

649 

WWUS20 KWNS 272225

SEL9

SPC WW 272225

COZ000-KSZ000-280500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 449

NWS STORM PREDICTION CENTER NORMAN OK

420 PM MDT SAT JUL 27 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EASTERN COLORADO

  SOUTHWEST KANSAS



* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 420 PM UNTIL

  1100 PM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH

NORTHWEST OF LIMON COLORADO TO 65 MILES SOUTH SOUTHWEST OF GARDEN

CITY KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...TSTMS EXPECTED TO CONTINUE FORMING IN SEASONABLY STRONG

ESELY UPSLOPE FLOW OVER THE CO FOOTHILLS...AND POSSIBLY ALONG SFC

BOUNDARY ARCING GENERALLY WNW ACROSS WRN KS INTO E CNTRL CO. AMPLE

LOW-LVL MOISTURE IS PRESENT N OF BOUNDARY TO SUPPORT STRONG

STORMS...ALTHOUGH SFC TEMPS ARE COOL BY LATE JULY STANDARDS.

LARGE-SCALE FORCING FOR ASCENT WILL BE MODEST...BUT WILL INCREASE

LATER THIS EVE WITH THE APPROACH OF UPR IMPULSE NOW CRESTING FLAT

RIDGE OVER WRN PARTS OF CO/WY. AT THE SAME TIME...SOME DEGREE OF

HIGH-LVL STORM VENTING WILL BE PROVIDED...ESPECIALLY IN KS...BY SWRN

FRINGE 100+ KT 250 MB NWLY JET STREAK CENTERED OVER SE NEB. OVERALL

SETUP APPEARS TO BE ONE THAT COULD SUPPORT A FEW SUSTAINED

STORMS/SUPERCELLS CAPABLE OF LARGE HAIL AND LOCALLY DMGG WIND. SOME

OF THE STORMS COULD MERGE INTO CLUSTERS OVER SE CO/SW KS LATER THIS

EVE AS SWLY LLJ STRENGTHENS WITH THE CONTINUED EWD MOTION OF UPR

IMPULSE.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 30020.





...CORFIDI

