Tropical Report

HEAVY RAINFALL COULD PRODUCE LIFE-THREATENING FLASH FLOODING ACROSS PORTIONS OF THE NORTHERN GULF COAST

Tropical Storm Cindy Discussion Number 7

NWS National Hurricane Center Miami FL AL032017

400 AM CDT Wed Jun 21 2017

Cindy does not look much like a tropical cyclone on satellite

images this morning. The deep convection is well-removed to the

north and northeast of an exposed low-level center, and there is a

rather linear north-south band of convection several hundred miles

east of the center. Water vapor imagery indicates that an

upper-level low is located a couple of hundred miles to the

northwest of Cindy’s center, suggesting that the system has at least

some subtropical characteristics. The current intensity is held at

50 kt for this advisory, although surface observations and a recent

ASCAT overpass suggest that this may be generous. Global model

forecasts indicate significant shear, with some mid-level dry air

wrapping around the circulation, over the next day or so. These

factors, along with the current lack of convection near the center,

should result in some weakening of the system prior to landfall,

perhaps more so than indicated in the NHC forecast. An Air Force

Reserve Unit Hurricane Hunter aircraft will investigate the cyclone

soon, to confirm the intensity and wind field.

The initial motion estimate remains northwestward, or 310/7 kt.

Cindy is expected to turn northward and move through a break in the

mid-level subtropical ridge along the northwest Gulf of Mexico

coast. Later in the forecast period Cindy, or its remnant, should

accelerate northeastward in the westerlies over the eastern United

States. The official track forecast is mainly a blend of the ECMWF

and GFS and also leans toward the latest HFIP Corrected Consensus

prediction.

The primary hazard from Cindy continues to be very heavy rainfall

over portions of the central and eastern Gulf Coast, which could

cause life-threatening flash flooding in some locations. For more

information on the flooding hazard, see products from your local

National Weather Service office and the Weather Prediction Center.

FORECAST POSITIONS AND MAX WINDS

INIT 21/0900Z 27.3N 91.9W 50 KT 60 MPH

12H 21/1800Z 28.0N 92.8W 50 KT 60 MPH

24H 22/0600Z 29.3N 93.5W 45 KT 50 MPH

36H 22/1800Z 30.9N 93.8W 35 KT 40 MPH…INLAND

48H 23/0600Z 33.2N 92.8W 25 KT 30 MPH…INLAND

72H 24/0600Z 36.0N 85.0W 20 KT 25 MPH…INLAND

96H 25/0600Z…DISSIPATED

$$

Forecaster Pasch

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

500 AM PDT Wed Jun 21 2017

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

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

$$

Forecaster Beven

Weather In Cayman

Synopsis

Moderate to fresh east to southeasterly winds and rough seas are expected to continue across the Cayman area for the next 24 hours as the pressure gradient tightens due to Tropical Storm Cindy. Radar images show isolated showers mainly to the west of Grand Cayman area moving towards the northwest.