27 Jun Weather in Cayman & Tropical Report

June 27, 2019

27 Jun Thu 2019

Tropical Report

ATLANTIC

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

800 AM EDT Thu Jun 27 2019

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

Forecaster Brennan

EASTERN PACIFIC

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

500 AM PDT Wed Jun 26 2019

For the eastern North Pacific…east of 140 degrees west longitude:

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

500 AM PDT Thu Jun 27 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Alvin, located several hundred miles south of the southerntip of the Baja California peninsula.

1. An area of low pressure is expected to develop in a few days several hundred miles southwest of the southern coast of Mexico. Some slow development of this system is possible thereafter and a tropical depression could develop by late this weekend or early next week while it moves westward to west-northwestward.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 5 days…medium…40 percent.

Forecaster Zelinsky

TINY ALVIN STRENGTHENS OVER THE OPEN PACIFIC OCEAN.

ropical Storm Alvin Discussion Number 7

NWS National Hurricane Center Miami FL EP012019

300 AM MDT Thu Jun 27 2019

Alvin’s satellite presentation is much improved since this time

yesterday, consisting of a small but distinct CDO with extremely

cold overshooting cloud tops of about -90C near the well-defined

center. Outflow is fairly symmetrical due to the low vertical wind

shear conditions affecting the compact cyclone. A 0435Z ASCAT-A pass

revealed that tropical-storm-force winds only extended 15-20 nmi

away from the center in the northern semicircle along with one peak

wind vector of 46 kt located in the northwestern quadrant near the

overshooting cloud tops. Given Alvin’s small size and likely

undersampling by the scatterometer instrument, the intensity is

raised to 50 kt, which is consistent with ADT and SATCON estimates.

The initial position and motion vector of 300/11 kt are based on

ASCAT-A/-C scatterometer wind data and passive microwave fixes.

Although the new track has been shifted north of the previous

advisory track, there otherwise are no significant changes to the

previous forecast track reasoning. Alvin is expected to move

steadily west-northwestward around the southwestern periphery of a

deep-layer subtropical ridge that extends westward from northwestern

Mexico. The latest track guidance has again shifted northward and

the new NHC track has likewise been shifted northward, but not quite

as far the consensus models out of the respect for the lower

latitude ECMWF and FSSE models.

Additional strengthening is expected during the next 12 to 24 hours

while Alvin remains over SSTs greater than 26 deg C and within a low

vertical wind shear regime. By 36 hours, however, the combination of

cooling SSTs and a more stable airmass is forecast to induce steady

to rapid weakening. Alvin is expected to degenerate into a remnant

low by late Saturday, and dissipate by Monday. The NHC intensity

forecast is similar to a blend of the consensus models IVCN. HCCA,

and FSSE.

FORECAST POSITIONS AND MAX WINDS

INIT 27/0900Z 15.1N 111.9W 50 KT 60 MPH

12H 27/1800Z 15.9N 113.5W 55 KT 65 MPH

24H 28/0600Z 17.3N 116.0W 55 KT 65 MPH

36H 28/1800Z 18.7N 118.1W 45 KT 50 MPH

48H 29/0600Z 19.6N 119.9W 35 KT 40 MPH

72H 30/0600Z 20.7N 122.7W 20 KT 25 MPH…POST-TROP/REMNT LOW

96H 01/0600Z…DISSIPATED

Forecaster Stewart

Global Tropics & Benefits Outlook

Weather in Cayman

SYNOPSIS

Showers along with light to moderate easterly winds and seas are expected across the Cayman area for the next 24 hours. Additionally, a tropical wave just west of Cayman will enhance our chances of heavy showers and thunder today. Radar images show isolated showers in and around the Cayman area moving towards the west.

Humidity: 71% (DOWN from yesterday)

UV: 12.2 EXTREME (UP from yesterday)

Temperature: Today’s expected temperatures – 78°F to 90°F. Yesterday: H 90.1° F L 77.9°F
Winds: Today ENE 10-20 mph Tonight ENE 10-15 mph
Barometer: 1014.90 mb Steady

Rain: Last month: 3.76 in

Last 24 hrs 0.07 in This month: 1.65 in

0 days since rain

6 rain days in June

2018 Season Total: 44.03 in

2019 Season Total: 14.59 in

All readings are from SOUTH SOUND.

Average rainfall in June 7.2 in.

Average temperature in June: 77°F to 90°F

Sea Temperature in June: 84°F

MOON: 30% illumination