Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
People
Research
Academics Application Contact_Us

Hawaiian_Weather
US_Mainland_Weather
Tropical_Weather
Satellite_Imagery
Polar_Imagery
Radar_Imagery
Marine
Numerical_Models
LAPS
Lightning_Data
Forecasts
Vog_Forecasts
Observations
Archive
Links Disclaimer
Space
SOEST_Home
University_of_Hawaii_Home

Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans:
Narrow the Menu List
Select Time Limit: 12 hours | 24 hours | 48 hours | 72 hours | No time limit
Select Product Type: All | Routine Bulletins/FCSTS | Warnings/Watches/Advisories | HAWN Weather | Tropical | Marine | Aviation | Daily Obs | Special
Atlantic Tropical Cyclone Discussion

674
WTNT42 KNHC 282041
TCDAT2

TROPICAL STORM BONNIE DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022016
500 PM EDT SAT MAY 28 2016

A 1431Z ASCAT-B overpass indicated two 34-kt wind vectors existed in
the northwest quadrant of the tropical cyclone in a region of deep
convection that was not sampled during the earlier reconnaissance
mission. Convection briefly weakened, but has redeveloped and
persisted in that same part of the storm circulation for the past 5
hours. Furthermore, NOAA Doppler velocity radar data from Charleston
and Jacksonville have indicated winds ranging from 50-55 kt between
15,000 and 20,000 feet in the same area of the 34-kt ASCAT wind
vectors. Based on these data, the depression has been upgraded
to Tropical Storm Bonnie.

The initial motion estimate is 320/09 kt. The exposed low-level
center near the southeastern edge of the deep convective cloud
canopy has been easy to track over the past several hours, and has
essentially been moving along the previous forecast track. The NHC
model guidance remains in good agreement on Bonnie gradually turning
toward the north-northwest as it moves around the west side of a
deep-layer ridge, and moving onshore between Charleston and
Beaufort, South Carolina, in about 18-24 hours. After landfall a
mid-level shortwave trough moving northeastward out of the
Mississippi Valley region is expected to significantly weaken the
ridge, causing the steering to collapse. The result is that Bonnie
is forecast to stall or meander along the coastal region of South
Carolina in 24-36 hours before drifting off to the east or northeast
by 48 hours. The NHC forecast track is similar to the previous
advisory track, and closely follows a blend of GFS and ECMWF models.

Bonnie is currently moving over the axis of warmest Gulf Stream
sea-surface temperatures of 27-28 deg C. Although slightly cooler
shelf water lies ahead of the cyclone, those ocean conditions do
not appear to be sufficient to significantly weaken Bonnie based on
rather vigorous convection that has developed just offshore of
South Carolina today. However, southerly vertical wind shear of at
least 20 kt is expected to prevent any rapid or significant
intensification before landfall. After 24 hours, land interaction
and the aforementioned wind shear should induce slow weakening,
although there could be some convective rain bands over water
producing wind gusts to tropical-storm force until about 48 hours.
The official intensity forecast is similar to the previous advisory
and follows the Decay-SHIPS model.

The primary impact from Bonnie is expected to be locally heavy
rainfall.

FORECAST POSITIONS AND MAX WINDS

INIT 28/2100Z 31.1N 79.4W 35 KT 40 MPH
12H 29/0600Z 31.9N 80.1W 40 KT 45 MPH
24H 29/1800Z 32.8N 80.5W 35 KT 40 MPH...INLAND
36H 30/0600Z 33.2N 80.1W 30 KT 35 MPH...INLAND
48H 30/1800Z 33.5N 79.4W 30 KT 35 MPH...INLAND
72H 31/1800Z 34.5N 77.8W 25 KT 30 MPH...INLAND
96H 01/1800Z 35.0N 76.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 02/1800Z 35.7N 75.3W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart


Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office



This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Wed, Dec 17 2014 - 1841 UTC
Send comments to: Ryan Lyman