THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


EXCESSIVE RAINFALL DISCUSSION


[Abbreviations and acronyms used in this product]
Geographic boundaries:    Map 1- [Color] [B/W Print Version]      Map 2 - [Color] [B/W Print Version]



EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
151 AM EDT THU OCT 02 2014

...VALID 06Z THU OCT 02 2014 - 12Z FRI OCT 03 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
35 NE STJ 15 SW FFL 10 WSW RFD 15 ENE MKE 15 ENE MDW 25 ENE GYY
20 W BIV 15 NW LDM TVC 35 SW OSC 10 SSE RMY 10 SSW PRG 15 E BPK
25 WSW RKR 20 NW TUL 10 NE MHK 35 NE STJ.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 N UIN 25 WNW AAA 15 NE ALN 30 NE VIH 40 SSW SZL 35 S IXD
15 SW MCI 10 S CDJ 10 SE IRK 15 N UIN.


PORTIONS OF THE PLAINS/MS VALLEY/MIDWEST/GREAT LAKES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
THERE IS A STRONG SIGNAL FOR HEAVY TO EXCESSIVE RAINFALL AMOUNTS
THIS PERIOD ACROSS IL/MO AHEAD OF HEIGHT FALLS MOVING
SOUTHEASTWARD FROM THE GREAT BASIN/CENTRAL ROCKIES REGION INTO THE
SOUTHERN HIGH PLAINS.   THE STATIONARY FRONTAL BOUNDARY STRETCHING
GENERALLY FROM WEST TO EAST ACROSS THE MID MS VALLEY AND THE
UPSTREAM NORTH TO SOUTH ORIENTED FRONT MOVING EASTWARD WITH TIME
FROM THE SOUTHERN TO CENTRAL PLAINS WILL BE THE FOCI FOR ACTIVE
CONVECTION THIS PERIOD IN A REGION OF WELL-DEFINED UPPER
DIFFLUENCE AND AN AXIS OF PW VALUES 1.5-2.0+ STANDARD DEVIATIONS
ABOVE THE MEAN (1.50-1.75"). CONVECTION HAS BECOME ELEVATED ACROSS
PORTIONS OF NORTHERN AND CENTRAL MO TO THE NORTH OF AN EAST-WEST
COMPOSITE BOUNDARY/OUTFLOW-REINFORCED FRONT ACROSS SOUTHERN MO
WHERE TRAINING IN A WEST TO EAST DIRECTION IS IN PROGRESS DUE TO
BROAD 25+ KT INFLOW OVERRIDING THE BOUNDARY.  THIS ORGANIZED
CONVECTION SHOULD CONTINUE UNTIL ROUGHLY 16Z AS RAP-BASED MOST
UNSTABLE CAPE VALUES REMAIN >1000 J/KG FOR THE REMAINDER OF THE
NIGHT/MORNING HOURS.  UPSTREAM CONVECTION PUSHING EASTWARD AHEAD
OF THE EASTWARD MOVING COLD FRONT DURING THURSDAY IS EXPECTED TO
MOVE ACROSS THIS AREA, POTENTIALLY PROLONGING HEAVY RAINFALL
ISSUES ACROSS MO.

AREAS OF NORTHEAST IL/IN/MI FARTHER UP THE BOUNDARY AND ACROSS
SOUTHEAST KS/EASTERN OK FARTHER DOWN THE FRONT AND PRE-FRONTAL
TROUGH ARE EXPECTED TO HAVE CONVECTION WITH HEAVY RAINFALL.  IN
THESE AREAS, LOW-LEVEL INFLOW IS NARROWER IN SCOPE (AND GREATER
FRONTAL PROGRESSION IS EXPECTED ACROSS IL/IN/MI) SO THE OVERALL
EXCESSIVE RAINFALL THREAT SHOULD BE MORE LIMITED.  HOWEVER, FLASH
FLOOD GUIDANCE VALUES ACROSS MUCH OF IL, NORTHERN IN, AND PORTIONS
OF THE LOWER PENINSULA OF MICHIGAN ARE RELATIVELY LOW, SO INCLUDED
THEM WITHIN THE SLIGHT RISK AS A PRECAUTION.  BUILDING INSTABILITY
DURING THE AFTERNOON AND EVENING HOURS COULD LEAD TO EXCESSIVE
RAINFALL CLOSER TO THE GREAT LAKES, WHILE THE RISK ACROSS EASTERN
OK SHOULD BE INTERMITTENT THROUGH THE PERIOD.

ROTH




Last Updated: 149 AM EDT THU OCT 02 2014