TROPICAL STORM GRACE FORECAST SYNOPSIS…ISSUED SEP. 05, 2015…8:25 P.M. EDT

TROPICAL STORM FORMATION: GRACE

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: 7
HURRICANES: 2
INTENSE HURRICANES: 1
U.S. LANDFALLS: 2

StormW’s Seasonal Forecast:

TOTAL STORMS:             8
HURRICANES:                   3
INTENSE HURRICANES: 1

Good day everyone!

Enter Tropical Storm GRACE.

Tropical Storm GRACE is located in the far eastern Atlantic, and is the seventh storm of the season.  As of the 5:00 p.m. EDT advisory from the NHC, the following information was available on GRACE:

5:00 PM AST Sat Sep 5
Location: 12.6°N 26.4°W
Moving: W at 14 mph
Min pressure: 1007 mb / 29.74 in
Max sustained: 40 mph
HURREVAC NHC TRACKING MAPS
HURREVAC.GRACE

HURREVAC.GRACE72

Analysis of satellite loop imagery indicates GRACE was better organized earlier this evening, and does not appear as well structured at the moment.  I attribute this to GRACE being affected by an upper level trof, currently located to her NW, in very close proximity, and the effect of somewhat drier air entering her northern portion (based on close up water vapor imagery).  Shear values are within conducive limits, however one will note, that she has moved out from under the upper level anticyclone that had been over her prior to now.  This has cause the upper level outflow to be less than optimal.

GRACE FLOATER SATELLITE LOOP IMAGERY
avn0grace-lalo

RAMSDIS CIRA METEOSAT 4 FLOATER
tropical_met_4km_ir4_floater

GRACE RECENT WIND SHEAR MAP
tccaptureshear

GRACE WATER VAPOR FLOATER LOOP IMAGERY
wv0grace-lalo

This should arrest any strengthening or further organization at the moment.  Based on the current wind shear forecast which is in line with the NHC forecast discussion, there should be an improvement in the upper level pattern, with the development of the upper level anticyclone once again over or very close to GRACE.  Based on this, but with the presence of the slightly drier air, organization may be slower to occur.  Recent OHC data indicates GRACE will be moving through some higher OCH during the next couple of days, and this may help temporarily in the mixing out of slight dry air intrusion.  In a few days however, as mentioned in the NHC forecast discussion, the low to mid levels of the atmosphere are expected to become drier.  This would definitely put a hamper on any further strengthening.  Based on the premise that the upper level environment is currently forecast to improve, and the presence of higher OHC to the west, I concur with the NHC intensity forecast at the moment, in that the storm should begin weakening as it encounters increasing SWLY shear, and pretty much matches the more accurate of the intensity models in the 18Z guidance.

NHC INTENSITY FORECAST

FORECAST POSITIONS AND MAX WINDS
INIT 05/2100Z 12.6N 26.4W 35 KT 40 MPH
12H 06/0600Z 12.9N 28.3W 40 KT 45 MPH
24H 06/1800Z 13.2N 30.8W 45 KT 50 MPH
36H 07/0600Z 13.5N 33.6W 50 KT 60 MPH
48H 07/1800Z 13.9N 36.4W 45 KT 50 MPH
72H 08/1800Z 14.8N 42.3W 45 KT 50 MPH
96H 09/1800Z 15.1N 48.4W 40 KT 45 MPH
120H 10/1800Z 15.7N 53.8W 35 KT 40 MPH

GRACE 18Z INTENSITY MODELS
GRACE 18Z INTENSITY GUIDANCE

GRACE OHC VALUES
tccaptureohc

ATLANTIC OHC MAP
ohc_aQG3_latest_natl
Based on analysis of the current forecast steering layers maps, valid for 00Z this evening, the subtropical ridge is forecast to fluctuate slightly during the next 96-120 hours, but pretty much maintains it’s southern periphery strong enough to keep GRACE on a W to WNW motion.  Based on this, and the probability of GRACE weakening per the forecast, I agree right now with the NHC westward motion near the end of the 5 day forecast period.  Should she strengthen more steadily than forecast prior to this, I would prefer the TVCN track in the 00Z Dynamic Guidance.

ATCF GRACE DYNAMIC MODEL GUIDANCE
GRACE 00Z DYNAMIC GUIDANCE

I will continue to monitor GRACE for any significant changes.

Elsewhere, Tropical Storm formation is not expected during the next 5-7 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.

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