Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm KARINA Forecast Discussion Number 50

2014-08-25 10:33:09| National Hurricane Center (East Pacific)

Issued at 200 AM PDT MON AUG 25 2014 000 WTPZ41 KNHC 250832 TCDEP1 TROPICAL STORM KARINA DISCUSSION NUMBER 50 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014 200 AM PDT MON AUG 25 2014 A small area of convection has developed just to the southwest of the center, probably a product of the diurnal maximum cycle. However, the deep convection that was earlier displaced well to the west-northwest has dissipated. Dvorak satellite intensity estimates continue to decrease and a blend of the T- and CI-numbers suggest an initial intensity of 35 kt. Moderate east-southeasterly vertical shear produced by Marie's large upper-level anticyclone to the east, is expected to further weaken Karina. Consequently, the cyclone should continue to spin down and become a post-tropical remnant low within the next 24 hours. The intensity forecast corresponds with the large-scale models and the SHIPS/LGEM statistical-dynamical guidance with dissipation or absorption forecast in 2-3 days. Shortwave-infrared satellite images show that the best estimate of initial motion is 110/9, and this general motion around the western to southwestern periphery of Marie is expected through the entire period before dissipation. The official NHC forecast track is an update of the previous package and is based on a compromise of the GFEX and TVCE multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 17.2N 128.4W 35 KT 40 MPH 12H 25/1800Z 17.1N 127.8W 30 KT 35 MPH 24H 26/0600Z 16.7N 127.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 26/1800Z 16.0N 125.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 27/0600Z 15.6N 124.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 28/0600Z...DISSIPATED $$ Forecaster Roberts

Tags: number discussion storm tropical

 

Hurricane MARIE Forecast Discussion Number 13

2014-08-25 04:35:31| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SUN AUG 24 2014 000 WTPZ43 KNHC 250235 TCDEP3 HURRICANE MARIE DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132014 800 PM PDT SUN AUG 24 2014 Marie has likely peaked in intensity. Deep convection in the hurricane's central dense overcast has warmed over the eastern semicircle and become less symmetric. The eye has also become cloud-filled in last-light visible satellite imagery, and has cooled some in infrared imagery. A 2332 UTC SSMI/S pass suggested that an eyewall replacement is underway, with a secondary eyewall noted at around 60 n mi radius at that time. The initial intensity is lowered to 130 kt for this advisory, based on a blend of Dvorak intensity estimates from 0000 UTC. The ongoing eyewall replacement could result in fluctuations of intensity in the short term for which there is little to no predictability. Regardless, Marie is expected to remain a major hurricane for the next day or two as it continues to move over relatively warm waters and through a moist, low-shear environment. Even though the shear should remain quite low after that time, Marie will be traversing considerably cooler waters and ingesting drier and more stable air. These factors should result in a rapid spin-down of the cyclone late in the forecast period, and remnant low status is now indicated on day 4. Considering the current reduction in intensity, the NHC wind speed forecast is lower than the previous one and lies between the multi-model consensus and the SHIPS model output. After wobbling a bit toward the west or west-southwest earlier today, the eye of Marie has resumed a west-northwestward motion of 290/10. There have been no significant changes regarding the track forecast philosophy. Marie is expected to be steered on a west- northwestward to northwestward course during the next few days around the southwestern periphery of a mid-tropospheric ridge extending into the subtropical eastern Pacific. After becoming a remnant low late in the forecast period, the cyclone is expected to turn north-northwestward and slow down. The latest track forecast is little to the right of the previous one, mostly as a result of Marie's discontinuous jog to the right earlier today. Although Marie is expected to remain well off the coast of Mexico, very large swells will affect southwestern Mexico through tomorrow and much of the Pacific coast of the Baja California peninsula during the next few days. Southerly swells will also reach the coast of southern California by Tuesday, producing life-threatening surf and rip currents, as well as minor coastal flooding. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 16.6N 112.8W 130 KT 150 MPH 12H 25/1200Z 17.5N 114.2W 125 KT 145 MPH 24H 26/0000Z 18.9N 116.1W 120 KT 140 MPH 36H 26/1200Z 20.2N 118.1W 105 KT 120 MPH 48H 27/0000Z 21.4N 120.3W 90 KT 105 MPH 72H 28/0000Z 23.9N 125.4W 60 KT 70 MPH 96H 29/0000Z 27.0N 129.7W 35 KT 40 MPH...POST-TROP/REMNT LOW 120H 30/0000Z 30.0N 131.6W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Kimberlain

Tags: number discussion marie forecast

 
 

Tropical Storm CRISTOBAL Forecast Discussion Number 6

2014-08-25 04:33:32| National Hurricane Center (Atlantic)

Issued at 1100 PM EDT SUN AUG 24 2014 000 WTNT44 KNHC 250233 TCDAT4 TROPICAL STORM CRISTOBAL DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL042014 1100 PM EDT SUN AUG 24 2014 Cristobal is not a well-organized tropical cyclone at this time. The deep convection has a ragged appearance, with little or no banding features evident, and this convection is mainly occurring well to the south of the estimated center location. After adjusting for rain inflation, SFMR winds from aircraft observations a few hours ago, indicated that the intensity is no more than 40 kt. Also, the fixes from the Air Force and NOAA planes, which were flying at altitudes of about 1000 and 8000 feet respectively, indicated a southward tilt of the center with height. This is consistent with some northerly shear over the storm as suggested by water vapor imagery. Given the currently disorganized state of Cristobal, not much intensification seems likely for the next 12 hours or so. Afterwards, the global models are predicting a little more favorable upper-tropospheric environment with increasingly diffluent flow over the tropical cyclone. The official intensity forecast is basically a blend of the SHIPS and LGEM guidance, and only a little above the model consensus. By 120 hours, the global models depict the cyclone embedded within a baroclinic zone, so extratropical transition should have occurred by that time. The motion has been rather erratic over the past several hours, but my best estimate is about 350/4 kt. Cristobal is currently situated near a col between 2 anticyclones in the mid-level flow, one over the United States, and one over the central subtropical Atlantic. The dynamical models indicate that, within a couple of days, the steering of the tropical cyclone will become dominated by flow on the northwest side of the Atlantic anticyclone and on the southern side of a mid-latitude trough. Therefore, the motion is expected to gradually bend to the right with some acceleration over the next several days. The official track forecast is somewhat faster than the previous one after 48 hours, but not as fast as the latest dynamical model consensus. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 24.8N 73.1W 40 KT 45 MPH 12H 25/1200Z 25.4N 73.1W 40 KT 45 MPH 24H 26/0000Z 26.4N 72.8W 45 KT 50 MPH 36H 26/1200Z 27.8N 72.4W 50 KT 60 MPH 48H 27/0000Z 29.8N 71.8W 55 KT 65 MPH 72H 28/0000Z 33.5N 69.0W 65 KT 75 MPH 96H 29/0000Z 37.5N 62.0W 70 KT 80 MPH 120H 30/0000Z 44.0N 50.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch

Tags: number discussion storm tropical

 

Tropical Storm KARINA Forecast Discussion Number 49

2014-08-25 04:33:32| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SUN AUG 24 2014 000 WTPZ41 KNHC 250233 TCDEP1 TROPICAL STORM KARINA DISCUSSION NUMBER 49 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014 800 PM PDT SUN AUG 24 2014 Karina's cloud pattern continues to rapidly degrade, with the remaining deep convection located about 90 miles west-northwest of the exposed center of circulation. The initial intensity is lowered to 40 kt based on a blend of the subjective and objective satellite intensity estimates and an earlier UW-CIMSS AMSU-A intensity estimation. Moderate southeasterly vertical shear, as a result of Marie's large upper-level anticyclone, should result in continued weakening to a depression in 12 hours. The cyclone is forecast to become a post-tropical remnant low in 24 hours and ultimately dissipate or become absorbed by major hurricane Marie in 3 days or less, as indicated by the SHIPS and LGEM guidance. The initial motion is estimated to be 095/8, within the diminishing low- to mid westerly flow produced by post-tropical cyclone Lowell to the north. Karina should turn toward the east-southeast around the 24 hour period as the cyclone is steered around the southwest periphery of approaching Hurricane Marie. The official NHC forecast track is nudged southward beyond the 24 hour period, following the trend in the GFEX and the TVCE guidance. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 17.5N 129.3W 40 KT 45 MPH 12H 25/1200Z 17.4N 128.2W 30 KT 35 MPH 24H 26/0000Z 17.2N 127.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 26/1200Z 16.5N 126.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 27/0000Z 15.9N 125.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 28/0000Z...DISSIPATED $$ Forecaster Roberts

Tags: number discussion storm tropical

 

Tropical Storm KARINA Forecast Discussion Number 48

2014-08-24 22:52:29| National Hurricane Center (East Pacific)

Issued at 200 PM PDT SUN AUG 24 2014 000 WTPZ41 KNHC 242052 TCDEP1 TROPICAL STORM KARINA DISCUSSION NUMBER 48 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014 200 PM PDT SUN AUG 24 2014 Strong vertical shear being induced by an upper-level high centered northeast of Karina continues to weaken the tropical storm. Deep convection continues in association with the cyclone, though it is occurring only over the western semi-circle and it has decreased in areal extent. In fact, in the last few visible images, the low-level center is popping out from underneath the thinning cirrus overcast. A "bulls-eye" ASCAT-B hit at 1802Z indicated a peak surface wind between 40 and 45 kt, so the initial intensity is set at 45 kt. Strong vertical shear should continue to afflict Karina, as the outflow from major hurricane Marie will soon begin to reach the tropical storm. The combination of high vertical shear, marginally warm SSTs, and fairly dry air should lead to a gradual weakening of the tropical cyclone. Karina should become a remnant low in about two days. However, the strong shear and mediocre thermodynamics may lead to remnant low status earlier. The intensity forecast is based upon a blend of the SHIPS and LGEM statistical models, and is a bit lower than that from the previous advisory due to the weakened initial condition of the cyclone. The aforementioned ASCAT-B pass confirmed the rather small tropical-storm-force wind radii of Karina. A gradual reduction in the cyclone's size is anticipated as the cyclone winds down. Karina is being steered eastward at 8 kt around the large circulation of post-tropical cyclone Lowell to its north-northeast. The center of the system is now well known, due to the ASCAT-B pass and the visible appearance of the low-level center. The steering influence of Lowell will diminish by tomorrow as the distance between the systems increases, and Karina should respond by slowing down and turning gradually to the east-southeast. In about 36 hours, Karina's track will mainly be influenced by the approaching large and powerful Marie. Karina or its remnant low should be accelerated toward the east until it becomes absorbed within Marie between two and three days. The forecast track is based upon the TVCN multi-model track consensus technique and is slightly faster than that issued in the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 24/2100Z 17.8N 130.4W 45 KT 50 MPH 12H 25/0600Z 17.7N 129.1W 35 KT 40 MPH 24H 25/1800Z 17.5N 127.9W 30 KT 35 MPH 36H 26/0600Z 17.2N 127.2W 25 KT 30 MPH 48H 26/1800Z 16.5N 126.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 27/1800Z...DISSIPATED $$ Forecaster Landsea

Tags: number discussion storm tropical

 

Sites : [1097] [1098] [1099] [1100] [1101] [1102] [1103] [1104] [1105] [1106] [1107] [1108] [1109] [1110] [1111] [1112] [1113] [1114] [1115] [1116] next »