MESOSCALE PRECIPITATION DISCUSSION 0079
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1144 PM EDT THU MAR 23 2017
AREAS AFFECTED...CENTRAL/NORTHEAST NEB...EXTREME SOUTHEAST
SD...EXTREME NORTHWEST IA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 240343Z - 240630Z
SUMMARY...HEAVY SHOWERS AND THUNDERSTORMS CONTINUE...WITH SOME
LOCALIZED TRAINING OF CELLS FOSTERING SOME FLASH FLOOD POTENTIAL.
DISCUSSION...IR SATELLITE IMAGERY SHOWS AN IMPRESSIVE AREA OF COLD
CONVECTIVE TOPS ACROSS AN AREA FROM CENTRAL TO NORTHEAST
NEB...WITH THE ACTIVITY FOCUSING JUST NORTH OF A STATIONARY FRONT.
LOW PRESSURE CONTINUES TO ORGANIZE MEANWHILE OVER EASTERN CO IN
ASSOCIATION WITH A STRONG UPPER TROUGH DIGGING EAST THROUGH THE
FOUR CORNERS REGION.
AHEAD OF THE UPPER TROUGH OVER THE CENTRAL PLAINS IS A VERY STRONG
LOW LEVEL JET...WITH VWP DATA INDICATING A SOUTHERLY FLOW AT 850
MB EXCEEDING 50 TO 60 KTS. THIS IS BEING INTERCEPTED BY THE
AFOREMENTIONED FRONTAL ZONE...WITH FORCING FURTHER ENHANCED BY
INCREASING UPPER LEVEL DIVERGENCE AHEAD OF THE TROUGH.
INSTABILITY OVER THE REGION IS QUITE MODEST WITH MUCAPE VALUES OF
GENERALLY 500 TO 1000 J/KG. MOISTURE PROFILES ARE ALSO QUITE
MODEST WITH PWATS OF CLOSE TO 1 INCH POOLED ALONG THE FRONT.
DESPITE THE RELATIVELY WEAK THERMODYNAMIC PROFILES...STRONG DEEPER
LAYER ASCENT AND WARM ADVECTION CONTINUES TO FOCUS CONVECTION OVER
THE NORTH-CENTRAL PLAINS WITH AN AXIS OF REPEATING/TRAINING
CONVECTION SEEN ACROSS PARTS OF CENTRAL AND NORTHEAST NEB. THIS
WILL LIKELY CONTINUE AT LEAST THROUGH 06Z GIVEN THE STRENGTH OF
THE LOW LEVEL JET AND CONTINUED ARRIVAL OF HEIGHT FALLS. SOME OF
THE ACTIVITY IS LIKELY TO FOCUS FARTHER NORTHEAST INTO FAR
SOUTHEAST SD AND NORTHWEST IA.
ALREADY SOME 2 TO 3 INCH RAINFALL AMOUNTS HAVE BEEN ESTIMATED PER
DUAL-POL DATA...AND WITH ADDITIONAL CONVECTION DEVELOPING...AND AN
ADDITIONAL 2 TO 3 INCHES CANNOT BE RULED OUT THROUGH 06Z.
THUS...EXPECT SOME FLASH FLOODING POTENTIAL OVER THE NEXT FEW
HOURS.
ORRISON
ATTN...WFO...FSD...GID...LBF...OAX...
ATTN...RFC...MBRFC...
LAT...LON 43209623 42659612 41729806 41229939 40730064
40950106 41460073 42309905 42749774
Last Updated: 1144 PM EDT THU MAR 23 2017