#290 Postby ouragans » Sun May 20, 2012 5:20 am
TROPICAL STORM ALBERTO FORECAST/ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012012
0900 UTC SUN MAY 20 2012
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
NONE.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SAVANNAH RIVER TO SOUTH SANTEE RIVER SOUTH CAROLINA
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE WITHIN 24 HOURS.
COASTAL INTERESTS ELSEWHERE FROM GEORGIA THROUGH THE OUTER BANKS OF
NORTH CAROLINA SHOULD MONITOR THE PROGRESS OF ALBERTO.
TROPICAL STORM CENTER LOCATED NEAR 31.7N 78.9W AT 20/0900Z
POSITION ACCURATE WITHIN 20 NM
PRESENT MOVEMENT TOWARD THE WEST-SOUTHWEST OR 245 DEGREES AT 5 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 998 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT....... 40NE 0SE 0SW 60NW.
12 FT SEAS.. 80NE 40SE 60SW 40NW.
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 31.7N 78.9W AT 20/0900Z
AT 20/0600Z CENTER WAS LOCATED NEAR 31.8N 78.7W
FORECAST VALID 20/1800Z 31.4N 79.3W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 40NE 20SE 20SW 60NW.
FORECAST VALID 21/0600Z 31.2N 79.5W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 40NE 20SE 20SW 60NW.
FORECAST VALID 21/1800Z 31.6N 78.8W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 50NE 30SE 30SW 40NW.
FORECAST VALID 22/0600Z 32.8N 77.1W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 50NE 30SE 30SW 30NW.
FORECAST VALID 23/0600Z 36.2N 72.6W...POST-TROPICAL
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 50SE 40SW 40NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 175 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY
OUTLOOK VALID 24/0600Z 39.0N 68.5W...POST-TROPICAL
MAX WIND 35 KT...GUSTS 45 KT.
OUTLOOK VALID 25/0600Z...DISSIPATED
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 31.7N 78.9W
NEXT ADVISORY AT 20/1500Z
$$
FORECASTER CANGIALOSI/BROWN
TROPICAL STORM ALBERTO ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012012
500 AM EDT SUN MAY 20 2012
...ALBERTO CHANGES LITTLE IN STRENGTH...
SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...31.7N 78.9W
ABOUT 100 MI...160 KM SE OF CHARLESTON SOUTH CAROLINA
ABOUT 130 MI...210 KM ESE OF SAVANNAH GEORGIA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WSW OR 245 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...
NONE.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SAVANNAH RIVER TO SOUTH SANTEE RIVER SOUTH CAROLINA
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE WITHIN 24 HOURS.
COASTAL INTERESTS ELSEWHERE FROM GEORGIA THROUGH THE OUTER BANKS OF
NORTH CAROLINA SHOULD MONITOR THE PROGRESS OF ALBERTO.
FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY
YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM EDT...0900 UTC...THE CENTER OF TROPICAL STORM ALBERTO WAS
LOCATED NEAR LATITUDE 31.7 NORTH...LONGITUDE 78.9 WEST. ALBERTO IS
MOVING TOWARD THE WEST-SOUTHWEST NEAR 6 MPH...9 KM/H...AND THIS
GENERAL MOTION WITH A DECREASE IN FORWARD SPEED IS EXPECTED TODAY.
A TURN TOWARD THE NORTHEAST IS FORECAST ON MONDAY.
MAXIMUM SUSTAINED WINDS REMAIN NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 48
HOURS.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM
FROM THE CENTER.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB...29.47 INCHES.
HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE POSSIBLE ALONG THE COAST OF
SOUTH CAROLINA IN THE WATCH AREA LATER TODAY OR MONDAY.
SURF...DANGEROUS SURF CONDITIONS ARE POSSIBLE ALONG THE COASTS OF
GEORGIA AND SOUTH CAROLINA THROUGH MONDAY. PLEASE SEE STATEMENTS
ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE FOR
INFORMATION SPECIFIC TO YOUR AREA.
NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 AM EDT.
NEXT COMPLETE ADVISORY...1100 AM EDT.
$$
FORECASTER CANGIALOSI/BROWN
TROPICAL STORM ALBERTO DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012012
500 AM EDT SUN MAY 20 2012
ALBERTO APPEARS TO BE MAINTAINING ITS STRENGTH. SATELLITE AND RADAR
IMAGES SHOW THAT DEEP CONVECTION REFORMED NEAR THE CENTER OF THE
TROPICAL STORM OVERNIGHT WITH A BROKEN BAND OF THUNDERSTORM
ACTIVITY REMAINING TO THE NORTH OF THE CENTER. AN ASCAT PASS AROUND
0300 UTC SHOWED MAXIMUM WINDS NEAR 40 KT. BASED ON THE
SCATTEROMETER DATA AND THE RECENT INCREASE IN THUNDERSTORM
ACTIVITY...THE INITIAL INTENSITY IS HELD AT 45 KT. ALTHOUGH ALBERTO
LIES OVER THE RELATIVELY WARM WATERS OF THE GULF STREAM...DRY AIR
IN THE VICINITY OF THE CYCLONE AND STRONG WEST-SOUTHWESTERLY SHEAR
SHOULD LIMIT THE INTENSIFICATION PROCESS. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ONE AND SHOWS ALBERTO REMAINING
STEADY STATE FOR THE NEXT COUPLE OF DAYS. WEAKENING AND A
TRANSITION TO A POST-TROPICAL CYCLONE IS FORECAST BEYOND THAT TIME
WHEN ALBERTO MOVES OVER COOLER WATERS AND INTO AN AREA OF VERY
STRONG UPPER-LEVEL WINDS.
ALBERTO IS CURRENTLY MOVING WEST-SOUTHWESTWARD AT ABOUT 5 KT. THIS
GENERAL HEADING WITH A DECREASE IN FORWARD SPEED IS EXPECTED TODAY
AS A DEEP-LAYER RIDGE OVER THE EASTERN UNITED STATES WEAKENS. THE
TROPICAL CYCLONE IS EXPECTED TO STALL OFF THE SOUTHEAST UNITED
STATES COAST TONIGHT AND EARLY MONDAY AS IT INTERACTIONS WITH AN
AREA OF LOW PRESSURE TO ITS NORTH NEAR THE MID-ATLANTIC STATES AND
A DEVELOPING LOW TO ITS SOUTHEAST. THEREAFTER...A MID-TO
UPPER-LEVEL TROUGH MOVING ACROSS THE EASTERN UNITED STATES SHOULD
CAUSE ALBERTO...OR ITS POST-TROPICAL REMNANTS...TO ACCELERATE
NORTHEASTWARD OVER THE WESTERN ATLANTIC. THE OFFICIAL TRACK
FORECAST HAS BEEN ADJUSTED SLIGHTLY EASTWARD TO BE IN BETTER
AGREEMENT WITH THE LATEST GUIDANCE. FUTURE ADJUSTMENTS IN THAT
DIRECTION MAY BE NECESSARY IF THE RECENT MODEL TRENDS CONTINUE.
FORECAST POSITIONS AND MAX WINDS
INIT 20/0900Z 31.7N 78.9W 45 KT 50 MPH
12H 20/1800Z 31.4N 79.3W 45 KT 50 MPH
24H 21/0600Z 31.2N 79.5W 45 KT 50 MPH
36H 21/1800Z 31.6N 78.8W 45 KT 50 MPH
48H 22/0600Z 32.8N 77.1W 45 KT 50 MPH
72H 23/0600Z 36.2N 72.6W 40 KT 45 MPH...POST-TROPICAL
96H 24/0600Z 39.0N 68.5W 35 KT 40 MPH...POST-TROPICAL
120H 25/0600Z...DISSIPATED
$$
FORECASTER CANGIALOSI/BROWN
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Personal forecast disclaimer
This post is a personal point of view, not an information. Please refer to official statements for life-threatening decisions.
David '79, Frederic '79, Hugo '89, Iris, Luis & Marilyn '95, Georges '98, Lenny '99, Dean '07, Irma '17, Maria '17, Fiona '22, Philippe '23, Tammy '23
16°13'33.3,"6N -61°36'39.5"W
You may very well be correct, I just think the jet to the S of Alberto is starting to make itself known on Alberto's circulation. The thing that would leave me optimistic is that radar presentation is still decent.
And that jet is key. But right now the CIMSS analysis and other synoptic analyses (and looking at the satellite loops) indicate that the jet is actually moving away. That is why Alberto is forecast to not move much, and also why the shear from that jet may not have much effect over the next few days. But is is a really close call. I'm more concerned that it will ingest some of that mid-level dry air to the north and west. It wouldn't take much of an ingestion at all to completely collapse the remaining thunderstorms for good.
