Mike Wilhelm's Alabama Weather Blog

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Bamawx.com

He made it to hurricane status tonight before making landfall in Mexico.

HURRICANE LORENZO FORECAST/ADVISORY NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL132007
0300 UTC FRI SEP 28 2007

A HURRICANE WARNING REMAINS IN EFFECT FOR THE GULF COAST OF MEXICO
FROM PALMA SOLA TO CABO ROJO. A HURRICANE WARNING MEANS THAT
HURRICANE CONDITIONS ARE EXPECTED WITHIN THE WARNING AREA.
PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD HAVE ALREADY BEEN
COMPLETED.

A TROPICAL STORM WARNING REMAINS IN EFFECT FROM SOUTH OF PALMA SOLA
TO VERACRUZ. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM
CONDITIONS ARE EXPECTED WITHIN THE WARNING AREA.

A TROPICAL STORM WATCH REMAINS IN EFFECT ALONG THE GULF COAST OF
MEXICO FROM NORTH OF CABO ROJO TO LA CRUZ.  A TROPICAL STORM WATCH
MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH
AREA.

HURRICANE CENTER LOCATED NEAR 20.5N  96.5W AT 28/0300Z
POSITION ACCURATE WITHIN  15 NM

PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT   5 KT

ESTIMATED MINIMUM CENTRAL PRESSURE  990 MB
EYE DIAMETER  20 NM
MAX SUSTAINED WINDS  70 KT WITH GUSTS TO  85 KT.
64 KT....... 10NE  20SE  20SW  10NW.
50 KT....... 15NE  30SE  30SW  15NW.
34 KT....... 40NE  40SE  60SW  40NW.
12 FT SEAS.. 60NE  60SE  60SW  60NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 20.5N  96.5W AT 28/0300Z
AT 28/0000Z CENTER WAS LOCATED NEAR 20.5N  96.2W

FORECAST VALID 28/1200Z 20.6N  97.4W...INLAND
MAX WIND  75 KT...GUSTS  90 KT.
64 KT... 20NE  15SE  15SW  15NW.
50 KT... 30NE  30SE  20SW  20NW.
34 KT... 60NE  40SE  50SW  50NW.

FORECAST VALID 29/0000Z 21.0N  98.5W...INLAND
MAX WIND  30 KT...GUSTS  50 KT.

FORECAST VALID 29/1200Z...DISSIPATED

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.5N  96.5W

NEXT ADVISORY AT 28/0900Z

HURRICANE LORENZO DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL132007
1100 PM EDT THU SEP 27 2007

WHEN THE LAST RECONNAISSANCE AIRCRAFT LEFT LORENZO AROUND 1930Z...
THE CENTRAL PRESSURE WAS FALLING AT A RATE OF ABOUT 2 TO 3 MB/HR.
AT THAT TIME...LORENZO WAS VERY CLOSE TO HURRICANE STRENGTH. SINCE
THEN...LORENZO HAS BEEN MAINTAINING VERY VIGOROUS CONVECTION THAT
HAS BECOME INCREASINGLY SYMMETRIC OVER THE CENTER. THE PRESENTATION
OF THE CENTER HAS ALSO IMPROVED DRAMATICALLY ON THE ALVARADO
RADAR...WHICH NOW SHOWS A CLOSED EYEWALL. GIVEN THIS...I HAVE NO
REASON TO BELIEVE THAT THE EARLIER DEEPENING TREND HAS ABATED...AND
THE ADVISORY INTENSITY IS INCREASED TO 70 KT. LORENZO STILL HAS
SEVERAL HOURS LEFT OVER WATER TO DEEPEN FURTHER...AND A CATEGORY
TWO HURRICANE AT LANDFALL WOULD NOT BE OUT OF THE QUESTION. THE
NEXT AIRCRAFT WILL ARRIVE IN THE HURRICANE IN 2 TO 3 HOURS.

THE INITIAL MOTION IS 270/5.  A MID-LEVEL RIDGE TO THE NORTH SHOULD
KEEP THE CYCLONE ON THIS BASIC TRACK FOR THE NEXT 12 HOURS OR
SO...WITH A GRADUAL BEND TO THE RIGHT AROUND THE RIDGE AFTER
LANDFALL.   

ALTHOUGH LORENZO IS A VERY SMALL HURRICANE...ITS SLOW MOTION WILL
LIKELY PRODUCE TORRENTIAL RAINS...UP TO 15 INCHES IN SPOTS...THAT
ARE EXPECTED TO CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.


FORECAST POSITIONS AND MAX WINDS

INITIAL      28/0300Z 20.5N  96.5W    70 KT
12HR VT     28/1200Z 20.6N  97.4W    75 KT...INLAND
24HR VT     29/0000Z 21.0N  98.5W    30 KT...INLAND
36HR VT     29/1200Z...DISSIPATED

$$
FORECASTER FRANKLIN

Tropical Storm Karen

Tropical storm Jerry is dying a slow, painful death in the North Atlantic and is no threat to land. He will soon become extra-tropical.

Karen was just born in the Eastern Atlantic. At the moment, the NHC predicts it to remain below hurricane strength for the next five days. She may turn northward over the Atlantic Ocean due to a weakness in the ridge north of the system. Time will tell.

First, I must admit that I was wrong in going with the models in predicting that tropical depression 93 would become Tropical Storm Jerry. The center developed much closer to the Florida coast than the models predicted and never had a fighting chance.

Nevertheless, we are in the peak of hurricane season and things are really getting interesting in the Gulf and the Atlantic. I will post more soon.

Here's the latest spaghetti plot. Models have been consistently creating Jerry in the eastern Gulf of Mexico and bring him ashore on the SE Louisiana coast. Brian Peters and J.B. Elliot have provided some good analyses and information this morning.

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1130 AM EDT THU SEP 20 2007
FOR THE NORTH ATLANTIC…CARIBBEAN SEA AND THE GULF OF MEXICO…SURFACE OBSERVATIONS INDICATE THAT A WEAK LOW PRESSURE AREA HASFORMED IN THE EASTERN GULF OF MEXICO IN ASSOCIATION WITH AN UPPER-LEVEL LOW. SHOWER ACTIVITY WITH THIS NON-TROPICAL SYSTEM REMAINS LIMITED AND DISORGANIZED. HOWEVER…THIS SYSTEM HAS THE POTENTIAL TO ACQUIRE SUBTROPICAL CHARACTERISTICS LATER TODAY OR TOMORROW AS IT MOVES WEST-NORTHWESTWARD OVER THE WARM WATERS OF THE GULF OF MEXICO. AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT IS SCHEDULED TO MONITOR THE SYSTEM THIS AFTERNOON. ALL INTERESTS ALONG THE NORTHERN GULF COAST SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

I realize nothing of significance has formed yet, but I am concerned about the following issues regarding the future Jerry:

• The GFDL says he will become a hurricane prior to landfall on the Louisiana coast
• Gulf waters are very warm
• Shear is expected to be minimal
• Humberto developed rapidly, exceeding the predictions of computer models
• New Orleans remains vulnerable to storm surge

There is much uncertainty with this yet-to-develop storm. Please stay tuned!

Article from the AP wire: NWS Changes Severe Weather Alerts

I think this is a good thing. The NWS in Birmingham has been doing this for awhile now. I like it. It may help reduce the high number of false alarms and improve public perception. Many people complain when their county is under a warning and they have sunny skies because the severe weather may be 20 miles away. This may help improve the overall process.

Excerpt:

BIRMINGHAM, Ala. (AP) — The National Weather Service is revamping the way it has issued severe weather warnings for decades with a new system designed to mark a geographic bull's eye where a storm will hit. The system, which goes into effect Oct. 1, switches from alerts based on county lines to notices aimed at specific communities, weather service officials said Tuesday. Using radar and computer modeling programs, the system is meant to predict the moment a storm will hit a community or even a certain crossroads. Known as storm-based warnings, the new alerts could reduce a warning area from thousands of square miles to a few hundred square miles, experts said.

The president of the Alabama Skywarn Foundation, Brian Peters, said the new system already is being used in some weather service warnings, which name a county being placed under alert and then specify a certain area that's particularly at risk. But, he said, highlighting too narrow an area for a warning could be hazardous since storms can change direction, and radar has its limits. An undetected tilt in a twister could send it toward an area that was not under a warning if alert boxes are too small. "That's what worries me, giving people a false sense of security," said Peters, a meteorologist with WBMA-TV in Birmingham who previously worked as the weather service's warning coordinator for Alabama. Jacks said new warnings will be issued as storms move.

The national Hurricane center is closely monitoring an area of disturbed weather between the Bahamas and the Atlantic Coast of Florida. These clouds and storms are caused by an upper level low over Florida and a tropical wave over the Bahamas. Models are showing this area moving across the Florida Peninsula over the next few days and strengthening into a tropical storm after it emerges in the Eastern Gulf of Mexico, perhaps by Thursday afternoon. The GFS model shows the system entering Southeast Louisiana on Saturday.

This is certainly a system to keep an eye on this week.

This weekend was what I refer to as a much-welcomed fall preview. The temperature Sunday morning dipped to 49.5 at my place. Just up the road at the Vinemont-Cullman Folsom Field Airport, the official temperature dipped to 46. I never have trusted the readings at that site. I know meteorologists who say the same thing.

Up in Chicago, IL, the temperature broke a 117 year record and dipped to 39 degrees, according to the WGN Weather Blog.

Friday was rainy day with several inched reported across much of North Alabama thanks to the remnants of Humberto. By Friday evening, the sky became partly cloudy. Saturday was an ideal day for tailgating in Tuscaloosa. Temperatures topped out in the 70's after a comfortable morning. The weather was cool enough to really enjoy the Tide's exciting win over the Arkansas Razorbacks.

Today looks really nice. Too nice to be stuck behind a computer for sure!

BULLETIN - EAS ACTIVATION REQUESTEDTORNADO WARNINGNATIONAL WEATHER SERVICE BIRMINGHAM AL1110 AM CDT FRI SEP 14 2007
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A
* TORNADO WARNING FOR…WESTERN JEFFERSON COUNTY IN CENTRAL ALABAMA…THIS INCLUDES THE CITIES OF…FORESTDALE…FAIRFIELD…
* UNTIL NOON CDT
* AT 1108 AM CDT…NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED ASEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 12 MILES WEST OFNORTH JOHNS…OR 14 MILES NORTHEAST OF HOLT…MOVING NORTHEAST AT20 MPH.
* THE TORNADO WILL BE NEAR…7 MILES NORTHWEST OF NORTH JOHNS BY 1135 AM CDT…6 MILES NORTHWEST OF VALLEY CREEK BY 1140 AM CDT…BIRMINGHAMPORT BY 1150 AM CDT…6 MILES NORTHWEST OF HUEYTOWN BY 1155 AM CDT…SYLVAN SPRINGS…MAYTOWN…MULGA AND MINOR BY NOON CDT…

ABC 33/40 Pinpoint Doppler

I thought about titling this post "Zero to 85 in 24 hours". Humberto formed in the western Gulf of Mexico and in about one day became a Cat 1 hurricane. This was the first hurricane to make landfall in the USA in two years.

Power was out in some areas and, according to an AP story, "Jefferson County's Emergency Operations Center in Beaumont, where wind speeds of 75 to 80 mph were noted, said Michael White, the county's assistant emergency management coordinator. Officials were forced to track the storm with laptops, he said."

~~~

Update: There has been at least one fatality in Texas as a carport collapsed in the wind.

~~~

Intensification Record? Check this out from the NHC:
BASED ON OPERATIONAL ESTIMATES…HUMBERTO STRENGTHENED FROM A 30 KTDEPRESSION AT 15Z YESTERDAY TO A 75 KT HURRICANE AT 09Z THISMORNING…AN INCREASE OF 45 KT IN 18 HOURS. TO PUT THISDEVELOPMENT IN PERSPECTIVE…NO TROPICAL CYCLONE IN THE HISTORICALRECORD HAS EVER REACHED THIS INTENSITY AT A FASTER RATE NEARLANDFALL. IT WOULD BE NICE TO KNOW…SOMEDAY…WHY THIS HAPPENED.

~~~

BULLETIN

HURRICANE HUMBERTO ADVISORY NUMBER 5

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

AL092007 400 AM CDT THU SEP 13 2007
…HURRICANE HUMBERTO JUST INLAND OVER SOUTHEASTERN TEXAS…

A HURRICANE WARNING REMAINS IN EFFECT FROM EAST OF HIGH ISLAND TEXASTO CAMERON LOUISIANA.

AT 400 AM CDT…THE CENTER OF HURRICANE HUMBERTO WAS LOCATED NEAR LATITUDE 29.9 NORTH…LONGITUDE 94.1 WEST OR ABOUT 60 MILES…95 KM…NORTHEAST OF GALVESTON TEXAS…AND ABOUT 25 MILES… 35KM…NORTHEAST OF HIGH ISLAND TEXAS.

HUMBERTO IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 8 MPH…13 KM/HR…AND THIS MOTION IS EXPECTED TO CONTINUE OVER THE NEXT 24 HOURS.ON THIS TRACK WILL BRING HUMBERTO FARTHER INLAND OVER EASTERN TEXASAND LOUISIANA OVER THE NEXT 24 HOURS.

DATA FROM AN AIR FORCE RECONNAISSANCE AIRCRAFT AND DOPPLER RADAR INDICATE THAT THE MAXIMUM SUSTAINED WINDS ARE NEAR 85 MPH…140KM/HR…WITH HIGHER GUSTS…CONFINED TO A SMALL AREA NORTHEAST OF THE CENTER. HUMBERTO IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON SCALE. WEAKENING IS FORECAST DURING THE NEXT24 HOURS AS HUMBERTO CONTINUES TO MOVE INLAND.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 15 MILES…30KM…NORTHEAST OF THE CENTER…AND TROPICAL STORM FORCE WINDSEXTEND OUTWARD UP TO 60 MILES…95 KM. AN OBSERVING STATION AT BEAUMONT TEXAS RECENTLY REPORTED WIND GUSTS TO 60 MPH…96 KM/HR.

MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY THE AIRCRAFT WAS 986MB…29.12 INCHES.

RAINFALL AMOUNTS OF 5 TO 10 INCHES ARE EXPECTED ALONG THE TRACK OF HUMBERTO FROM SOUTHWESTERN TO NORTHEASTERN LOUISIANA…ACROSS FARSOUTHEASTERN ARKANSAS AND INTO CENTRAL AND NORTHERN MISSISSIPPI…WITH ISOLATED MAXIMUM ACCUMULATIONS OF 15 INCHES POSSIBLE. COASTAL STORM SURGE FLOODING OF 3 TO 4 FEET ABOVE NORMAL TIDE LEVELSMOST LIKELY OCCURRED NEAR AND TO THE EAST OF WHERE THE CENTER MADELANDFALL AND SHOULD SUBSIDE THIS MORNING.

ISOLATED TORNADOES ARE POSSIBLE IN SOUTHEASTERN TEXAS ANDSOUTHWESTERN LOUISIANA THROUGH THIS AFTERNOON.

REPEATING THE 400 AM CDT POSITION…29.9 N…94.1 W. MOVEMENT TOWARD…NORTH-NORTHEAST NEAR 8 MPH. MAXIMUM SUSTAINED WINDS…85MPH. MINIMUM CENTRAL PRESSURE…986 MB.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANECENTER AT 700 AM CDT FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 1000AM CDT.

$$FORECASTER MAINELLI/AVILA

August 2007

Monthly Weather Summary

MONTHLY AVERAGE TEMPERATURES FOR HUNTSVILLE AND MUSCLE SHOALS
SET RECORDS FOR THE MONTH OF AUGUST. IN FACT...AUGUST 2007
RANKS AS THE HOTTEST MONTH ON RECORD SINCE TEMPERATURE RECORDS
BEGAN AT EACH STATION...1907 AT HUNTSVILLE...AND 1893 AT MUSCLE
SHOALS. IN ADDITION...NUMEROUS DAILY RECORDS WERE ALSO TIED OR
BROKEN AT EACH STATION. AN UNUSUALLY STRONG AND PERSISTENT RIDGE
OF HIGH PRESSURE BUILT INTO THE SOUTHEAST UNITED STATES DURING
THE MONTH...EFFECTIVELY STEERING MOST WEATHER SYSTEMS AWAY FROM
THE TENNESSEE VALLEY...AND HELPING TEMPERATURES TO WARM
SIGNIFICANTLY. FOLLOWING ARE TEMPERATURE STATISTICS FOR THE
MONTH OF AUGUST FOR BOTH CLIMATE LOCATIONS.

- THE MONTHLY AVERAGE TEMPERATURE FOR AUGUST 2007 AT HUNTSVILLE
WAS 85.7 DEGREES...WHICH WAS 7.1 DEGREES ABOVE THE NORMAL AUGUST
TEMPERATURE OF 78.6 DEGREES BASED ON A 1971-2000 CLIMATOLOGY. THIS
WAS 3.26 STANDARD DEVIATIONS FROM THE NORMAL AUGUST TEMPERATURE FOR
THE SAME CLIMATOLOGICAL PERIOD. THIS NOW RANKS AS THE WARMEST AUGUST
ON RECORD...SHATTERING THE OLD RECORD OF 82.8 DEGREES SET IN 2006
AND 1954. IN ADDITION...THIS RANKS AS THE WARMEST CALENDAR MONTH ON
RECORD FOR HUNTSVILLE...BREAKING THE OLD RECORD OF 83.9 DEGREES SET
IN JULY 1930. RECORD DAILY HIGH TEMPERATURES WERE SET ON 8
DAYS...INCLUDING THE 10TH, 12TH, 13TH, 14TH, 15TH, 16TH, 22ND, AND
23RD. THE AVERAGE HIGH TEMPERATURE FOR THE MONTH WAS 98.2 DEGREES
AND THE AVERAGE LOW WAS 73.3 DEGREES, WHICH ALSO SET RECORDS FOR THE
MONTH OF AUGUST. THE COOLEST AUGUST ON RECORD WAS IN 1967...WITH AN
AVERAGE TEMPERATURE OF 73.8 DEGREES.

- THE MONTHLY AVERAGE TEMPERATURE FOR AUGUST 2007 AT MUSCLE SHOALS
WAS 85.5 DEGREES...WHICH WAS 6.4 DEGREES ABOVE THE NORMAL AUGUST
TEMPERATURE OF 79.1 DEGREES BASED ON A 1971-2000 CLIMATOLOGY. THIS
NOW RANKS AS THE WARMEST AUGUST ON RECORD...BREAKING THE OLD RECORD
OF 84.2 DEGREES SET IN 1954. IN ADDITION...THIS RANKS AS THE WARMEST
CALENDAR MONTH ON RECORD FOR MUSCLE SHOALS...ECLIPSING THE OLD
RECORD OF 85.4 DEGREES SET IN JULY 1980. RECORD DAILY HIGH
TEMPERATURES WERE SET ON 9 DAYS...INCLUDING THE 10TH, 12TH, 13TH,
14TH, 15TH, 16TH, 22ND, 23RD, AND 24TH. THE AVERAGE HIGH TEMPERATURE
FOR THE MONTH WAS 98.6 DEGREES, AND THE AVERAGE LOW WAS 72.4
DEGREES, WHICH ALSO SET RECORDS FOR THE MONTH OF AUGUST. THE COOLEST
AUGUST ON RECORD WAS IN 1967...WITH AN AVERAGE TEMPERATURE OF 74.1
DEGREES.

PRECIPITATION IN AUGUST FELL EXCLUSIVELY IN THE SECOND HALF OF THE
MONTH...AS THE PERSISTENT RIDGE BROKE DOWN BRIEFLY A FEW TIMES.
INTERESTINGLY...PRECIPITATION ENDED AT NEAR NORMAL VALUES FOR BOTH
LOCATIONS FOR THE MONTH OF AUGUST. FOLLOWING ARE PRECIPITATION
STATISTICS FOR BOTH CLIMATE LOCATIONS.

- NO MEASURABLE RAINFALL OCCURRED AT HUNTSVILLE FOR THE FIRST 16
DAYS OF THE MONTH...ONLY THE FOURTH TIME ON RECORD THAT HAS
HAPPENED...AND THE FIRST TIME SINCE 1918. A COUPLE OF HEAVY RAIN
EVENTS LATE IN THE MONTH PUSHED THE TOTAL AT HUNTSVILLE
INTERNATIONAL AIRPORT TO 3.11 INCHES...WHICH WAS JUST 0.21 INCHES
BELOW NORMAL...AND TIES FOR THE 49TH DRIEST ON RECORD DATING BACK TO
1894. SOME PORTIONS OF THE HUNTSVILLE METRO RECEIVED MORE THAN EIGHT
INCHES OF RAIN IN AUGUST...BUT THE HEAVIEST RAIN MISSED THE AIRPORT.

- IN MUSCLE SHOALS...NO RAIN...NOT EVEN A TRACE...FELL THROUGH
AUGUST 15TH. THIS WAS ONLY THE SECOND TIME THIS HAS OCCURRED. THE
OTHER OCCURRENCE WAS IN 1918. A TRACE FELL IN THE FIRST HALF OF
AUGUST IN 1900 AND 1981. A COUPLE OF HEAVIER RAIN EVENTS DURING THE
SECOND HALF OF THE MONTH BROUGHT THE FINAL TOTAL TO 3.26
INCHES...WHICH WAS 0.30 INCHES ABOVE NORMAL...AND IS THE 48TH DRIEST
ON RECORD DATING BACK TO 1893. THIS WAS THE SECOND MONTH IN A ROW IN
THE SHOALS WITH ABOVE NORMAL RAINFALL.

Today she made landfall on the North Carolina coast. Top winds before landfall were 60 mph. The models were pretty impressive with this storm. Before it formed the models were in good agreement not only that it would form but that it would make landfall on the NC coast. Despite the fact that the initial disturbance almost completely disintegrated with a passing trough, the models hung in there and proved quite accurate. One of the early models (I think it was the GFDL) overestimated the strength, showing it as a Cat 3 at landfall. But, this was early on. Overall the models did a good job with this storm. Even back on Thursday night, most models were saying that it would be a strong TS or minimal hurricane making landfall on the NC coast Sunday morning. That's basically what happened.

I first referred to the possibility of referring this storm as "Felix the Cat" a few weeks ago when it appeared that a disturbance near the Bahamas appeared to be on the verge of becoming Felix. I really like the way Bill Murray of Alabamawx.com took the nomenclature a step further by referring to him as "Felix the Cat 5".

Felix intensified very rapidly over the weekend. As a matter of fact, he now holds second place to Wilma for rapid intensification during a 24 hour period. By Sunday he had become a Cat 5 storm. Yesterday he dipped down to Cat 4 status, only to restrengthen last night to Cat 5 status prior to landfall.

Yes, I am a weather geek, but....

There is life outside of posting about weather.

Weather stops for no one and I'll be catching up on Felix the Cat 5 and other wx stuff this week.