hilda, seen here exposed to the Southwest of major pockets of convection, is continuing to hold together against the wind shear in the region.  The shear is expected to continue for the next several days and weaken Hilda until her dissipation.  Tropical showers continue to move through the region but are small in size and are moving quickly across the island.

Tropical Satellite

 

While Hawaii is likely to experience large waves and gusty winds in some tropical downpours.   My forecast does not call for sustained Tropical Storm conditions in the state as Hilda weakens and stay to the South.

 

Forecaster Robert Millette

Tropical Storm Watches continue as Hilda downgrades from a Hurricane

In the latest information on Hilda, she has officially been downgraded to a Tropical Storm with maximum sustained winds of 65 MPH.  Hilda is now at 17.0  North, and 152.2 West and is moving towards the West at 4 MPH, currently 265 miles Southeast of Hilo, Hawaii.  Hilda will continue to move between West and Northwest over the next day and then move to the South of the Hawaiian Islands on Thursday and Friday.

Forecast map

 

 

The Satellite imagery taken throughout the day has shown the wind shear beginning to take Hilda’s core apart and  the deep convection around the core has been pulled away from the central circulation. This shear is assisting in the turn towards the West.  The beginning of this process was observed this morning by a run of the 53rd Weather Recon Squadron, who reported the start of this process.  Currently, the Squadron is back in the air on their way to make another pass of Hilda.

Tropical Satellite

 

Outer bands from the Tropical Storm have begun to move into the region around the big island and heavy rainfall will begin to move into the area over the course of next day.   A Tropical Storm Watch is now in effect for Hawaii County where winds over 40 MPH are still expected over the next 2 days.  However, Hilda is quickly diminishing in strength and is expected to continue to weaken over the next 48 hours so winds of the current 65 mph are not expected in the area.

 

 

Forecaster Robert Millette

Hurricane Hilda approaches Hawaiian Islands; Tropical Storm Watches expected

Hurricane Hilda continues her slow approach to the Hawaiian Islands this morning as she continues to move to the Northwest at around 5-6 mph.  This motion is expected to continue for several hours before a turn to the West and a slight increase in forward speed.  As of 11 PM Hawaiian Standard time (5 AM Eastern Daylight time), Hilda was located at 17.1 North and 105.9 West with maximum sustained winds at 90 mph and a central pressure of 981 millibars .  Hilda is 330 miles East Southeast of Hilo Hawaii.

Forecast map

Hurricane Hilda strengthened some during the day on Monday as visible satellite imagery showed significant improvement in Hilda’s structural integrity and deep convection continued to develop over the low level circulation despite the strong area of wind shear that continues to be present.  This increased activity seemed to diminish after nightfall.

Tropical Satellite

The 53rd Weather Reconnaissance Squadron, known as the Hurricane Hunters, sampled the conditions in the inner core of Hilda late Monday night, and found that Hilda continued her weakening trend as the central pressure increased to 981 millibars from its low point during the day of 976 millibars.  Despite this increase, Hilda’s winds have held steady around 90 MPH and her hurricane force winds continues to extend out over 20 miles from the center of circulation.  The Recon Squadron will perform another pass of Hilda Tuesday morning Hawaii time and will then begin to perform additional runs every 6 hours starting Tuesday evening.

As Hilda approaches Hawaii, large swells associated with the hurricane will produce large waves along east and southeast facing shorelines of the major Hawaiian islands. Heavy rain is expected Thursday and Friday and Flash floods are a possibility later on Thursday and into Friday night. A Tropical Storm Watch is likely to be posted for the big island overnight as Tropical Storm force winds could begin on Thursday.

Firsthand Weather will continue to put out the latest information on Hurricane Hilda as it comes in with our next update expected this evening.

Forecaster Robert Millette