Issued at 1100 PM AST Sat Aug 24 2019 000WTNT45 KNHC 250248TCDAT5Tropical Storm Dorian Discussion Number 3NWS National Hurricane Center Miami FL AL0520191100 PM AST Sat Aug 24 2019Dorian's structure hasn't changed substantially since the lastadvisory. Although southeasterly shear and surrounding dry airappear to be limiting convection, the most recent availablemicrowave imagery showed that the small cyclone is maintainingwell-defined convective banding. The initial intensity is still35 kt, based primarily on the most recent TAFB Dvorak fix.Confidence in the intensity forecast is particularly low due to anumber of factors. The small size of Dorian could make itsusceptible to large short-term swings in intensity (up or down).While SHIPS diagnostics suggest that the wind shear will be below 10kt for at least the next 72 h, UW-CIMSS shear diagnostics indicatethat the current shear is higher, more like 15-20 kt. And theintensity guidance spread is also notably large, further decreasingconfidence in the forecast. For now, the NHC intensity forecast hasnot been significantly changed, and shows Dorian near hurricanestrength when it approaches the Lesser Antilles in a few days. Thisis a little above the intensity consensus and it should be stressedthat it is still too soon to pinpoint potential wind impacts acrossthose islands, given the large uncertainty in the forecast. Theofficial forecast then shows Dorian maintaining hurricane strengthacross the northeast Caribbean, but it is certainly possible that itcould be weaker, especially given the expected surrounding dryenvironment and a possible increase in wind shear forecast by theGFS and ECMWF models. By the end of the forecast period, the NHCintensity forecast is very close to HCCA and IVCN.An ASCAT-B overpass at 0024 UTC revealed that Dorian is movingslightly faster than previously estimated, now 280/12 kt. Unlike theintensity guidance, the track models are in quite good agreement onthe track of Dorian. The tropical storm should continue movingwestward to west-northwestward at a similar forward speed, steeredprimarily by a mid-level ridge stretching across most of the centralAtlantic. The NHC forecast is nearly on top of the previous advisoryand remains very near the TVCN and HCCA consensus aids.Key Messages:1. Dorian is forecast to strengthen and could be near hurricanestrength when it approaches the Lesser Antilles on Tuesday.2. It is too soon to determine the specific timing or magnitude ofimpacts in the Lesser Antilles, but tropical storm or hurricanewatches will likely be needed for a portion of the islands onSunday.FORECAST POSITIONS AND MAX WINDSINIT 25/0300Z 10.9N 50.4W 35 KT 40 MPH 12H 25/1200Z 11.2N 52.0W 40 KT 45 MPH 24H 26/0000Z 11.7N 54.1W 45 KT 50 MPH 36H 26/1200Z 12.5N 56.2W 50 KT 60 MPH 48H 27/0000Z 13.2N 58.2W 55 KT 65 MPH 72H 28/0000Z 15.0N 62.3W 65 KT 75 MPH 96H 29/0000Z 17.0N 66.5W 70 KT 80 MPH120H 30/0000Z 19.0N 70.0W 55 KT 65 MPH...INLAND$$Forecaster Zelinsky

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