Saturday, April 30, 2011

April 30: MANDATORY EVACUATION FOR FLOODWATER (Cairo, Illinois)

The following areas are under a Mandatory evacuation at this time:
-Cairo Illinois

All residents have been ordered to evacuate due to the potential imminent failure of a levee.
Take this warning seriously.
Staying behind could result in death.

More rain is predicted to fall.

Again, all residents of Cairo, Illinois are ordered to evacuate now.

Remember:
Turn around, don't drown.

April 30: Special Update Tonight's Thunderstorm Forecast

The Rapid Refresh (RR) model is painting a new scenario for tonight's storms.
It calls for storms to NOT develop in the Wisconsin/IL areas.
However, there is a more potent threat of storms in Texas than previously thought.

That is all.

April 30: Tornado Warning (Damage Reported)- Atlanta, TX



THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL BOWIE COUNTY IN NORTHEAST TEXAS...
  CASS COUNTY IN NORTHEAST TEXAS...
  THIS INCLUDES THE CITY OF ATLANTA...

* UNTIL 1030 PM CDT

* AT 944 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 12 MILES WEST OF
  LINDEN...OR 3 MILES NORTHEAST OF HUGHES SPRINGS...MOVING EAST
  NORTHEAST AT 20 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  BIVINS...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
GOLFBALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

DAMAGE HAS BEEN REPORTED IN DOWNTOWN HUGHES SPRINGS FROM A CONFIRMED
TORNADO. IF YOU ARE IN THE PATH OF THIS STORM...TAKE COVER
IMMEDIATELY!

May 8-9 Potential Midwest/Great Lakes Severe Storm System (Issued April 30)

There is concern building for a potentially significant severe weather event May 8-9.
 We will see a strong low pressure system drop from Canada into the Upper Midwest. The low will bring with it a supply of cold air. This image is for the period May 8th at 7pm CDT.
The above image is forecast for 1 am, May 9. By then, the low pressure will have quickly moved into Michigan. This does not display what is forecast for temperature differences, though.
The image above is still 1 am CDT May 9th, but it displays projected temperature differences 5,000 feet above the ground. As you can see, a rush of cooler air will be following the low, suggesting some form of cold front or force moving the air into the region.
More concerning, though is the temperature differences. It is projected to be a 10 degree temperature difference, which could turn out to be a 15 degree difference on the ground. That is a pretty substantial difference. With such a strong low and big temperature differences, there is definitely concern for tornadoes.
The image above is the Best Lifted Index. The lower numbers, the more unstable. As you can see, here is a noticeable area of instability in Nebraska, with a number of -8. The image above is actually in the time frame of May 8th at 1 am. That displays an able set-up going into the event.

Lastly, also at 1 am May 8th, is the image depicting a cap. A cap suppresses storms, the more negative the stronger the cap. As we can see on this image, the cap is as low as the legend can go, which is -500 to -900. That is an extremely strong cap. It is very worrying, combined with such instability, strong low pressure.

These two images are the jet stream. The jet stream was up to 150 mph on the April 27 tornado outbreak down south. The first image is May 9th at 1 am, while the second is May 9th at 7 am.
We see the jet stream will be fairly strong, at it reaches up to 100 mph in the Ohio Valley.
Finally, above, is the lower level jet stream forecast at May 9th at 1 am. The lower level jet stream will not be terribly strong, meaning the tornado threat should not be as strong as it was on April 27.
In conclusion, there is a threat for a tornado outbreak and severe weather, but it would not be nearly as strong as April 27.

April 27 Aftermath: Outbreak Map from Birmingham, AL NWS


April 27 Aftermath: Updated Tornado Surveys (April 30) Birmingham, AL


Storm Survey Status
This page will be updated with the latest status for ongoing and planned storm surveys for major tornado outbreak of April 27, 2011.  Due to the immense scope of the event, both in the degree of damage and the large geographical area that it covered, it will likely be a week or more before all surveys can be finalized.

Location(s)

Damage Survey Status

HackleburgEF-3+ Tornado. Winds: At least
180mph. Path Length: 25.2 miles,
Path Width 3/4 mile. Further Evaluation Underway
Expert Analysis to be released soon.
Other portions of Marion, Lamar, Fayette, and Winston CountiesShotsville: EF-3+ Tornado. Winds:
Around 140mph. Path Length:
19.1 miles in Marion County .
Path Width: 3/4 mile. Further Evaluation Underway.
Haleyville: EF-3+ Tornado.
Winds: Around 140mph.Path Length:
31.8 miles, Path Width: 3/4 mile. The
track may have continued into the
Tennessee Valley.
Pickens County into Northern Tuscaloosa CountyOngoing (Aerial)
Walker and Blount CountiesOngoing (Aerial)
TuscaloosaEF-3+ Tornado. Expert Analysis to be released soon.
Jefferson County/Birmingham MetroEF-3+ Tornado. Expert Analysis to be released soon.
Western portions of Tuscaloosa-Birmingham Supercell (Sumter and Green Counties)Ongoing Today
Eastern portions of Tuscaloosa-Birmingham Supercell (Saint Clair to Cherokee County)EF-3+ Tornado. Winds: Potentially up to 180mph.
Path Length: 72 miles, continued up to 26 miles
into Georgia. Path Width: Up to 1.25 miles.
Further Evaluation Underway.
Sumter-Green-Hale-Bibb CountiesEF-3 Tornado.  Winds: Around 145mph.
Path Length: 71.3 miles. Path Width: 1 mile.
Started near the Tombigbee River in Greene
County and continued into Northeast Bibb County.
Pell City-Talladega-Calhoun-Cleburne CountiesOngoing Today
Marengo (continuation from Choctaw County)Being Finalized
Perry-Dallas-Chilton CountiesTo Be Surveyed by Monday.
 Autauga-Elmore-Tallapoosa-Chambers (including Dadeville)EF-3+ Tornado. Details Being Finalized.

April 30: Blizzard Warning- West ND



...A BLIZZARD WARNING REMAINS IN EFFECT FOR WESTERN AND PORTIONS OF
CENTRAL NORTH DAKOTA...

.A STRONG LOW PRESSURE SYSTEM IN SOUTHEASTERN NORTH DAKOTA WILL
CONTINUE TO MOVE EAST TONIGHT. SNOW IN WESTERN AND CENTRAL NORTH
DAKOTA COMBINED WITH STRONG WINDS GUSTING TO 60 MPH WILL CAUSE
BLIZZARD CONDITIONS. HEAVY WET SNOW COMBINED WITH THE STRONG WINDS
COULD CAUSE DOWNED LINES AND POWER OUTAGES IN SOME AREAS.
CONDITIONS WILL IMPROVE IN THE WEST THIS EVENING AND IN CENTRAL
NORTH DAKOTA AFTER MIDNIGHT.

ALONG AND SOUTHEAST OF A LINE FROM SHIELDS TO STEELE AND
JAMESTOWN...WINDS GUSTING TO 60 MPH COMBINED WITH SNOW OF LESSER
INTENSITY WILL RESULT IN 1/2 MILE VISIBILITIES. THE GREATEST
IMPACT WILL BE FROM THE WINDS. AS A RESULT...A HIGH WIND WARNING
IS IN EFFECT FOR THE AFOREMENTIONED AREA. TRAVEL WILL STILL BE
HAZARDOUS.

STORM TOTAL SNOWFALL ACCUMULATIONS OF 6 TO 9 INCHES WILL OCCUR IN
THE VICINITY OF DICKINSON...WILLISTON...MINOT...AND BOTTINEAU.
SNOW ACCUMULATIONS OF 3 TO 6 INCHES ARE EXPECTED NEAR AMIDON...
BISMARCK...AND HARVEY. SNOWFALL TOTALS OF 1 TO 3 INCHES ARE
EXPECTED NEAR BOWMAN...SHIELDS...AND JAMESTOWN.

PLEASE MONITOR FUTURE NATIONAL WEATHER SERVICE FORECASTS TO STAY
INFORMED ABOUT THIS WINTER STORM.

NDZ001-002-009-010-017-018-031>033-040-041-043-044-010300-
/O.CON.KBIS.BZ.W.0010.000000T0000Z-110501T0300Z/
DIVIDE-BURKE-WILLIAMS-MOUNTRAIL-MCKENZIE-DUNN-GOLDEN VALLEY-
BILLINGS-STARK-SLOPE-HETTINGER-BOWMAN-ADAMS-
INCLUDING THE CITIES OF...CROSBY...BOWBELLS...WILLISTON...
NEW TOWN...WATFORD CITY...KILLDEER...BEACH...MEDORA...DICKINSON...
MARMARTH...MOTT...BOWMAN...HETTINGER
318 PM CDT SAT APR 30 2011 /218 PM MDT SAT APR 30 2011/

...BLIZZARD WARNING REMAINS IN EFFECT UNTIL 10 PM CDT /9 PM MDT/
THIS EVENING...

A BLIZZARD WARNING REMAINS IN EFFECT UNTIL 10 PM CDT /9 PM MDT/
THIS EVENING.

* SNOW WILL BE HEAVY AT TIMES.

* STRONG NORTHWEST WINDS 35 TO 40 MPH WITH GUSTS TO 60 MPH
  COMBINED WITH SNOW WILL CAUSE BLIZZARD CONDITIONS.

* TRAVEL WILL BE HAZARDOUS DUE TO SNOW COVERED ROADS AND BLOWING
  SNOW SIGNIFICANTLY REDUCING VISIBILITIES.

* STORM TOTAL SNOWFALL ACCUMULATIONS OF 6 TO 9 INCHES WILL OCCUR
  IN THE VICINITY OF DICKINSON...WILLISTON...MINOT...AND
  BOTTINEAU. SNOW ACCUMULATIONS OF 3 TO 6 INCHES ARE EXPECTED
  NEAR AMIDON...BISMARCK...AND HARVEY. SNOWFALL TOTALS OF 1 TO 3
  INCHES ARE EXPECTED NEAR BOWMAN...SHIELDS...AND JAMESTOWN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITEOUT
CONDITIONS...MAKING TRAVEL EXTREMELY DANGEROUS. DO NOT TRAVEL. IF
YOU MUST TRAVEL...HAVE A WINTER SURVIVAL KIT WITH YOU. IF YOU GET
STRANDED...STAY WITH YOUR VEHICLE.

April 30: Extreme Fire Danger- Many Areas (NWS Office Omaha/Valley NE)


RANGELAND FIRE DANGER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
147 PM CDT SAT APR 30 2011

NEZ015>018-030>033-042-010300-
THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-STANTON-CUMING-
PLATTE-
147 PM CDT SAT APR 30 2011

...EXTREME FIRE DANGER TODAY...

THE GRASSLAND FIRE DANGER INDEX WILL BE IN THE EXTREME CATEGORY
THIS AFTERNOON.

EXTREME FIRE DANGER MEANS THAT FIRES START QUICKLY...SPREAD
FURIOUSLY AND BURN INTENSELY. ALL FIRES ARE POTENTIALLY SERIOUS.
ALL OUTDOOR BURNING SHOULD BE AVOIDED IN AREAS WITH EXTREME FIRE
DANGER.

April 30: Civil Emergency Message- Memphis Shelby County, TN


TNC157-011815-

BULLETIN - EAS ACTIVATION REQUESTED...CORRECTED
CIVIL EMERGENCY MESSAGE
MEMPHIS SHELBY COUNTY EMERGENCY MANAGEMENT AGENCY
RELAYED BY NATIONAL WEATHER SERVICE MEMPHIS TN
332 PM CDT SAT APR 30 2011

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE
MEMPHIS SHELBY COUNTY EMERGENCY MANAGEMENT AGENCY.

FLOOD WARNING

ALL SHELBY RESIDENTS SHOULD TAKE PRECAUTION NOW...ESPECIALLY
IF YOU LIVE WITHIN THE 100 YEAR FLOOD PLAIN OF RIVERS AND
STREAMS...TO BE PREPARED TO EVACUATE HOMES AND BUSINESSES IF
FLOODING OCCURS.

NEAR RECORD FLOODING IS FORECAST ALONG THE MISSISSIPPI RIVER AS IT
BORDERS SHELBY COUNTY.

A MESSAGE FROM THE SHELBY COUNTY MAYOR MARK H. LUTTRELL...THIS IS
THE TIME TO GATHER ALL IMPORTANT ITEMS AND BE READY TO LEAVE YOUR
PROPERTY. THERE IS A VERY REAL POSSIBILITY PORTIONS OF SHELBY
COUNTY COULD BE AFFECTED BY THE RISING WATERS.

A C WHARTON...THE MAYOR OF MEMPHIS ADDED...WE WANT TO REASSURE OUR
CITIZENS THAT DISASTER TEAMS ARE IN PLACE AND WILL BE DOING
EVERYTHING POSSIBLE TO KEEP EVERYONE SAFE.

SEVERAL INCHES OF RAIN ARE PREDICTED DURING THE NEXT SEVERAL DAYS.
RIVERS AND CREEKS ARE QUICKLY RISING IN THE WESTERN AREA OF SHELBY
COUNTY AND WILL LIKELY BACK UP INTO NEIGHBORHOODS NEAR CREEKS AND
STREAMS. FLOOD WATERS MAY ALSO RISE INTO NEIGHBORHOODS THROUGH
STORM DRAINS. CONDITIONS MAY WORSEN EACH DAY WITH THE CONTINUAL
RISE OF THE MISSISSIPPI RIVER.

GO IMMEDIATELY TO HIGHER GROUND IF WATER STARTS TO RISE. AVOID
FLOOD WATERS.

April 30: Local Area Emergency- Richland County, MT


MTC083-010030-

URGENT - IMMEDIATE BROADCAST REQUESTED
LOCAL AREA EMERGENCY
MONTANA EMERGENCY MANAGEMENT AGENCY GLASGOW MONTANA
RELAYED BY NATIONAL WEATHER SERVICE GLASGOW MT
253 PM MDT SAT APR 30 2011

...LOCAL AREA EMERGENCY...

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE DES
COORDINATOR FOR RICHLAND COUNTY.

BLIZZARD CONDITIONS AND ICY ROADS ARE PRODUCING DANGEROUS TRAVEL
CONDITIONS ACROSS RICHLAND COUNTY THIS AFTERNOON. MANY ROADS ARE
CLOSED AND FOR EMERGENCY PERSONNEL ONLY.

April 30: Tonight's Thunderstorm Forecast

The image above is for 9:00 pm CDT tonight. At 9pm, we expect storms to gradually develop in West Tennessee and into Arkansas. This will be due to a cold front pulled by a low pressure system in Canada. The cold front will also initiate some weaker storms in Wisconsin into Illinois.
Looking ahead to 11:00pm CDT tonight, the storms will increase in Wisconsin and a bit more into Illinois. More interestingly, there will be stronger storms in West Tennessee and West Kentucky. The storms will also increase in coverage in Arkansas. Some spotty showers are possible into Texas as well.
The above image is valid at 2am CDT. As the cold front continues to move east, the storms will increase in coverage and strength, especially in the Northern portion. The best probability of storms will be in West Tennessee and West Kentucky. Probabilities will reach up to 90% in the Michigan area into Indiana. Spotty storms will be possible into Texas.

April 27 Aftermath: Tornado Assessment (Birmingham, AL NWS Office)







April 27 Aftermath: Satellite Image of Tornado Tracks

Images from DigitalGlobe



April 27 Aftermath: April 25,26,27 Storm Reports

April 25
 April 26
April 27

April 27 Historic Tornado Death Toll Continues to Climb (April 30)

The death toll from the April 27 tornado outbreak has risen to 355 people dead.
The National Weather Service also reported 211 confirmed tornadoes on that horrible day.
There were the most deaths in Alabama, with 254 deaths reported.
Tennessee and Mississippi followed respectfully in 2nd and 3rd place, each with 34 deaths.
In 4th place came Georgia with 15 deaths.
Arkansas- 11
Virginia- 5
Kentucky and Louisiana each had 1 death.

April 30: Daytime Thunderstorm Forecast

The image above is for around 4:00 pm CDT. We do see some storms beginning to develop in the Southeast Arkansas/North Louisiana area around this time as a strong low pressure in Canada with a trailing cold front works its way across the South US. There will also be some isolated storms in South Florida.
This cold front will cross the entire US, pretty much for everyone east of the Mississippi River.
However, with a more ample supply of humid air down south, there is a slight risk of severe storms. A tornado outbreak is not expected. Below is the slight risk area.
The slight risk extends through the following areas:
-Extreme South IL
-Extreme West KY
-Extreme Southeast MO
-Much of Arkansas
-Extreme West TN
-Extreme Northwest MS
-Portions of North TX
-Extreme Southeast OK

There will also be a threat for plain thunderstorms in green, but again, the supply of humid air will keep south, thus the slight risk.
This is an image of the probability of thunderstorms for 6:00 pm CDT today. We see a much more defined area of potential storms in Arkansas, where the highest percentage threat of REGULAR thunderstorms is up to 95%.
By the way, I don't know why this map has percentages over 100. I didn't make the map, so unfortunately I can't answer that.
Thunderstorms will be somewhat of an isolated nuisance in Southern Florida while way offshore there will be storms.
Check back tonight for tonight's thunderstorm forecast.