Watches issued for portions of the Leewards (5am Tuesday)
Posted by
Chris in Tampa on 8/25/2015, 4:56 am
Track:
http://www.nhc.noaa.gov/refresh/graphics_at5+shtml/083703.shtml?5day?large#contents
TROPICAL STORM ERIKA DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052015
500 AM AST TUE AUG 25 2015
The cloud pattern of Erika has not changed much overnight, with the
convection located near the center and in the southern semicircle.
The latest Dvorak estimates are T2.5/35 kt from TAFB and SAB, and
the initial intensity remains 40 kt based on the earlier buoy data.
Erika will be moving over warming SSTs with light to moderate shear
for the next 36 to 48 hours, and the NHC forecast shows steady
intensification during this time. After that, Erika could encounter
increasing westerly shear due to interaction with an upper-level low
near Hispaniola and there is the potential for land interaction with
the Greater Antilles. The HWRF and LGEM models show more
strengthening during this time, while the GFDL and SHIPS models are
less aggressive. There is also disagreement among the global models.
The GFS weakens Erika to a trough by 5 days while the ECMWF has
trended stronger and the UKMET continues to show a more robust
cyclone. The NHC intensity forecast has been adjusted upward a bit
at days 4 and 5 and is close to or a bit below the IVCN intensity
consensus. Due to the large spread in the guidance, the intensity
forecast at days 3-5 is of even lower confidence than usual.
The initial motion estimate of 275/17 is based largely on
continuity, given the difficulty locating the center with infrared
imagery. The track guidance is in good agreement through 36 hours,
as Erika should be steered westward to west-northwestward south of
the subtropical ridge. At 48 hours and beyond, there are two
distinct camps of track guidance. The UKMET, HWRF, and GFDL
show a deeper system that moves northwestward, while the GFS, ECMWF,
and GEFS ensemble mean show a weaker cyclone and a more west-
northwestward motion. The NHC forecast has been nudged a bit
to the right this cycle and remains close to the ECMWF and GEFS
ensemble mean. This track is to the right of the GFS but well left
of the TVCA multi-model consensus. Given the divergence in the
guidance, confidence in the track forecast late in the period is
low.
Based on the new forecast, Tropical Storm Watches have been issued
for portions of the Lesser Antilles.
FORECAST POSITIONS AND MAX WINDS
INIT 25/0900Z 14.6N 49.4W 40 KT 45 MPH
12H 25/1800Z 15.2N 51.9W 45 KT 50 MPH
24H 26/0600Z 16.0N 54.8W 50 KT 60 MPH
36H 26/1800Z 16.9N 57.9W 55 KT 65 MPH
48H 27/0600Z 17.6N 61.0W 60 KT 70 MPH
72H 28/0600Z 19.3N 66.2W 60 KT 70 MPH
96H 29/0600Z 21.5N 71.0W 65 KT 75 MPH
120H 30/0600Z 24.0N 75.0W 70 KT 80 MPH
$$
Forecaster Brennan
TROPICAL STORM ERIKA ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052015
500 AM AST TUE AUG 25 2015
...TROPICAL STORM WATCHES ISSUED FOR PORTIONS OF THE LEEWARD
ISLANDS...
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...14.6N 49.4W
ABOUT 840 MI...1355 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
The Meteorological Service of Antigua has issued a Tropical Storm
Watch for Montserrat, Antigua, Barbuda, St. Kitts, Nevis, and
Anguilla.
The Meteorological Service of Curacao has issued a Tropical Storm
Watch for Saba and St. Eustatius.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for...
* Montserrat
* Antigua
* Barbuda
* St. Kitts and Nevis
* Anguilla
* Saba
* St. Eustatius
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests elsewhere in the Leeward Islands should monitor the
progress of Erika, as watches may be required for additional areas
later today.
For storm information specific to your area, please monitor products
issued by your national meteorological service.
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 AM AST (0900 UTC), the center of Tropical Storm Erika was
located near latitude 14.6 North, longitude 49.4 West. Erika is
moving toward the west near 20 mph (31 km/h), and a westward to
west-northwestward motion with a slight decrease in forward speed
are expected during the next 48 hours. On the forecast track, the
center of Erika will approach the Leeward Islands Wednesday night
and early Thursday.
Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Some strengthening is forecast during the next couple of days.
Tropical storm force winds extend outward up to 80 miles (130 km)
from the center.
The estimated minimum central pressure is 1003 mb (29.62 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are possible within the watch
area by Wednesday night or early Thursday.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 AM AST.
Next complete advisory at 1100 AM AST.
$$
Forecaster Brennan |
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Watches issued for portions of the Leewards (5am Tuesday) - Chris in Tampa, 8/25/2015, 4:56 am Post A Reply
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