24 Sep Weather in Cayman & Tropical Report, 1 TS, 1 TD, 2 Dist
24 Sep Mon 2018
Tropical Report
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Sep 24 2018
For the North Atlantic…Caribbean Sea and the Gulf of Mexico:
The National Hurricane Center is issuing advisories on Tropical
Depression Kirk, located about 1000 miles west-southwest of the
Cabo Verde Islands, and on Subtropical Storm Leslie located more
than 1000 miles west of the Azores.
1. A broad area of low pressure located about midway between Bermuda
and the Bahamas continues to produce a limited amount of shower and
thunderstorm activity. Environmental conditions are forecast to
become slightly more conducive for development during the next
day or so while the system moves west-northwestward to
northwestward. By Tuesday night and Wednesday, upper-level winds
are expected to increase, limiting the chances for additional
development, while the system moves northward near the southeastern
United States coast.
* Formation chance through 48 hours…low…30 percent.
* Formation chance through 5 days…medium…40 percent.
2. A non-tropical low pressure system is expected to form north of
Subtropical Storm Leslie along a cold front over the central
Atlantic by Wednesday. Leslie and the non-tropical low are expected
to merge over the central Atlantic, where conditions appear
conducive for the low to acquire tropical or subtropical
characteristics by the end of the week.
* Formation chance through 48 hours…low…near 0 percent.
* Formation chance through 5 days…medium…50 percent.
Public Advisories on Leslie are issued under WMO header WTNT33
KNHC and under AWIPS header MIATCPAT3. Forecast/Advisories on
Leslie are issued under WMO header WTNT23 KNHC and under AWIPS
header MIATCMAT3.
Forecaster Pasch
KIRK ACCELERATING WESTWARD OVER THE EASTERN TROPICAL ATLANTIC
Tropical Depression Kirk Discussion Number 8
NWS National Hurricane Center Miami FL AL122018
500 AM AST Mon Sep 24 2018
After having a minimal amount of deep convection late yesterday,
Kirk is now producing some thunderstorm activity in fragmented bands
around the estimated center. However, earlier ASCAT data and low
cloud motion suggest that the circulation resembles a sharp trough
instead of a closed low that is necessary for a tropical cyclone.
Hopefully more visible satellite images and additional scatterometer
data will help better assess the circulation and status of Kirk.
For now, advisories are being maintained on the system, and the
initial intensity is held at 30 kt based on the earlier ASCAT data
and a blend of the Dvorak estimates.
Kirk is moving very quickly to the west at about 21 kt, which is
likely the reason why the system has been struggling. A continued
westward motion but at a decreasing forward speed is expected during
the next two to three days while the cyclone remains on the south
side of a low- to mid-level ridge. After that time, a large
deep-layer low pressure system over the central Atlantic should
cause Kirk to gain more latitude. The NHC track forecast is largely
an update of the previous one, and remains near the southern side of
the guidance envelope near the GFS and ECMWF models. This forecast
takes Kirk toward the Lesser Antilles in 3 to 4 days and interests
there should monitor the progress of this system.
Although Kirk will be moving over warmer SSTs and remain in
relatively moist conditions, its fast forward speed will likely
limit the system from strengthening significantly during the next
few days, so only a little intensification is predicted. The global
models show a notable increase in westerly shear when Kirk reaches
the eastern Caribbean Sea in about 4 days, and that should cause
weakening and possibly even dissipation by the end of the forecast
period. The NHC intensity forecast lies near the lower side of the
guidance envelope, in best agreement with the NOAA HCCA model.
FORECAST POSITIONS AND MAX WINDS
INIT 24/0900Z 9.5N 37.4W 30 KT 35 MPH
12H 24/1800Z 9.9N 40.5W 30 KT 35 MPH
24H 25/0600Z 10.2N 44.6W 35 KT 40 MPH
36H 25/1800Z 10.5N 48.4W 35 KT 40 MPH
48H 26/0600Z 10.9N 51.7W 40 KT 45 MPH
72H 27/0600Z 12.1N 57.1W 40 KT 45 MPH
96H 28/0600Z 13.2N 61.5W 35 KT 40 MPH
120H 29/0600Z 14.0N 66.0W 30 KT 35 MPH
$$
Forecaster Cangialosi
LESLIE CHANGES LITTLE IN STRENGTH OVER THE CENTRAL ATLANTIC
Subtropical Storm Leslie Discussion Number 4
NWS National Hurricane Center Miami FL AL132018
500 AM AST Mon Sep 24 2018
Leslie has changed little overnight. The large subtropical cyclone
continues to produce patches of deep convection, mostly to the south
and east of the center. The initial intensity is again held at 35
kt, which is near the upper end of the satellite intensity
estimates.
The subtropical storm is moving southward at 5 kt. The steering
currents around Leslie are expected to collapse later today and
little overall motion is forecast during the next 12-18 hours.
After that time, a cold front is expected to approach the system,
and that should cause Leslie to move eastward tonight and Tuesday.
The front is expected to merge with Leslie by Tuesday night, causing
it to become extratropical. While little change in intensity is
expected during the next day or so, due to dry air and moderate
shear, some strengthening as an extratropical low is likely due to
baroclinic forcing. In fact, after becoming extratropical, the
models show Leslie merging with another frontal low to its north,
leading to the formation of a powerful slow-moving non-tropical low
with gale- or storm-force winds over the central Atlantic later this
week.
FORECAST POSITIONS AND MAX WINDS
INIT 24/0900Z 32.6N 48.6W 35 KT 40 MPH
12H 24/1800Z 32.6N 48.3W 35 KT 40 MPH
24H 25/0600Z 32.6N 46.9W 35 KT 40 MPH
36H 25/1800Z 32.5N 44.8W 35 KT 40 MPH
48H 26/0600Z 32.7N 42.0W 45 KT 50 MPH…POST-TROP/EXTRATROP
72H 27/0600Z…MERGED WITH FRONTAL SYSTEM
$$
Forecaster Cangialosi
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Mon Sep 24 2018
For the eastern North Pacific…east of 140 degrees west longitude:
1. Showers and thunderstorms associated with an area of low pressure
located a little over 300 miles south of Manzanillo, Mexico,
continue to become better organized. Environmental conditions are
expected to be conducive for development, and a tropical depression
is likely to form within the next couple days while the system moves
west-northwestward well off the coast of Mexico.
* Formation chance through 48 hours…high…70 percent.
* Formation chance through 5 days…high…90 percent.
2. An area of low pressure is expected to form over the far western
portion of the eastern North Pacific basin in a couple of days.
Some gradual development of this system is possible after that time
while it moves westward toward the central Pacific.
* Formation chance through 48 hours…low…near 0 percent.
* Formation chance through 5 days…low…30 percent.
Forecaster Roberts
Global Tropics & Benefits Outlook
Weather in Cayman
SYNOPSIS
Light winds and slight seas are also expected over the next 24 hours due to a weak pressure gradient across the northwest Caribbean. Radar images show isolated showers in and around the Cayman area moving towards the southwest. The National Hurricane Center (NHC) is issuing advisories on Tropical Depression Kirk and Tropical Storm Leslie. These systems pose no immediate threat to the Cayman Islands. For further information please visit www.nhc.noaa.gov.
Humidity: 74% (UP from yesterday)
UV: 11.7 EXTREME (DOWN from yesterday)
Temperature: Today’s current temperature – See weather forecast top right of website. Yesterday: H 89.8°F L 78.3°F
Wind direction TODAY: E 10-20 mph GC
Wind direction TONIGHT: E 10-20 mph GC
Barometer: 1014.40 mb Steady Rain: Last month: 1.83 in Last 24 hrs 0.00 This month: 12.21 in 2 days since rain 12 rain days in September
2017 Season Total: 62.94 in 2018 Season Total: 36.22 in
Average Yearly Rainfall 56.20 in (Note: National Weather Service 2017 Season Total – measured at Owen Roberts Airport GT – was 59.32 in)
All readings are from SOUTH SOUND.
Average rainfall in September 8.2 in. Average temperature in September: 77°F to 90°F
Sea Temperature in September 84°F
MOON:
100% FULL MOON
TIDES, SUNRISE, SUNSET, MOON RISE, MOON SET AND MOON PHASE
GRAND CAYMAN SEPTEMBER 2018 – Click to enlarge
LOCAL 5 DAY FORECAST
http://www.weather.gov.ky/portal/page?_pageid=4421,7428393&_dad=portal&_schema=PORTAL
FOR RADAR IMAGE GO TO: http://www.weather.gov.ky/portal/page/portal/nwshome/forecasthome/radar
Also see Weather In Cayman: http://www.weatherincayman.com/
Moon info and graphic:
https://www.timeanddate.com/moon/uk/georgetown
Atlantic satellite image: http://www.intellicast.com/global/satellite/infrared.aspx?region=hiatlsat
Description:
The Global Infrared Satellite image shows clouds by their temperature. Red and blue areas indicate cold (high) cloud tops. Infrared (IR) radiation is electromagnetic radiation whose wavelength is longer than that of visible light, but shorter than that of terahertz radiation and microwaves. Weather satellites equipped with scanning radiometers produce thermal or infrared images which can then enable a trained analyst to determine cloud heights and types, to calculate land and surface water temperatures, and to locate ocean surface features.
Tropical storm data and graphics from National Hurricane Center at: https://www.nhc.noaa.gov/
Weathernerds: https://www.weathernerds.org/
Mikes Weather Page: http://www.spaghettimodels.com/
