je.st
news
Tag: discussion
Hurricane Eta Forecast Discussion Number 9
2020-11-02 21:52:52| National Hurricane Center (Atlantic)
Issued at 400 PM EST Mon Nov 02 2020 000 WTNT44 KNHC 022052 TCDAT4 Hurricane Eta Discussion Number 9 NWS National Hurricane Center Miami FL AL292020 400 PM EST Mon Nov 02 2020 Eta is an extremely impressive hurricane in both visible and infrared satellite imagery. The hurricane has a very small eye that is located within a symmetric Central Dense Overcast with cloud top temperatures below -80C. Although objective Dvorak estimates are lower due to the technique's difficulty in analyzing the correct scene type because of the pinhole eye, data T-numbers from both TAFB and SAB analysts reached 6.0 on the Dvorak scale at 18Z, which equates to a wind speed of 115 kt. A recent UW/CIMSS SATCON intensity estimate also supports category 4 intensity. As mentioned in previous advisories over the past 24 hours, the environment ahead of Eta is forecast to remain quite favorable with low vertical wind shear and warm sea surface temperatures. These conditions should allow for additional strengthening, however a difficult-to-predict eyewall replacement cycle could begin at any time which could cause Eta's intensity to begin to level off. Since there are no signs of an eyewall replacement yet, the updated NHC intensity forecast calls for continued rapid strengthening for another 6 to 12 hours, and it is again at the upper-end of the guidance envelope. After landfall, Eta should quickly weaken while it moves over the mountainous terrain of Central America. The hurricane has turned west-southwestward with an initial motion estimate of 255/8 kt. The track forecast reasoning is unchanged from this morning. A mid-level ridge over the south-central United States should steer Eta west-southwestward toward the coast of Nicaragua with the hurricane making landfall tonight or early Tuesday. After landfall, Eta is forecast to turn westward, and then west-northwestward while it moves over Central America through midweek. Eta's surface circulation may not survive its trek over the mountainous terrain of Central America, but most of the global models continue to depict a cyclone over the northwestern Caribbean Sea by later this week and into the weekend which appears to develop from at least a part of Eta's remnants. Therefore, the NHC track forecast continues to show the system emerging over the northwestern Caribbean late in the period, however the long range portion of the forecast remains quite uncertain. Since Eta is likely to be a very slow-moving system after it makes landfall in Central America, torrential rains and flooding will be a major threat. Key Messages: 1. Catastrophic wind damage is expected where Eta's eyewall moves onshore along the northeastern coast of Nicaragua tonight or early Tuesday. Tropical storm force winds are beginning to reach the coast within the Hurricane Warning area in Nicaragua, and residents there should have completed their preparations. A Tropical Storm Warning is also in effect for the northeastern coast of Honduras. 2. A catastrophic and life-threatening storm surge, along with destructive waves, are expected along portions of the northeastern coast of Nicaragua near and to the north of where the center makes landfall. Water levels could reach as high as 12 to 18 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should now be complete. 3. Through Friday evening, heavy rainfall from Eta will likely lead to catastrophic, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, southeast Mexico, El Salvador, southern Haiti, and the Cayman Islands. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 14.5N 82.3W 115 KT 130 MPH 12H 03/0600Z 14.1N 83.1W 130 KT 150 MPH 24H 03/1800Z 14.0N 83.7W 90 KT 105 MPH...INLAND 36H 04/0600Z 14.0N 84.5W 45 KT 50 MPH...INLAND 48H 04/1800Z 14.2N 85.5W 30 KT 35 MPH...INLAND 60H 05/0600Z 14.7N 86.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 05/1800Z 15.5N 88.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/1800Z 16.7N 88.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 07/1800Z 18.0N 86.0W 30 KT 35 MPH...TROPICAL DEPRESSION $$ Forecaster Brown/Berg
Tags: number
discussion
forecast
hurricane
Hurricane Eta Forecast Discussion Number 8
2020-11-02 15:56:18| National Hurricane Center (Atlantic)
Issued at 1000 AM EST Mon Nov 02 2020 000 WTNT44 KNHC 021456 TCDAT4 Hurricane Eta Discussion Number 8 NWS National Hurricane Center Miami FL AL292020 1000 AM EST Mon Nov 02 2020 Eta has become an impressive November hurricane as it continues to undergo rapid strengthening. Visible and infrared satellite imagery reveals a very symmetric Central Dense Overcast with cloud top temperatures below -80C. A warm spot has recently become apparent in infrared imagery while a small eye has been seen microwave imagery and recent visible satellite data. An Air Force Reserve Hurricane Hunter aircraft that completed two center penetrations into Eta this morning reported a minimum pressure of around 972 mb, and flight- level and SFMR winds that supported an intensity of around 85 kt. The plane also reported a 12 n-mi-wide eye on its second pass through the center. With the continued improvement in organization since the plane departed, the initial intensity has been increased to 95 kt, as the eye has become more apparent. Low vertical wind shear and warm sea surface temperatures ahead of Eta are expected to allow for continued rapid strengthening during the next 12 to 24 hours. The updated NHC intensity forecast is above all of the intensity aids and now calls for Eta to become a category 4 hurricane before it nears the coast of Nicaragua. After landfall, Eta should quickly weaken while it moves over the mountainous terrain of Central America. The hurricane is moving westward or 265 degrees at 8 kt, a little slower than before. A mid-level ridge building over the south-central United States is expected to cause Eta to turn west-southwestward later today, and this motion should bring the center of the hurricane near the coast of Nicaragua within the hurricane warning area Tuesday morning. Eta is forecast to then turn westward, moving farther inland over Central America. The track guidance is tightly clustered during the first 48 hours or so, but the models generally show a slower forward motion than before, and the NHC track forecast has been adjusted accordingly. Although Eta's low-level center may not survive after being inland over Central America for so long, most of the global models depict a cyclone over the northwestern Caribbean Sea later this week and into the weekend which appears to develop from at least a part of Eta's remnants, and the new NHC track forecast shows the system emerging over the northwest Caribbean Sea after 96 h. However, the uncertainty in the long-range portion of the forecast remains quite high. Since Eta likely to be a very slow-moving system after it makes landfall in Central America, torrential rains and flooding will be a major threat from Eta. Key Messages: 1. Eta is forecast to strengthen to a major hurricane very soon, and additional strengthening is likely before it reaches the northeastern coast of Nicaragua on Tuesday. Catastrophic wind damage is expected where Etas eyewall moves onshore, and preparations should be rushed to completion within the Hurricane Warning area. 2. Through Friday evening, heavy rainfall from Eta will likely lead to catastrophic, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, southeast Mexico, El Salvador, southern Haiti, and the Cayman Islands. 3. A potentially catastrophic and life-threatening storm surge, along with battering waves, is expected along portions of the northeastern coast of Nicaragua near and to the north of where the center makes landfall. Water levels could reach as high as 12 to 18 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should be rushed to completion. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 14.8N 81.5W 95 KT 110 MPH 12H 03/0000Z 14.4N 82.4W 115 KT 130 MPH 24H 03/1200Z 14.0N 83.1W 120 KT 140 MPH 36H 04/0000Z 13.9N 83.6W 90 KT 105 MPH...INLAND 48H 04/1200Z 13.9N 84.5W 45 KT 50 MPH...INLAND 60H 05/0000Z 14.2N 85.7W 30 KT 35 MPH...INLAND 72H 05/1200Z 14.6N 87.0W 25 KT 30 MPH...INLAND 96H 06/1200Z 15.8N 87.7W 25 KT 30 MPH...INLAND 120H 07/1200Z 17.5N 86.5W 30 KT 35 MPH...OVER WATER $$ Forecaster Brown
Tags: number
discussion
forecast
hurricane
Hurricane Eta Forecast Discussion Number 7
2020-11-02 09:50:40| National Hurricane Center (Atlantic)
Issued at 400 AM EST Mon Nov 02 2020 000 WTNT44 KNHC 020850 TCDAT4 Hurricane Eta Discussion Number 7 NWS National Hurricane Center Miami FL AL292020 400 AM EST Mon Nov 02 2020 Eta has continued to become better organized, with a distinct Central Dense Overcast surrounded by many banding features. A low-level eye feature was seen in GPM Microwave Imager data, and Dvorak intensity estimates are at 65 kt from both TAFB and SAB. Based on this, the system is upgraded to a hurricane. Continued strengthening is likely, given the very high oceanic heat content and only moderate easterly vertical shear. The official forecast calls for rapid intensification, in line with the SHIPS Rapid Intensification Index which shows a 48 percent chance of a 30 kt increase over 24 hours. Although not explicitly shown, Eta could very well be a 100-kt major hurricane when it crosses the coastline. After landfall, weakening will occur while the cyclone interacts with the very mountainous terrain of Central America. Even though official forecast points are shown through day 5, it is doubtful that the surface circulation could survive after being inland that long over the mountains of Nicaragua and Honduras. Although some of the global models are showing a cyclone over the northwestern Caribbean later this week and into the weekend, it is not certain whether this is Eta, or a new system that could form in that area. The hurricane is moving westward, or at about 265/10 kt. The track forecast philosophy remains basically unchanged. For the next few days, Eta should move westward or west-southwestward to the south and southeast of a mid-tropospheric high pressure system centered near the western Gulf of Mexico coast. The official track forecast is nearly identical to the previous one, and also very similar to the various model consensus predictions. Since this is likely to be a very slow-moving system after it makes landfall in Central America, torrential rains and flooding will be a major threat from Eta. Key Messages: 1. Eta is forecast to continue to strengthen, and it could become a major hurricane before it reaches the northeastern coast of Nicaragua early Tuesday, where a Hurricane Warning is in effect. A Tropical Storm Warning is in effect for a portion of the northeastern coast of Honduras. 2. Through Friday evening, heavy rainfall from Eta will lead to catastrophic, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, southeast Mexico, El Salvador, southern Haiti, and the Cayman Islands. 3. A life-threatening storm surge, along with damaging waves, is expected along portions of the northeastern coast of Nicaragua near and to the north of where the center makes landfall. Water levels could reach as high as 10 to 15 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should be rushed to completion. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 14.8N 80.9W 65 KT 75 MPH 12H 02/1800Z 14.6N 82.0W 80 KT 90 MPH 24H 03/0600Z 14.2N 83.0W 95 KT 110 MPH 36H 03/1800Z 14.0N 83.7W 85 KT 100 MPH...INLAND 48H 04/0600Z 13.9N 84.5W 45 KT 50 MPH...INLAND 60H 04/1800Z 14.0N 85.7W 30 KT 35 MPH...INLAND 72H 05/0600Z 14.4N 86.9W 25 KT 30 MPH...INLAND 96H 06/0600Z 15.2N 88.6W 25 KT 30 MPH...INLAND 120H 07/0600Z 15.8N 88.8W 20 KT 25 MPH...INLAND $$ Forecaster Pasch
Tags: number
discussion
forecast
hurricane
Tropical Storm Eta Forecast Discussion Number 6
2020-11-02 03:52:11| National Hurricane Center (Atlantic)
Issued at 1000 PM EST Sun Nov 01 2020 000 WTNT44 KNHC 020252 TCDAT4 Tropical Storm Eta Discussion Number 6 NWS National Hurricane Center Miami FL AL292020 1000 PM EST Sun Nov 01 2020 Eta has continued to become better organized this evening, including the development of an impressive Central Dense Overcast (CDO) with cloud tops colder than -90C near the center, improved banding features in the northwestern semicircle, and the formation of a pinhole mid-level eye noted in 01/2322Z 91GHz SSMI/S microwave imagery. Water vapor imagery also indicates that the upper-level outflow pattern has continued to expand, with dual outflow channels having formed to the northeast and the southwest. Satellite intensity estimates are a consensus T3.5/55 kt from TAFB, SAB, and UW-CIMSS ADT. However, the initial intensity is set a little higher at 60 kt based on the pinhole eye feature...and this intensity estimate is probably conservative. An Air Force Reserve hurricane hunter aircraft is scheduled to investigate Eta in a few hours. Eta has slowed down but is still moving westward, or 270/11 kt. An expansive subtropical ridge that extends from the southwestern Atlantic across the Bahamas, Florida, and into the Gulf of Mexico is expected to keep Eta moving in a general westward direction through Monday morning. By Monday afternoon and evening, the portion of the ridge over the Gulf is forecast to build southward and eastward in the wake of an exiting mid-latitude trough currently moving across the eastern and southeastern United States. The increased ridging will act to force Eta west-southwestward and eventually southwestward over the next 36 hours, resulting in landfall along the northeastern coast of Nicaragua. After moving inland, steering currents are forecast to weaken significantly on days 3-5 as another trough digs southeastward out of the U.S. Plains and into the Gulf of Mexico, eroding the Gulf ridge and causing Eta to drift slowly westward across Central America. Compared to the preponderance of the the model guidance, the HWRF solution of Eta remaining just offshore over the northwestern Caribbean Sea is considered to be an outlier. The new NHC track forecast is very similar to the previous advisory track, and lies close to the simple-consensus models TVCA and GFEX, which are a little to the right of the corrected-consensus model, HCCA. Based on the new NHC track forecast, no changes are required to the existing tropical cyclone warnings and watches in effect. Eta has rapidly intensified 20 kt during the past 12 h. Given the much improved inner-core structure as noted in the SSMI/S imagery, combined with sea-surface temperatures in excess of 29 deg C, mid-level humidity values greater than 80 percent, and the already impressive outflow pattern, Eta should continue to rapidly strengthen until landfall occurs. The main question is: how much strengthening will take place? Some of the more reliable intensity guidance brings the cyclone up to 105-110 kt in 36 hours, with the HWRF model bringing Eta to near category-4 strength. The new NHC intensity forecast shows Eta as a major hurricane in 36 hours when it is expected to be located just inland over northeastern Nicaragua, but a stronger intensity is highly probable just before landfall occurs. Rapid weakening is forecast thereafter while the cyclone moves over the rugged, mountainous terrain of Nicaragua and Honduras, with Eta possibly devolving into a large, quasi-stationary Central American Gyre (CAG). Key Messages: 1. Eta is forecast to strengthen into a hurricane by early Monday morning. Additional strengthening is forecast thereafter, and Eta is expected to be a major hurricane before it reaches the northeastern coast of Nicaragua Monday night or early Tuesday, where a Hurricane Warning is in effect. A Tropical Storm Warning is in effect for a portion of the northeastern coast of Honduras. 2. Through Friday evening, heavy rainfall from Eta will lead to catastrophic, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, southeast Mexico, El Salvador, southern Haiti, and the Cayman Islands. 3. A life-threatening storm surge, along with damaging waves, is expected along portions of the northeastern coast of Nicaragua near and to the north of where the center makes landfall. Water levels could reach as high as 10 to 15 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should be rushed to completion. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 14.9N 80.0W 60 KT 70 MPH 12H 02/1200Z 14.8N 81.3W 75 KT 85 MPH 24H 03/0000Z 14.5N 82.6W 90 KT 105 MPH 36H 03/1200Z 14.1N 83.4W 100 KT 115 MPH...INLAND 48H 04/0000Z 14.0N 84.2W 60 KT 70 MPH...INLAND 60H 04/1200Z 14.0N 85.3W 45 KT 50 MPH...INLAND 72H 05/0000Z 14.2N 86.5W 30 KT 35 MPH...INLAND 96H 06/0000Z 14.9N 88.4W 25 KT 30 MPH...INLAND 120H 07/0000Z 15.7N 88.5W 25 KT 30 MPH...INLAND $$ Forecaster Stewart
Tags: number
discussion
storm
tropical
Tropical Storm Eta Forecast Discussion Number 5
2020-11-01 21:54:05| National Hurricane Center (Atlantic)
Issued at 400 PM EST Sun Nov 01 2020 000 WTNT44 KNHC 012053 TCDAT4 Tropical Storm Eta Discussion Number 5 NWS National Hurricane Center Miami FL AL292020 400 PM EST Sun Nov 01 2020 Eta has continued to quickly become better organized today with an increase in banding and the development of a central dense overcast feature. A NOAA Hurricane Hunter aircraft that has provided a couple of center fixes this afternoon has found a strengthening tropical storm. The aircraft has reported a minimum pressure of 992 mb and a 30 n-mi-wide eye that is open to the southwest. A blend of the SFMR and flight-level wind data support an initial wind speed of 55 kt for this advisory. Given the much improved inner-core structure as reported by the reconnaissance aircraft and the favorable environmental conditions of low vertical wind shear and high ocean heat content, additional strengthening is likely. The intensity guidance is much higher this cycle, and the various rapid intensification models show a much more significant chance of rapid strengthening over the next 24 to 36 hours. The DTOPS model indicates a 71 percent chance of a 30-kt increase in wind speed over the next 24 hours, while the SHIPS Rapid Intensification Index shows a 53 percent chance of a 45-kt increase over the next 36 hours. Based on the higher initial intensity and the more bullish guidance, the NHC intensity forecast has been increased and essentially calls for rapid strengthening until Eta reaches the coast of Central America. Once inland, Eta should quickly weaken over the mountainous terrain of Nicaragua and Honduras. Eta is still moving steadily westward or 270 degrees at about 14 kt. A westward motion at a somewhat slower forward speed is expected tonight. On Monday, Eta is forecast to turn southwestward at a slower forward speed when a mid-level ridge builds to the north and northwest of the cyclone. Eta is forecast to move inland over northeastern Nicaragua within the Hurricane Warning area Monday night or early Tuesday. The dynamical models are in relatively good agreement through about 72 hours, expect for the HWRF which shows a more northern track and keeps Eta offshore for much of the period. This solution is considered an outlier at this time, and the NHC track is in good agreement with the various global models and the HFIP corrected consensus model. Some model solutions still suggest Eta or its remnants will re-emerge over the northwestern Caribbean Sea at or beyond day 5. The new NHC 5-day position is still inland near the Gulf of Honduras close to the various consensus aids, but large uncertainty exists in the forecast at that time range due to the large spread in the track guidance. Key Messages: 1. Eta is forecast to strengthen into a hurricane tonight, and additional strengthening is forecast before it reaches the northeastern coast of Nicaragua Monday night or early Tuesday, where a Hurricane Warning is in effect. A Tropical Storm Warning is in effect for a portion of the northeastern coast of Honduras. 2. Through Friday afternoon, heavy rainfall from Eta will lead to significant, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, Southern Haiti, and the Cayman Islands. 3. A life-threatening storm surge, along with damaging waves, is expected along portions of the northeastern coast of Nicaragua near and to the north of where the center makes landfall. Water levels could reach as high as 10 to 15 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should be rushed to completion. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 14.9N 78.9W 55 KT 65 MPH 12H 02/0600Z 15.0N 80.5W 65 KT 75 MPH 24H 02/1800Z 14.7N 82.1W 80 KT 90 MPH 36H 03/0600Z 14.2N 83.1W 95 KT 110 MPH 48H 03/1800Z 14.0N 83.8W 75 KT 85 MPH...INLAND 60H 04/0600Z 14.0N 84.7W 50 KT 60 MPH...INLAND 72H 04/1800Z 14.1N 85.7W 35 KT 40 MPH...INLAND 96H 05/1800Z 14.7N 88.0W 25 KT 30 MPH...INLAND 120H 06/1800Z 15.5N 88.5W 25 KT 30 MPH...INLAND $$ Forecaster Brown
Tags: number
discussion
storm
tropical
Sites : [139] [140] [141] [142] [143] [144] [145] [146] [147] [148] [149] [150] [151] [152] [153] [154] [155] [156] [157] [158] next »