Basement-dwelling pseudo-otaku with a thrill for forecasting on the side.
By: KoritheMan , 4:59 AM GMT on October 26, 2013
Tropical Storm Raymond continues to move over the open Pacific well away from any land areas. As of the latest NHC advisory, the following information was posted on the storm:
Wind: 50 mph, with higher gusts
Location: 12.9°N 110.8°W
Movement: WSW at 10 mph
Pressure: 1000 mb
Raymond has mysteriously not strengthened in what I would deem as a favorable environment. A blend of the various satellite estimates suggests that the NHC's operational intensity of 45 kt is probably a decent one, A 1630Z ASCAT pass captured the circulation of Raymond and indicates that it has become less-defined, and that the winds may not even be 40 kt, much less 45 kt.
Figure 1. Latest infrared satellite image of Tropical Storm Raymond. Image credit: NOAA's Satellite Services Division (SSD).
Raymond's cloud pattern is a little amorphous-looking, with microwave data suggesting the center lies along the northern edge of the small area of central convection. In addition, the orientation of the large and linear convective band to the south kind of gives the hint that Raymond may be caught up in the ITCZ. While there's not a ton of evidence to support this assertion, it is a possibility; additionally, northeasterly shear appears to be affecting the cyclone due to a deep-layer ridge over the Gulf of Mexico. Since there does not appear to be enough dry air in the near storm environment to cause the disheveled appearance of the cyclone, and since the waters are warm, the aforementioned factors are the best in situ explanations I can infer; perhaps a post-season analysis by the National Hurricane Center and yours truly will shed some light on the situation.
The above factors notwithstanding, all known meteorological parameters appear conducive for strengthening, and Raymond is still forecast to regain hurricane strength in a couple of days. After that time, the SHIPS and GFS show southerly shear increasing significantly as a mid- to upper-level trough currently off the coast of California digs southward over the subtropical Pacific. In addition, waters will gradually cool and the air will become less buoyant, both of which should aid the shear in what should be a rather quick decapitation of Raymond at longer ranges. Raymond is anticipated to become a remnant low on day five, but it could occur as much as 24 hours sooner.
Based on a couple of microwave passes over the last few hours, Raymond appears to have continued to move west-southwest. However, Raymond is about to encounter a steering change that goes from southeasterly to easterly as the ridge stabilizes and the cyclone moves underneath its southern periphery. This should cause Raymond to assume a due westward motion over the next 24-36 hours. Subsequent to that period, Raymond is expected to encounter a well-established break in the subtropical ridge near 120W and turn northward and northeastward. The GFS continues to be significantly faster than the ECMWF, taking Raymond to a landfall in southern Baja in five days as Raymond follows the trough. The ECMWF shows a somewhat weaker Raymond at those time ranges that appears more reasonable given current and expected forecast trends, and my forecast is close to the National Hurricane Center prediction, and leans more strongly to the ECMWF scenario of a shear apart and stall situation.
Raymond is not very likely to make landfall in Baja as a tropical cyclone, much less reach the latitude and longitude of that peninsula.
Intensity forecast and positions
INITIAL 10/26 0300Z 12.7°N 111.0°W 45 KT 50 MPH
12 hour 10/25 1200Z 12.7°N 112.7°W 45 KT 50 MPH
24 hour 10/27 0000Z 12.7°N 114.6°W 50 KT 60 MPH
36 hour 10/26 1200Z 12.9°N 116.0°W 55 KT 65 MPH
48 hour 10/28 0000Z 14.1°N 117.2°W 65 KT 75 MPH
72 hour 10/29 0000Z 16.7°N 116.7°W 55 KT 65 MPH
96 hour 10/30 0000Z 18.2°N 115.8°W 40 KT 45 MPH
120hour 10/31 0000Z 19.0°N 114.8°W 30 KT 35 MPH...POST-TROPICAL/REMNANT LOW
Figure 2. My forecast track for Raymond.
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.