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Coastal Watches/Warnings and Forecast Cone for Storm Center

* If the storm is forecast to dissipate within 3 days, the “Full Forecast” and “3 day” graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.

Note:  A detailed definition of the NHC track forecast cone is also available.

Coastal Watches/Warnings and Forecast Cone for Storm Center

* If the storm is forecast to dissipate within 3 days, the “Full Forecast” and “3 day” graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.

Note:  A detailed definition of the NHC track forecast cone is also available.

  000 WTNT41 KNHC 030842 TCDAT1  Tropical Storm Wanda Discussion Number  14 NWS National Hurricane Center Miami FL       AL212021 900 AM GMT Wed Nov 03 2021  Wanda has changed little in organization since yesterday evening.   Bands of moderately deep convection continue around the storm  center, but upper-level outflow is not as well-defined as in a  typical tropical cyclone.  The advisory intensity estimate  remains at 45 kt, in agreement with a subjective Dvorak satellite  estimate from SAB.  This is also in general agreement with earlier  scatterometer observations.  The cyclone remains fairly small, with  most of the stronger winds occurring over its eastern semicircle.  The storm continues moving a little east of north, or near 015/7  kt.  Wanda should move on the eastern side of a mid-latitude trough  for the next day or so.  After that time, the trough is likely to  weaken and this should result in the system slowing down and  turning eastward.  In 2 to 3 days, a narrow mid-tropospheric ridge  is forecast to build to the northwest of Wanda which should cause  the cyclone to move southeastward.  In 4 to 5 days, the cyclone is  expected to accelerate northeastward ahead of another mid-latitude  trough.  The official forecast track is similar to the previous one  except a little more to the northeast in 36-60 hours.  This follows  the latest simple and corrected model consensus solutions, and is  also close to the average of the latest ECMWF and GFS model tracks.  The system has maintained its intensity in spite of being over sea  surface temperatures of only about 23 deg C.  Wanda will pass over  even cooler waters while it moves farther northward during the next  24 hours or so, which may make it difficult for the system to  produce much deep convection.  However, the storm has been resilient  to seemingly hostile conditions so far, and the official forecast  calls for Wanda to maintain its intensity for much of the forecast  period.  This is similar to the latest intensity model consensus  guidance.  By 96 hours, however, dry air and shear are likely to  result in Wanda losing organized convection and becoming a  post-tropical cyclone.  In 5 days, if not sooner, Wanda is likely  to merge with a frontal zone, and return to its former  extratropical status.   FORECAST POSITIONS AND MAX WINDS  INIT  03/0900Z 38.0N  40.0W   45 KT  50 MPH  12H  03/1800Z 39.3N  39.8W   45 KT  50 MPH  24H  04/0600Z 41.0N  39.7W   45 KT  50 MPH  36H  04/1800Z 41.9N  39.4W   45 KT  50 MPH  48H  05/0600Z 41.6N  38.1W   45 KT  50 MPH  60H  05/1800Z 40.0N  37.0W   45 KT  50 MPH  72H  06/0600Z 38.5N  36.5W   45 KT  50 MPH  96H  07/0600Z 39.7N  34.5W   45 KT  50 MPH...POST-TROPICAL 120H  08/0600Z 46.0N  27.0W   40 KT  45 MPH...POST-TROP/EXTRATROP  $$ Forecaster Pasch  

Coastal Watches/Warnings and Forecast Cone for Storm Center

* If the storm is forecast to dissipate within 3 days, the “Full Forecast” and “3 day” graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.

Note:  A detailed definition of the NHC track forecast cone is also available.

  000 WTNT41 KNHC 030232 TCDAT1  Tropical Storm Wanda Discussion Number  13 NWS National Hurricane Center Miami FL       AL212021 300 AM GMT Wed Nov 03 2021  Bands of convection have continued to wax and wane around the  center of Wanda over the past 6-12 hours, with a band currently  located over the western portion of the cyclone.  A timely 2320 UTC  ASCAT-B overpass detected peak winds of around 40 kt and given the  known undersampling of that instrument for small tropical cyclones,  the 45-kt initial intensity is maintained.  That is also supported  by a recent SATCON intensity estimate of 42 kt.  The ASCAT data did  show that the area of tropical-storm-force winds has increased in  size over the eastern semicircle and now extends outward up to about  80 n mi in that portion of the storm.   Wanda is moving northward or 010/8 kt. The cyclone should continue  moving northward ahead of an approaching mid-latitude trough during  the next 24-36 hours.  After that time however, the trough is  expected to weaken and lift northward causing Wanda to slow down  and turn eastward.  After 48 hours, the track guidance has  continued its southward shift when a narrow ridge is forecast to  build to the northwest of the system. The NHC track forecast is  again shifted southward in the 60 to 96 h time period.  By late in  the period, Wanda is forecast to accelerate northeastward ahead of  yet another mid-latitude trough. There is a bit more confidence in  the latest track prediction as the dynamical model guidance has  come into a bit better agreement, however additional southwestward  or westward adjustments during the middle portion of the forecast  period could be required.   Little overall change in strength is anticipated over the next  several days.  As Wanda moves northward during the next day or so,  it will be moving over slightly cooler waters which could cause  the cyclone to struggle to produce deep convection. After day 2,  there are indications of increasing shear, but a nearby baroclinic  zone could help the system maintain its intensity.  Later in the  period, shear and decreasing mid-level relative humidity are likely to cause Wanda to become post-tropical, and by day 5 the  guidance indicates Wanda will merge with a frontal boundary and  become extratropical.     FORECAST POSITIONS AND MAX WINDS  INIT  03/0300Z 37.3N  40.3W   45 KT  50 MPH  12H  03/1200Z 38.5N  40.0W   45 KT  50 MPH  24H  04/0000Z 40.1N  39.9W   45 KT  50 MPH  36H  04/1200Z 41.2N  39.8W   45 KT  50 MPH  48H  05/0000Z 41.2N  39.2W   45 KT  50 MPH  60H  05/1200Z 40.2N  38.1W   45 KT  50 MPH  72H  06/0000Z 38.5N  37.7W   45 KT  50 MPH  96H  07/0000Z 38.0N  36.0W   45 KT  50 MPH...POST-TROPICAL 120H  08/0000Z 43.5N  29.5W   40 KT  45 MPH...POST-TROP/EXTRATROP  $$ Forecaster Brown  

Coastal Watches/Warnings and Forecast Cone for Storm Center

* If the storm is forecast to dissipate within 3 days, the “Full Forecast” and “3 day” graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.

Note:  A detailed definition of the NHC track forecast cone is also available.

  232  WTNT41 KNHC 022041 TCDAT1  Tropical Storm Wanda Discussion Number  12 NWS National Hurricane Center Miami FL       AL212021 900 PM GMT Tue Nov 02 2021  Late-arriving 1201 UTC ASCAT-B scatterometer data indicated that a  small patch of 40-kt winds was located about 30 nmi east and  southeast of the well-defined center. Owing to known undersampling  by the scatterometer instrument for tropical cyclones that possess a  small radius of maximum of winds (RMW), those 40-kt winds support  the previous advisory intensity of 45 kt. That 45-kt intensity  estimate has been maintained for this advisory based on Wanda having  developed a small, closed eye-like feature in shallow convection,  with a curved band of deeper convection having recently developed  in the RMW where those 40-kt ASCAT surface winds were detected.  Wanda's overall convective organization has improved with more and  tighter curved low-level cloud lines now evident in visible  satellite imagery.  The initial motion estimate is northward, or 010/07 kt. There remain  no significant changes to the previous forecast track or reasoning  through 60 h. Thereafter, however, the latest model guidance has  made a significant southward shift in the track on days 3-5. For the  next couple of days, Wanda is forecast to move slowly poleward ahead  of an approaching mid- to upper-tropospheric trough. As the trough  weakens and lifts out to the north of the cyclone on day 3, Wanda is  expected to move slowly eastward before being forced southeastward  to southward by a narrow shortwave ridge that is forecast to trail  the aforementioned trough. The GFS and UKMET models show Wanda  merging with a frontal system on day 4 and lifting out to the  northeast, whereas the ECMWF drives the cyclone farther south ahead  of the cold front and turns the system into a  convective-free  post-tropical cyclone on day 5. For now, the official track forecast  remains similar to the previous advisory track through 60 h, and  then shows Wanda turning sharply southeastward on day 4, which is  well to the right of the previous forecast track. The cyclone is  then forecast to lift out to the northeast on day 5 as an  extratropical low pressure system after merging with a cold front.  The official forecast track is similar to the tightly packed  consensus models through 60 h, and then is to the left or north of  the consensus aids in the 72-120-h period. There is  lower-than-normal confidence in the forecast track after 72 h due  to the major difference between the GFS and ECMWF model solutions.  Wanda's robust low-level circulation should be able to continue to  mix out occasional dry air intrusions, allowing for inner-core  convection to redevelop and resultant slight strengthening to occur  during the next 24-48 h. However, if a band of moderate convection  ends up developing around the aforementioned eye-like feature, then  Wanda could strengthen a little more than currently forecast. By day  3 and beyond, slow weakening is expected due to a sharp increase in  vertical wind shear and a decrease in mid-level moisture. Based on  what now appears to be stronger baroclinic forcing in the 60-96-h  period, the status of Wanda has been changed to a tropical cyclone  on day 3, with the day 4 and 5 statuses indicating extratropical  transition due to merger with a frontal system. The new NHC  intensity forecast is basically just an update of the previous  advisory forecast, and remains close to an average of the intensity  consensus models IVCN, NOAA-HCCA, and FSSE.   FORECAST POSITIONS AND MAX WINDS  INIT  02/2100Z 36.6N  40.4W   45 KT  50 MPH  12H  03/0600Z 37.9N  40.0W   50 KT  60 MPH  24H  03/1800Z 39.5N  39.8W   50 KT  60 MPH  36H  04/0600Z 41.1N  39.7W   45 KT  50 MPH  48H  04/1800Z 41.8N  39.4W   45 KT  50 MPH  60H  05/0600Z 41.8N  38.0W   45 KT  50 MPH  72H  05/1800Z 40.0N  37.5W   45 KT  50 MPH  96H  06/1800Z 39.0N  36.0W   45 KT  50 MPH...POST-TROP/EXTRATROP 120H  07/1800Z 43.0N  29.5W   40 KT  45 MPH...POST-TROP/EXTRATROP  $$ Forecaster Stewart   

  231  WTNT31 KNHC 022041 TCPAT1  BULLETIN Tropical Storm Wanda Advisory Number  12 NWS National Hurricane Center Miami FL       AL212021 900 PM GMT Tue Nov 02 2021  ...WANDA GETTING A LITTLE BETTER ORGANIZED WHILE MOVING NORTHWARD OVER THE NORTHERN ATLANTIC...   SUMMARY OF 900 PM GMT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...36.6N 40.4W ABOUT 740 MI...1195 KM W OF THE AZORES MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES   WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect.   DISCUSSION AND OUTLOOK ---------------------- At 900 PM GMT (2100 UTC), the center of Tropical Storm Wanda was located near latitude 36.6 North, longitude 40.4 West. Wanda is moving toward the north near 8 mph (13 km/h), and this general motion should continue overnight. A turn toward the north-northeast  is forecast by early Wednesday, followed by a northeastward motion  later on Wednesday. An eastward motion at a slower forward speed is  expected on Thursday.  Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Some slight strengthening is possible during the next day or two. A  slow weakening trend is forecast to begin by late Thursday.  Wanda is a small tropical cyclone. Tropical-storm-force winds only  extend outward up to 45 miles (75 km) from the center.  The estimated minimum central pressure is 992 mb (29.30 inches).   HAZARDS AFFECTING LAND ---------------------- None.   NEXT ADVISORY ------------- Next complete advisory at 300 AM GMT.  $$ Forecaster Stewart   

Coastal Watches/Warnings and Forecast Cone for Storm Center

* If the storm is forecast to dissipate within 3 days, the “Full Forecast” and “3 day” graphic will be identical

Click Here for a 5-day Cone Printer Friendly Graphic

How to use the cone graphic (video):

About this product:

NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.

It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.

Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.

Note:  A detailed definition of the NHC track forecast cone is also available.

  000 WTNT41 KNHC 021435 TCDAT1  Tropical Storm Wanda Discussion Number  11 NWS National Hurricane Center Miami FL       AL212021 300 PM GMT Tue Nov 02 2021  After the overnight burst of deep convection and associated improved  organization, dry air has wrapped into the system from all quadrants  and has temporarily eroded Wanda's inner-core convection. Despite  the recent convective degradation, visible satellite imagery  indicates that the cyclone's low-level circulation has improved,  with well-defined, curved low-level cloud lines and shallow  convection having become more evident. Based on improved low-level  structure, the intensity estimate remains at 45 kt despite the  overall loss of deep convection.  During the past 6 h, Wanda has made the expected sharp left-hand  turn and is now moving northward, or 010/08 kt. There are no  significant changes to the previous forecast track or reasoning.  Over the next couple of days, the latest model guidance is in  excellent agreement that Wanda should remain embedded within a  deep-layer trough, and gradually turn toward the north-northeast  later today, followed by a northeastward motion tonight and  Wednesday as the cyclone moves through the trough-to-ridge flow  pattern. By 48-60 hours, the cyclone is forecast to move toward the  east and east-southeast as a ridge builds to the northwest and west  of Wanda.  The new NHC official forecast track is very similar to  the previous advisory track, and lies close to the middle of the  simple- and corrected-consensus guidance envelope.  The aforementioned improved low-level structure should act to force  new convection later today and especially tonight during the  nocturnal convective maximum period. Thus, Wanda has another 24-36 h  to strengthen while the system remains over marginally warm  sea-surface temperatures (SST) near 23 deg C and within a  relatively low vertical wind shear environment. Thereafter, slow but  steady weakening is likely due to an increase in southwesterly wind  shear, a decrease in mid-tropospheric moisture, and a decrease in  SSTs. However, baroclinic effects associated with an approaching  mid-tropospheric trough from the west could partially offset the  weakening process. Wanda is expected become a post-tropical cyclone  around 72 h, but this could be delayed if the baroclinic forcing on  day 3 ends up stronger than currently expected.  The new official  intensity forecast is essentially just an update of the previous  intensity forecast, and is close to an average of the intensity  consensus models IVCN, NOAA-HCCA, and FSSE.   FORECAST POSITIONS AND MAX WINDS  INIT  02/1500Z 35.6N  40.6W   45 KT  50 MPH  12H  03/0000Z 37.0N  40.0W   45 KT  50 MPH  24H  03/1200Z 38.8N  39.6W   50 KT  60 MPH  36H  04/0000Z 40.7N  39.5W   45 KT  50 MPH  48H  04/1200Z 42.1N  39.3W   45 KT  50 MPH  60H  05/0000Z 42.7N  38.1W   45 KT  50 MPH  72H  05/1200Z 42.5N  36.1W   45 KT  50 MPH...POST-TROPICAL  96H  06/1200Z 41.0N  33.0W   45 KT  50 MPH...POST-TROPICAL 120H  07/1200Z 42.5N  29.5W   40 KT  45 MPH...POST-TROPICAL  $$ Forecaster Stewart