Tropical Storm Hernan

Post Tropical Storm Herman Track 1500 Hours August 28 2020
Post Tropical Storm Herman Track 1500 Hours August 28 2020

Tropical-Storm-Herman-Wind-Speed-FieldTropical Storm HernanNWS National Hurricane Center Miami FL 300 PM MDT Fri Aug 28, 2020

Satellite imagery, scatterometer data, and surface observations indicate that Hernan has degenerated into a broad low-pressure area near the southern end of the Baja California peninsula. The remnant low is forecast to move generally westward for the next 12-24 h until it is absorbed into the monsoon gyre that includes Tropical Storm Iselle.

This is the last advisory issued by the National Hurricane Center on this system.

FORECAST POSITIONS AND MAX WINDS

INIT  28/2100Z 23.2N 110.1W   25 KT  30 MPH - Low (WNW Cabo San Lucas, Mexico)
 12H  29/0600Z 23.3N 111.8W   20 KT  25 MPH - Low (WSW Todos Santos, Mexico)
 24H  29/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 900 AM MDT Fri Aug 28, 2020

Satellite imagery shows that Hernan has become less organized since the last advisory with most of the associated convection dissipating. In addition, surface observations in the coastal areas near the cyclone suggest the possibility that it no longer has a closed circulation, although there are no observations over water to confirm this. Based on decreasing satellite intensity estimates, Hernan is downgraded to a tropical depression. Additional weakening is forecast, and Hernan is expected to degenerate to a remnant low pressure area as it moves over the Baja California peninsula later today and tonight. The system is then expected to weaken to a trough on Saturday.

The initial motion is a somewhat uncertain 295/18. Hernan is moving around the northeastern side of the monsoon gyre that contains Tropical Storm Iselle, and a general west-northwestward motion is expected until the system dissipates on Saturday.

FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 23.4N 109.1W   30 KT  35 MPH - Depression (ESE San Jose del Cabo, Mexico)
 12H  29/0000Z 24.1N 110.5W   20 KT  25 MPH - Low (WSW La Paz, Mexico)
 24H  29/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 900 PM MDT Thu Aug 27, 2020

A burst of strong convection has developed near the center of Hernan during the past several hours, but overall the storm remains poorly organized. Indeed, a westerly surface wind observed in the Isla Marias Islands to the north of the center makes it unclear if a closed circulation still exists, a question that upcoming scatterometer data will hopefully resolve. The initial intensity remains 35 kt based mainly on satellite intensity estimates from TAFB and SAB.

The initial motion is now north-northwestward or 335/7 kt. The cyclone is expected to turn northwestward and then west- northwestward as it rotates around the northeastern side of the approaching Tropical Storm Iselle. The new forecast track is nudged to the north of the previous track and lies near the various consensus models.

A combination of continued strong easterly shear and interaction with the larger Iselle should cause Hernan to weaken during the next 48 h or so. The new intensity forecast shows the system weakening to a depression after 12 h and degenerating to a remnant low by 36 h. After that, the cyclone is currently forecast to degenerate to a trough by 60 h as it gets absorbed into Iselle, and several of the global models suggest this could happen earlier. The new intensity forecast is an update of the previous forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  28/0300Z 20.5N 107.0W   35 KT  40 MPH - Tropical Storm (WSW Puerto Vallarta, Mexico)
 12H  28/1200Z 21.6N 108.3W   35 KT  40 MPH - Tropical Storm (WSW Cabo San Lucas, Mexico)
 24H  29/0000Z 22.3N 110.0W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico)
 36H  29/1200Z 23.0N 111.9W   25 KT  30 MPH - Low (WSW Cabo San Lucas, Mexico)
 48H  30/0000Z 23.4N 113.9W   20 KT  25 MPH - Low (WNW Cabo San Lucas, Mexico)
 60H  30/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 300 PM MDT Thu Aug 27, 2020

Hernan has had a rather ragged appearance today with intermittent convection firing around, but never really over the center. There were no ASCAT overpasses during the day that directly sampled the system’s circulation. The latest Dvorak intensity estimates from TAFB and SAB support 35 kt and 30 kt, respectively, while the UW-CIMSS ADT and SATCON numbers range from 30 to 40 kt. Based on a blend of these values, the initial intensity is being lowered to 35 kt.

Hernan should at least maintain its current strength through tonight as it remains over very warm waters while battling moderate easterly shear. This shear is not forecast to abate during the forecast period. And by 24 h, the cyclone is expected to begin moving over progressively cooler waters. The combination of these two factors should induce a weakening trend. By 60 h, simulated satellite imagery by global models suggest that the cyclone will become devoid of deep convection. After that time, the remnant low is expected to be absorbed within the broader circulation of Iselle to its west. The latest NHC intensity forecast is in agreement with the various intensity consensus aids. Hernan is now moving northwest at about 5 kt. There is no change to the track forecast reasoning.

Hernan is expected to remain caught within a large-scale, eastern North Pacific cyclonic gyre during the next few days, which will result in Hernan moving counter-clockwise around the eastern and northern periphery of the gyre. The cyclone is expected to continue to parallel the coast of southwestern Mexico through this evening and should begin to increase its forward speed tonight. A turn to the west-northwest then west is forecast Friday through Friday night. The westward motion should continue until the system becomes absorbed early next week.

FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 19.6N 106.5W   35 KT  40 MPH - Tropical Storm (WSW Puerto Vallarta, Mexico)
 12H  28/0600Z 20.7N 107.6W   35 KT  40 MPH - Tropical Storm (WNW Puerto Vallarta, Mexico)
 24H  28/1800Z 21.6N 109.4W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico))
 36H  29/0600Z 22.3N 111.1W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico))
 48H  29/1800Z 22.5N 113.0W   25 KT  30 MPH - Depression (WSW Cabo San Lucas, Mexico))
 60H  30/0600Z 22.6N 114.8W   25 KT  30 MPH - Low (WSW Cabo San Lucas, Mexico)
 72H  30/1800Z...ABSORBED

NWS National Hurricane Center Miami FL 900 AM MDT Thu Aug 27, 2020

First light visible satellite imagery reveals that Hernan remains a sheared tropical cyclone with most of the deep convection confined to the western semicircle. Even though convection has waned a bit overnight, there appears to be a new cluster developing. Therefore the initial intensity is being held at 40 kt, based on the earlier morning ASCAT overpass.

Hernan should at least maintain its current strength for the next 12-24 h as it remains over very warm waters while battling moderate easterly shear. This shear is not forecast to abate during the forecast period. And after 24 h, the cyclone is expected to begin moving over progressively cooler waters. The combination of these two factors should induce a weakening trend. By 60 h, simulated satellite imagery by global models suggest that the cyclone will become devoid of deep convection. After that time, the remnant low is expected to be absorbed within the broader circulation of Hernan to its west. The latest NHC intensity forecast is close to the IVCN/ICON intensity consensus.

Hernan has turned to the north-northwest and is moving at about 4 kt. There is no change to the track forecast reasoning. Hernan is expected to remain caught within a large-scale, eastern North Pacific cyclonic gyre during the next few days, which will result in Hernan moving counter-clockwise around the eastern and northern periphery of the gyre. The cyclone will continue to parallel the coast of southwestern Mexico through this evening, followed by a northwestward then westward turn tonight and Friday. The westward motion should continue until the system becomes absorbed early next week.

FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 19.1N 106.2W   40 KT  45 MPH - Tropical Storm (WSW Manzanillo, Mexico)
 12H  28/0000Z 20.1N 107.0W   40 KT  45 MPH - Tropical Storm (WSW Acapulco, Mexico)
 24H  28/1200Z 21.2N 108.5W   35 KT  40 MPH - Tropical Storm (WSW Cabo san Lucas, Mexico)
 36H  29/0000Z 22.2N 110.2W   30 KT  35 MPH - Depression (WSW Cabo san Lucas, Mexico)
 48H  29/1200Z 22.8N 112.3W   30 KT  35 MPH - Depression (WSW Cabo san Lucas, Mexico)
 60H  30/0000Z 22.5N 113.9W   30 KT  35 MPH - Low (WSW Cabo san Lucas, Mexico)
 72H  30/1200Z...ABSORBED

NWS National Hurricane Center Miami FL 1000 PM CDT Wed Aug 26, 2020

Hernan remains a sheared tropical cyclone with a new burst of deep convection, characterized by cloud tops of -75C to -85C, having developed near and southwest of the well-defined low-level circulation center. The initial intensity remains 35 kt based on a TAFB Dvorak satellite classification of T2.5/35 kt using a shear pattern.

Up until a few hours ago, Hernan had been moving slowly north-northeastward, but the motion is now estimated to be northward or 360/05 kt. Hernan is forecast to remain trapped within and move around the northeastern periphery of a large-scale, eastern North Pacific monsoon gyre during the next few days. This is expected to result in a slow northward motion tonight, followed by a turn toward the northwest on Thursday, and a west-northwestward motion on Friday. By Saturday, Hernan is forecast to degenerate into a remnant low pressure system and be steered generally westward by the low-level easterly flow on the north side of the gyre. On the forecast track, Hernan and most of its significant winds and convection should remain just offshore the southwestern coast of Mexico tonight and Thursday, and pass near or just south of the southern tip of Baja California Sur on Friday and Saturday.

The new NHC track is a very similar to the previous advisory track, and lies close to the simple track consensus models TVCE and GFEX, and lies to the left of the NOAA-HCCA corrected-consensus model. Hernan is expected to remain a sheared tropical cyclone throughout its lifetime due to moderate to strong east to northeasterly vertical wind shear. However, the cyclone will also be over warm waters and within a moist mid-level environment for the next 48 hours or so. Although the official intensity forecast calls for no change in strength, some slight intensification to 40 kt can’t be ruled out, especially tonight during the approaching convective maximum period. By 60 hours and beyond, Hernan is forecast to move over marginal sea-surface temperatures and be affected by strong easterly shear of at least 20 kt, which should cause the cyclone to weaken into a remnant low. The NHC intensity forecast follows the IVCN intensity consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT  27/0300Z 18.3N 105.8W   35 KT  40 MPH - Tropical Storm (WSW Manzanillo, Mexico)
 12H  27/1200Z 19.0N 105.9W   35 KT  40 MPH - Tropical Storm (WSW Manzanillo, Mexico)
 24H  28/0000Z 20.2N 106.6W   35 KT  40 MPH - Tropical Storm (WSW Puerto Vallarta, Mexico)
 36H  28/1200Z 21.4N 108.1W   35 KT  40 MPH - Tropical Storm (WNW Puerto Vallarta, Mexico)
 48H  29/0000Z 22.0N 109.9W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico)
 60H  29/1200Z 22.5N 112.3W   30 KT  35 MPH - Low (WSW Cabo San Lucas, Mexico)
 72H  30/0000Z 22.5N 113.8W   25 KT  30 MPH - Low (WSW Cabo San Lucas, Mexico)
 96H  31/0000Z 22.4N 115.7W   20 KT  25 MPH - Low (WSW Cabo San Lucas, Mexico)
120H  01/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 400 PM CDT Wed Aug 26, 2020 

Despite the rather poor presentation in satellite imagery, a recent ASCAT overpass showed that tropical-storm-force winds partially associated with a broader scale monsoon gyre are occurring over the southern portion of the circulation about 50-90 n mi from the center. Based on the wind data, the initial intensity has been raised to 35 kt, and the depression has been upgraded to Tropical Storm Hernan.

Hernan is a sheared tropical cyclone, with only a small area of deep convection just to the south of the center. The SHIPS guidance indicates that this shear will continue throughout the forecast period. While the cyclone remains over very warm waters of about 29 degrees C for the next 24-36 h, there should be sufficient convection to maintain Hernan’s current intensity. However, after 36 h the cyclone will move over relatively cooler waters of about 26 C. These very marginal water temperatures combined with the ongoing shear should cause Hernan to weaken, and the system is expected to degenerate to a remnant low by 60 h, as indicated by the GFS simulated satellite. The NHC intensity is a blend of the various corrected consensus aids and the SHIPS intensity guidance.

Hernan appears to have made its anticipated turn to the northeast and the initial motion is 040/5 kt. The cyclone is expected to turn north then northwest over the next 24 h as it pivots around inside a cyclonic gyre that includes Tropical Depression Fourteen-E to its west. After that time, Hernan should be steered west-northwestward to westward by a mid-tropospheric ridge anchored over the southwestern U.S.. On this forecast track, Hernan and most of its winds and convection should remain just offshore the southwestern coast of Mexico today and Thursday, and pass near or just south of the southern tip of Baja California Sur on Friday and Saturday. The official NHC forecast is little changed from the previous one, and is near the various consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 17.7N 105.8W   35 KT  40 MPH - Tropical Storm (WSW Manzanillo, Mexico)
 12H  27/0600Z 18.4N 105.7W   35 KT  40 MPH - Tropical Storm (WSW Manzanillo, Mexico)
 24H  27/1800Z 19.5N 106.1W   35 KT  40 MPH - Tropical Storm (WNW Manzanillo, Mexico)
 36H  28/0600Z 20.7N 107.3W   35 KT  40 MPH - Tropical Storm (WSW Puerto Vallarta, Mexuco)
 48H  28/1800Z 21.7N 108.9W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico)
 60H  29/0600Z 22.2N 110.7W   30 KT  35 MPH - Low (WSW Cabo San Lucas, Mexico)
 72H  29/1800Z 22.5N 112.7W   25 KT  30 MPH - Low (WSW Cabo San Lucas, Mexico)
 96H  30/1800Z 22.4N 115.1W   20 KT  25 MPH - Low (WSW Cabo San Lucas, Mexico)
120H  31/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 900 AM MDT Wed Aug 26, 2020

CORRECTED ADVISORY NUMBER The depression remains poorly organized this morning with the ill-defined surface circulation decoupled well to the east of the convective mass. Subjective satellite intensity estimates from both TAFB and SAB support 30 kt for this advisory.

UW-CIMSS shear analysis product shows stiff 20-25 kt of east-northeasterly shear impinging on the east portion of the depression. Both the FV3/GFS and ECMWF SHIPS statistical-dynamical intensity models indicate that the strong shear will persist through the forecast period. Consequently, little strengthening is expected during the next several days. Because of the vertical direction and magnitude, the forecast tropical-storm-force winds and the heaviest rainfall should remain offshore of the southwestern coast of Mexico. The NHC intensity forecast follows a blend of the multi-model intensity guidance, and the global models beyond the 48 hr period which indicate the depression degenerating into a remnant low on day 3, and dissipation by day 5.

The initial motion is estimated to be a drift east-northeastward, or 065/2 kt. The cyclone is embedded within an northeast-to-southwest oriented cyclonic gyre, similar to a reverse monsoon trough that typically forms in the western Pacific during the summer months. The depression is forecast to drift today in a general east-northeast to northeast direction followed by a turn slowly north-northeastward tonight. A motion toward the north-northwest is expected on Thursday. Afterward, a mid-tropospheric ridge anchored over the southwestern U.S. should force the cyclone west-northwestward to westward on Friday and Saturday. On the forecast track, the depression should remain just offshore the southwestern coast of Mexico today and Thursday, and pass near or just south of the southern tip of Baja California Sur on Friday and Saturday. The official track forecast is basically an update of the previous advisory and is nudged toward the NOAA HFIP Corrected Consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 17.3N 106.1W   30 KT  35 MPH - Depression (WSW Manzanillo, Mexico)
 12H  27/0000Z 18.1N 106.1W   30 KT  35 MPH - Depression (WNW Manzanillo, Mexico)
 24H  27/1200Z 19.0N 106.3W   35 KT  40 MPH - Tropical Storm (WNW Manzanillo, Mexico)
 36H  28/0000Z 20.4N 107.2W   35 KT  40 MPH - Tropical Storm (WSW Puerto Vallarta, Mexuco)
 48H  28/1200Z 21.4N 108.5W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico)
 60H  29/0000Z 22.2N 110.1W   30 KT  35 MPH - Depression (WSW Cabo San Lucas, Mexico)
 72H  29/1200Z 22.6N 112.2W   25 KT  30 MPH - LoW (WSW Cabo San Lucas, Mexico)
 96H  30/1200Z 22.6N 114.7W   20 KT  25 MPH - LoW (WSW Cabo San Lucas, Mexico)
120H  31/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 PM PDT Tue Aug 25, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. A low-pressure system located a few hundred miles south-southeast of the southern tip of the Baja California peninsula continues to show signs of organization. This system will likely become a tropical depression or tropical storm during the next day or two while it moves slowly east-northeastward or northeastward, near or just west of the southwestern coast of Mexico. For more information on this system, see High Seas forecasts issued by the National Weather Service. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…90 percent.
  • 2. An elongated area of low pressure near the coast of south-central Mexico continues to produce disorganized showers and thunderstorms. Development of this system has become unlikely due to unfavorable upper-level winds and close proximity to land. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…low...20 percent.
  • 3. Another low-pressure system is located several hundred miles southwest of the southern tip of the Baja California peninsula. Although this system is currently producing limited shower and thunderstorm activity, its circulation has become better defined during the past several hours. Some additional development of the disturbance is expected and it will likely become a tropical depression during the next few days while it moves slowly east-northeastward to northeastward. * Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Tue Aug 25, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. A low-pressure system is located a few hundred miles south-southeast of the southern tip of the Baja California peninsula. Showers and thunderstorms have become better organized during the past several hours and the surface circulation has become a little better defined. Although upper-level winds are marginally conducive for further development, a tropical depression is likely to form during the next day or two while the system moves slowly east-northeastward to northeastward toward the southwestern coast of Mexico. * Formation chance through 48 hours…high…80 percent. * Formation chance through 5 days…high…90 percent.
  • 2. Satellite derived wind data indicate that the small low pressure system that was located just off of the coast of south-central Mexico near Puerto Angel has opened up into a trough of low pressure. Consequently, development of this system appears to be less likely. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…medium...40 percent.
  • 3. Another low-pressure system is located several hundred miles southwest of the southern tip of the Baja California peninsula. Gradual development of this system is possible during the next couple of days, and a tropical depression could form while it moves slowly east-northeastward. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…medium…60 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Tue Aug 25, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. A broad low-pressure system is located a few hundred miles south-southeast of the southern tip of the Baja California peninsula. Showers and thunderstorms are beginning to show some signs of organization, and environmental conditions appear conducive for a tropical depression to form during the next couple of days while the system moves slowly east-northeastward to northeastward toward the southwestern coast of Mexico. * Formation chance through 48 hours…high…80 percent. * Formation chance through 5 days…high…90 percent.
  • 2. A small low pressure system is located just offshore of the south-central Mexico coast near Puerto Angel. The low is forecast to meander or move slowly westward to west-northwestward over or near the southern coast of Mexico, and a tropical depression could still form if the system remains offshore over the next day or two. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…70 percent.
  • 3. Another small low-pressure system has developed several hundred miles southwest of the southern tip of the Baja California peninsula. Some gradual development is possible during the next couple of days while the system moves slowly east-northeastward. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Mon Aug 24, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated zone of disturbed weather is located several hundred miles south-southwest of the southern tip of the Baja California peninsula. Environmental conditions appear conducive for a tropical depression to form later this week while the system meanders or drifts northward a few hundred miles offshore of the coast of southwestern Mexico. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.
  • 2. A small low-pressure system located near the Gulf of Tehuantepec continues to show signs of organization. This low is forecast to meander or move slowly west-northwestward near the southern coast of Mexico, and a tropical depression is likely to form over the next day or two, assuming the center of circulation remains offshore. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…high…80 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Mon Aug 24, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated zone of disturbed weather is located several hundred miles south-southwest of the southern tip of the Baja California peninsula. This weather is expected to consolidate in a couple of days, and environmental conditions appear conducive for a tropical depression to form later this week while the system meanders or drifts northward a few hundred miles offshore of the coast of southwestern Mexico. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.
  • 2. A small low-pressure area located a couple of hundred miles southwest of the Gulf of Tehuantepec continues to produce disorganized shower and thunderstorm activity. Conditions appear conducive for additional development of this system if it does not move inland over Mexico, and a tropical depression is likely to form within the next couple of days while it moves slowly northwestward, near or parallel to the southwestern coast of Mexico. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Sun Aug 23, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated area of low pressure located several hundred miles south of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. Conditions appear favorable for development, and a tropical depression is expected to form during the next couple of days while the system meanders or drifts northward a few hundred miles offshore the coast of southwestern Mexico. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.
  • 2. Satellite images indicate that the circulation of a low-pressure area which formed earlier this morning a couple of hundred miles south-southwest of the Gulf of Tehuantepec is becoming better defined. Conditions appear conducive for additional development of this system, and a tropical depression is likely to form by the middle of the week while it moves slowly northwestward, near or parallel to the southwestern coast of Mexico. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Sun Aug 23, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. Conditions appear favorable for development, and a tropical depression is likely to form by the middle of this week while the system meanders or drifts northward a few hundred miles offshore the coast of southwestern Mexico. * Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high…80 percent.
  • 2. An area of low pressure appears to be forming a couple of hundred miles south-southwest of the Gulf of Tehuantepec. Conditions appear conducive for additional development of this system, and a tropical depression is likely to form by the middle of the week while it moves slowly northwestward, near or parallel to the southwestern coast of Mexico. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Sat Aug 22, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. Conditions appear favorable for gradual development, and a tropical depression is likely to form during the early- to-middle part of next week while the system drifts a few hundred miles offshore the coast of southwestern Mexico. * Formation chance through 48 hours…medium…50 percent. * Formation chance through 5 days…high…80 percent.
  • 2. An area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. A tropical depression is likely to form by the middle of next week while the system moves slowly northwestward or northward, near or parallel to the southwestern coast of Mexico. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Sat Aug 22, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. This system is forecast to drift eastward for the next couple of days. Conditions appear favorable for gradual development, and a tropical depression is likely to form during the early to middle part of next week when the system is expected to move slowly off the coast of Mexico. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…high...80 percent.
  • 2. Another area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. A tropical depression could form by the middle of next week while the system moves slowly northwestward or northward, near or parallel to the southwestern coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…60 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Sat Aug 22, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. This system is forecast to move generally eastward for the next couple of days. Conditions appear favorable for gradual development and a tropical depression is likely to form during the early to middle part of next week when the system is expected to slow and meander off the coast of Mexico. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…high…80 percent.
  • 2. Another area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. A tropical depression could form by the middle of next week while the system moves slowly northwestward or northward, near or parallel to the southwestern coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Fri Aug 21, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center has issued its last advisory on Post-Tropical Cyclone Genevieve, located a couple hundred miles west of the central Baja California peninsula.

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized cloudiness and thunderstorms. This system is forecast to move generally eastward for the next couple of days. Conditions appear favorable for gradual development and a tropical depression is likely to form during the early to middle part of next week when the system is expected to slow down and meander off the coast of Mexico. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…70 percent.
  • 2. Another area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. A tropical depression could form by the middle of next week while the system moves slowly northwestward or northward, near or parallel to the southwestern coast of Mexico. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Fri Aug 21, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Genevieve, located a couple of hundred miles west of Cabo San Lazaro, Mexico.

  • 1. An elongated area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula is producing a large area of disorganized cloudiness and thunderstorms. Conditions appear favorable for some gradual development of this system, and a tropical depression is likely to form during the early to middle part of next week while it moves little. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high...70 percent.
  • 2. Another area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. Some slow development of this system is possible thereafter while it drifts northwestward or northward. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Thu Aug 20, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Genevieve, located near the southwestern coast of the Baja California peninsula.

  • 1. An area of low pressure is expected to form this weekend several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form by the middle of next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.
  • 2. Another area of low pressure is likely to form south of the Gulf of Tehuantepec early next week. Some slow development of this system is possible thereafter while it drifts northward. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low...20 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Thu Aug 20, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Genevieve, located about 100 miles west-northwest of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form this weekend several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form by the middle of next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Wed Aug 19, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located about 45 miles south-southwest of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week and over the weekend several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form by mid next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Wed Aug 19, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located less than 100 miles south-southwest of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week and over the weekend several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form early next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Wed Aug 19, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located just over a hundred miles south of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form this weekend or early next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium...50 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Wed Aug 19, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located a couple hundred miles south of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form this weekend or early next week while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 1100 PM PDT Tue Aug 18, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located a few hundred miles south-southeast of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system this weekend while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 500 PM PDT Tue Aug 18, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located a few hundred miles south-southeast of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system this weekend while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Tue Aug 18, 2020

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Genevieve, located a few hundred miles south-southeast of the southern tip of the Baja California peninsula.

  • 1. An area of low pressure is expected to form later this week several hundred miles west of the southwestern coast of Mexico. Conditions appear favorable for some development of this system this weekend while it moves little. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

If this system is named, it will become Tropical Storm Hernan.

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