...NO SVR TSTM AREAS FORECAST... ...SUMMARY... ISOLATED TO SCATTERED THUNDERSTORMS...A FEW OF WHICH MAY BE STRONG...WILL DEVELOP ACROSS THE PLAINS INTO THE TENNESSEE VALLEY. GUSTY WINDS AND HAIL WILL BE POSSIBLE DURING THE AFTERNOON AND EVENING WITH THE STRONGEST STORMS IN THESE LOCATIONS. ADDITIONAL THUNDERSTORMS ARE ALSO EXPECTED ACROSS THE ROCKIES AND INTO THE SOUTHEASTERN UNITED STATES. ...SYNOPSIS... GENERALLY WEAK UPPER LEVEL FLOW REGIME WILL CONTINUE ACROSS THE CONUS TODAY. THE LOW-AMPLITUDE RIDGE OVER THE HIGH PLAINS WILL BUILD SLIGHTLY...WHILE SEVERAL SHORTWAVE IMPULSES EJECTING FROM THE WESTERN CONUS TROUGH TRACK OVER THE ROCKIES AND INTO THE PLAINS. ACROSS THE EAST...THE UPPER LOW OVER NEWFOUNDLAND AND TRAILING EAST COAST TROUGH WILL SLOWLY TRACK E/NE TOWARD THE WESTERN ATLANTIC...WHILE A WEAK EASTWARD MIGRATING SHORTWAVE IMPULSE RESULTS IN WIDESPREAD THUNDERSTORM DEVELOPMENT FROM THE MID-MS/TN VALLEY REGION AND INTO SOUTHEAST STATES. AT THE SFC...A WEAK LOW WILL DEVELOP IN THE VICINITY OF THE RED RIVER VALLEY OVER SW OK WITH A WEAK BOUNDARY EXTENDING E/NE ACROSS OK INTO THE MID-MS AND LOWER OH VALLEY. THE LOCATION OF THIS BOUNDARY WILL BE A FOCUS FOR THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON AND EVENING ACROSS THE SOUTHERN PLAINS. ADDITIONAL THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG A SFC TROUGH EXTENDING NWD THROUGH THE CNTRL HIGH PLAINS IN MOIST UPSLOPE FLOW. ...CENTRAL/SOUTHERN PLAINS... CONVECTION ONGOING ACROSS WRN/CNTRL KS INTO THE OK/TX PANHANDLES EARLY THIS MORNING IS EXPECTED TO CONTINUE TO DIMINISH/WEAKEN WITH EASTWARD EXTENT. THIS CONVECTION WILL HELP TO REINFORCE A WEAK SFC BOUNDARY/COOL FRONT ACROSS SRN KS/NRN OK...AND BECOME A FOCUS FOR THUNDERSTORM DEVELOPMENT LATER TODAY. DEEP-LAYER SHEAR ACROSS SE CO INTO SW KS/NW OK OF 30+ KT AND STEEP LAPSE RATES COULD FAVOR ISOLATED SUPERCELLS WITH THE POTENTIAL FOR UPSCALE DEVELOPMENT INTO FORWARD PROPAGATING CLUSTERS -- SHOULD THE SFC BOUNDARY REMAIN IN THE VICINITY OF NRN OK. THIS SCENARIO IS UNCERTAIN AS SOME HI-RES GUIDANCE SUGGESTS THE BOUNDARY WILL MIGRATE FURTHER SOUTH TOWARD THE RED RIVER INTO A LESS FAVORABLE /WEAKER SHEAR/ ENVIRONMENT FOR SEVERE THUNDERSTORM DEVELOPMENT. THE SOUTHWARD PROGRESSION OF THE BOUNDARY IS ENTIRELY POSSIBLE DUE TO COLD POOL GENERATION WITH ONGOING/EARLY MORNING CONVECTION. GIVEN LOW CONFIDENCE IN WHERE THIS BOUNDARY WILL RESIDE...WILL DELAY UPGRADING TO A SLIGHT RISK FOR WIND/HAIL UNTIL MESOSCALE PROCESSES BECOME MORE CLEAR AND WARRANT SUCH AN UPGRADE. FURTHER NORTH ALONG THE SFC TROUGH FROM THE TX PANHANDLE INTO ERN CO NWD TO FAR SE WY/WRN NEB...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN MOIST UPSLOPE FLOW...SIMILAR TO THURSDAY AFTERNOON. MODEST DEEP-LAYER SHEAR AND MLCAPE LESS THAN 1500 J/KG SHOULD LIMIT SEVERE THREAT...BUT SOME MARGINAL WIND/HAIL EVENTS ARE POSSIBLE WITH THE STRONGEST STORMS. ...PORTIONS OF THE MID-MS TO LOWER OH/TN VALLEYS... A WEAK SHORTWAVE IMPULSE WILL TRACK EWD ACROSS THE REGION TODAY...RESULTING IN WEAK HEIGHT FALLS AND MODEST DEEP-LAYER SHEAR. SCATTERED THUNDERSTORMS WILL DEVELOP IN A MODERATELY UNSTABLE AIRMASS BY EARLY AFTERNOON. HOWEVER...EFFECTIVE BULK SHEAR LESS THAN 25 KT AND POOR LAPSE RATES SHOULD LIMIT ORGANIZATION TO MAINLY PULSE-TYPE SEVERE...BUT PW VALUES NEAR 2 INCHES COULD RESULT IN A WET DOWNBURST OR TWO.
Posted on: Fri, 08 Aug 2014 07:36:04 +0000
Trending Topics
Recently Viewed Topics
© 2015