*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********
...WEDNESDAY OCTOBER 16 2019 11:09 PM EDT...
Tropical depression fifteen dissipates over the Republic of Cabo Verde before having the chance to deliver impacts to the islands..see remnants of fifteen section below for details. See area of interest sections below for all areas being monitored for tropical cyclone formation. Elsewhere...the broad western Atlantic surface trough of low pressure well northeast of Puerto Rico is currently disorganized...and is being disrupted by upper vorticity currently extending from an eastern Canada upper trough. Because upper-level winds will be more favorable to area of interest #2 approaching from the southeast...I suspect this disturbance will not develop while getting absorbed by the area of interest in about 24 to 48 hours.
REMNANTS OF FIFTEEN...Southwesterly wind shear and dry saharan air have taken their toll on tropical depression fifteen moving through the Republic of Cabo Verde Islands...this system has degenerated into a surface trough of low pressure absent of thunderstorms before having the chance to produce notable weather over the islands. As this system is no longer a tropical cyclone...this is my final statement on this feature on this blog.
AREA OF INTEREST #1...The developing tropical low pressure located over coastal Veracruz and offshore Bay of Campeche waters continues shifting north as it transitions into a system supported by the eastern divergence zone of a Texas cut-off upper trough left behind by the central US frontal system moving through the Great Lakes...therefore once again adjusting my forecast to be much faster to the northeast than before. I have also increased the odds of tropical cyclone formation as the thunderstorm activity on the east side of the developing circulation has become more expansive and better organized. It appears we may be in for an unusual setup...one could argue subtropical in nature...as this system now appears it will move rapidly northeastward with the supportive cold core cut-off upper trough...across the Gulf of Mexico and into northern Florida already by 48 hours. After 48 hours...as this system settles on the west side of the fast-moving surface ridge currently over the central US...the ridge appears it will block this system from moving eastward out to sea...likely bending the track of this system northward parallel to the eastern US coast. Although the cold core cut-off upper trough shifts southeastward and away while warm core upper ridging builds overhead in warm air advection ahead of two strong frontal lows forecast to eject from the western US during the forecast period...I drop the odds of tropical cyclone formation to 50% at 96 and 120 hours as the 96-hour point is southeast of the warm Gulf stream waters...and the 120-hour forecast point is north of the Gulf stream. Regardless of tropical cyclone formation or not...the cut-off upper trough looks like it will produce a surface circulation capable of heavy rainfall and possibly some damaging gusty winds for coastal Alabama...southern Georgia...and northern Florida in as soon as 48 hours.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Oct 18)...70% chance of tropical cyclone formation (western Gulf of Mexico near 24N-95W)
IOH 48 Hr Outlook (0000Z Oct 19)....70% chance of tropical cyclone formation (northeastern Gulf of Mexico near 27.5N-87.5W)
IOH 72 Hr Outlook (0000Z Oct 20)...70% chance of tropical cyclone formation (offshore of the southeastern United States near 31N-79W)
IOH 96 Hr Outlook (0000Z Oct 21)...50% chance of tropical cyclone formation (offshore of the eastern United States near 34N-71W)
IOH 120 Hr Outlook (0000Z Oct 22)...50% chance of tropical cyclone formation (south of Cape Cod Massachusetts near 39N-70W)
AREA OF INTEREST #2...The tropical wave in the central Atlantic now east of the Lesser Antilles is currently featuring a few disorganized thunderstorm pockets...watching to see if this activity increases in the next couple of days while the wave interacts with the eastern divergence zone of a sharp upper trough over the Lesser Antilles to be cut-off from its parent upper trough over the northwest Atlantic/eastern Canada by amplfiying Gulf of Mexico upper ridging. I have dropped the odds of tropical cyclone formation due to the current disorganized appearance of the thunderstorm activity...and will only increase them should concentrated and organized thunderstorms develop in the divergence zone of the cut-off upper trough. Because the upper trough will be sharp in nature...this will keep wind shear lower over this disturbance which could aid in tropical development. The upper trough will also likely curve any disturbance that develops northward. In addition a northward turn would be induced in the low-levels as the Great Lakes frontal system moves into the western Atlantic. My forecast points are adjusted eastward as the latest GFS model run has the north portion of the upper trough titled further to the east. After 48 hours...the surface ridge weakness begins closing...which would begin a westward turn of any disturbance that develops. My longer range forecast track is adjusted southward as it no longer appears in the modeling that broad upper westerly flow in the wake of the Great Lakes frontal system will overspread the western Atlantic and try to drag any tall circulation that this disturbance develops northward. Instead an area of upper anticyclonic flow with less shear is now shown in the latest GFS model to occur out ahead of the cut-off upper trough supporting area of interest #1...thus I show rising instead of lowering odds of development in the longer range. But as the cut-off upper trough from area of interest #1 seperates from that area of interest and settles over this disturbance by 120 hours...it could either disrupt the disturbance which is why I show slightly lower odds by then...or alternatively re-energize the disturbance with its eastern divergence zone...and in a low shear environment as this cut-off upper trough too is shown in the latest GFS to be sharp in nature as well.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Oct 18)...0% chance of tropical cyclone formation (just east of the northern Lesser Antilles near 17.2N-59.2W)
IOH 48 Hr Outlook (0000Z Oct 19)...10% chance of tropical cyclone formation (just northeast of the northern Lesser Antilles near 20N-59.2W)
IOH 72 Hr Outlook (0000Z Oct 20)...15% chance of tropical cyclone formation (northeast of Puerto Rico near 22.2N-62.5W)
IOH 96 Hr Outlook (0000Z Oct 21)...20% chance of tropical cyclone formation (western Atlantic near 23N-66W)
IOH 120 Hr Outlook (0000Z Oct 22)...15% chance of tropical cyclone formation (western Atlantic near 24N-68W)