This makes Sandra the 18th named storm of the 2015 eastern North Pacific hurricane season. Our friends and families in Texas should keep a close eye on the development of this storm. TS Sandra is forecast to become a hurricane 11-25-15 and follow almost the same path as Hurricane Patricia on 10-23-15. NHS Eastern Pacific Link: http://www.nhc.noaa.gov/?epac Sandra Link: http://www.nhc.noaa.gov/graphics_ep2.shtml?5-daynl#contents
USNO JWTC: http://www.usno.navy.mil/JTWC/ JTWC Sandra Forecast Plot: http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/warnings/ep2215.gif
Latest GOES Satellite imagery showing water vapor formation: Link: http://www.ssd.noaa.gov/goes/comp/nhem/wv-animated.gif
SANDRA PRONÓSTICO PARA FORTALECER HOY - CAT 2 El Centro Nacional de Huracanes divulga un nuevo video sobre la surgencia en Español http://www.nhc.noaa.gov/pdf/20151120_pa_SpanishStormSurgeVideo_sp.pdf http://w4ehw.fiu.edu/wx4nhc-contact.html
One interesting note from this mornings 0800 AM forecast discussion. The 2015 hurricane season ends November 30. Latest projection shows Sandra at only 40 knots (gusts to 50) when reaching Cabo San Lucas on 11-28-15 1200 UTC. (1 knot <kt> equals 1.15 mph) 000 WTPZ42 KNHC 251435 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 800 AM MST WED NOV 25 2015 Sandra's convective pattern continues to become better organized, and a pinhole eye was observed in a 1201 UTC SSMIS microwave pass. An eye has also been apparent in the latest infrared satellite images. The intensity is increased to 85 kt based on Dvorak estimates of T5.0/90 kt from TAFB and T4.8/85 kt from the UW-CIMSS ADT. This intensity makes Sandra the strongest hurricane in the eastern North Pacific Ocean for this late in the year (the previous record was Hurricane Winnie of 1983, which reached an intensity of 80 kt on December 6).
CAT 3 is forecast to last only a few hours.......... Outer bands of Sandra reached the southern edge of Texas about 11-25-15 1900 UTC. 000 WTPZ42 KNHC 252033 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 200 PM MST WED NOV 25 2015 Sandra's intensification has continued at a rapid pace. The hurricane now has a clearer eye in infrared satellite imagery that is completely surrounded by a white ring on the Dvorak enhancement curve. Dvorak estimates from TAFB and SAB were T5.5/102 kt and T5.0/90 kt, respectively, although data-T numbers were up to 6.0. The UW-CIMSS ADT scheme has been flopping between different scene types, but when it has used an eye pattern it has yielded estimates in the 5.5-6.0 range. Based on these numbers, the initial intensity is raised to 100 kt, making Sandra a category 3 hurricane. There have now been 9 major hurricanes over the eastern North Pacific Ocean during the 2015 season, which is a record for that basin.
At 11-26-15 0400 UTC the hurricane eye is moving north on the 110 degree longitude meridian. Cabo San Lucas is at about 22.5 degrees north at 110 degrees west just north of the GOES image in post #5. All images in this thread update when viewed. 000 WTPZ42 KNHC 260239 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 800 PM MST WED NOV 25 2015 The intensification of Sandra seems to have slowed during the past few hours. The cloud tops in the eyewall have continued to cool with temperatures now colder than -80C. However, as this has occurred the eye has become less distinct. Satellite intensity estimates are 115 kt from SAB and 102 kt from TAFB, and there is a recent CIMSS ADT estimate of 110 kt. A blend of these data is used for the initial intensity of 105 kt.
Sandra has reached CAT 4 and still moving due north. 000 WTPZ42 KNHC 260835 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 200 AM MST THU NOV 26 2015 Sandra has intensified during the past few hours. The eye has become quite distinct and is surrounded by an area of very deep convection. CIMSS ADTs have been oscillating around 6.5, which is the same as the T-number provided by TAFB. On this basis, the initial intensity has been increased to 125 kt, making Sandra a category 4 hurricane. Most likely, Sandra has already reached its peak intensity, and although the ocean is still warm, the hurricane is expected to soon encounter very strong southwesterly shear, which should result in rapid weakening. This is reflected in both the GFS and the ECMWF global models which separate the mid-level circulation for the surface center in about 36 to 48 hours due to shear. Sandra is expected to be a weakening storm by the time its center passes south of the southern portion the Baja California peninsula in about 48 hours. The cyclone is forecast to be a dissipating remnant low over mainland Mexico in about 3 days.
000 WTPZ42 KNHC 261439 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 800 AM MST THU NOV 26 2015 Sandra has begun to fill. The well-defined eye seen in conventional satellite imagery overnight has since disappeared while the shape and distribution of deep convection within the central dense overcast has become asymmetric. The onset of weakening coincides with an increase in southwesterly vertical shear as depicted in UW-CIMSS shear analyses now that Sandra is well north of the upper-level ridge axis. Dvorak intensity estimates are decreasing, and the initial intensity is lowered to 115 kt in agreement with the latest TAFB satellite classification.
000 WTPZ42 KNHC 262002 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 200 PM MST THU NOV 26 2015 Sandra's satellite presentation features a large CDO and impressive outflow in the northern semicircle. However, increasing shear has begun to restrict outflow in the southwestern quadrant. The initial intensity has been lowered to 105 kt based on a blend of the latest Dvorak Final-T and CI numbers (T5.0/6.0) from TAFB and SAB. Further quick weakening is expected as the shear is forecast to increase to about 35 kt in 24 hours and 50 kt by 48 hours. This should result in Sandra's low-level circulation becoming decoupled as the mid- and upper-level warm core is sheared off to the northeast. The new NHC intensity forecast closely follows the latest SHIPS model guidance, and shows Sandra weakening to a remnant low by 48 hours. A 72-h point is shown for continuity, but the low-level center of Sandra should dissipate quickly after it moves inland over mainland Mexico after 48 hours.
000 WTPZ42 KNHC 270257 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 800 PM MST THU NOV 26 2015 Despite the presence of at least 25 kt of southwesterly vertical wind shear, the satellite appearance of Sandra unexpectedly improved near 0000 UTC when the eye became better defined. Whatever re-intensification this represents has ended, however, as the eye has again begun to lose definition. The initial intensity will be held at 105 kt for this advisory, and the hurricane could have been a little stronger than that three hours ago based on satellite intensity estimates. In addition to heavy rains over portions of Mexico, the remnant mid-/upper-level moisture associated with Sandra will contribute to a significant precipitation event expected to occur over portions of the south-central United States this weekend. For more information on this event, please see products from the NOAA Weather Prediction Center and local NWS Weather Forecast Offices.
000 WTPZ42 KNHC 270834 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 200 AM MST FRI NOV 27 2015 It appears that the strong shear is finally affecting the structure of the hurricane. The cloud pattern has rapidly deteriorated and the eye is no longer observed. In fact, most of the deep convection is now on the northeastern portion of the cyclone. Both objective and subjective numbers are decreasing, and the initial intensity has been lowered to 90 kt. The shear is forecast to increase even more, and most of the global models continue to separate the surface center from the mid-level circulation. As suggested by guidance, the NHC forecast calls for weakening and brings Sandra near the coast of mainland Mexico below tropical storm strength.
