Hurricane season is fast approaching

[Groomlakearea51]

Water Vapor levels - amazing what these spiffy mil satellites can do for the tax payer!!!

[Groomlakearea51]

Sea surface temperature anomalies which affect strengthening:

[Groomlakearea51]

Jimena, however is now predicted to do loops over the Baja....

[Groomlakearea51]

Here's the track plots for Jimena:

[Groomlakearea51]

For those interested in how the "cone of death" is predicted by the NHC...

Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2008 for the Atlantic and eastern North Pacific basins are given in the table below.

One can also examine historical tracks to determine how often the entire 5-day path of a cyclone remains completely within the area of the cone. This is a different perspective that ignores most timing errors. For example, a storm moving very slowly but in the expected direction would still be within the area of the cone, even though the track forecast error could be very large. Based on forecasts over the previous 5 years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60-70% of the time.

Radii of NHC forecast cone circles for 2008, based on error statistics from 2003-2007:

Forecast Period (hours)	2/3 Probability Circle, Atlantic Basin (nautical miles)	2/3 Probability Circle, Eastern North Pacific Basin (nautical miles)
12	39	36
24	67	66
36	92	92
48	118	115
72	170	161
96	233	210
120	305	256

[Groomlakearea51]

Erika tracks have been shifted to the left (towards Florida....) since this morning.

WTNT41 KNHC 021447
TCDAT1
TROPICAL STORM ERIKA DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009
1100 AM AST WED SEP 02 2009

VISIBLE SATELLITE IMAGES AND AIR FORCE RESERVE HURRICANE HUNTER
DATA SHOW THAT ERIKA IS A POORLY ORGANIZED SYSTEM. THERE ARE
MULTIPLE SWIRLS APPARENT ON THE SATELLITE IMAGERY ROTATING IN THE
LARGER CIRCULATION ENVELOPE WITH A MEAN CENTER TO THE WEST OF THE
DEEP CONVECTION. THE SFMR EARLIER REPORTED WINDS OF ABOUT 35
KT...WHICH IS IN GOOD AGREEMENT WITH SATELLITE INTENSITY
ESTIMATES...SO THAT VALUE WILL BE USED AS THE INITIAL INTENSITY.

VERTICAL WIND SHEAR HAS INCREASED EARLIER THAN EXPECTED...WITH CIMSS
DIAGNOSING ABOUT 15-20 KT OF SHEAR. AT FIRST GLANCE...THE SHEAR DOES
NOT APPEAR TO BE TOO STRONG OVER THE SYSTEM WITH SOUTH OR
SOUTHEASTERLY WINDS REPORTED AT 200 MB OVER THE NORTHERN LEEWARD
ISLANDS. HOWEVER...UPPER-AIR DATA FROM GUADELOUPE AND ST. MAARTEN
SUGGEST THAT THE SHEAR IS PRIMARILY COMING FROM SOUTHWESTERLY WINDS
BETWEEN 300 MB-250 MB...AND THIS IS APPARENTLY UNDERCUTTING THE
OUTFLOW LAYERS AT 200 MB AND ABOVE. MOST OF THE GLOBAL MODELS DO
NOT SHOW MUCH RELAXATION OF THIS SHEAR...AND ACTUALLY SHOW IT
INCREASING SIGNIFICANTLY IN A COUPLE OF DAYS. DESPITE ALL THIS
SHEAR...ALL RELIABLE GUIDANCE RESTRENGTHENS THIS SYSTEM TO NEAR
HURRICANE STRENGTH IN A FEW DAYS. THIS REINTENSIFICATION
DOES NOT SEEM VERY LIKELY AND THE NHC FORECAST IS MUCH LOWER THAN
THE GUIDANCE. GIVEN THE POSSIBLE SHEAR DURING THE FORECAST
PERIOD...IT WOULD NOT BE SURPRISING IF ERIKA DISSIPATED.

A 24-HOUR MOTION IS ABOUT 275/9. A WEST-NORTHWESTWARD TRACK IS
PREDICTED TO RESUME AS THE STORM MOVES TO THE SOUTH OF A WEAK
SUBTROPICAL RIDGE FOR A COUPLE OF DAYS. THIS RIDGE IS FORECAST TO
WEAKEN SOMEWHAT IN A FEW DAYS...AND A NORTHWESTWARD MOTION IS
POSSIBLE BY THE END OF THE FORECAST. THE OFFICIAL FORECAST HAS BEEN
SHIFTED LEFT OF THE PREVIOUS ONE AND IS LEFT OF THE DYNAMICAL
CONSENSUS DUE TO THE ANTICIPATION OF ERIKA REMAINING WEAK. IT
SHOULD BE EMPHASIZED THAT...OVERALL...THIS IS A LOW-CONFIDENCE
TRACK FORECAST.

TROPICAL STORM WATCHES COULD BE REQUIRED FOR THE U.S. AND BRITISH
VIRGIN ISLANDS AS WELL AS PUERTO RICO LATER TODAY.


FORECAST POSITIONS AND MAX WINDS

INITIAL 02/1500Z 16.5N 60.4W 35 KT
12HR VT 03/0000Z 16.9N 61.5W 35 KT
24HR VT 03/1200Z 17.4N 62.8W 40 KT
36HR VT 04/0000Z 18.0N 64.2W 45 KT
48HR VT 04/1200Z 18.6N 65.5W 40 KT
72HR VT 05/1200Z 20.0N 68.5W 35 KT
96HR VT 06/1200Z 21.5N 71.5W 30 KT
120HR VT 07/1200Z 23.5N 73.5W 30 KT

[Groomlakearea51]

Here's the new "cone of death"....

[Groomlakearea51]

and the track plots.....

[Groomlakearea51]

Off to the house to work at home and get the hurricane boards out of the garage....[:S]

[Dflip]

Erika is now headed towards Florida, but it's listed as a pretty small storm after 5 days. It could pick up after that, but it seems to be getting less intense each day. The next storm on the list is no longer posted, but off the coast of Africa there is the making of a good storm, but a lot can happen between now and when it approaches the leeward islands. It's been quiet so far, hopefully it will continue. We are already at the first of September without a major hurricane.

[dtel]

Good luck groomlake hope it's just a dry run for you.

[Groomlakearea51]

Erica is supposed to allegedly dissipate, but TD's and remnant lows can produce massive quantities of rain....

Last night from about 11 PM through 2:00 AM we got almost 3 inches of rain. Pastures under water, big puddles in the yard, etc. It'll drain, but that's what happens when a slow mover passes over.

In any even, the latest NHC track:

[Groomlakearea51]

Heres' the track models:

[Groomlakearea51]

WTNT41 KNHC 031437
TCDAT1
TROPICAL STORM ERIKA DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009
1100 AM AST THU SEP 03 2009

DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOW THAT
ERIKA HAS MOVED VERY SLOWLY OVER THE PAST FEW HOURS...AND THAT THE
CENTER IS SOMEWHAT ELONGATED. THE AIRCRAFT ALSO REPORTED THAT THE
CENTRAL PRESSURE HAS COME UP A LITTLE...TO 1010 MB. THERE WERE A
FEW UN-FLAGGED SFMR READINGS OF WINDS NEAR TROPICAL-STORM FORCE IN
THE CONVECTION WELL EAST OF THE CENTER...SO THE INTENSITY IS HELD
AT 35 KT FOR THIS ADVISORY. THE 1200 UTC RADIOSONDE DATA STILL SHOW
WESTERLY AND SOUTHWESTERLY FLOW AT THE 250 MB LEVEL WEST OF
ERIKA...AND THE SAN JUAN RAOB SHOWS A RELATIVELY DRY MID- AND
UPPER-TROPOSPHERIC ENVIRONMENT AHEAD OF THE CYCLONE. ALL OF THIS
EVIDENCE...PLUS THE POTENTIAL FOR LAND INTERACTION...SUGGESTS THAT
ERIKA SHOULD SLOWLY WEAKEN THROUGH THE PERIOD. DESPITE THIS...
ALMOST ALL OF THE INTENSITY GUIDANCE KEEPS ERIKA AS AT LEAST A
TROPICAL STORM THROUGH THE FORECAST PERIOD. THE OFFICIAL FORECAST
IS SIMILAR TO THE PREVIOUS ADVISORY...HOLDING ERIKA AS A TROPICAL
STORM THROUGH 12 HOURS AND SLOWLY WEAKENING THE CYCLONE TO A
REMNANT LOW BY DAY 3.

AIRCRAFT DATA AND SURFACE OBSERVATIONS...INCLUDING DATA FROM NOAA
BUOY 42060...SUGGESTED THAT THE CENTER OF ERIKA WAS LOCATED BETWEEN
THE ISLAND OF ST. KITTS AND THE BUOY. HOWEVER...THESE DATA ALSO
SUGGEST THAT THE CENTER IS STILL NOT TERRIBLY WELL DEFINED. ERIKA
IS MOVING SLOWLY WEST-NORTHWESTWARD AROUND THE SOUTHERN PERIPHERY
OF THE ATLANTIC SUBTROPICAL RIDGE...AND THE INITIAL MOTION ESTIMATE
IS A RATHER UNCERTAIN 300/07. THE GLOBAL MODEL GUIDANCE SUGGESTS
THAT THE RIDGE WILL BUILD WESTWARD NORTH OF ERIKA...WHICH SHOULD
RESULT IN A SLIGHT INCREASE IN FORWARD SPEED IN NEXT DAY OR TWO.
THE OFFICIAL FORECAST HAS BEEN SHIFTED SLIGHTLY TO THE RIGHT...OR
NORTHWARD...TO ACCOUNT FOR THE INITIAL POSITION AND A SLIGHT SHIFT
IN THE MODEL CONSENSUS.

WHILE IT IS LIKELY THAT ANY TROPICAL STORM FORCE WINDS ARE OCCURRING
IN ISOLATED AREAS WELL EAST OF THE CENTER...THE NEW FORECAST TRACK
IS CLOSE ENOUGH TO THE VIRGIN ISLANDS AND PUERTO RICO IN THE NEXT
12 TO 24 HOURS TO REQUIRE THE ISSUANCE OF A TROPICAL STORM WARNING
FOR THOSE ISLANDS AT THIS TIME.

EVEN IF ERIKA LOSES ITS TROPICAL CYCLONE STATUS LATER IN THE
FORECAST PERIOD...IT COULD MAINTAIN VIGOROUS DEEP CONVECTION WHICH
WOULD PRODUCE VERY HEAVY RAINS ALONG ITS TRACK.

FORECAST POSITIONS AND MAX WINDS

INITIAL 03/1500Z 16.9N 63.5W 35 KT
12HR VT 04/0000Z 17.5N 64.5W 35 KT
24HR VT 04/1200Z 18.4N 66.1W 30 KT...INLAND
36HR VT 05/0000Z 19.2N 67.5W 30 KT
48HR VT 05/1200Z 20.0N 68.8W 30 KT
72HR VT 06/1200Z 21.5N 71.0W 25 KT...REMNANT LOW
96HR VT 07/1200Z 23.0N 73.5W 20 KT...REMNANT LOW
120HR VT 08/1200Z...DISSIPATED

[Groomlakearea51]

The low pressure area off the coast of Africa is now back on the NHC "radar screen".

[Groomlakearea51]

They are not really specific about it at the moment.

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU SEP 3 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM ERIKA LOCATED ABOUT 80 MILES SOUTH OF ST. CROIX.

1. A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS
LOCATED ABOUT 450 MILES EAST-SOUTHEAST OF THE CAPE VERDE ISLANDS.
ALTHOUGH SHOWER ACTIVITY ASSOCIATED WITH THIS LOW HAS DIMINISHED
OVER THE PAST FEW HOURS...SLOW DEVELOPMENT OF THIS SYSTEM IS
POSSIBLE OVER THE NEXT COUPLE OF DAYS AS IT MOVES WESTWARD AT 10 TO
15 MPH OVER THE FAR EASTERN TROPICAL ATLANTIC. THERE IS A LOW
CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

[Groomlakearea51]

They are looking at two systems this morning; both of which, fortunately, will likely not have any impact - at least for the next 10 days in the case of the second. Erika is headed to the "hurricane morgue" of the great North Atlantic, as well it should for threatening us like that.....

[Groomlakearea51]

Here's the HNC analysis as of this morning:

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT FRI SEP 4 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. THE REMNANTS OF TROPICAL DEPRESSION ERIKA ARE LOCATED JUST SOUTH OF
PUERTO RICO AND ARE MOVING SLOWLY WESTWARD AT 5 TO 10 MPH. WHILE
SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED OVER THE PAST FEW
HOURS...UPPER-LEVEL WINDS ARE NOT CURRENTLY FAVORABLE FOR
RE-DEVELOPMENT OF THIS SYSTEM. REGARDLESS OF ANY DEVELOPMENT...
HEAVY RAINFALL IS POSSIBLE OVER PUERTO RICO AND THE VIRGIN ISLANDS
TODAY. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

2. A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS
LOCATED NEAR AND TO THE SOUTH OF THE CAPE VERDE ISLANDS. WHILE THIS
SYSTEM HAS CHANGED LITTLE IN ORGANIZATION DURING THE PAST SEVERAL
HOURS...IT STILL HAS THE POTENTIAL FOR SLOW DEVELOPMENT OVER THE
NEXT COUPLE OF DAYS AS IT MOVES WESTWARD AT 10 TO 15 MPH OVER THE
FAR EASTERN TROPICAL ATLANTIC. THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

[Groomlakearea51]

Erika's track plot estimates pretty much agree that she is off to the high seas....

[Groomlakearea51]

Officially.... We still have two months to go, and September is the peak month for hurricanes. We are up to five of the seven predicted named storms, and have only had one of at least three predicted hurricanes.

While the trend appears to be a below-normal season, it would be unwise for those of us in harms way to not follow these storms. Below is the NHC estimate for 2009. It was released a few months ago, but for those interested in the storms, it's very informative.

NOAA’s Climate Prediction Center, a division of the National Weather Service, now predicts a 50 percent probability of a near-normal season, a 40 percent probability of a below-normal season, and a 10 percent probability of an above-normal season. Forecasters say there is a 70 percent chance of seven to 11 named storms, of which three to six could become hurricanes, including one to two major hurricanes (category 3, 4 or 5).

The main change from the May outlook is an increased probability of a below-normal season, and an expectation of fewer named storms and hurricanes. The May outlook called for nine to 14 named storms, of which four to seven could become hurricanes, including one to three major hurricanes. During an average season, there are 11 named storms with winds of at least 39 mph, of which six become hurricanes with winds of 74 mph or greater and two of those become major hurricanes with winds of 111 mph or higher.

In recent weeks, forecasts for the return of El Niño – warmer than normal waters along the equatorial central and eastern Pacific Ocean – have come to fruition.

“El Niño continues to develop and is already affecting upper-level atmospheric pressure and winds across the global tropics,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center. “El Niño produces stronger upper-level westerly winds over the Caribbean Sea and tropical Atlantic Ocean, which help to reduce hurricane activity by blowing away the tops of growing thunderstorm clouds that would normally lead to tropical storms.”

“El Niño may mean fewer storms compared to recent seasons, but it doesn’t mean you can let your guard down,” said Jack Hayes, Ph.D., director of NOAA’s National Weather Service. “History shows that hurricanes can strike during an El Niño.” Some examples include Betsy in 1965, Camille in 1969, Bob in 1991, Danny in 1997 and Lili in 2002.

Even though El Niño tends to decrease the number of storms, other climate factors may help to create some storms. As predicted in May, conditions associated with the high-activity era that began in 1995 are in place, and include enhanced rainfall over west Africa and warmer tropical Atlantic Ocean water, which favor storm development.

The calm start to this hurricane season is not a reliable indicator of the overall activity for the entire season. The 1992 Atlantic hurricane season, for example, had a below-normal number of named storms and hurricanes. The first storm did not form until late August, when Hurricane Andrew hit southern Florida as a destructive Category 5 storm.

“These outlooks are extremely valuable when determining cycles and trends for the season, however they don’t tell us when the next storm will occur or where it may strike,” said FEMA administrator Craig Fugate. “It only takes one storm to put a community at risk. That is why we need to take action and prepare ourselves and our families before the next storm hits, including developing a family disaster plan. By taking a few simple steps now we can help ensure that we are better prepared and that our first responders are able to focus on our most vulnerable citizens.”

Predicting where and when a storm may hit land depends on the weather conditions in place at the time the storm approaches. Therefore NOAA’s seasonal outlook, which spans multiple months, does not include landfall projections. But once a storm appears to be forming, NOAA’s National Hurricane Center will issue track and intensity forecasts.