MESOSCALE PRECIPITATION DISCUSSION 0167
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1147 PM EDT WED JUN 03 2015
AREAS AFFECTED...EASTERN WYOMING...SOUTHWEST SOUTH
DAKOTA...WESTERN NEBRASKA...SOUTHEAST MONTANA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 040346Z - 040946Z
SUMMARY...UPSCALE GROWTH OF CONVECTIVE COMPLEX WITH INCREASING
RAINFALL EFFICIENCY FOR CONTINUED POSSIBLE FLASH FLOODING.
DISCUSSION...PER 0124Z SPENES WITH ADDITIONAL COORDINATION WITH
SATELLITE ANALYSTS...OVERALL PATTERN REMAINS IN LINE THOUGH
SLIGHTLY SHIFTED NORTH TO INCLUDE SE MONTANA.
SHORTWAVE ENERGY EJECTING OVER HIGHER TERRAIN CONTINUES TO
STRENGTH LOW LEVEL FLOW IN RESPONSE TO THE SOUTH CENTRAL WY
SURFACE LOW. VWP AND RAP ANALYSIS FIELDS SHOW 700 MB SOUTH-SOUTH
EASTERLY 30-35KT JET ADVECTING INCREASED MOISTURE... SURFACE
DEWPOINTS IN THE UPPER 50S AND TOTAL PWATS NEARING 1.0".
ADDITIONALLY THIS LOW LEVEL FLOW SHOULD REMAIN STRONG THROUGHOUT
THE EARLY MORNING HOURS ALLOWING FOR CONTINUED TRANSPORT OF
INSTABILITY NORTHWEST FROM NEBRASKA/NORTHERN COLORADO. MUCAPES
OVER 1000 J/KG SHOULD BE AVAILABLE TO ADVECT UP AND OVER WEAK
SURFACE BOUNDARY THAT EXTENDS FROM THE SURFACE LOW TO THE NORTHERN
BLACK HILLS. THIS ALLOWS FOR CONTINUATION OF ELEVATED CONVECTION
THROUGH 09Z EVEN AFTER SB CAPES ARE ERODED. IN THE UPPER
LEVELS...STRENGTHENING 300 MB JET ACROSS NORTHERN MONTANA LEAVES
DISCUSSION AREA WITHIN RIGHT ENTRANCE FOR FAVORED OUTFLOW SUPPORT
FOR CONTINUED STRONG UVVS...IN ADDITION TO INCREASED DIVERGENCE
FROM THE SHARP NEGATIVE TILT ORIENTATION OF THE SHORTWAVE ACROSS
IDAHO/SOUTHWEST WYOMING.
WITH THESE DYNAMIC AND THERMODYNAMIC CONDITIONS IN PLACE AND
GETTING BETTER AND MOISTENING PROFILES...SLIGHTLY INCREASED
RAINFALL EFFICIENCY SHOULD BE IN PLACE FOR HIGHER RATES WITH AN
ADDITIONAL 1-3" LIKELY AND SOME POCKETS OF 3-4" POSSIBLE IN LINE
WITH CONVECTION/QPF TRENDS IN THE MOST RECENT RUNS OF THE HRRR.
GALLINA
ATTN...WFO...BYZ...CYS...LBF...RIW...UNR...
ATTN...RFC...MBRFC...
LAT...LON 46010468 45100275 43400268 41910274 41430424
42540556 43330802 44950740
Last Updated: 1147 PM EDT WED JUN 03 2015