[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 180248
TCDAT4

TROPICAL STORM HUMBERTO DISCUSSION NUMBER  31
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
1100 PM AST TUE SEP 17 2013

THE TROPICAL STORM IS NOT WELL ORGANIZED THIS EVENING.  ONLY SOME
FRAGMENTED BANDS ARE ON THE EASTERN SIDE OF THE ELONGATED
CIRCULATION...WITH THE CENTER ON THE SOUTHWESTERN SIDE OF THE
CONVECTION.  AN ASCAT PASS SHOWED A SMALL AREA OF 30-35 KT WINDS...
AND 35 KT IS USED AS THE INITIAL INTENSITY.  SOME INCREASE IN
STRENGTH IS POSSIBLE WHILE THE SHEAR REMAINS LOW AND HUMBERTO
REMAINS OVER MARGINAL SSTS DURING THE NEXT COUPLE OF DAYS.  SHIPS/
LGEM ARE HIGHER THAN MOST OF THE GUIDANCE AND SHOW HUMBERTO CLOSE
TO A HURRICANE AGAIN...ALTHOUGH THE CURRENT AND FORECAST SSTS FROM
SHIPS SEEM TOO HIGH COMPARED WITH AVAILABLE OBSERVATIONS.  THUS...
THE OFFICIAL FORECAST STILL REMAINS ON THE CONSERVATIVE SIDE...
CLOSE TO A BLEND OF THE PREVIOUS FORECAST AND THE INTENSITY
CONSENSUS.

THE INITIAL MOTION HAS BEEN CHALLENGING TO DETERMINE SINCE THE
CIRCULATION IS NOT VERY COMPACT...BUT IS ESTIMATED AT 345/6. A
TROUGH OVER THE WESTERN ATLANTIC OCEAN SHOULD TURN HUMBERTO TO THE
NORTH THEN NORTHEAST OVER THE NEXT COUPLE OF DAYS WITH A
SIGNIFICANT INCREASE IN FORWARD SPEED IN THE 48-72H PERIOD. MOST OF
THE GLOBAL MODELS SHOW THIS SYSTEM BECOMING EXTRATROPICAL IN ABOUT
3 DAYS...AND ABSORBED WITHIN A LARGER MID-LATITUDE LOW IN 4-5 DAYS.
THE GUIDANCE IS VERY TIGHTLY PACKED AND NO SIGNIFICANT CHANGES WERE
MADE TO THE PREVIOUS NHC FORECAST.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0300Z 30.8N  43.3W   35 KT  40 MPH
 12H  18/1200Z 31.6N  43.4W   35 KT  40 MPH
 24H  19/0000Z 32.8N  43.4W   40 KT  45 MPH
 36H  19/1200Z 34.3N  42.7W   40 KT  45 MPH
 48H  20/0000Z 36.3N  41.2W   45 KT  50 MPH
 72H  21/0000Z 43.0N  35.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 96H  22/0000Z 54.5N  24.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  23/0000Z...ABSORBED

$$
FORECASTER BLAKE



This weather bulletin was brought to you by:
www.nashvilleweather.net