je.st
news
Tag: discussion
Tropical Depression Ana Forecast Discussion Number 7
2021-05-23 22:43:41| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sun May 23 2021 000 WTNT41 KNHC 232043 TCDAT1 Tropical Depression Ana Discussion Number 7 NWS National Hurricane Center Miami FL AL012021 500 PM AST Sun May 23 2021 Other than brief puff of convection late this morning, tiny Ana has been devoid of organized deep convection for several hours. ASCAT overpass data from this morning indicated that the peak winds had deceased to 35 kt. Due to the lack of convection since that time, it is reasonable to assume that the vortex has spun down a bit, and therefore the initial advisory intensity has been lowered to 30 kt. Ana is over cool waters and surrounded by very dry air in the mid-troposphere. The brief convection that did occur today was quickly stripped away, indicating that the anticipated increase in shear has begun. Satellite imagery suggests that the circulation of Ana is approaching a strong subtropical upper-level jet just to its east, which is expected to produce even stronger shear over the cyclone. These conditions should prevent further convection, if any, from surviving, and the cyclone is expected to degenerate into a remnant low by tonight. What is left of Ana's low-level circulation should open into a trough on Monday as it is absorbed by a large baroclinic zone approaching from the northwest. The depression continues to accelerate northeastward, and the forward motion is now northeastward at 15 kt. An accelerating northwestward motion is anticipated until dissipation as Ana gets caught up in increasing deep-layer southwesterly flow. FORECAST POSITIONS AND MAX WINDS INIT 23/2100Z 37.5N 57.7W 30 KT 35 MPH 12H 24/0600Z 39.4N 53.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 24/1800Z...DISSIPATED $$ Forecaster Latto
Tags: number
discussion
ana
tropical
Tropical Storm Ana Forecast Discussion Number 6
2021-05-23 16:42:33| National Hurricane Center (Atlantic)
Issued at 1100 AM AST Sun May 23 2021 000 WTNT41 KNHC 231442 TCDAT1 Tropical Storm Ana Discussion Number 6 NWS National Hurricane Center Miami FL AL012021 1100 AM AST Sun May 23 2021 Ana is barely holding on as a tropical cyclone this morning, as the core of the system has become devoid of organized deep convection. A recent ASCAT overpass showed that wind field is slowly weakening, with peak winds of 35 kt located just to the southeast of the center. Based on this data, the initial advisory intensity has also been decreased to 35 kt. The cyclone is currently located over cool SSTs of about 20 degrees C and surrounded by very dry air in the mid-troposphere. The environmental conditions will only become more hostile through tonight, as Ana gets caught between a digging mid- to upper-level trough to its northwest and a strong subtropical upper-level jet to its southeast. These features will impart increasing southwesterly shear over the system by later today, and any convection that tries to regenerate should be stripped away. Whatever is left of Ana's low-level circulation should then open into a trough on Monday as it becomes absorbed by a large approaching baroclinic zone associated with the upper-trough. The storm is now moving northeastward at 12 kt, and an accelerating forward speed is anticipated until dissipation as Ana gets caught up in increasing deep-layered southwesterly flow. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 36.6N 59.4W 35 KT 40 MPH 12H 24/0000Z 38.0N 56.7W 35 KT 40 MPH 24H 24/1200Z 41.7N 50.3W 35 KT 40 MPH...POST-TROPICAL 36H 25/0000Z...DISSIPATED $$ Forecaster Latto
Tags: number
discussion
ana
storm
Tropical Storm Ana Forecast Discussion Number 5
2021-05-23 10:30:25| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sun May 23 2021 381 WTNT41 KNHC 230830 TCDAT1 Tropical Storm Ana Discussion Number 5 NWS National Hurricane Center Miami FL AL012021 500 AM AST Sun May 23 2021 Satellite images indicate that Ana has contracted significantly since yesterday and now has a compact area of moderate convection around the center. Given the tight low-level circulation, small radius of maximum wind, and compact central convection, Ana is now estimated to have transitioned from a subtropical storm to a tropical storm. The initial intensity remains 40 kt for this advisory based on the earlier ASCAT data, which indicated that the tropical-storm-force winds were confined to the south side of the circulation. Ana is not expected to be around much longer. The storm is headed for an environment of lower SSTs, drier air, and increasing wind shear. All of these factors should cause the compact cyclone to lose strength and ultimately open into a trough in 24 to 36 hours. In fact, some of the models suggest that the storm could dissipate even sooner than that. The remnants of Ana will likely be absorbed by a cold front on Monday. The storm continues to increase its forward speed, and the initial motion is now estimated to be 045/10 kt. A faster motion to the northeast is expected until the cyclone dissipates. FORECAST POSITIONS AND MAX WINDS INIT 23/0900Z 35.7N 60.5W 40 KT 45 MPH 12H 23/1800Z 36.7N 58.7W 40 KT 45 MPH 24H 24/0600Z 39.4N 53.9W 35 KT 40 MPH 36H 24/1800Z...DISSIPATED $$ Forecaster Cangialosi
Tags: number
discussion
ana
storm
Subtropical Storm Ana Forecast Discussion Number 4
2021-05-23 04:51:20| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Sat May 22 2021 000 WTNT41 KNHC 230251 TCDAT1 Subtropical Storm Ana Discussion Number 4 NWS National Hurricane Center Miami FL AL012021 1100 PM AST Sat May 22 2021 Ana continues to produce a small, but concentrated area of moderate convection near its center. The storm remains embedded in a large-scale upper-level trough axis, and convection near the center has not been deep or expansive enough to result in significant upper-level anticyclonic outflow. This structure suggests that the system remains subtropical. However, scatterometer imagery also indicates that Ana's radius of maximum winds is very small. A recent METOP-B ASCAT pass at 0054 UTC had a peak wind retrieval of 36 kt just southeast of Ana's center. Due to the small size of Ana's wind field and allowing for some undersampling of this instrument, the initial intensity was bumped up to 40 kt for this advisory. Ana has begun to accelerate to the northeast and its initial motion is now 050/8 kt. A continued northeastward motion at an increasing forward speed is expected as deep-layer southwesterly steering flow increases between a deepening mid-latitude trough to the northwest and a subtropical high to the southeast. The upper-level trough axis that Ana remains centered in has kept the tiny cyclone in a small region of light upper-level flow, allowing convection to persist near the center. However, as Ana accelerates northeastward, this trough axis will gradually decay and upper-level northerly flow is expected to increase after 12 h. The resulting increase in northeasterly shear will import dry mid-latitude air and likely strip away the remaining convection associated with Ana by tomorrow night. The latest intensity forecast calls for slow weakening after 12 h with dissipation by 48 h, though it is possible that Ana could dissipate earlier than currently forecast. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 35.0N 61.4W 40 KT 45 MPH 12H 23/1200Z 35.8N 60.0W 40 KT 45 MPH 24H 24/0000Z 37.5N 56.3W 35 KT 40 MPH 36H 24/1200Z 41.1N 50.5W 35 KT 40 MPH 48H 25/0000Z...DISSIPATED $$ Forecaster Papin/Brown
Tags: number
discussion
ana
storm
Subtropical Storm Ana Forecast Discussion Number 3
2021-05-22 22:39:50| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sat May 22 2021 000 WTNT41 KNHC 222039 TCDAT1 Subtropical Storm Ana Discussion Number 3 NWS National Hurricane Center Miami FL AL012021 500 PM AST Sat May 22 2021 While Ana continues to produce convection near the center, the amount of convection has decreased during the past several hours. In addition, earlier scatterometer data and recent satellite intensity estimates from TAFB suggest the cyclone has weakened. The initial intensity is reduced to 35 kt. A combination of increasing shear, dry air, and decreasing SSTs should cause Ana to gradually weaken, and most of the global models now show the system decaying to a trough in about 36 h. The new intensity forecast calls for a slow weakening with dissipation just after that time, and it is possible that Ana could dissipate earlier than currently forecast. Ana made a small counter-clockwise loop during the past few hours, and the initial motion is now 050/4. A continued northeastward motion at an increasing forward speed, due to the southwesterly flow associated with a developing mid-latitude cyclone to the north and northwest, is expected until the cyclone dissipates. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 34.5N 62.4W 35 KT 40 MPH 12H 23/0600Z 34.9N 61.6W 35 KT 40 MPH 24H 23/1800Z 36.2N 59.0W 35 KT 40 MPH 36H 24/0600Z 38.3N 54.3W 30 KT 35 MPH 48H 24/1800Z...DISSIPATED $$ Forecaster Beven
Tags: number
discussion
ana
storm
Sites : [115] [116] [117] [118] [119] [120] [121] [122] [123] [124] [125] [126] [127] [128] [129] [130] [131] [132] [133] [134] next »