Tropical Storm Gert

[Somerset Squall]

Invest 94L has become TD 07L to the southwest of dissipated TS Franklin. I'll have more later:

TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011 1100 PM EDT SAT AUG 13 2011 SATELLITE IMAGERY INDICATES THAT THE LOW PRESSURE AREA SOUTH-SOUTHEAST OF BERMUDA HAS DEVELOPED PERSISTENT CENTRAL CONVECTION AROUND A TIGHTLY-WOUND LOW-LEVEL CENTER. SATELLITE INTENSITY ESTIMATES FROM SAB AND TAFB ARE 30 KT...AND BASED ON THESE ADVISORIES ARE INITIATED ON THE SYSTEM AS TROPICAL DEPRESSION SEVEN. THE INITIAL MOTION IS 290/9. THE DEPRESSION IS CURRENTLY ON THE SOUTHWEST SIDE OF A LARGE LOW-/MID-LEVEL RIDGE OVER THE CENTRAL NORTH ATLANTIC. A DEEP-LAYER TROUGH ADVANCING INTO THE THE EASTERN UNITED STATES AND THE NORTHWESTERN ATLANTIC WILL BREAK DOWN THE WESTERN END OF THE RIDGE...CAUSING THE DEPRESSION TO TURN NORTHWARD BY 36 HR AND RECURVE NORTHEASTWARD INTO THE WESTERLIES BY 72 HR. THE FORECAST TRACK FOLLOWS THIS SCENARIO...WITH THE FORECAST BEING A BLEND OF THE ECMWF AND GFDL MODEL FORECASTS. A POTENTIAL COMPLICATION TO THE TRACK FORECAST IS SHOWN BY THE UKMET MODEL... WHICH FORECASTS THE DEPRESSION TO EXPERIENCE ERRATIC MOTION DURING THE NEXT 48 HR AS IT INTERACTS WITH A DISTURBANCE CURRENTLY ABOUT 400 N MI TO THE SOUTHEAST. IF SUCH INTERACTION OCCURS...IT WOULD DELAY THE APPROACH OF THE DEPRESSION TO BERMUDA. WATER VAPOR IMAGERY SHOWS SMALL UPPER-LEVEL LOWS TO THE SOUTHWEST AND NORTHEAST OF THE DEPRESSION. THESE SYSTEMS ARE HELPING TO PRODUCE LIGHT NORTHWESTERLY VERTICAL WIND SHEAR...AS WELL AS ADVECTING UPPER-LEVEL DRY AIR INTO THE DEPRESSION. IN ADDITION... A LARGE PLUME OF AFRICAN DUST AND ASSOCIATED DRY AIR ARE APPROACHING THE DEPRESSION FROM THE EAST. WHILE VERTICAL SHEAR SHOULD BE LIGHT ENOUGH FOR THE NEXT 48 HR TO ALLOW DEVELOPMENT... THE ABUNDANT DRY AIR AROUND THE SYSTEM SHOULD AT LEAST SLOW INTENSIFICATION. THE INTENSITY FORECAST CALLS FOR GRADUAL STRENGTHENING THROUGH 48 HR WHILE THE CYCLONE REMAINS OVER WARM WATER. AFTER 72 HR...THE CYCLONE IS EXPECTED TO BE ABSORBED INTO A FRONTAL SYSTEM OVER THE FAR NORTH ATLANTIC. THE FORECAST TRACK AND WIND RADII REQUIRE A TROPICAL STORM WATCH FOR BERMUDA AT THIS TIME. A TROPICAL STORM WARNING WILL LIKELY BE REQUIRED SOMETIME ON SUNDAY.

[Cookie]

[Somerset Squall]

Convection diminished from TD7 this afternoon but has increased again this evening. The depression has been upgraded to Tropical Storm Gert (a female name, short for Gertrude), with intensity climbing to 40kts. Gert is in an area of low shear and warm sea temperatures, however the air is still a little dry which will limit intensification. NHC forecast a peak of 50kts before Gert goes the same way as Franklin ie becoming extratropical whilst moving to the northeast.

[Robbie Garrett]

Well there's the first of the Autumn storms for the UK, looks set to hit us within 1-1/2 weeks?

[Somerset Squall]

Well there's the first of the Autumn storms for the UK, looks set to hit us within 1-1/2 weeks?

Looks likely Gert will become extratropical and then dissipate long before reaching our shores Robbie.

Gert is strengthening, and intensity has risen to 50kts. Gert looks like it's going to have a damn good try at becoming the first hurricane of the season, and NHC now forecast a peak of 60kts. Convection has remained concentrated over the LLC, and Gert has developed a feeder band into the eastern quadrant of the storm, which appears to be stealing moisture and eventually absorbing invest 92L. Shear will remain low over the next 24hrs, and waters remain above 26C for this period also, which suggests further intensification in the near term. After this time, sea temps cool along track and southwesterly shear increases, bringing about weakening and the extatropical transition (ET). After ET is complete, Gert is forecast to be absorbed by a cold front in about 4 days time.

Weather conditions will deteriorate through today for Bermuda. NHC have made the very vaild point to not just focus on the center of Gert, and any deviation west of current heading will mean worse weather for Bermuda.

[onlyME]

Gert is still at 50 kt(60 mph) and it is unlikely to intensify any more.

Discussion from NHC --->

the low-level center of the tropical cyclone appears to be near thenortheastern edge of the main mass of deep convection...andmicrowave data suggest some northeastward tilt of the center withheight. Dvorak estimates of intensity range from 35 to 55 kt andthe current intensity is held at 50 kt for this advisory. Gertshould be traversing warm water for only another 12 to 18 hours...so weakening is likely to commence in 24 hours...if not sooner. The official intensity forecast is in line with the statistical-dynamical guidance. Global models show the system becomingembedded within a baroclinic zone in 36 hours and becoming absorbedby a large North Atlantic low in 2 to 3 days. The officialforecast follows this scenario.Center fixes have become more uncertain this evening but my bestestimate is that there has been an increase in forward speed andthe motion is now near 030/16. Gert is being swept up in the flowahead of a large trough moving off the U.S. East Coast. A gradualturn to the right is anticipated as the cyclone moves into higherlatitudes and becomes influenced by a more zonal steering current. Thd official track forecast is a little to the north of theprevious one and on the south side of the guidance suite.Forecast positions and Max winds init 16/0300z 34.7n 61.6w 50 kt 60 mph 12h 16/1200z 37.3n 59.6w 50 kt 60 mph 24h 17/0000z 40.8n 55.0w 50 kt 60 mph 36h 17/1200z 44.0n 49.0w 45 kt 50 mph...Post-trop/extratrop 48h 18/0000z 46.5n 41.5w 40 kt 45 mph...Post-trop/extratrop 72h 19/0000z...dissipated $$forecaster Pasch

[Cookie]

current scorecard,

ATL will be 7/0/0.

EPAC will be 6/5/3.

[Somerset Squall]

Gert is no longer a tropical cyclone as convection has remained scarce near the LLC. re-development is not expected due to cool sea temps and high shear.

I wouldn't be so sure of the 6/5/3 for the East Pac Cookie. Latest forecast brings Fernanda to hurricane status!