Records fall in the Plains; We get close here

It may feel a little like summer as dew points and temperatures rise through the afternoon.  After a very mild morning highs will reach the middle, if not upper, 80s by the time you head home from work.  The warmth will spread across the middle of the nation while cooler weather can be found in the west and into the northeast.

This is all thanks to a blocking pattern that has set up; an Omega block because it resembles the Greek letter Omega.  An area of low pressure in the northern Atlantic will remain for the next couple of days while another low sits in the west.  This causes the jetstream to buckle through the Midwest.  Look at some of the highs for today; 90s and possibly triple digits again for some in the Plains.  Yesterday afternoon a record high of 95° was set in Topeka, KS while Wichita, KS recorded it's earliest 100° reading ever!  Records fell not only in Wichita, but also Russell and Salina (both in Kansas).

Warmer air continues to stream in aloft likely keeping our atmosphere capped through this afternoon.  So with mostly sunny skies temperatures across the immediate Stateline will reach the middle 80s! Our record high for today is 91° set back in 1922, 1896 and 1895!   Enjoy it while it lasts, though!

New Day 1 Severe Outlook

Any storms that do develop tonight should fall short of severe criteria according to the Storm Prediction Center in Norman, OK. (This is their new forecast at right.) Warm air in the upper levels of the atmosphere across the Stateline should inhibit the growth of convective activity. Any storms that do develop will probably produce wind gusts of less than 40 mph and only small hail of pea-size or less.

Warmth and storms this week

Noon Update:   Slight risk still remains for thunderstorms later this afternoon.  Early morning thunderstorm complex continues to move east through Wisconsin bringing heavy rainfall, gusty winds and hail.  A few light showers could still be possible early this afternoon with a few sunny breaks possible later today.  There is some clearing behind the clouds out towards western Iowa and temperatures there have soared into the 70s and even 80s.  There is still the possibility that some redevelopment may occur later this afternoon and evening, but I think the atmosphere will remain capped through the better part of the day.  If we were to see any storms develop it likely wouldn't be until evening as the warm front moves closer and the cap starts to break down.  Gusty winds and hail still look to remain the primary threats, should storms occur.  This will be something we'll have to watch fairly closely going into the afternoon.


(11:30:33 AM) nwsbot: MKX: Janesville [Rock Co, WI] law enforcement reports HAIL of half inch size (M0.50 INCH) at 11:25 AM CDT -- rock county sheriff deputy reports marble size hail near intersection of highway 11 and highway d.

11:00 am Update:  One particular cell now moving just southwest of Brodhead in Green county will continue to move northeast around 35 mph.  Hail up to dime size could be possible with this cell as it moves into Rock County in southern Wisconsin.

10:40 am Update:  Already hearing some rumbles of thunder this morning; look for a few storms to move through the Rockford metro within the next 15 minutes.

10:10 am Update:  Showers with a few embedded thunderstorms have developed out ahead of a storm system in eastern Iowa, across northwest Illinois.  Look for heavy rainfall and maybe even small hail with any of the storms as they move through.  Once this initial band passes, storms could redevelop again later this afternoon.                                      

7:00 am Update: A cluster of thunderstorms continue to move east out of Minneapolis this morning and into Wisconsin producing gusty winds, heavy rainfall and hail.  We'll watch for any further southward development along this line or any storms that may fire up in eastern Iowa this morning.  These storms are riding over top a ridge of high pressure that extends all the way into the northern Plains.

An area of low pressure currently in central Nebraska will continue to strengthen and move east through the afternoon lifting a warm front closer to northern Illinois.  As the warm front moves closer, storms could redevelop along the front as mild and moist air lifts into the Great Lakes.  The one thing that may prevent any storms from developing would be the already very mild air in place several thousand feet above.  This may act as a cap, or lid, on the atmosphere.  However, if storms were to develop the threat would be there for gusty winds as well as hail.  The Storm Prediction Center has highlighted parts of the area in a slight risk for later this afternoon.  We'll continue to keep you updated throughout the morning and afternoon so be sure to keep checking back.

Big Warm Up By Tuesday... Thunderstorms in the PIcture Too

High pressure ridging from Hudson Bay in Canada across the Great Lakes into Illinois was responsible for a fabulous day across our part of the midwest on Mother's Day. It is moving eastward, however, and that will allow a system over the plains to begin to affect the northwestern part of Illinois with a slight chance of showers and maybe an isolated thunderstorm after midnight. Moisture from the Gulf of Mexico will overrun a warm front situated from southern Illinois westward across Missouri and Kansas into an area of low pressure over the Nebraska panhandle. Skies will be mostly cloudy on Monday with a good chance of showers and thunderstorms. The system is a very slow mover, so showers and thunderstorms will be a possibility on a daily basis through Friday. Tuesday and Wednesday will be very warm with a high in the low 80's.

The Pattern Will be Active Next Week Again

Low pressure is drifting southeast across southern Illinois overnight. The low clouds have cleared out but there continue to be high clouds streaming from west to east across northern Illinois.  A bubble of weak high pressure has  taken control of area weather, and skies will remain partly cloudy through Sunday afternoon.    Mother's Day will start off cool... in the middle 40's, but  it will turn out to be a very comfortable day with a high near 70 degrees by mid afternoon. Clouds will increase during the afternoon along with a slight chance of some showers in western areas... ie Freeport, Davis, Dakota, Mt. Morris, Mt. Carrol, and Shannon.  as a new low pressure storm system begins to develop over the plains. A disturbance associated with that system along, with an increasing southerly air flow of Gulf moisture up and over a warm front to our south, will give the Stateline a good chance of showers and thunderstorms on Monday.  The storm on the plains will be a slow mover this week with the atmospheric circulation jammed fup over the nation's midsection.  So, it will take some time for the system to work it's way through the midwest.  There is potential for some generous rainfall amounts in the coming week with a warm front stretching east/west across the southern tip of Illinois on Monday.  Gulf moisture will run up and over the front spawning shower and thunderstorms into our area beginning on Monday.  The warm front will reach northern Illinois on Tuesday, and temperatures will soar into the low 80's on Tuesday and Wednesday.  Again, because of the slow movement of this system, there will be daily chances for showers and thunderstorms through Friday, and possibly even into Saturday.  Early estimates for rainfall for the next 7 days are around 1", but that is difficult to estimate, because thunderstorms tend to be hit and miss. If an area gets hit by several thunderstorms,  it could receive much more than 1".

Things get backed up next week

The weather the past week or so has been fairly tranquil, cool but quiet.  This will all be changing starting as early as Sunday night.  A blocking pattern will begin to set up with high pressure building in the Gulf of Mexico and low pressure on the east and west coasts in the upper levels.  With the digging trough out west, an area of low pressure will begin to develop in the middle of the U.S.  Because of the blocking pattern the low won't really have any place to go.  A warm front will continue to lift northward through Monday bringing an isolated chance of a few storms. 

Depending upon where exactly this warm front will sit will mean the difference between highs in the 80s or 60s/70s.  It will also mean the difference in whether or not we see any heavy rainfall during that period.  If the front were to remain overhead, moisture would continue to pool along the front with disturbances moving along it, providing the threat for heavy rainfall.  If the front were to continue north the atmosphere would likely remained cap and the threat for heavy rain would sit just to the north. 

New April Tornado Outbreak Information

From NOAA:

"I observed some of the devastating tornado damage with a NOAA forensic meteorology team in Tuscaloosa, Ala. Aerial and ground surveys document the strength of the storm and provide information to improve future warnings. The damage is heartbreaking; the human stories are both tragic and heroic. I'm immensely proud of the spectacular job our National Weather Service teams did to warn communities and save lives."
Dr. Jane Lubchenco, NOAA administrator



NOAA's preliminary estimate is that there were 305 tornadoes during the entire outbreak from 8:00 a.m. EDT April 25 to 8:00 a.m. April 28, 2011.

 The NWS Storm Prediction Center issued severe weather outlooks five days in advance and tornado watches hours in advance.  NWS Weather Forecast Offices issued life-saving tornado warnings, with an average lead-time of 24 minutes. NWS issued warnings for more than 90 percent of these tornadoes.

NWS decision support for this event has been extensive. NWS Weather Forecast Offices in the affected areas of Arkansas, Tennessee, Mississippi, Alabama and Georgia advertised the potential for severe weather in the Tuesday through Wednesday timeframe since late last week. Local offices provided direct decision support services to meet the specific needs of local emergency manager partners and the general public. NWS Weather Forecast Offices issued Hazardous Weather Outlooks up to six days in advance noting the greater threat of strong, long-track tornadoes was expected.

The largest previous number of tornadoes on record in one event occurred from April 3-4, 1974, with 148 tornadoes.

NOAA will conduct a detailed analysis of tornado numbers using all available data to make any final determinations about records. This typically takes months to complete.  There were approximately 318 fatalities during the entire outbreak from April 25 to April 28

There were approximately 309 fatalities during the 24-hour-period from 8:00 a.m. April 27 to 8:00 a.m. April 28. This is currently the fifth deadliest day of tornadoes on record.

Ongoing (preliminary) List of Tornadoes by EF Rating (EF0 to EF5):
EF-5 2
EF-4 12
EF-3 21
EF-2 47
EF-1 62
EF-0 57

Total: 201

The Tuscaloosa-Birmingham tornado during the April 2011 event caused at least 65 fatalities. This tornado had a maximum width of 1.5 miles and a track 80 miles long. These are the most fatalities from a single tornado in the United States since May 25, 1955, when 80 people were killed in a tornado in southern Kansas with 75 of those deaths in Udall, Kansas.

The deadliest single tornado on record in the United States was the Tri-State tornado (Mo., Ill., Ind.) on March 18, 1925, when 695 died.

According to National Weather Service Weather Forecast Office Storm Survey teams, from 8 a.m. April 27 to 8 a.m. April 28 there were 20+ killer tornadoes in five states--Mississippi, Alabama, Georgia, Tennessee and Virginia--that caused 309+ fatalities.

Note: All numbers are based on combined NOAA and historical research records and current fatality estimates. The historical research records extend back to 1680.