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. As ALWAYS, follow the National Hurricane Center, National Weather Service, and your local Emergency Management officials for emergency decisions. In addition, this is strictly a FORECAST OFFICE. I CANNOT make decisions regarding travel plans, etc. My purpose, is to provide you the information, based solely on information I analyze, and the accuracy of the information at hand of the time of analysis, so you may make informed decisions.
(T. F. "Storm" Walsh)
For those who have donated to my site, your help has been greatly appreciated. If you are not aware, donations to my site help pay for subscriptions to sites I use as well as software updates, which provide all the models and information used in my forecasts. To donate, please click the DONATE button to the right side of the page, or on the graphic of the dog. Any help you provide is immensely appreciated!
DONATIONS NEEDED AND APPRECIATED
Please be aware, even though I do not post every night, rest assured I am continuously monitoring various areas for any significant weather. I will be taking Sundays off (family time), unless we have active systems that may be posing a threat (i.e. Tropical, Winter Weather, Coastal Storms, etc.).
STORM WALSH PRE-SEASON FORECAST
TOTAL NAMED STORMS: 17 – 20
TOTAL HURRICANES : 7 – 9
MAJOR HURRICANES: 4 – 5
AVERAGE HURRICANE SEASON:
TOTAL NAMED STORMS: 14
TOTAL HURRICANES: 7
MAJOR HURRICANES: 3
2021 SEASON TOTALS:
TOTAL NAMED STORMS: 12
TOTAL HURRICANES: 5
MAJOR HURRICANES: 2
TOTAL U. S. LANDFALLS: 6
The following is the list of storm names for the 2021 Atlantic Hurricane Season:
Ana Bill Claudette Danny Elsa Fred Grace Henri Ida Julian Kate Larry
Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda
As a storm becomes named, I will be marking it in bold red to keep track of the activity for this Atlantic season.
Please note..when we are dealing with multiple systems, they will be listed in order as to the greatest threat to land or the U. S. , to the least threat.
Good evening everyone,
The following are satellite animations of the Tropical Atlantic and Africa
TROPICAL ATLANTIC
AFRICA SATELLITE
LARRY has become a Category ONE hurricane, with maximum sustained winds of 80 mph (or stronger since 80 mph was at 5:00 p.m.). As of the 5:00 p.m. EDT advisory, the following was available on LARRY:
5:00 PM AST Thu Sep 2
Location: 13.7°N 35.8°W
Moving: W at 18 mph
Min pressure: 985 mb / 29.09 in
Max sustained: 80 mph
The satellite signature of LARRY continues to improve, and shows a rather large overall circulation, and now improving CDO (Central Dense Overcast)
HURRICANE LARRY SATELLITE ANIMATION IR AND SWIR (SHORTWAVE IR)
In the NHC forecast discussion, it was mentioned that LARRY could be undergoing an EWRC (EyeWall Replacement Cycle), as evidenced by microwave imagery. However, I have to disagree with this, as for one, I don't detect an eye in satellite imagery right now, and two, I need someone to explain to me HOW, a low end Category ONE hurricane induces an EWRC. To the best of my knowledge, an EWRC is a process that occurs in "intense" hurricanes due to the dynamics that occur. Based on my analysis of the satellite loop imagery this evening, this image seen in microwave imagery (which I don't have access to) may have presented itself as such, however I believe dry air eroded the portion of the circulation, north of the CDO and cloud cover, noted by the "dark band" circulating just north of the solid cloud cover. I based my dry air analysis on the fact you can see a large "arc" cloud pushing away from LARRY on the western side of the storm (thin, solid looking cloud). Here is a link regarding EWRC's:
https://en.wikipedia.org/wiki/Eyewall_replacement_cycle
Regardless, LARRY was reported to have 80 mph winds. Based on my analysis of the current wind shear, and relative humidity forecasts from the GFS and ECMWF, conditions should remain very favorable during the next 66 - 72 hours, with a shear and upper level wind pattern as we saw with Hurricane IDA. After about 72 hours in the forecast period, conditions differ between models, with the ECMWF showing an increase in wind shear, but still maintaining a fairly radial outflow pattern, and the GFS indicating a more favorable pattern with a continued favorable shear pattern, and better radial outflow pattern. However, BOTH models do indicate after 72 hours, closer to 96 hours in the forecast period, that mid level moisture begins to weaken, and some intrusion of dry air at the 500 mb level. Currently, upper level outflow seems to be almost textbook, and shear is at 5 - 10 kts. Based on the forecast favorable conditions, I once again believe rapid intensification should occur during the next 24 -36 hours, and deepening should continue until if and when the less favorable conditions are encountered (which will depend on which model is correct on the shear forecast). Based on this analysis, I currently agree with the NHC in that LARRY will eventually become a Category FOUR hurricane on the Saffir - Simpson scale. Although current intensity guidance indicates a weaker hurricane of Category THREE, I have to concur with the NHC intensity guidance until I can see how well LARRY begins to consolidate..
ECMWF AND GFS WIND SHEAR FORECAST
ECMWF AND GFS 200 MB FORECAST
CURRENT UPPER LEVEL WINDS
500 MB RELATIVE HUMIDITY FORECAST
NHC INTENSITY FORECAST
INIT 02/2100Z 13.7N 35.8W 70 KT 80 MPH
12H 03/0600Z 14.0N 38.4W 80 KT 90 MPH
24H 03/1800Z 14.7N 41.3W 95 KT 110 MPH
36H 04/0600Z 15.7N 43.9W 105 KT 120 MPH
48H 04/1800Z 16.9N 46.3W 110 KT 125 MPH
60H 05/0600Z 18.3N 48.6W 120 KT 140 MPH
72H 05/1800Z 19.7N 50.6W 120 KT 140 MPH
96H 06/1800Z 22.2N 54.0W 115 KT 130 MPH
120H 07/1800Z 25.1N 57.0W 110 KT 125 MPH
Larry was moving to the west (or just north of west) at 18 mph . Based on analysis of current and forecast steering layers maps, I expect the west, or more of a WNW motion to continue through the next 66 - 72 hours. Thereafter, the ridge is forecast to shift NE somewhat, and a more northwest motion should ensue. This forecast track should be induced by then, from the change in flow of the forecast steering layer. This is the flow LARRY will be in for the next 24 hours (hint, look north and west of the storm)
24 HOUR STEERING FLOW
54 HOUR STEERING FLOW
Based on the future forecast intensity of LARRY, and forecast steering layers flow, I agree with the NHC forecast track, and last guidance from 18Z today:
NHC FORECAST TRACK
18Z ATCF GUIDANCE
Elsewhere, the other two areas marked by the NHC in the GTWO, do not concern me at the moment. Upper level conditions are marginal for both at this time, and some slow development could begin, however during the next 72 hours, upper level winds are forecast to become less favorable.
You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com
Have a blessed evening!
T. F. "STORM" WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
WordPress.com
No comments:
Post a Comment