SUBTROPICAL STORM ALBERTO FORECAST/ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012018
0300 UTC SAT MAY 26 2018
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
NONE.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A STORM SURGE WATCH IS IN EFFECT FOR...
* HORSESHOE BEACH FLORIDA TO THE MOUTH OF THE MISSISSIPPI RIVER
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* TULUM TO CABO CATOCHE MEXICO
* CUBAN PROVINCE OF PINAR DEL RIO
* INDIAN PASS TO GRAND ISLE
* LAKE PONTCHARTRAIN AND LAKE MAUREPAS
A STORM SURGE WATCH MEANS THERE IS A POSSIBILITY OF LIFE-
THREATENING INUNDATION... FROM RISING WATER MOVING INLAND FROM THE
COASTLINE... IN THE INDICATED LOCATIONS DURING THE NEXT 48 HOURS.
FOR A DEPICTION OF AREAS AT RISK... PLEASE SEE THE NATIONAL WEATHER
SERVICE STORM SURGE WATCH/WARNING GRAPHIC... AVAILABLE AT
HURRICANES.GOV.
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE YUCATAN AND CUBA PORTIONS OF THE WATCH AREA... IN
THIS CASE WITHIN THE NEXT 24 HOURS.
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE UNITED STATES PORTION OF THAT WATCH AREA WITHIN
48 HOURS.
SUBTROPICAL STORM CENTER LOCATED NEAR 19.4N 85.7W AT 26/0300Z
POSITION ACCURATE WITHIN 40 NM
PRESENT MOVEMENT TOWARD THE EAST OR 90 DEGREES AT 4 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB
MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT.
34 KT.......120NE 100SE 0SW 0NW.
12 FT SEAS..120NE 0SE 0SW 0NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 19.4N 85.7W AT 26/0300Z
AT 26/0000Z CENTER WAS LOCATED NEAR 19.3N 85.8W
FORECAST VALID 26/1200Z 20.7N 85.4W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT...120NE 100SE 0SW 0NW.
FORECAST VALID 27/0000Z 22.9N 85.1W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT...120NE 100SE 0SW 0NW.
FORECAST VALID 27/1200Z 25.4N 85.4W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 50NE 0SE 0SW 0NW.
34 KT...120NE 120SE 0SW 0NW.
FORECAST VALID 28/0000Z 27.0N 86.3W...TROPICAL CYCLONE
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 50NE 50SE 0SW 0NW.
34 KT...130NE 120SE 0SW 80NW.
FORECAST VALID 29/0000Z 29.5N 87.5W...TROPICAL CYCLONE
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 50NE 50SE 0SW 0NW.
34 KT...130NE 120SE 0SW 80NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
OUTLOOK VALID 30/0000Z 32.5N 88.0W...INLAND
MAX WIND 30 KT...GUSTS 40 KT.
OUTLOOK VALID 31/0000Z 36.5N 85.5W...INLAND
MAX WIND 20 KT...GUSTS 30 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.4N 85.7W
NEXT ADVISORY AT 26/0900Z
$$
FORECASTER BEVEN
BULLETIN
Subtropical Storm Alberto Advisory Number 3
NWS National Hurricane Center Miami FL AL012018
1000 PM CDT Fri May 25 2018
...ALBERTO STILL MOVING SLOWLY OVER THE NORTHWESTERN CARIBBEAN
SEA...
...HEAVY RAINFALL EXPECTED TO AFFECT THE YUCATAN PENINSULA...WESTERN
CUBA...FLORIDA...AND THE NORTHEASTERN GULF COAST THROUGH THE
WEEKEND...
SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.4N 85.7W
ABOUT 110 MI...175 KM SE OF COZUMEL MEXICO
ABOUT 180 MI...290 KM SSW OF THE WESTERN TIP OF CUBA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
None.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Watch is in effect for...
* Horseshoe Beach Florida to the Mouth of the Mississippi River
A Tropical Storm Watch is in effect for...
* Tulum to Cabo Catoche Mexico
* Cuban province of Pinar del Rio
* Indian Pass Florida to Grand Isle Louisiana
* Lake Pontchartrain and Lake Maurepas
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.
A Tropical Storm Watch means that tropical storm conditions are
possible in the Yucatan and Cuba portions of the watch area, in
this case within the next 24 hours.
A Tropical Storm Watch means that tropical storm conditions are
possible in the United States portion of that watch area within
48 hours.
For storm information specific to your area in the United States,
including possible inland watches and warnings, please monitor
products issued by your local National Weather Service forecast
office. For storm information specific to your area outside the
United States, please monitor products issued by your national
meteorological service.
DISCUSSION AND OUTLOOK
----------------------
At 1000 PM CDT (0300 UTC), the center of Subtropical Storm Alberto
was located near latitude 19.4 North, longitude 85.7 West. The storm
is moving toward the east near 5 mph (7 km/h). A turn toward the
north is expected later tonight, with a faster motion toward the
north expected Saturday through Sunday. A turn toward the
north-northwest is expected on Monday.
Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Gradual strengthening is forecast during the next 48 hours, with
little change in strength forecast on Monday.
Winds of 40 mph extend outward up to 140 miles (220 km) mainly to
the east of the center.
The estimated minimum central pressure is 1006 mb (29.71 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: Alberto is expected to produce total rain accumulations
of 10 to 15 inches with isolated totals of 25 inches across the
northeastern portions of the Yucatan Peninsula and western Cuba.
These rains could produce life-threatening flash floods and
mudslides. Rainfall accmumulations of 4 to 8 inches with maximum
amounts of 12 inches are possible across the Florida Keys and
southern and southwestern Florida. Heavy rain will likely begin
to affect the central Gulf Coast region and the southeastern United
States later this weekend and continue into early next week.
Flooding potential will increase across this region early next
week as Alberto is forecast to slow down after it moves inland.
WIND: Tropical storm conditions are possible within the watch
area in Cuba and the Yucatan Peninsula through Saturday. Tropical
storm conditions are possible within the United States watch
area beginning on Sunday.
STORM SURGE: The combination of storm surge and the tide will cause
normally dry areas near the coast to be flooded by rising waters
moving inland from the shoreline. The water could reach the
following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...
Horseshoe Beach to the Mouth of the Mississippi River...2 to 4 ft
The deepest water will occur along the immediate coast. Surge-
related flooding depends on the relative timing of the surge
and the tidal cycle, and can vary greatly over short distances. For
information specific to your area, please see products issued by
your local National Weather Service forecast office.
TORNADOES: A tornado or two may occur over the Florida Keys and
parts of southern and southwestern Florida beginning Saturday
evening.
SURF: Swells generated by Alberto are affecting portions of the
coast of eastern Yucatan Peninsula and western Cuba. These swells
are likely to cause life-threatening surf and rip current
conditions. Hazardous surf conditions are likely to develop along
much of the central and eastern U.S. Gulf Coast this weekend. For
more information, consult products from your local weather office.
NEXT ADVISORY
-------------
Next intermediate advisory at 100 AM CDT.
Next complete advisory at 400 AM CDT.
$$
Forecaster Beven
Subtropical Storm Alberto Discussion Number 3
NWS National Hurricane Center Miami FL AL012018
1000 PM CDT Fri May 25 2018
Satellite imagery, earlier aircraft data, and surface observations
indicate that Alberto is rather disorganized. A prominent mid-level
center is near the western tip of Cuba, with the convection somewhat
organized around it. However, the low-level center is about 170 n
mi south-southwest of the mid-level center. There are no recent
observations of gale-force winds, so the initial intensity will
remain an uncertain 35 kt. An upper-level trough just to the west
and northwest of the cyclone is advecting cool and dry air into
Alberto, and thus the system remains a subtropical cyclone at this
time.
The initial motion is a somewhat uncertain 090/4. Alberto should
turn northward during the next 12 h or so in response to the
nearby upper-level trough, with this motion continuing through
about 36 h. After that, a north-northwestward motion is likely as
the aforementioned trough becomes a closed low over the central
Gulf of Mexico and Alberto moves around the northeast side. This
evolution should cause Alberto to move through the eastern Gulf of
Mexico during the next 2-3 days, and then make landfall on the
northern Gulf Coast between 72-96 h. After landfall, Alberto should
continue northward through the southeastern United States. The new
forecast track is nudged a bit to the east of the previous track
during the first 36 h based on the initial position, and it lies
just to the west of the consensus models. One uncertainty in the
track forecast is the possibility that the center could re-form to
the north, which at the least could change the timing of the
forecast track.
The dynamical models forecast Alberto to reach an area of stronger
upper-level divergence in about 24 h, with the models agreeing on
more significant development starting about that time. The
intensity forecast shows a slower development rate for the first 24
h than the previous forecast, then shows a faster development to
the 55-kt peak intensity of the previous forecast. After landfall,
Alberto should quickly weaken over land. The new intensity forecast
is near the intensity consensus and the SHIPS model.
Some of the intensity guidance suggests that Alberto could become a
hurricane before landfall. If the guidance trends stronger, a
hurricane watch could be needed for a portion of the Gulf Coast on
Saturday.
KEY MESSAGES:
1. Regardless of its exact track and intensity, Alberto is expected
to produce heavy rainfall and flash flooding over the northeastern
Yucatan Peninsula of Mexico, western Cuba, southern Florida and the
Florida Keys. Rainfall and flooding potential will increase across
the central U.S. Gulf Coast region and the southeastern United
States later this weekend and early next week when Alberto is
expected to slow down after it moves inland.
2. Tropical-storm-force winds and hazardous storm surge are
possible along portions of the central and eastern U.S. Gulf Coast
beginning on Sunday, including areas well east of the track of
Alberto's center, and tropical storm and storm surge watches are in
effect for portions of these areas. Residents in the watch areas are
encouraged not to focus on the details of the forecast track of
Alberto and should follow any guidance given by their local
government officials.
3. Dangerous surf and rip current conditions are affecting portions
of the Yucatan Peninsula and western Cuba and will likely spread
along the eastern and central U.S. Gulf Coast later this weekend.
FORECAST POSITIONS AND MAX WINDS
INIT 26/0300Z 19.4N 85.7W 35 KT 40 MPH
12H 26/1200Z 20.7N 85.4W 35 KT 40 MPH
24H 27/0000Z 22.9N 85.1W 40 KT 45 MPH
36H 27/1200Z 25.4N 85.4W 50 KT 60 MPH
48H 28/0000Z 27.0N 86.3W 55 KT 65 MPH...TROPICAL CYCLONE
72H 29/0000Z 29.5N 87.5W 55 KT 65 MPH...TROPICAL CYCLONE
96H 30/0000Z 32.5N 88.0W 30 KT 35 MPH...INLAND
120H 31/0000Z 36.5N 85.5W 20 KT 25 MPH...INLAND
$$
Forecaster Beven