128 
WTNT45 KNHC 051439
TCDAT5

Tropical Depression Omar Discussion Number  20
NWS National Hurricane Center Miami FL       AL152020
1100 AM AST Sat Sep 05 2020

Omar is barely a tropical cyclone.  The center is completely exposed 
to the north of a slowly shrinking area of sheared deep convection.  
The initial intensity is held at 30 kt for this advisory.  Omar 
remains in an environment of northerly wind shear, dry air, and it 
is headed toward cool waters.  These conditions should cause Omar to 
finally become a remnant low soon.  Although the forecast shows the 
system becoming a remnant low at 24 hours, it certainty could become 
one at any time before then after its limited amount of deep 
convection dissipates.  Satellite images show an approaching cold 
front about 300 n mi to the northwest of Omar.  This front is 
expected to merge with the system, causing Omar or its remnants to 
become extratropical by Sunday afternoon.

The tropical depression is now moving northward at 9 kt.  A much 
faster north-northeast to northeast motion is expected during the 
remainder of the weekend as Omar, or its remnants, become more 
embedded in the fast steering flow ahead of the aforementioned cold 
front.

FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 37.4N  57.3W   30 KT  35 MPH
 12H  06/0000Z 39.0N  56.3W   30 KT  35 MPH
 24H  06/1200Z 41.9N  53.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  07/0000Z 45.2N  49.7W   30 KT  35 MPH...POST-TROP/EXTRATROP
 48H  07/1200Z...DISSIPATED

$$
Forecaster Cangialosi

000
WTNT45 KNHC 040232
TCDAT5

Tropical Depression Omar Discussion Number  14
NWS National Hurricane Center Miami FL       AL152020
1100 PM AST Thu Sep 03 2020

The larger mass of deep convection from earlier today that was south 
of the exposed low-level center of Omar has since dissipated. The 
only convection that remains is a few small patches in the eastern 
semicircle. The initial intensity is being lowered to 25 kt, and is 
based off a recent ASCAT overpass showing peak 26 kt wind vectors. 
If the current state of the tropical depression persists through 
much of tonight, then by definition the system would no longer 
qualify as a tropical cyclone. The only chance for Omar to hang on 
despite very strong northerly wind shear is the fact that it is 
still over SSTs of about 27 C. After 24 h, dry air is expected to 
envelop the system. Therefore, over this weekend whatever remains of 
Omar is expected to dissipate ahead of an approaching mid-latitude 
frontal system. The official NHC forecast shows Omar degenerating 
into a remnant low by Friday morning and dissipating by Sunday 
morning, and this scenario is in agreement with the global models.

The depression continues to move east-southeast at 9 kt in steering
flow around a subtropical ridge to its south, and another, larger
low pressure system to its northeast. The other low is forecast to
continue to lift northeastward, which should result in an end to the
southerly component of Omar's motion tonight or early Friday. By
Friday night, a turn to the northeast is expected to occur as Omar
gets caught in southwesterly flow ahead of the approaching frontal
system. The latest NHC track forecast is little changed from the
previous one, and lies near the various consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 35.2N  59.1W   25 KT  30 MPH
 12H  04/1200Z 35.2N  58.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  05/0000Z 35.6N  57.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  05/1200Z 36.8N  56.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  06/0000Z 38.3N  55.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  06/1200Z...DISSIPATED

$$
Forecaster Latto

000
WTNT45 KNHC 021448
TCDAT5

Tropical Storm Omar Discussion Number   8
NWS National Hurricane Center Miami FL       AL152020
1100 AM AST Wed Sep 02 2020

Although is seems as though we've been predicting it ad nauseam,
the persistent, blistering shear has finally begun to dramatically
affect the cyclone.  What remains of the deep convective cloud mass
is separated more than 100 miles east-southeast of the exposed
surface circulation.  The initial intensity is held at 35 kt based 
on the Dvorak satellite intensity estimates from TAFB and SAB using 
the shear scene-type.  Omar's winds should begin to decrease later 
tonight as the exposed surface center further decouples from the 
convective mass.  A few of the large-scale models show Omar 
dissipating as soon as Friday, but for this NHC intensity forecast, 
I'll indicate weakening to a depression Thursday, followed by 
degeneration to a remnant low in 36 hours, similar to the 
multi-model consensus intensity aids and the LGEM.  

Omar's initial motion is estimated to be eastward, or 080/11 kt, and 
is being steered by the deep-layer mid-latitude westerlies produced 
by a subtropical ridge anchored over the central Atlantic.  Omar 
should continue on this general course through Friday.  On 
Saturday, the remnant low is expected to slow a bit, and turn 
toward the east-northeast in response to an approaching frontal 
boundary moving away from the Canadian Maritimes.  No significant 
changes were made to the previous track forecast, and the new NHC 
forecast is based on a blend of the HCCA and GFEX consensus models.



FORECAST POSITIONS AND MAX WINDS

INIT  02/1500Z 36.2N  67.4W   35 KT  40 MPH
 12H  03/0000Z 36.5N  65.4W   35 KT  40 MPH
 24H  03/1200Z 36.5N  62.4W   30 KT  35 MPH
 36H  04/0000Z 36.3N  59.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  04/1200Z 36.2N  58.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  05/0000Z 36.4N  56.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  05/1200Z 37.0N  55.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  06/1200Z...DISSIPATED

$$
Forecaster Roberts

000
WTNT45 KNHC 010239
TCDAT5

Tropical Depression Fifteen Discussion Number   2
NWS National Hurricane Center Miami FL       AL152020
1100 PM EDT Mon Aug 31 2020

Tropical Depression Fifteen is a sheared tropical cyclone, with the 
edge of the deep convection displaced nearly 30 n mi to the east of 
the exposed low-level center. An Air Force Reserve Hurricane Hunter 
mission earlier this evening provided SFMR instrument measurements 
of nearly 30 kt in the southeast quadrant. And, a recent ASCAT 
overpass showed several wind vectors in that same general area 
between 25-30 kt. Therefore, the initial intensity is being held at 
30 kt. 

The depression is moving northeast at 12 kt around the northwestern 
periphery of the subtropical ridge. A turn to the east-northeast is 
expected to occur on Tuesday as the cyclone moves along the 
northern periphery of the ridge. Late in the forecast period, what 
is left of the cyclone is forecast to get caught in the flow 
between building high pressure to its northeast, and an approaching 
trough to its northwest, which should induce a more northerly 
component of motion. The latest NHC forecast is little changed from 
the previous one, and is near the tightly clustered track guidance. 

The cyclone has moved into an environment with moderate westerly 
shear of about 20 kt, as indicated by the latest UW-CIMSS deep-layer 
shear analysis product. The SHIPS guidance by both the GFS and ECMWF 
indicate that the shear magnitude will more than double between 18 h 
and 36 h from now.  So it is anticipated that the only window of 
time for the depression to strengthen will be tonight through 
tomorrow, while the system is over warm waters and in a moist 
atmospheric environment. After 48 h, when the vertical wind shear is 
forecast to be between 40 and 50 kt, the cyclone is forecast to 
weaken, and by 96 h the NHC forecast now shows the system 
degenerating into a remnant low. Exactly what transpires with the 
cyclone later in the forecast period remains uncertain, as some of 
the global models suggest that the cyclone will open into a trough 
in a few days, while others indicate that the system could be 
absorbed by a larger mid-latitude trough around day 5. Regardless of 
what occurs by those time frames, the models all suggest that the 
system should not gain much more strength than it currently has. The 
official NHC intensity forecast is in good agreement with the 
various intensity consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 33.2N  75.7W   30 KT  35 MPH
 12H  01/1200Z 34.2N  74.0W   35 KT  40 MPH
 24H  02/0000Z 35.1N  71.2W   35 KT  40 MPH
 36H  02/1200Z 36.0N  68.6W   35 KT  40 MPH
 48H  03/0000Z 36.9N  65.9W   35 KT  40 MPH
 60H  03/1200Z 37.7N  63.3W   30 KT  35 MPH
 72H  04/0000Z 38.1N  60.5W   30 KT  35 MPH
 96H  05/0000Z 38.7N  55.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  06/0000Z 41.6N  50.4W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Latto