INVEST 99L FORECAST SYNOPSIS…ISSUED OCT. 19, 2016…11:35 A.M. EDT

TROPICAL CYCLONE FORMATION: INVEST 99L: HIGH (80%)

Disclaimer:  This site is not affiliated with the National Hurricane Center, Hurricane Hunters, Storm Prediction Center, or National Weather Service.  ALL forecasts herein are the result of my analysis, and I am solely responsible for the content.
(T. F. “Storm” Walsh III)

For those who have donated to my site, your help has been greatly appreciated.  For those not aware, donations to my site help me offset my out of pocket expenses…such as some of the model maps you view on here, which are only available due to my subscription to the corresponding sites.  The F5 Data maps I post as well, is another out of pocket expense (monthly subscription).  Updates to software (weather related), and costs for my domain name are also out of pocket to me.  To donate, please click the DONATE button to the right.  Any help you provide is immensely appreciated!

CURRENT 2016 ATLANTIC TROPICAL CYCLONE TOTALS:

TOTAL STORMS: 14
HURRICANES: 6
MAJOR HURRICANES: 3
U.S.LANDFALLS: 5

StormW’s Seasonal Hurricane Forecast:
TOTAL STORMS: 13-15
HURRICANES: 6-7
INTENSE HURRICANES: 3-4

Good day everyone!

The area of cloudiness and showers NE of the Turks and Caicos Islands associated with a broad surface low, remains very disorganized.  The NHC states that upper level winds could become a little more conducive by Wednesday, and have now designated a HIGH (80%) probability of development during the next 5 days.

NHC 5 DAY GRAPHICAL TROPICAL WEATHER OUTLOOK
two_atl_5d0

The following information was available on INVEST 99L in the ATCF BTK 12Z product:

8:00 AM EDT Wed Oct 19
Location: 24.8°N 68.6°W
Moving: N at 5 mph
Min pressure: 1008 mb / 29.65 in
Max sustained: 35 mph

The 12 hour averaged motion yielded a 5 mph North drift.

Based on analysis of satellite loop imagery, a broad surface low can be identified.  Thunderstorm and shower activity is well east of this surface feature, as INVEST 99L continues to be affected by 30-40 kts of westerly wind shear.  The NHC indicates upper level winds are still forecast to become more conducive, and that a sub-tropical or tropical cyclone within the next couple of days.  The operational GFS and ECMWF do indicate development of 99L, however, there appears to be some conflicting data regarding wind shear.  The GFS wind shear forecast does indicate a small upper level anticyclone develops, which would allow for development of the system, however based on my analysis of the shear/200 mb streamline pattern forecast, upper elves winds may not become conducive until after 48  hours in the forecast period from 06Z this morning, or when 99L is well to the east of FL.  On the other hand, information on shear magnitude from the NOAA RUC TC Diagnosis page, indicate shear values remaining on an average of 20-30 kts.  Based on this, if development occurs, I believe it may be somewhat slower than forecast, and would most likely favor sub-tropical development.

CARIBBEAN SATELLITE LOOP IMAGERY
avn-l-caribbean

rgb-l-caribbean

INVEST 99L WIND SHEAR FROM CIMSS
tccaptureshear-99l

Forecast track should be considered preliminary given there isn’t any organized system at the moment.  For all intents and purposes at the moment, the forecast thinking is for 99L to eventually begin to move toward the NNW, then begin a turn to the NNE by the end of the week. Now, this is where we have 2 different scenarios.  Both the GFS and ECMWF EPS guidance keeps the system offshore and away from the U.S., which appears to be the idea the NHC is proposing.  The Operational GFS and ECMWF, indicate that the system merges with the 500 mb trof, creating another low which absorbs 99L, affecting portions of the New England area (GFS), or the system remaining subtropical, and coming ashore over the NE and New England region (ECMWF) in about 4 days.  This poses an unknown variable at the moment as far as future path.  Should this remain well offshore as indicated by the NHC, the possibility of some minor beach erosion at the time of high tide, as the system makes its CPA to the NE states, does exist, given the large SE to NW fetch, with seas possibly reaching 5-7 ft close to the coast.

GEFS GUIDANCE
gefs_al99_2016101906
GFS AND ECMWF OPERATIONAL
gfs_mslp_sig_watl_1

gfs_mslp_sig_watl_9

gfs_mslp_sig_watl_13

gfs_mslp_sig_watl_14

ecmwf_mslp_sig_watl_1

ecmwf_mslp_sig_watl_15

I will continue to monitor this, however will not have another update until late Sunday, which would place the system north of the New England area at that time.  The following NWS Warnings and Hazards display is provided, which will allow you to pull information from your local NWS office, should any hazards occur from this system by the weekend.  Mouse over, and click on your area of interest.  Please note, the graphic itself does not update automatically.

NWS WARNINGS AND HAZARD DISPLAY
us

Elsewhere, both the GFS and ECMWF indicate  a lowering of 500 mb pressure heights ENE of the Lesser Antilles in about 6 days

GFS 500 MB NORMALIZED ANOMALY 132 HOURS
gfs_z500_norm_atlantic_23

Elsewhere, Tropical Storm formation is not expected during the next 7-10 days.

Have a blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
CoCoRAHS OBSERVER

Advertisements

About palmharborforecastcenter

I am a Tropical Forecast meteorologist, providing hurricane forecasts during the Atlantic Hurricane Season. I retired from the U.S. Coast Guard in July of 2001. Meteorology became my passion in high school, and I have continued my educational background in meteorology since 1996, when I undertook the study of Tropical Meteorology. While working toward my degree, I had to unexpectedly withdraw from college due to my oldest sons medical reasons. I do however, meet the educational criteria of the AMS to be recognized as a meteorologist. Studies include, but are not limited to the Navy Aerographers Mate course, Naval METOC meteorology course, Meteorology 2010 Sophomore level course while attending St. Petersburg College, Clearwater, FL., Basic Forecasting course for operational meteorologists from Rapid WX, meteorology institute, a four month meteorological internship, and extensive research on numerous meteorological topics such as the MJO, NAO, satellite imagery interpretation, etc. I have been forecasting Tropical Weather (Tropical Storms and Hurricanes) since 1996, with my main client being three different Coast Guard Commands.
Image | This entry was posted in Tropical Synopsis. Bookmark the permalink.

5 Responses to INVEST 99L FORECAST SYNOPSIS…ISSUED OCT. 19, 2016…11:35 A.M. EDT

  1. dellamom says:

    Storm, thank you for all your hard work on our behalf. I see today where the NHC has the disturbance near the Caribbean islands as only a medium development chance, but they also have it not curving. Even if it does not develop and is “merely” a disturbance, Florida, Georgia and the Carolinas can’t take much more in the way of weather, I would imagine, nor can Bermuda if it does decide to curve eastward. Prayers to all in the path of whatever becomes of this disturbed weather.

  2. originallt says:

    Thanks Storm. You must be real busy!

  3. dellamom says:

    Thank you, Storm.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s