| |
KF5JRV > WX 28.09.18 13:04l 62 Lines 2677 Bytes #999 (0) @ NA
BID : 22157_KF5JRV
Read: GUEST
Subj: NWS NHC Eastern N Pacific WX - Sept 28
Path: IW8PGT<CX2SA<HP2BWJ<LU4ECL<PI8LAP<PI8CDR<VE3TOK<VA3TOK<VE3UIL<VA7RBP<
KF5JRV
Sent: 180928/1125Z 22157@KF5JRV.#NWAR.AR.USA.NA BPQ6.0.16
692
WTPZ45 KNHC 280838
TCDEP5
Hurricane Rosa Discussion Number 13
NWS National Hurricane Center Miami FL EP202018
200 AM PDT Fri Sep 28 2018
Although enhanced BD-curve infrared imagery shows that Rosa's 20 n
mi wide eye has continued to warm (+16C) this morning, the southwest
quadrant of the eyewall appears to have weakened, or collapsed, and
the inner ring cloud tops have warmed considerably. This change in
the cloud pattern maybe the early stage of an eyewall replacement
cycle (ERC). It's certainly worth noting, however, that the
satellite presentation about 3 hours ago indicated that Rosa may
have reached a peak intensity of 130-135 kt which was also
indicated in the ADT adjusted raw T-numbers. For this advisory,
the initial intensity is set at 125 kt and is based on a compromise
of the subjective and objective satellite intensity estimates.
Rosa has a small window of opportunity to complete its ERC and
restrengthen before it encounters decreasing oceanic temperatures,
and increasing southwesterly shear. These inhibiting factors, along
with Rosa moving into a more stable air mass, should cause a
downward intensity trend by early next week, and for the cyclone to
weaken to a tropical storm by Tuesday, and a tropical depression as
it quickly moves northeastward over the southwestern U.S. The
intensity forecast is similar to my predecessor's and is close to
the IVCN consensus through 48 hours, then quite similar to the
NOAA-HCCA intensity model beyond that forecast period.
The initial motion is estimated to be westward, or 270/6 kt. A
mid-level ridge over the southwestern United States is forecast to
weaken over the next couple of days in response to an approaching
mid-level shortwave trough from the northwest. This growing
weakness in the ridge should influence Rosa to gradually turn
northward through mid-period, and afterward, turn northeastward
within the strong mid- to upper tropospheric southwesterly flow
produced by the aforementioned trough. The NHC track forecast was
adjusted ever so slightly to the left of the previous one to light
more closely to the TVCN and HCCA multi-model guidance.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0900Z 16.9N 117.3W 125 KT 145 MPH
12H 28/1800Z 17.4N 117.9W 130 KT 150 MPH
24H 29/0600Z 18.4N 118.4W 120 KT 140 MPH
36H 29/1800Z 20.1N 118.8W 100 KT 115 MPH
48H 30/0600Z 22.0N 118.8W 85 KT 100 MPH
72H 01/0600Z 25.9N 117.6W 65 KT 75 MPH
96H 02/0600Z 30.6N 115.0W 40 KT 45 MPH...INLAND
120H 03/0600Z 38.2N 109.4W 25 KT 30 MPH...POST-TROP/INLAND
$$
Forecaster Roberts
73 de Scott KF5JRV
Pmail: KF5JRV@KF5JRV.#NWAR.AR.USA.NA
email: KF5JRV@ICLOUD.COM
Read previous mail | Read next mail
| |
