Tropical Storm MATTHEW
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TROPICAL STORM MATTHEW DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152010
1100 AM EDT FRI SEP 24 2010
AN AIR FORCE PLANE INVESTIGATING MATTHEW THIS MORNING FOUND THAT THE
TROPICAL CYCLONE HAS NOT BECOME ANY STRONGER. EASTERLY SHEAR HAS
KEPT THE LOW-LEVEL CENTER NEAR THE NORTHEAST EDGE OF A ROUND BLOB
OF VERY DEEP CONVECTION AS INDICATED BY THE AIR FORCE PLANE AND
MICROWAVE DATA. SATELLITE INTENSITY ESTIMATES SUPPORT AN INITIAL
INTENSITY OF 45 KNOTS...BUT DATA FROM THE RECONNAISSANCE PLANE SO
FAR SUGGEST THAT THIS ESTIMATE COULD BE GENEROUS. MATTHEW ONLY HAS
12 HOURS OR LESS TO STRENGTHEN BEFORE LANDFALL...AND GIVEN THAT THE
ENVIRONMENT IS ONLY MARGINALLY FAVORABLE FOR INTENSIFICATION DUE TO
SHEAR...THE OFFICIAL FORECAST NO LONGER FORECAST MATTHEW TO BECOME
A HURRICANE.
THE CYCLONE HAS INCREASED ITS FORWARD SPEED AND THE BEST ESTIMATE OF
THE INITIAL MOTION IS TOWARD THE WEST OR 275 DEGREES AT 17 KNOTS.
MATTHEW IS EMBEDDED WITHIN A STRONG DEEP EASTERLY FLOW AND THERE IS
HIGH CONFIDENCE IN THE FORECAST THAT THE CYCLONE WILL CONTINUE
WESTWARD OVER CENTRAL AMERICA FOR THE NEXT DAY OR TWO. BEYOND TWO
DAYS...MODELS SHOW DIFFERENT SCENARIOS AND THE FORECAST BECOMES
HIGHLY UNCERTAIN. THE MOST LIKELY SCENARIO IS THAT THE MID-LEVEL
CENTER CONTINUES WESTWARD AND DISSIPATES...WHILE THE LOW-LEVEL
CIRCULATION WEAKENS AND BECOMES PART OF A NEARLY STATIONARY BROAD
AREA OF LOW PRESSURE OVER CENTRAL AMERICA. SUCH A WEATHER PATTERN
WOULD LIKELY PRODUCE DANGEROUS TORRENTIAL RAINS IN CENTRAL AMERICA
OVER THE NEXT FEW DAYS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 24/1500Z 14.4N 82.2W 45 KT
12HR VT 25/0000Z 14.6N 84.2W 35 KT...INLAND
24HR VT 25/1200Z 15.4N 86.5W 30 KT...INLAND
36HR VT 26/0000Z 16.0N 89.0W 30 KT...INLAND
48HR VT 26/1200Z 17.0N 90.0W 25 KT...INLAND
72HR VT 27/1200Z 18.0N 90.5W 20 KT...POST-TROP/REMNT LOW
96HR VT 28/1200Z 18.5N 90.5W 20 KT...POST-TROP/REMNT LOW
120HR VT 29/1200Z 18.5N 90.5W 20 KT...POST-TROP/REMNT LOW
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FORECASTER AVILA
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