Home discussion
 

Keywords :   


Tag: discussion

Hurricane NICOLE Forecast Discussion Number 46

2016-10-15 16:59:24| National Hurricane Center (Atlantic)

Issued at 1100 AM AST SAT OCT 15 2016 000 WTNT45 KNHC 151459 TCDAT5 HURRICANE NICOLE DISCUSSION NUMBER 46 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 AM AST SAT OCT 15 2016 Nicole has intensified since the last advisory, likely due to baroclinic influences from a nearby upper-level trough. Just-received ASCAT-B data shows 70-75 kt winds to the southwest of the center, and a drifting buoy south of the center reported a pressure 966.6 mb at 1000 UTC, suggesting a falling central pressure. Based on these data, the intensity is increased to 75 kt. It should be noted that the cloud pattern has some characteristics of a subtropical cyclone due to the cyclone's interaction with the upper-level trough. The GFS and the ECMWF continue to forecast organized central convection for the next 48 hours or so, indicating that Nicole is likely to maintain tropical cyclone characteristics despite cooler air entraining into the circulation. After that time, the cyclone should move over sea surface temperatures of 16 deg C or less that should cause the central convection to dissipate. Based on this, the intensity forecast calls for Nicole to become post-tropical by 72 hours and then fully extratropical by 96 hours. The new intensity forecast is adjusted upward for the first 12 hours based on the current intensity, and after that it is an update of the previous forecast. Overall, the forecast lies near the upper end of the intensity guidance. Nicole appears to be slowing its forward motion, and the motion estimate is now 075/11. A slow easterly motion is expected during the next 36 hours or so while the cyclone is an area of weaker flow in the mid-latitude westerlies. After that time, a large mid-latitude trough moving into eastern Canada should steer the cyclone north-northeastward with an increase in forward speed. The new forecast track is again similar to the previous track and lies near the various consensus models. Guidance from the NOAA Ocean Prediction Center was used for the forecast wind radii. Swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 15/1500Z 39.0N 50.3W 75 KT 85 MPH 12H 16/0000Z 39.3N 48.4W 75 KT 85 MPH 24H 16/1200Z 39.4N 47.0W 70 KT 80 MPH 36H 17/0000Z 39.8N 45.8W 65 KT 75 MPH 48H 17/1200Z 41.1N 44.3W 65 KT 75 MPH 72H 18/1200Z 47.5N 39.5W 65 KT 75 MPH...POST-TROPICAL 96H 19/1200Z 56.5N 35.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 20/1200Z 64.5N 32.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven

Tags: number discussion nicole forecast

 

Tropical Storm NICOLE Forecast Discussion Number 45

2016-10-15 10:34:53| National Hurricane Center (Atlantic)

Issued at 500 AM AST SAT OCT 15 2016 000 WTNT45 KNHC 150834 TCDAT5 TROPICAL STORM NICOLE DISCUSSION NUMBER 45 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 AM AST SAT OCT 15 2016 The cloud pattern has not changed much since the last advisory. Patches of deep convection keep reforming near and to the north of the center. The circulation appears to be elongated, but it is still well defined. Initial intensity is kept at 60 kt. As mentioned by my predecessor, the future structure of Nicole is difficult to forecast. Given the strong shear and cold SSTs, one should tend to foreast weakening or extratropical transition. However, both the GFS and the ECMWF simulated infrared imagery continue to forecast the development of an eye feature in a day or so. Given these model solutions, the NHC forecast keeps Nicole with tropical characteristics during the next 3 days and calls for the cyclone to become post-tropical thereafter. After an increased in forward speed last evening, Nicole has slowed down a little, and is now moving toward the east-northeast at about 15 kt. The cyclone is already embedded within a mid-latitude trough and will continue to move with the trough on the same general track with a decrease in forward speed for the next 2 to 3 days. After that time, another trough will approach Nicole and will probably kick the cyclone toward the north-northeast. The NHC forecast is in the middle of the guidance envelope and is not different from the previous one. Guidance from the NOAA Ocean Prediction Center was used for the forecast wind radii. Swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 15/0900Z 38.1N 51.6W 60 KT 70 MPH 12H 15/1800Z 38.7N 50.0W 70 KT 80 MPH 24H 16/0600Z 38.8N 48.2W 70 KT 80 MPH 36H 16/1800Z 39.0N 47.0W 70 KT 80 MPH 48H 17/0600Z 39.5N 46.0W 65 KT 75 MPH 72H 18/0600Z 44.0N 42.0W 65 KT 75 MPH 96H 19/0600Z 54.5N 36.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 20/0600Z 62.5N 32.5W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Avila

Tags: number discussion storm tropical

 
 

Hurricane NICOLE Forecast Discussion Number 43

2016-10-14 22:37:49| National Hurricane Center (Atlantic)

Issued at 500 PM AST FRI OCT 14 2016 000 WTNT45 KNHC 142037 TCDAT5 HURRICANE NICOLE DISCUSSION NUMBER 43 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 PM AST FRI OCT 14 2016 A few patches of disorganized deep convection have formed closer to the center of Nicole, although the majority of the cloud pattern is still comprised of low- to mid-level clouds and shallow convection. Based on a satellite intensity estimate of 65 kt from TAFB and earlier scatterometer data, the initial intensity is reduced to 65 kt. The initial motion is 065/17. There is no change in the track forecast philosophy from the last advisory. Nicole is embedded in the mid-latitude westerlies to the southeast of a deep-layer trough moving eastward through southeastern Canada. The dynamical models forecast the trough to bypass Nicole to the north after 24 hours, which will weaken the steering flow and reduce Nicole's forward speed during the 24-72 hour period. Subsequently, a new mid- latitude trough moving through southeastern Canada should steer Nicole northeastward at a faster forward speed. The guidance is still tightly clustered through 72 hours, and this part of the forecast track is an update of the previous track. Beyond that time, the guidance has again shifted northward, with the ECMWF in particular being faster and farther to the north than its previous run. Based on this, the latter part of the new forecast track is again nudged northward. The dynamical models remain in good agreement that Nicole should interact with the mid-latitude trough starting in 12 hours or less, with the models forecasting the winds to increase slightly and the central pressure to fall to 940-950 mb by 36 hours. As this occurs, the cyclone is most likely to develop into a post-tropical cyclone with a convection-less warm core secluded inside an encircling cooler air mass. However, an alternative scenario suggested by the GFS and ECMWF models is that organized convection re-develops inside the warm seclusion during the next 48-72 hours and allows Nicole to maintain tropical cyclone characteristics over sea surface temperatures of about 24C. The intensity forecast continues to call for the cyclone to become post-tropical, but there is lower confidence that this will happen than on the previous advisory. As done before, the post-tropical portion of Nicole's intensity and wind radii forecasts have been modified based on input from the NOAA Ocean Prediction Center. Swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 36.5N 55.7W 65 KT 75 MPH 12H 15/0600Z 37.5N 52.9W 70 KT 80 MPH 24H 15/1800Z 38.3N 50.3W 70 KT 80 MPH...POST-TROPICAL 36H 16/0600Z 38.5N 48.6W 70 KT 80 MPH...POST-TROPICAL 48H 16/1800Z 38.7N 47.6W 65 KT 75 MPH...POST-TROPICAL 72H 17/1800Z 40.5N 45.5W 65 KT 75 MPH...POST-TROPICAL 96H 18/1800Z 47.0N 40.0W 60 KT 70 MPH...POST-TROPICAL 120H 19/1800Z 53.0N 36.0W 60 KT 70 MPH...POST-TROPICAL $$ Forecaster Beven

Tags: number discussion nicole forecast

 

Hurricane NICOLE Forecast Discussion Number 42

2016-10-14 16:43:49| National Hurricane Center (Atlantic)

Issued at 1100 AM AST FRI OCT 14 2016 000 WTNT45 KNHC 141443 TCDAT5 HURRICANE NICOLE DISCUSSION NUMBER 42 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 AM AST FRI OCT 14 2016 Nicole continues to become less organized in satellite imagery, with the main convective area now well removed from the center over the northern semicircle and only shallow convection remaining near the center. The latest subjective intensity estimates from TAFB and SAB are 77 and 55 kt respectively, and the latest CIMSS SATCON estimate is 68 kt. Based on these data and the decay of the cloud pattern, the initial intensity is reduced to 70 kt. The initial motion is 060/16. Nicole is embedded in the mid-latitude westerlies to the southeast of a deep-layer trough moving eastward through southeastern Canada. The dynamical models forecast the trough to bypass Nicole to the north after 24 hours or so, which will weaken the steering flow and reduce Nicole's forward speed during the 24-72 hour period. Subsequently, a new mid- latitude trough moving through southeastern Canada should steer Nicole northeastward at a faster forward speed. The guidance is tightly clustered through 48-72 hours, and this part of the forecast track is an update of the previous track. Beyond that time, the guidance has shifted northward, and the new forecast track is also nudged northward. The dynamical models are in good agreement that Nicole should interact with the mid-latitude trough starting in the next 12-24 hours, with the models forecasting a central pressure below 950 mb in about 36 hours. As this occurs, the cyclone is expected to develop into a post-tropical cyclone with the warm core secluded inside an encircling cooler air mass. The guidance suggests that Nicole will not fully develop frontal features during the forecast period, so the new intensity forecast calls for the system to remain a powerful post-tropical cyclone through 120 hours. The post-tropical portion of Nicole's intensity and wind radii forecasts have been modified based on input from the NOAA Ocean Prediction Center. Note that swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 35.8N 58.0W 70 KT 80 MPH 12H 15/0000Z 36.9N 55.0W 70 KT 80 MPH 24H 15/1200Z 38.1N 51.7W 70 KT 80 MPH...POST-TROPICAL 36H 16/0000Z 38.5N 49.6W 70 KT 80 MPH...POST-TROPICAL 48H 16/1200Z 38.7N 48.2W 65 KT 75 MPH...POST-TROPICAL 72H 17/1200Z 40.0N 46.0W 65 KT 75 MPH...POST-TROPICAL 96H 18/1200Z 44.5N 42.0W 60 KT 70 MPH...POST-TROPICAL 120H 19/1200Z 51.0N 37.0W 55 KT 65 MPH...POST-TROPICAL $$ Forecaster Beven

Tags: number discussion nicole forecast

 

Hurricane NICOLE Forecast Discussion Number 41

2016-10-14 10:34:52| National Hurricane Center (Atlantic)

Issued at 500 AM AST FRI OCT 14 2016 000 WTNT45 KNHC 140834 TCDAT5 HURRICANE NICOLE DISCUSSION NUMBER 41 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 AM AST FRI OCT 14 2016 The cloud pattern has degraded significantly during the past few hours. The low-level center is difficult to locate, but it appears to be separated and well to the southwest of an area of weakening convection due to southwesterly shear. This is supported by an ASCAT pass a few hours ago, which showed the vigorous surface circulation to the southwest of the limited thunderstorm activity. Based on Dvorak T-numbers which are weakening as fast as the rules allow, and data from ASCAT, the initial intensity is lowered to 75 kt. Although Nicole should continue to weaken in the next 12 hours due to the strong shear and low SSTs, global models indicate that the system should remain a powerful cyclone for a few days. The new NHC intensity forecast is lower than the previous one, following the trend of the latest hurricane intensity guidance. It is expected that Nicole becomes a post-tropical cyclone is about 24 hours or so, but it is uncertain when Nicole will complete the extratropical transition. The best estimate of the initial motion is be 065/18. Nicole is well embedded within the mid-latitude flow, and this pattern should steer Nicole generally east-northeastward for the next day or so. Some decrease in forward speed is anticipated beyond 36 hours while Nicole interacts with passing shortwaves. The NHC forecast is in the middle of the tight guidance envelope primarily during the next 2 to 3 days. The post-tropical portion of Nicole's track, intensity, and wind radii forecast has been coordinated with the NOAA Ocean Prediction Center. Note that swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 35.4N 59.2W 75 KT 85 MPH 12H 14/1800Z 36.5N 56.2W 70 KT 80 MPH 24H 15/0600Z 37.7N 52.5W 70 KT 80 MPH...POST-TROPICAL 36H 15/1800Z 38.5N 50.0W 65 KT 75 MPH...POST-TROPICAL 48H 16/0600Z 39.0N 48.0W 65 KT 75 MPH...POST-TROPICAL 72H 17/0600Z 39.0N 46.0W 60 KT 70 MPH...POST-TROPICAL 96H 18/0600Z 42.5N 42.5W 60 KT 70 MPH...POST-TROPICAL 120H 19/0600Z 48.0N 38.0W 55 KT 65 MPH...POST-TROPICAL $$ Forecaster Avila

Tags: number discussion nicole forecast

 

Sites : [779] [780] [781] [782] [783] [784] [785] [786] [787] [788] [789] [790] [791] [792] [793] [794] [795] [796] [797] [798] next »