TORNADO WATCH - 201006260015

UPDATE 260600Z - TORNADO WATCH EXPIRED.

TORNADO WATCH - 201006251720

UPDATE 260030Z - THE TORNADO WATCH CONTINUES FOR ALL AREAS

UPDATE 260600Z - TORNADO WATCH EXPIRED.

24HR - SEVERE WEATHER OUTLOOK

24HR SEVERE WEATHER OUTLOOK
ISSUED: 251700Z
VALID:   260000Z - 261200Z

DEFINITIONS...


NOTICE LEVEL...THIS REPRESENTS A GREATER THAN 5 % CHANCE OF SEVERE WEATHER OCCURING WITHIN THE GREEN REGION ON THE MAP.

CAUTION LEVEL...THIS REPRESENTS A GREATER THAN 10% CHANCE OF SEVERE WEATHER OCCURING WITHIN THE YELLOW REGION ON THE MAP.

ALERT LEVEL...THIS REPRESENTS A GREATER THAN 30% CHANCE OF SEVERE WEATHER OCCURING WITHIN THE RED REGION ON THE MAP.

SYNOPSIS...
WE EXPECT ONE OR TWO LARGE COMPLEXES OF THUNDERSTORMS TO BE ON GOING THROUGH THE NIGHT, HOWEVER, WE DO NOT EXPECT THEM TO BE LONG-LIVED IN THAT A NEW LOW MOVING IN FROM THE CENTRAL CA COAST WILL PULL ENERGY AWAY FROM THE CURRENT DISTURBANCE MOVING THROUGH THE NORTHERN PLAINS.  THUS WE BELIEVE THE LOW LEVEL JET WILL NOT BE SUPPORTIVE OF FURTHER ENHANCEMENT DOWNSTREAM.  HOWEVER, WE ARE CONTINUING A CAUTION LEVEL IN THAT WE EXPECT SEVERE WEATHER TO OCCUR, BUT WILL NOT BE QUITE AS WIDESPREAD AS WHEN THE STORMS INITIATED.

WE ADDED A NOTICE AREA TO THE CENTRAL ROCKIES IN THAT WE THINK MOISTURE FLOWING NORTH OUT OF NM AND AZ WILL GET ENTRAINED IN FRONT OF DEVELOPING TROUGH OVER CENTRAL CA.  WE THINK STORMS THOUGH ISOLATED IN NATURE COULD BECOME SEVERE DUE TO DYNAMICS WITH NEW LOW.

RISKS IN CAUTION LEVEL...

...TORNADOES...< 5%
...DAMAGING WINDS...< 20%
...DAMAGING HAIL... 20 > %

RISKS IN NOTICE LEVEL...

...TORNADOES...NONE
...DAMAGING WINDS...< 10 %
...DAMAGING HAIL...< 5%

RS...

12HR - SEVERE WEATHER OUTLOOK

SEVERE WEATHER OUTLOOK

ISSUED: 251621Z

VALID:  251600Z - 260000Z

DEFINITIONS...

NOTICE LEVEL...THIS REPRESENTS A GREATER THAN 5 % CHANCE OF SEVERE WEATHER OCCURING WITHIN THE GREEN REGION ON THE MAP.

CAUTION LEVEL...THIS REPRESENTS A GREATER THAN 10%  CHANCE OF SEVERE WEATHER OCCURING WITHIN THE YELLOW REGION ON THE MAP.

ALERT LEVEL...THIS REPRESENTS A GREATER THAN 30% CHANCE OF SEVERE WEATHER OCCURING WITHIN THE RED REGION ON THE MAP.

SYNOPSIS...

STRONG MID AN UPPER LEVEL JET CONTINUES OVER NORTH 1/2 OF US.  EMBEDDED WITHIN THIS JET ARE UPR AIR DISTURBANCES THAT CONTINUE THE RECYCLING OF SEVERE WEATHER WITHIN THIS REGION.

ONE SUCH LOW PRESSURE SYSTEM IS BEING ENHANCED BY A MOD LOW LEVEL JET OF 30+KTS UP THE FRONT RANGE OF THE ROCKIES.  THIS COULPLED WITH BACKING WINDS SUGGESTS AN ALERT REGION TO BE SET UP FOR MOST OF NE SOUTH DAKOTA, SE NORTH DAKOTA AND EXTREME SW MINNESOTA.

THE THINKING IS CURRENT THUNDERSTORM ACTIVITY WILL BEGIN TO WANE OVER WESTERN MN, BUT BEHIND THIS WEAKENING COMPLEX NEW STORMS WILL RAPIDLY DEVELOP AS THE MID LVL JET NOSES INTO A DEEP LAYER OF MOISTURE.

THE ONLY INHIBITING FACTOR IS THERE IS QUITE A BIT OF CINH OVER MOST OF SD AND NE.  CAPE VALUES OF +3000 ARE LIKELY OVER EASTERN SD BY MID TO LATE AFTERNOON.  SO IF STORMS DEVELOP THEY WILL TURN SEVERE QUITE RAPIDLY.

SURROUNDING THE ALERT AREA IS A LARGE CAUTION AREA IN WHICH WE EXPECT SCT STRONG TO SVR THUNDERSTORMS TO DEVELOP, BUT MOST OF THE ACTIVITY WILL DEVELOP INTO ONE OR TW LARGE COMPLEXES OF STORMS AND RAPIDLY MOVE ESE.

RISK LEVEL IN ALERT REGION...

...TORNADOES...< 10%

...DAMANGING WINDS...<40 %

...DAMAGING HAIL...<50 %

RISK LEVER IN CAUTION REGION...

...TORNADOES...<5%
...DAMAGING WINDS...20 >%
...DAMAGING HAIL...20 >%

RS...