East coast Hybrid Invest 90L ?

[J Kinkaid]

Dvorak T Number ST 2.5/2.5 Should see model runs on this system later today

http://www.ssd.noaa.gov/PS/TROP/positions.html

Seems to be doing very good considering it's over 69 degree water

[B Ozanne]

A "Hurricane Force Wind Warning" is up for a large portion of offshore waters on the east coast. I've never seen this before. I thought a storm warning had no upper limits and covered all extra-tropical systems.

Edit: An interesting part of the warning states higher winds over the Gulf Stream. Due to increased mixing, I guess.

[Tarmo Tanilsoo]

In fact they do issue hurricane force warnings. In the old days(early August 2005-late October 2006) when I had only GPRS connection in my cell phone, I browsed NWS WAP site and High Seas Forecast to track Atlantic cyclones. Even ex-Hurricane(extratropical remnants of...) Maria, what caused hurricane force winds for some time over the ocean, was mentioned under "Hurricane Force Warning". So was also any hurricane-force cyclone.

I guess with the hurricane season approaching, we are looking more into tropics. However, 69 degrees water is way too cold for tropical development. However, intense extratropical cyclones what have wreaked havoc in Northern Europe(including Estonia) throughout the history, have occurred in such SST's.

[Mike Davis]

That is why they are called Hybrids. Exceptional circumstances for a given event. Just shows that Mother Nature did not read the book!

[cdcollura]

These hybrid systems are strange and interesting things.

They feed off BOTH baroclinic (fronts) and heat-energy processes (less on the latter).

Some have warm cores, some, like this one (90L) do not. Some have fronts AND feeder bands.

Many bad examples, including the "perfect storm" in 1991, were owed to hybrid (subtropical) systems. These account for less than 2% of large-scale cyclone types aside from tropical and extratropical (mid lattitude / wave) cyclones.

The one in this case (90L) is weakening, but has already created a large wave setup with gusts near hurricane force (not a true hurricane, so you will see "storm warning", but extra "wording" of hurricane forced winds outside a tropical system).

Needless to say, EXPECT 20 foot plus swells affecting SE coast into FL, something that has not happened in some time since 1997. There will be severe beach erosion, flooding, and wave damage - even long after the winds die.

[J Kinkaid]

I don't think that it's weakening .



twd 2:05 Pm
Western Atlantic...
Attention Remains Focused On A Rapidly Strengthening Low Pres
Center Off The Se Of United States. A 998 Mb Low Is Analyzed On
The 12z Map Near 32n73w.


07/1745 UTC 31.6N 73.9W ST2.5/2.5 90L -- Atlantic Ocean

http://www.ssd.noaa.gov/PS/TROP/positions.html

[William Coyle]

What a wind and wave maker this low is. With the lack of rain in the system and the strong winds people were blasted by sand moving in the 50mph plus winds in Virginia Beach.Here is some video I shot on Sunday May 6, 2007...enjoy


Video Link Here: http://www.valightning.com/050607videopage.html

[rdale]

Pretty early in the year for a DSA!

WONT41 KNHC 081346
DSAAT
SPECIAL TROPICAL DISTURBANCE STATEMENT
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
950 AM EDT TUE MAY 8 2007

A NON-TROPICAL LOW PRESSURE SYSTEM...CENTERED ABOUT 230 MILES
EAST-SOUTHEAST OF THE GEORGIA AND SOUTH CAROLINA COASTS...HAS BEEN
MOVING SLOWLY WESTWARD AT 5 TO 10 MPH. THIS SYSTEM IS PRODUCING
GALE-FORCE WINDS AND HEAVY SURF ALONG THE COASTS OF NORTH
CAROLINA...SOUTH CAROLINA...AND GEORGIA...WITH STRONGER WINDS
OFFSHORE. ASSOCIATED SHOWER ACTIVITY HAS INCREASED SINCE
YESTERDAY...BUT NO SIGNIFICANT STRENGTHENING OF THIS SYSTEM IS
EXPECTED. THE LOW IS BEING MONITORED FOR SIGNS OF TROPICAL OR
SUBTROPICAL CYCLONE DEVELOPMENT...AND AN AIR FORCE RESERVE
RECONNAISSANCE AIRCRAFT WILL BE AVAILABLE TO INVESTIGATE THE SYSTEM
TOMORROW MORNING...IF NECESSARY.

INTERESTS ALONG THE COAST OF THE SOUTHEASTERN UNITED STATES SHOULD
MONITOR PRODUCTS ISSUED BY LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICES. ADDITIONAL INFORMATION ON THIS SYSTEM CAN ALSO BE FOUND
IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$
FORECASTER KNABB

[J Kinkaid]

000
Nous42 Knhc 081330
Weather Reconnaissance Flights
Carcah, National Hurricane Center, Miami, Fl.
0930 Am Edt Tue 08 May 2007
Subject: Tropical Cyclone Plan Of The Day (wspod)
Valid 09/1100z 10/1100z May 2007
Wspod Number.....07-001

I. Atlantic Requirements
1. Flight One Area Off South Carolina
A. 09/1200z
B. Afxxx 01aaa Invest
C. 09/0930z
D. 31.8n 79.4w
E. 09/1100z-09/1800z
F. Sfc To 10,000ft

2. Outlook For Succeeding Day.....negative.

Ii. Pacific Requirements
1. Negative Reconnaissance Requirements.
2. Outlook For Succeeding Day.....negative
Wvw

[J Kinkaid]

http://www.sfwmd.gov/org/omd/ops/weather/plots/storm_90.gif

[J Kinkaid]

000
WONT41 KNHC 082003
DSAAT
SPECIAL TROPICAL DISTURBANCE STATEMENT
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
400 PM EDT TUE MAY 8 2007

A NON-TROPICAL LOW PRESSURE SYSTEM...CENTERED ABOUT 200 MILES
SOUTHEAST OF THE GEORGIA AND SOUTH CAROLINA COASTS...HAS BEEN
MOVING SLOWLY WESTWARD AT 5 TO 10 MPH. THE LOW IS PRODUCING
GALE-FORCE WINDS NEAR THE COASTS OF NORTH CAROLINA...SOUTH
CAROLINA...AND GEORGIA. THIS SYSTEM HAS CHANGED LITTLE SINCE THIS
MORNING...AND NO SIGNIFICANT STRENGTHENING IS EXPECTED. THE LOW IS
BEING MONITORED FOR SIGNS OF TROPICAL OR SUBTROPICAL CYCLONE
DEVELOPMENT...AND AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT WILL
BE AVAILABLE TO INVESTIGATE THE SYSTEM TOMORROW MORNING...IF
NECESSARY.

INTERESTS ALONG THE COAST OF THE SOUTHEASTERN UNITED STATES SHOULD
MONITOR PRODUCTS ISSUED BY LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICES. ADDITIONAL INFORMATION ON THIS SYSTEM CAN ALSO BE FOUND
IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...
UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.


$$
FORECASTER KNABB

[cdcollura]

Good day all,

Interesting images from Florida...

http://www.sky-chaser.com/image/schurr/schhyb2.jpg

Webcam atop sand transfer station on Singer Island (Palm Beach) FL at Lake Worth Inlet showing high surf.

http://www.sky-chaser.com/image/schurr/schhyb3.jpg

Here is another picture of the surf (provided by Palm Beach county webcam) at Boynton Beach plus two nice satellite pictures of the storm system itself.

The one to the right appear much more "tropical" than the one on the left a day earlier.

[J Kinkaid]

Special Tropical Disturbance Statement
Nws Tpc/national Hurricane Center Miami Fl
905 Am Edt Wed May 9 2007

Satellite Imagery And Preliminary Reports From An Air Force Reserve
Reconnaissance Aircraft This Morning Indicate That The Area Of Low
Pressure Centered About 150 Miles East Of Jacksonville Is Acquiring
The Characteristics Of A Subtropical Cyclone. The System Continues
Moving Generally Westward At About 5 Mph. If Present Trends
Continue... Advisories On Subtropical Storm Andrea Would Be
Initiated Later This Morning.

Dangerous Surf Conditions Continue Along The Coasts Of The
Carolinas... Georgia... And Northeastern Florida. Interests In
These Areas Should Continue To Monitor Products Issued By Local
National Weather Service Forecast Offices. Additional Information
On This System Can Also Be Found In High Seas Forecasts Issued By
The National Weather Service... Under Awips Header Nfdhsfat1 And
Wmo Header Fznt01 Kwbc.

[Ed Schoenborn]

Thanks Mr. Kinkaid for your noaa intensity link and your posts on the 90L topic. Without it I would not have learned about 90L until today. I have added your link to my favorites. Ed

[J Kinkaid]

Andrea per NRL site with max recon winds of 45mph

[J Kinkaid]

Tropical Storm Public Advisory

Statement as of 11:00 am EDT on May 09, 2007


...Early-season subtropical storm forms off the southeast U.S.
Coast...
Satellite imagery and aircraft data indicate that the low pressure
system off the southeast U.S. Coast has acquired subtropical
characteristics.

At 11 am EDT...1500 UTC...a tropical storm watch has been issued
along the southeast coast of the United States from Altamaha Sound
Georgia southward to Flagler Beach Florida. A tropical storm watch
means that tropical storm conditions are possible within the watch
area...generally within the next 36 hours.

For storm information specific to your area...including possible
inland watches and warnings...please monitor products issued
by your local weather office.

At 1100 am EDT...1500z...the center of subtropical storm Andrea was
located near latitude 30.8 north...longitude 79.3 west or about 140
miles...225 km...southeast of Savannah Georgia and about 150 miles
...240 km...northeast of Daytona Beach Florida.

Andrea is moving generally toward the west near 3 mph. A continued
slow motion and a gradual turn toward the southwest are expected
during the next 24 hours. Along this track...the center of Andrea
is expected to remain offshore of the U.S. Coast through at least
Thursday morning.

Maximum sustained winds are near 45 mph...75 km/hr...with higher
gusts. Little change in strength is forecast during the next 24
hours.

Winds of 40 mph extend outward up to 115 miles...185 km...mainly to
the east of the center.

The latest minimum central pressure reported by an Air Force Reserve
reconnaissance aircraft was 1003 mb...29.62 inches.
Since the heaviest rains associated with Andrea are expected to
remain offshore during the next 24 hours... Andrea is not expected
to produce significant rainfall over any land areas through at
least Thursday morning.