TROPICAL STORM DANNY FORECAST SYNOPSIS…ISSUED AUG. 19, 2015…1:25 P.M. EDT

SEVERE WEATHER THREAT: SLIGHT
TROPICAL STORM FORMATION: TROPICAL STORM DANNY

ALL forecasts contained on this site,  are based on my analysis and knowledge of various forecast tools, including information contained in NHC products, and are not copies from any other entity.

*NOTE: In the TROPICAL STORM FORMATION line above, probabilities are for during the next 5 day period.  My personal probability will be listed as either NONE, MONITORING or PROBABLE.  This does not necessarily mean something will develop, but that certain forecast conditions are likely to be present, favoring development.  Once NHC products become available, then the appropriate probability and percentage will be used.

Please refer to the link for the Storm Prediction Center in the box at the top of the page, just below the Hurricane Hunter graphics.

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 personal out of pocket expenses…such as some of the model maps you view on here, are only available due to my subscription to the corresponding site.  The F5 Data maps I post, also 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.  Any help you provide is immensely appreciated!  Although it may seem I am not here and working in support of your donation, I have to work my forecasting time around my ever changing work schedule.
money-dog-300x300

Current Storm Total for 2015:

TOTAL STORMS: 4
HURRICANES: 0
INTENSE HURRICANES: 0
U.S. LANDFALLS: 2

StormW Seasonal Forecast:

TOTAL STORMS:             8
HURRICANES:                   3
INTENSE HURRICANES: 1

Good day everyone!

Tropical Storm Danny continues to move to the west at around 12 mph.  As of the 11:00 a.m. advisory from the NHC, the following information was available on Danny:

Location: 11.2°N 41.1°W
Moving: W at 12 mph
Min pressure: 1000 mb /29.53 in
Max sustained: 50 mph

The following maps are from HURREVAC, and are the same as the NHC tracking maps.

HURREVAC NHC TRACKING MAPS
HURREVAC.DANNY

HURREVAC.DANNY72

Satellite imagery this morning indicates DANNY is not as impressive as he appeared yesterday evening.  The main factor for this, is the entertainment of some slightly drier air on the south and SE portion of the storm, as seen in close up water vapor satellite loop imagery.  There is also noted some possible slight interaction and competition with convection to the east of DANNY.

DANNY FLOATER SATELLITE LOOP IMAGERY
avn0-laloDANNY

rgb0-danny

DANNY WATER VAPOR LOOP
wv0-lalodanny

CATL SATELLITE LOOP
avncatl-l

Another slight mitigating factor is, earlier, the upper level anticyclone (clockwise flow) over DANNY was displaced somewhat to the west, possibly inducing a very slight tilt in the storm.

CIMSS WIND SHEAR FROM THIS MORNING
tccaptureshear

Based on analysis of the wind shear forecast maps, upper level winds are forecast to remain conducive for further slow development of DANNY.  The GFS indicates keeping an upper level anticyclone over DANNY, for at least the next 5-6 days in the forecast period.  This same time frame places the storm at or over the northern Leeward islands.  Based on the premise of favorable upper level winds over the next 5-6 days, the only real inhibiting factor in DANNY strengthening would be dry air intrusion.  However, satellite loop images would indicate the core of DANNY has become a little tighter.  Close up water vapor imagery seems to indicate that the environment around DANNY is not too terribly dry, and loop imagery seems to indicate thunderstorm activity may be trying to wrap around the center from the NW.  It is unknown at the moment whether this is a trend, or just intermittent.  Given the tight core, DANNY could begin to mix out some of the dry air, as he approaches some higher OHC over the next 36-48 hours.

GFS WIND SHEAR FORECAST
850200shear20

GFS 200 MB STREAMLINE FORECAST
200 mb streamline
OHC MAP
tccaptureohc

Based on the premise of the upper level wind forecast, and higher OHC, and the uncertainty of how much dry air may be entrained, I have to concur with the NHC intensity forecast for the next 5 days.  The 12Z intensity forecast models have backed down somewhat on intensity as well.

NHC INTENSITY FORECAST

FORECAST POSITIONS AND MAX WINDS
INIT 19/1500Z 11.2N 41.1W 45 KT 50 MPH
12H 20/0000Z 11.4N 42.6W 50 KT 60 MPH
24H 20/1200Z 11.9N 44.2W 55 KT 65 MPH
36H 21/0000Z 12.4N 45.8W 60 KT 70 MPH
48H 21/1200Z 13.1N 47.5W 70 KT 80 MPH
72H 22/1200Z 14.4N 51.5W 80 KT 90 MPH
96H 23/1200Z 15.6N 56.2W 75 KT 85 MPH
120H 24/1200Z 16.6N 61.5W 70 KT 80 MPH

12Z ATCF INTENSITY MODELS
DANNY 12Z INTENSITY GUIDANCE

DANNY continues to move toward the west, however satellite loop images indicate more of a WNW motion over the past few hours, which would coincide more given the weakness in the subtropical ridge to the NW of the storm.  Based on my analysis of forecast steering maps, DANNY should continue this motion during the next 48-72 hours.  Thereafter, track will depend on two things…the strength of DANNY, and how fast ridging builds back in north of the storm.  Based on a blend of the global models, consensus, and GFS Ensemble models, I have to agree with the NHC forecast track at the moment. This is based on the premise of DANNY following the intensity guidance, in being a weaker hurricane than originally anticipated.  Should he strengthen more, he would have a tendency to follow a track possibly just skirting the northern Antilles.

12Z DYNAMIC MODEL TRACK GUIDANCE
DANNY 12Z DYNAMIC GUIDANCE

CONSENSUS MODELS
DANNYLATE.CONSENSUS

GFS ENSEMBLES
DANNY.LATEGFSENS
Based on all of these parameters, Hurricane Watches could be posted for areas within the error cone sometime on Saturday.

All interests in the Windward and Leeward islands should closely monitor the progress of Danny during the next 5 days for any significant changes.  Residents within the error cone should begin reviewing their Hurricane Preparedness plans.  IF you do not have a plan, please visit my “links” section on the right hand side of the page.  I will continue to monitor Danny during the next 72-96 hours for any significant forecast changes to the steering pattern and upper level pattern.

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.

8 Responses to TROPICAL STORM DANNY FORECAST SYNOPSIS…ISSUED AUG. 19, 2015…1:25 P.M. EDT

  1. dellamom says:

    Storm, I hope that dry air kills it so it doesn’t have the characteristics to reform, especially if it gets into the warmer waters between the islands and South America and leading to the Gulf. The projections, as is their nature, wobble from above Jamaica-DR-Haiti/across the islands/under the islands. That last one does not make me happy, although I appreciate that the residents of the islands would not agree with me. Prayer for all in Danny’s path (and selfishly hoping it is not I).

      • dellamom says:

        Eat your Wheaties, Storm. There were two yellow Xs and Danny on the nhc site this morning. Danny is supposed to be going into a decline, but I am still worried about the fact that is it still showing as a TS coming off the Dominican Republic/Haiti. I know there’s dry air in that area, but with weather, anything can change, and it usually does. God bless you, Storm. We need your gift for weather forecasting. I will be at my sister’s house this weekend, but will be keeping an eye out on my Kindle. 🙂

  2. Elliot Lisak says:

    Hello Storm,
    Very Interesting thing this storm Danny. It reminds me of a slow semi-drama. I think we are going to
    require a lot of popcorn and Coca-Cola (caffeine). It makes me think that this is going to wake everyone up here is South Florida.

    On the serious side … even if it gets beat-up Peurto Rico, Hispanola,and the Bahamas isn’t there enough warm water and a decent environment to regenerate and come up to a quick Rapid Intensification storm on our door step in South Florida.?

    Thank you for you on going synopsis they are appreciated.

  3. grannyMS says:

    Thank you, Storm.

  4. dellamom says:

    Thank you, Storm. I will be watching closely. Prayers to all in the path of Danny.

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