000WTNT43 KNHC 140233TCDAT3Tropical Storm Gert Discussion Number 5NWS National Hurricane Center Miami FL AL0820171100 PM EDT Sun Aug 13 2017Gert continues to gradually become better organized on satelliteimagery. A large curved band feature has formed in the easternsemicircle, with very deep convection. It still appears the centeris on the northwest side of the convection, somewhat displaced tothe north of the mid-level center. Intensity estimates are a littlehigher than the last advisory, so the wind speed is raised to 40 kt.Gert should remain in a light-to-moderate northerly wind shearenvironment for the next couple of days, with anomalously warm SSTsand increasing mid-level moisture in the forecast path. Almost allof the historically reliable guidance now show Gert becoming ahurricane in a couple of days under these moderately favorableconditions, and so does the official forecast. The latest NHCprediction is raised from the previous one but remains below themodel consensus, closest to the LGEM model. Gert should rapidlyweaken as it undergoes extratropical transition in 3-4 days over thecold north Atlantic waters.Gert is moving north-northwestward at 8 kt on the southwesternperiphery of a subtropical ridge. A northward turn is expectedon Monday while the system rounds the western side of the ridge, andGert is expected to be about midway between Bermuda and NorthCarolina on Tuesday. After that time, a progressively faster motionto the northeast and east-northeast is forecast as the systembecomes embedded in the mid-latitude westerlies until it dissipatesin about 5 days. The guidance has shifted a little bit to the westafter recurvature, so the official forecast is moved in thatdirection.FORECAST POSITIONS AND MAX WINDSINIT 14/0300Z 28.8N 71.9W 40 KT 45 MPH 12H 14/1200Z 30.0N 72.1W 50 KT 60 MPH 24H 15/0000Z 31.6N 72.1W 55 KT 65 MPH 36H 15/1200Z 33.6N 71.2W 60 KT 70 MPH 48H 16/0000Z 36.0N 68.5W 65 KT 75 MPH 72H 17/0000Z 41.0N 55.5W 65 KT 75 MPH 96H 18/0000Z 48.0N 41.0W 45 KT 50 MPH...POST-TROP/EXTRATROP120H 19/0000Z...DISSIPATED$$Forecaster Blake
NHC Atlantic OpsCuenta verificada @NHC_Atlantic 26 minHace 26 minutos #Gert is now forecast to become a #hurricane while it recurves away from the United States in a couple of days. http://hurricanes.gov
Michael VentriceCuenta verificada @MJVentrice 30 minHace 30 minutos Possible rapid intensification of #Gert taking place; Now has a robust eye with two vortical hot towers cyclonically rotating around the eye
000WTNT43 KNHC 142047TCDAT3Tropical Storm Gert Discussion Number 8NWS National Hurricane Center Miami FL AL082017500 PM EDT Mon Aug 14 2017The satellite presentation of Gert has continued to improve today.Convective banding has increased around the center, and a largebanded eye has appeared in recent visible satellite pictures.Satellite intensity estimates from TAFB, SAB, and UW-CIMSS supportedan intensity of around 55 kt at 18z, but due to the continuedincrease in organization, the initial wind speed is set at 60 ktfor this advisory. Although there is some light northerly shearover the system, it should not prevent additional strengtheningduring the next day or so while Gert remains over SSTs of 28 to29 deg C. Gert is expected to become a hurricane within 12 hours,and the updated NHC intensity forecast calls for a bit higher peakintensity than before. The NHC forecast is a little above thestatistical guidance and calls for peak intensity a little soonerthan most of the guidance. The HWRF continues to be very bullishin bringing the system to major hurricane status, but since itshows peak intensity well after the system is expected to encounterwesterly shear and cooler SSTs, less weight has been placed on thatscenario. Gert is expected to complete extratropical transitionwithin 72 hours, then gradually weaken over the North Atlanticbefore it merges with a larger extratropical cyclone in 4 to 5 days.Gert has been moving more slowly than expected today while it hasbeen rounding the western portion of the ridge. The storm isexpected to turn north-northeastward and begin to accelerateTuesday ahead of a shortwave trough approaching the northeasternUnited States. The track guidance continues to be in excellentagreement, but is generally slower than before. As a result, littlecross-track change was required in the NHC track through 72 h, butthe new forecast is slower than the previous one to account for thelatest trend in the latest guidance.Swells from Gert are expected to spread northward along themid-Atlantic coast of the United States during the next few days.These swells are likely to produce dangerous surf and rip currentconditions. Please consult products from your local NationalWeather Service office.FORECAST POSITIONS AND MAX WINDSINIT 14/2100Z 30.6N 72.3W 60 KT 70 MPH 12H 15/0600Z 31.6N 72.3W 70 KT 80 MPH 24H 15/1800Z 33.3N 71.6W 75 KT 85 MPH 36H 16/0600Z 35.6N 69.0W 80 KT 90 MPH 48H 16/1800Z 38.0N 64.0W 80 KT 90 MPH 72H 17/1800Z 44.5N 48.0W 70 KT 80 MPH...POST-TROP/EXTRATROP 96H 18/1800Z 52.0N 39.0W 50 KT 60 MPH...POST-TROP/EXTRATROP120H 19/1800Z...ABSORBED BY LARGER EXTRATROPICAL LOW$$Forecaster Brown
000WTNT43 KNHC 150833TCDAT3Hurricane Gert Discussion Number 10NWS National Hurricane Center Miami FL AL082017500 AM EDT Tue Aug 15 2017After a period of intensification several hours ago, recentsatellite images show that the cloud pattern has deteriorated alittle bit. The eye is no longer discernible, and the center is nowlocated to the west of an area of very deep convection. Dvoraknumbers still support an initial intensity of 65 kt. Gert has anopportunity to gather some strength in the next day or so afterrecurvature. The new NHC forecast is not as aggressive as theprevious one, and it follows very closely the intensity consensus.Only the HWRF model significantly strengthens the cyclone. After twodays, Gert will be completely embedded within the mid-latitudewesterlies and should become a post-tropical cyclone.The best estimate of the initial motion is toward the north or 360degrees at 10 kt. Gert is being steered northward by the flow aroundthe western edge of the subtropical ridge. The cyclone should thenturn to the northeast with an increase in forward speed later todayas it becomes embedded within the mid-latitude flow. The NHC trackforecast is similar to the previous one, and is in the middle of thetight guidance envelope.Swells from Gert are expected to spread northward along themid-Atlantic coast of the United States during the next few days.These swells are likely to produce dangerous surf and rip currentconditions. Please consult products from your local NationalWeather Service office.FORECAST POSITIONS AND MAX WINDSINIT 15/0900Z 31.8N 72.5W 65 KT 75 MPH 12H 15/1800Z 33.3N 71.5W 70 KT 80 MPH 24H 16/0600Z 35.5N 68.9W 75 KT 85 MPH 36H 16/1800Z 37.8N 64.0W 75 KT 85 MPH 48H 17/0600Z 40.0N 57.0W 70 KT 80 MPH 72H 18/0600Z 46.5N 41.0W 65 KT 75 MPH...POST-TROP/EXTRATROP 96H 19/0600Z 52.0N 36.0W 50 KT 60 MPH...POST-TROP/EXTRATROP120H 20/0600Z...DISSIPATED$$Forecaster Avila
Philip KlotzbachCuenta verificada @philklotzbach 7 hHace 7 horas Hurricane #Gert now has max winds of 105 mph - the strongest August hurricane north of 40°N since Alex (2004).