Home › discussion
 

Keywords :   


Tag: discussion

Tropical Storm ENRIQUE Forecast Discussion Number 4

2015-07-13 10:42:20| National Hurricane Center (East Pacific)

Issued at 200 AM PDT MON JUL 13 2015 000 WTPZ41 KNHC 130842 TCDEP1 TROPICAL STORM ENRIQUE DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062015 200 AM PDT MON JUL 13 2015 Satellite images indicate that the cyclone has become a bit better organized with a growing curved band in the southern semicircle and more persistent convection near the center. Given the improved satellite presentation and the 35-kt Dvorak estimates, I've elected to upgrade the depression to Enrique for this advisory. The tropical storm has a day or two to strengthen before it moves into an area of cooler SSTs, drier air, and higher vertical wind shear. Most of the guidance support some intensification, so the intensity forecast will remain close to the previous one, on the higher side of the model envelope. After a bit of a northward jump, Enrique appears to be moving northwestward at about 9 kt. The track should gradually bend back to the west-northwest over the next couple of days while the storm is steered by a building mid-level ridge. The long-range forecast is rather uncertain due to possible interactions with both Dolores to the east and a mid-latitude trough to the north. Overall, the guidance has shifted north and west at most of the forecast points, and the NHC track prediction follows suit, lying near or just to the southeast of the consensus at most forecast times. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 15.2N 126.4W 35 KT 40 MPH 12H 13/1800Z 16.1N 127.4W 40 KT 45 MPH 24H 14/0600Z 16.8N 128.9W 45 KT 50 MPH 36H 14/1800Z 17.4N 130.4W 50 KT 60 MPH 48H 15/0600Z 17.8N 131.9W 45 KT 50 MPH 72H 16/0600Z 18.5N 135.0W 40 KT 45 MPH 96H 17/0600Z 19.5N 137.5W 35 KT 40 MPH 120H 18/0600Z 19.3N 138.0W 35 KT 40 MPH $$ Forecaster Blake

Tags: number discussion storm tropical

 

Tropical Depression SIX-E Forecast Discussion Number 3

2015-07-13 04:36:50| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SUN JUL 12 2015 000 WTPZ41 KNHC 130236 TCDEP1 TROPICAL DEPRESSION SIX-E DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062015 800 PM PDT SUN JUL 12 2015 The cloud pattern of the depression has not changed much during the last several hours. Deep convection remains mainly confined to a curved band to the south of the center and in an area over the northeastern quadrant. Although the latest Dvorak classifications from TAFB and SAB support raising the intensity to minimal tropical storm strength, 35 kt, I am maintaining the wind speed at 30 kt based on the steady state nature of the system since the ASCAT pass earlier today. The depression has wobbled northward over the past few hours, but a longer term motion is west-northwestward at 5 kt. A slightly faster west-northwestward to northwestward motion is predicted during the next 3 to 4 days while the cyclone is steered by a narrow mid-level ridge. Beyond that time, the system is expected to slow down when the steering currents collapse due to the approach of Dolores to its east. The NHC track forecast has been nudged to the north of the previous one, primarily to account for the more northward initial position. The cyclone has an opportunity to strengthen during the next couple of days while it remains in low wind shear conditions and over relatively warm water. There does appear to be a fair amount of stable air to the north of the system, however, and that could limit the amount of intensification that occurs. Beyond 48 hours, the cyclone is expected to move over cooler water and into a drier air mass. These conditions should provoke weakening. The NHC intensity forecast is the same as the previous one, and is in best agreement with the SHIPS model. It is worth noting that none of the intensity guidance shows much strengthening of the system. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 14.0N 126.0W 30 KT 35 MPH 12H 13/1200Z 15.0N 127.1W 35 KT 40 MPH 24H 14/0000Z 15.7N 128.4W 40 KT 45 MPH 36H 14/1200Z 16.4N 129.9W 45 KT 50 MPH 48H 15/0000Z 16.9N 131.4W 50 KT 60 MPH 72H 16/0000Z 17.7N 134.1W 45 KT 50 MPH 96H 17/0000Z 18.5N 136.2W 40 KT 45 MPH 120H 18/0000Z 18.6N 137.0W 35 KT 40 MPH $$ Forecaster Cangialosi

Tags: number discussion tropical depression

 
 

Tropical Storm DOLORES Forecast Discussion Number 6

2015-07-12 22:53:50| National Hurricane Center (East Pacific)

Issued at 400 PM CDT SUN JUL 12 2015 000 WTPZ45 KNHC 122053 TCDEP5 TROPICAL STORM DOLORES DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052015 400 PM CDT SUN JUL 12 2015 There has been no significant change in Dolores' organization during the past several hours. Satellite imagery continues to show most of the cyclone's deep convection remaining in a band over the northeastern semicircle of the circulation. This convective asymmetry is likely related to some west-northwesterly shear as diagnosed by UW-CIMSS and SHIPS shear analyses. An ASCAT-B pass showed the center barely underneath the convective mass, with peak uncontaminated winds around 45 kt. Based on the ASCAT data, the initial intensity is raised to 45 kt. The ASCAT pass showed the center of Dolores to be a bit farther south than previous estimates, and the heading is estimated to be more westerly or 295/09. A subtropical ridge over the south-central United States should guide Dolores generally west-northwestward with a decrease in forward speed during the next 48 hours. The cyclone's heading should become more northwesterly by 72 hours, when Dolores reaches the western periphery of the ridge. Later in the forecast period, Dolores' track should bend back toward the west- northwest as the subtropical ridge reasserts itself. The official track forecast is similar to but a little to the left of the previous one through 48 hours and slightly to the right after that. The track forecast after 48 hours is near a multi-model consensus that excludes the GFDL solution which unrealistically takes Dolores toward the Baja California peninsula. Thermodynamic variables in the near-storm environment are quite conducive for intensification, with sea surface temperatures of 29-30 deg C and plenty of deep-layer moisture. Some west- northwesterly shear is forecast to persist and perhaps even increase over the next day or so before decreasing from 72 hours through the remainder of the forecast period. However, the shear is not expected to be strong enough to impede steady intensification. With a sharp gradient in SSTs along 20N, the intensity late in the period is very much dependent on how much latitude Dolores gains by that time. The NHC intensity forecast is about the same as the previous one and is very similar to the multi-model consensus (ICON) through 48 hours but above ICON after that, closest to the SHIPS model guidance. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 15.6N 103.0W 45 KT 50 MPH 12H 13/0600Z 16.2N 104.5W 55 KT 65 MPH 24H 13/1800Z 16.8N 106.0W 65 KT 75 MPH 36H 14/0600Z 17.2N 107.1W 75 KT 85 MPH 48H 14/1800Z 17.7N 108.0W 80 KT 90 MPH 72H 15/1800Z 18.9N 109.7W 95 KT 110 MPH 96H 16/1800Z 20.0N 112.0W 90 KT 105 MPH 120H 17/1800Z 20.9N 114.9W 85 KT 100 MPH $$ Forecaster Kimberlain

Tags: number discussion storm tropical

 

Tropical Depression SIX-E Forecast Discussion Number 2

2015-07-12 22:51:17| National Hurricane Center (East Pacific)

Issued at 200 PM PDT SUN JUL 12 2015 000 WTPZ41 KNHC 122051 TCDEP1 TROPICAL DEPRESSION SIX-E DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062015 200 PM PDT SUN JUL 12 2015 The convective structure of the tropical cyclone has improved somewhat today, with a band of deep convection wrapping around the south and southwestern portions of the circulation. Although Dvorak data T-numbers have increased to T2.5 from both agencies, a recent ASCAT pass suggests that the system is still below tropical storm strength. Environmental conditions consisting of warm water and low vertical wind shear should allow for strengthening during the next couple of days. The primary inhibiting factor appears to be some drier and more stable air to the north and northwest of the cyclone. The NHC intensity forecast is similar to the previous advisory and is in close agreement with the SHIPS guidance during the first 48 hours. After that time, increasing southerly shear, cooler waters, and a more stable airmass are expected to cause weakening. Visible satellite images indicate that the initial position of the cyclone is a little south of the previous estimate. As a result, the initial motion is a somewhat uncertain 300/6. The depression is expected to move on a general west-northwest to northwest heading during the next several days while it remains to the south of a narrow mid-level ridge. Near the end of the forecast period, the global models continue to show weakening of the steering flow over the far eastern Pacific as the large circulation of Dolores approaches from the east. This is likely to cause the cyclone's forward speed to decrease. The track guidance remains in agreement on this scenario, and the NHC forecast is close to the GFS ensemble mean, and just south of the model consensus. The new NHC track is a little south of the previous advisory due to the more southward initial position. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 13.6N 125.8W 30 KT 35 MPH 12H 13/0600Z 14.5N 127.0W 35 KT 40 MPH 24H 13/1800Z 15.3N 128.2W 40 KT 45 MPH 36H 14/0600Z 15.9N 129.5W 45 KT 50 MPH 48H 14/1800Z 16.4N 130.9W 50 KT 60 MPH 72H 15/1800Z 17.0N 133.5W 45 KT 50 MPH 96H 16/1800Z 18.0N 135.5W 40 KT 45 MPH 120H 17/1800Z 18.3N 136.5W 35 KT 40 MPH $$ Forecaster Brown

Tags: number discussion tropical depression

 

Tropical Depression SIX-E Forecast Discussion Number 1

2015-07-12 18:01:22| National Hurricane Center (East Pacific)

Issued at 900 AM PDT SUN JUL 12 2015 000 WTPZ41 KNHC 121601 TCDEP1 TROPICAL DEPRESSION SIX-E SPECIAL DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062015 900 AM PDT SUN JUL 12 2015 Convection associated with the area of low pressure located well southwest of the southern tip of Baja California has become better organized since yesterday, with a band now wrapping around the western semicircle of the system. Overnight scatterometer data and early morning visible satellite pictures indicate that the circulation has become sufficiently well defined, therefore advisories are being initiated on the sixth tropical depression of the 2015 eastern Pacific hurricane season. The initial intensity is set at 30 kt, which is in agreement with a TAFB Dvorak classification of 2.0. The depression is forecast to remain over warm water and in a low shear environment during the next few days, however, drier and more stable air to the northwest of the cyclone may prevent significant intensification. The NHC intensity forecast calls for gradual strengthening during the next few days, and is in best agreement with the SHIPS guidance. The cyclone is expected to move over cooler waters which should induce some weakening at days 4 and 5. The initial motion is a somewhat uncertain 305/6. The depression is forecast to turn west-northwestward as a ridge builds to its north during the next day or two. After that time, the cyclone should maintain a general westward to west-northwestward track. Later in the period, global models suggest that the steering flow should weaken around the depression as Dolores' circulation approaches from the west. This pattern should cause the depression's forward speed to decrease. Although the track guidance is in general agreement with this scenario, there is some spread in how much latitude the depression will gain during the next couple of days. The NHC track is closest to the GFS ensemble mean, which is a little south of the multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 12/1600Z 13.6N 125.3W 30 KT 35 MPH 12H 13/0000Z 14.5N 126.0W 35 KT 40 MPH 24H 13/1200Z 15.6N 127.4W 40 KT 45 MPH 36H 14/0000Z 16.3N 128.9W 45 KT 50 MPH 48H 14/1200Z 16.8N 130.4W 50 KT 60 MPH 72H 15/1200Z 17.5N 133.5W 45 KT 50 MPH 96H 16/1200Z 17.8N 136.5W 40 KT 45 MPH 120H 17/1200Z 18.2N 138.0W 35 KT 40 MPH $$ Forecaster Brown

Tags: number discussion tropical depression

 

Sites : [1010] [1011] [1012] [1013] [1014] [1015] [1016] [1017] [1018] [1019] [1020] [1021] [1022] [1023] [1024] [1025] [1026] [1027] [1028] [1029] next »