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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.

  003  WTNT41 KNHC 312042 TCDAT1  Subtropical Storm Wanda Discussion Number   4 NWS National Hurricane Center Miami FL       AL212021 900 PM GMT Sun Oct 31 2021  Wanda has struggled a bit this afternoon, as it appears that some  dry air has entrained into its circulation. Deep convection is now mainly confined to a band wrapping around the eastern semicircle of  the cyclone. Remarkably, the 3 ASCAT overpasses today missed  the core of Wanda, however, the latest Dvorak intensity estimates  from TAFB, and the UW-CIMMS ADT and SATCON remain consistent, and  indicate an initial advisory intensity of 45 kt.  The storm made a rather abrupt halt in its eastward motion this  morning, and for much of the day has been drifting westward, with an  initial motion of 90/1 kt. Wanda is expected to make a slow, nearly  180 degree turn to the south, east, then northeast through Tuesday  as it pivots around a mid-tropospheric trough. A faster northeast to  north motion is expected through Wednesday as ridging builds to the  east of the cyclone. The model guidance is in reasonable agreement  on this scenario, and there were only minor tweaks to this portion  of the NHC track forecast. Thereafter, the guidance has made quite a  startling change from the previous runs, and is now indicating that  a blocking ridge may build to the north of Wanda by late this week.  This is a major shift in the guidance from previous runs that showed  the cyclone accelerating northeastward into the mid-latitudes. The  latest NHC track forecast tries to adjust for this change by  indicating a slower forward speed and less poleward motion late in  the 5-day forecast period, but this remains well north and east of  the bulk of the guidance. There is also a large amount of spread now  in the guidance beyond 72 h, and therefore, that portion of the  track forecast is of low confidence.   The upper-trough supporting the subtropical nature of Wanda is  forecast to lift out to the northeast by Monday. In addition, over  the past day or so, with each passing advisory cycle the cyclone has  taken on a little more of the appearance of a tropical cyclone  versus a subtropical cyclone. Model guidance is in good agreement on  this transition occurring soon, as per the latest FSU phase space  forecasts. Therefore, Wanda is expected to transition to a tropical  cyclone by Monday. The recent ingestion of dry air may have ended  the chance for further strengthening of the storm, and the latest  NHC intensity forecast shows no change in strength over the next few  days. Beyond 72 h, the intensity forecast becomes murky as there  is now a high level of uncertainty as to where Wanda may be headed  later this week. The previous NHC forecast had the cyclone moving  over much cooler waters late this week. However, the latest shift in  the track guidance suggests the cyclone could remain over the  current 24 degrees C waters throughout the next 5 days. Regardless  of the differing tracks and resulting sea surface temperatures  below, the cold pool of air in the upper troposphere that has been  giving Wanda a chance to maintain its deep convection will begin to  vanish by midweek, therefore, weakening is indicated in the  official NHC intensity forecast. The latest NHC intensity forecast  was decreased slightly from the previous one, and is close to the  various intensity consensus solutions.    FORECAST POSITIONS AND MAX WINDS  INIT  31/2100Z 36.3N  43.2W   45 KT  50 MPH  12H  01/0600Z 35.7N  43.0W   45 KT  50 MPH  24H  01/1800Z 35.2N  42.2W   45 KT  50 MPH...TROPICAL CYCLONE  36H  02/0600Z 35.6N  41.1W   45 KT  50 MPH  48H  02/1800Z 36.8N  40.2W   45 KT  50 MPH  60H  03/0600Z 38.6N  39.7W   45 KT  50 MPH  72H  03/1800Z 40.7N  39.4W   45 KT  50 MPH  96H  04/1800Z 44.1N  37.0W   45 KT  50 MPH 120H  05/1800Z 45.4N  32.0W   40 KT  45 MPH...POST-TROPICAL  $$ Forecaster Latto   

  000 WTNT31 KNHC 312038 TCPAT1  BULLETIN Subtropical Storm Wanda Advisory Number   4 NWS National Hurricane Center Miami FL       AL212021 900 PM GMT Sun Oct 31 2021  ...WANDA CREEPING OVER THE CENTRAL ATLANTIC WATERS... ...MAY TRANSFORM INTO A TROPICAL CYCLONE SOON...   SUMMARY OF 900 PM GMT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...36.3N 43.2W ABOUT 900 MI...1445 KM W OF THE AZORES MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 1 MPH...2 KM/H MINIMUM CENTRAL PRESSURE...990 MB...29.24 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 Subtropical Storm Wanda was  located near latitude 36.3 North, longitude 43.2 West. The storm is  drifting toward the west near 1 mph (2 km/h). A slow southward  motion is expected tonight, followed by an eastward motion on  Monday, then a turn to the northeast or north on Tuesday.  Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Little change in strength is forecast during the next few days.  Winds of 40 mph extend outward up to 140 miles (220 km) from the center.  The estimated minimum central pressure is 990 mb (29.24 inches).   HAZARDS AFFECTING LAND ---------------------- None   NEXT ADVISORY ------------- Next complete advisory at 300 AM GMT.  $$ Forecaster Latto  

  000 WTNT21 KNHC 312038 TCMAT1  SUBTROPICAL STORM WANDA FORECAST/ADVISORY NUMBER   4 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL212021 2100 UTC SUN OCT 31 2021  THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.  SUBTROPICAL STORM CENTER LOCATED NEAR 36.3N  43.2W AT 31/2100Z POSITION ACCURATE WITHIN  30 NM  PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT   1 KT  ESTIMATED MINIMUM CENTRAL PRESSURE  990 MB MAX SUSTAINED WINDS  45 KT WITH GUSTS TO  55 KT. 34 KT....... 90NE  30SE  70SW 120NW. 12 FT SEAS..420NE 420SE 540SW 540NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.  REPEAT...CENTER LOCATED NEAR 36.3N  43.2W AT 31/2100Z AT 31/1800Z CENTER WAS LOCATED NEAR 36.5N  43.3W  FORECAST VALID 01/0600Z 35.7N  43.0W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 80NE  30SE  60SW 100NW.  FORECAST VALID 01/1800Z 35.2N  42.2W...TROPICAL CYCLONE MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 80NE  50SE  60SW  80NW.  FORECAST VALID 02/0600Z 35.6N  41.1W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 70NE  70SE  60SW  60NW.  FORECAST VALID 02/1800Z 36.8N  40.2W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 70NE  70SE  60SW  60NW.  FORECAST VALID 03/0600Z 38.6N  39.7W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 60NE  70SE  60SW  50NW.  FORECAST VALID 03/1800Z 40.7N  39.4W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 60NE  70SE  60SW  50NW.  EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY  OUTLOOK VALID 04/1800Z 44.1N  37.0W MAX WIND  45 KT...GUSTS  55 KT.  OUTLOOK VALID 05/1800Z 45.4N  32.0W...POST-TROPICAL MAX WIND  40 KT...GUSTS  50 KT.  REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 36.3N  43.2W  NEXT ADVISORY AT 01/0300Z  $$ FORECASTER LATTO   

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 311453 TCDAT1  Subtropical Storm Wanda Discussion Number   3 NWS National Hurricane Center Miami FL       AL212021 300 PM GMT Sun Oct 31 2021  Wanda is gradually taking on characteristics of a symmetric  warm-core cyclone, with bands of organized convection now located  across both the northern and southeastern portions of the  circulation. The 500-mb heights are slowing rising, while some  cirrus outflow is becoming evident to the north of the cyclone.  Although Wanda is still considered a subtropical storm due to the  presence of the surrounding baroclinic circulation and  upper-trough, the baroclinic circulation has been getting more  detached from the storm over time.  Even though the convective  structure continues to evolve, this convection has not been able to  become more concentrated near the system's core since last night.  Therefore, the initial advisory intensity remains 45 kt, which is  consistent with the latest average of the satellite intensity  estimates from TAFB, and UW-CIMSS ADT and SATCON.  The storm has slowed its forward motion and is now moving at 100/07  kt.  A turn to the southeast is expected today as Wanda wobbles  within the upper-level tropospheric trough that it is embedded  within.  The upper-trough is forecast to lift out on Monday,  leaving Wanda within the weak steering flow near a cutoff mid-level  trough.  By Tuesday, a ridge is forecast to build to the east of  the cyclone, resulting in a turn to the northeast or north, along  with an increase in forward speed.  By late this week, Wanda should  accelerate northeastward within the southwesterly mid-latitude flow.  The model guidance is in good agreement on this track scenario, and  the latest NHC track forecast is very similar to the previous one.  Despite being over sea surface temperatures below the ideal warmth  to support a classic tropical cyclone, the colder-than-typical upper  tropospheric temperatures over Wanda should continue to help support  deep convection for the next few days.  Therefore, some slight  strengthening is possible during that time. As mentioned above, the  upper-trough is expected to leave Wanda behind by Monday, which  should allow the cyclone to complete a tropical transition by that  time.  Various global model solutions within the Florida State  University cyclone phase evolution forecasts agree with this  scenario taking place over the next 24 h.  After 72 h, decreasing  water temperatures in the path of Wanda should cause the cyclone to  weaken and become post-tropical by the end of the 5-day forecast  period.  The latest NHC intensity forecast is unchanged from the  previous one, with the only change being the tropical phase of  Wanda beginning Monday.    FORECAST POSITIONS AND MAX WINDS  INIT  31/1500Z 36.4N  43.2W   45 KT  50 MPH  12H  01/0000Z 35.9N  42.8W   50 KT  60 MPH  24H  01/1200Z 34.9N  42.4W   50 KT  60 MPH...TROPICAL CYCLONE  36H  02/0000Z 34.8N  41.2W   50 KT  60 MPH  48H  02/1200Z 35.6N  40.0W   50 KT  60 MPH  60H  03/0000Z 37.4N  39.1W   50 KT  60 MPH  72H  03/1200Z 39.4N  38.7W   45 KT  50 MPH  96H  04/1200Z 43.4N  37.3W   45 KT  50 MPH 120H  05/1200Z 47.2N  30.0W   40 KT  45 MPH...POST-TROPICAL  $$ Forecaster Latto  

  767  WTNT31 KNHC 311452 TCPAT1  BULLETIN Subtropical Storm Wanda Advisory Number   3 NWS National Hurricane Center Miami FL       AL212021 300 PM GMT Sun Oct 31 2021  ...WANDA SLOWING DOWN... ...MAY TRANSITION TO A TROPICAL CYCLONE BY MONDAY...   SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...36.4N 43.2W ABOUT 895 MI...1445 KM W OF THE AZORES MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...E OR 100 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES   WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect.   DISCUSSION AND OUTLOOK ---------------------- At 300 PM GMT (1500 UTC), the center of Subtropical Storm Wanda was located near latitude 36.4 North, longitude 43.2 West. The storm is moving toward the east near 8 mph (13 km/h). A turn to the  southeast is expected today, followed by an eastward motion on  Monday, then a turn to the northeast or north on Tuesday.  Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.  Slight strengthening is possible during the next couple of days, and  Wanda could transition to a tropical cyclone by Monday.   Winds of 40 mph extend outward up to 105 miles (165 km) from the center.  The estimated minimum central pressure is 987 mb (29.15 inches).   HAZARDS AFFECTING LAND ---------------------- None   NEXT ADVISORY ------------- Next complete advisory at 900 PM GMT.  $$ Forecaster Latto   

 ZCZC MIATCMAT1 ALL TTAA00 KNHC DDHHMM  SUBTROPICAL STORM WANDA FORECAST/ADVISORY NUMBER   3 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL212021 1500 UTC SUN OCT 31 2021  THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.  SUBTROPICAL STORM CENTER LOCATED NEAR 36.4N  43.2W AT 31/1500Z POSITION ACCURATE WITHIN  30 NM  PRESENT MOVEMENT TOWARD THE EAST OR 100 DEGREES AT   7 KT  ESTIMATED MINIMUM CENTRAL PRESSURE  987 MB MAX SUSTAINED WINDS  45 KT WITH GUSTS TO  55 KT. 34 KT....... 90NE  30SE  70SW  90NW. 12 FT SEAS..420NE 420SE 540SW 540NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.  REPEAT...CENTER LOCATED NEAR 36.4N  43.2W AT 31/1500Z AT 31/1200Z CENTER WAS LOCATED NEAR 36.5N  43.3W  FORECAST VALID 01/0000Z 35.9N  42.8W MAX WIND  50 KT...GUSTS  60 KT. 50 KT...  0NE  40SE  40SW   0NW. 34 KT... 90NE  90SE  70SW  50NW.  FORECAST VALID 01/1200Z 34.9N  42.4W...TROPICAL CYCLONE MAX WIND  50 KT...GUSTS  60 KT. 50 KT...  0NE  40SE  40SW   0NW. 34 KT... 80NE  80SE  60SW  60NW.  FORECAST VALID 02/0000Z 34.8N  41.2W MAX WIND  50 KT...GUSTS  60 KT. 50 KT...  0NE  40SE  40SW   0NW. 34 KT... 80NE  80SE  60SW  60NW.  FORECAST VALID 02/1200Z 35.6N  40.0W MAX WIND  50 KT...GUSTS  60 KT. 50 KT...  0NE  40SE   0SW   0NW. 34 KT... 80NE  80SE  60SW  60NW.  FORECAST VALID 03/0000Z 37.4N  39.1W MAX WIND  50 KT...GUSTS  60 KT. 50 KT... 40NE  40SE   0SW   0NW. 34 KT... 60NE  80SE  60SW  50NW.  FORECAST VALID 03/1200Z 39.4N  38.7W MAX WIND  45 KT...GUSTS  55 KT. 34 KT... 60NE  80SE  60SW  50NW.  EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY  OUTLOOK VALID 04/1200Z 43.4N  37.3W MAX WIND  45 KT...GUSTS  55 KT.  OUTLOOK VALID 05/1200Z 47.2N  30.0W...POST-TROPICAL MAX WIND  40 KT...GUSTS  50 KT.  REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 36.4N  43.2W  NEXT ADVISORY AT 31/2100Z  $$ FORECASTER LATTO   NNNN 

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.

  479  WTNT41 KNHC 310841 TCDAT1  Subtropical Storm Wanda Discussion Number   2 NWS National Hurricane Center Miami FL       AL212021 900 AM GMT Sun Oct 31 2021  Satellite imagery indicates that the convection associated with  Wanda has become better organized since the last advisory, with a  convective band now wrapping more than halfway around the center.   However, the cyclone remains embedded in a deep-layer baroclinic  circulation, and based on this structure, the system is still a  subtropical storm.  Satellite intensity estimates are in the 40-50  kt range, and the intensity is set at a possibly conservative 45 kt.  The initial motion is a little slower toward the east-southeast at  105/14 kt.  As mentioned in the previous advisory, a slower  east-southeast to southeast motion is expected during the next day  or so as Wanda moves with the deep-layer trough that it is embedded  within.  After that time, the trough is expected to cut off, and  Wanda will likely meander on Monday before turning sharply northward  or northeastward by the middle of next week when the system moves in  the flow between the cut off low and a building ridge.  By the end  of the forecast period, the cyclone is expected to turn  northeastward in southwesterly mid-latitude flow.  The new track  guidance is similar to the previous guidance, but is a little slower  after 72 h. Thus, the new forecast track is similar to the previous  track and also slower in the later periods.  Given the increasing organization, it is likely that Wanda will  strengthen some during the next 24 h.  After that, the intensity  guidance suggests little change in strength through 48 h as the  cyclone moves over sea surface temperatures of 24 C.  Beyond 48 h,  gradual weakening is expected as Wanda moves over colder waters,  with the system expected to become post-tropical due to a lack of  convection by 120 h.  It should be noted that the GFS and UKMET  suggest the possibility that Wanda could transition into a tropical  storm by 48 h.  However, due to the expectation that the cyclone  will continue to remain embedded in a cold upper-level trough, the  intensity forecast will not explicitly call for tropical transition  at this time.   FORECAST POSITIONS AND MAX WINDS  INIT  31/0900Z 36.5N  43.9W   45 KT  50 MPH  12H  31/1800Z 36.2N  43.0W   50 KT  60 MPH  24H  01/0600Z 35.3N  42.8W   50 KT  60 MPH  36H  01/1800Z 34.6N  42.0W   50 KT  60 MPH  48H  02/0600Z 34.8N  40.7W   50 KT  60 MPH  60H  02/1800Z 36.2N  39.6W   50 KT  60 MPH  72H  03/0600Z 38.3N  39.0W   45 KT  50 MPH  96H  04/0600Z 43.0N  38.0W   45 KT  50 MPH 120H  05/0600Z 47.0N  32.5W   40 KT  45 MPH...POST-TROPICAL  $$ Forecaster Beven