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
1030 AM EDT WED JUL 29 2015

...VALID 15Z WED JUL 29 2015 - 12Z THU JUL 30 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 S GAG 15 NW AMA 25 WNW CVS 15 SSE 4CR 45 SW ABQ 15 SSE 4SL
10 NNW SKX 30 NW RTN 20 N CAO 20 SSE GCK 20 SSW GBD 20 SW HUT
40 NNW WDG 30 S GAG.


...NEW MEXICO AND THE SOUTHERN HIGH PLAINS...

ORGANIZED AFTERNOON/EVENING CONVECTION WILL FOCUS OVER NEW MEXICO
AND THE SOUTHERN HIGH PLAINS OF NM/TX/OK/KS ALONG AND NORTH OF A
SURFACE FRONTAL BOUNDARY. LAPSE RATES PER 12Z SOUNDINGS WERE NOT
VERY STEEP...SO INITIAL ACTIVITY MAY NEED THE ELEVATION OF CENTRAL
NEW MEXICO TO GET STARTED IN ANY LARGE SCALE AND ORGANIZED
FASHION...FORCED BY POST FRONTAL UPSLOPE AS WELL AS AN UPPER
DIFLUENCE MAXIMUM. MODELS SHOW GREATER SPREAD WITH RESPECT TO
TIMING OF CONVECTION FARTHER EAST ON THE PLAINS. A MID LEVEL SHEAR
AXIS IS FORECAST TO STRETCH OUT FROM CENTRAL NM TOWARD SW KS BY
AFTERNOON. LOW LEVEL CONVERGENCE PER THE RAP MAXIMIZES AFTER 00Z
OVER SOUTHWEST KANSAS. CONVECTION THAT POTENTIALLY DEVELOPS
HERE...ALONG WITH THE NEW MEXICO CONVECTION...SHOULD PROPAGATE
SLOWLY EAST WHILE GRADUALLY FILLING IN ALONG A WSW-ENE ORIENTED
INSTABILITY AXIS THAT WOULD INCLUDE THE TX/OK PANHANDLE AND FAR NW
OK. PW VALUES OF 1.0 TO 1.4 INCHES REMAIN ABOVE
AVERAGE...ESPECIALLY RELATIVE TO CLIMATOLOGY IN THE HIGHER
ELEVATIONS OF NEW MEXICO. VERY SLOW CELL MOTIONS...0-6 KM MEAN
WINDS 0-10 KNOTS ARE ALSO CAUSE FOR CONCERN...SUPPORTING POTENTIAL
FOR HEAVY RAINFALL.


SOUTHERN TO CENTRAL APPALACHIANS INTO THE MID ATLANTIC

SIMILAR TO PREVIOUS DAYS...ABOVE AVERAGE PW VALUES WILL PERSIST
ACROSS THE SOUTHERN TO CENTRAL APPALACHIANS INTO THE MID ATLANTIC.
 SCATTERED LATE AFTERNOON-EVENING THUNDERSTORMS ARE AGAIN
EXPECTED. LOW CONFIDENCE ON QPF DETAILS...WITH LITTLE ORGANIZATION
ABOVE THE STORM SCALE...BUT THERE WILL BE POTENTIAL FOR LOCALLY
HEAVY TOTALS. FLASH FLOOD GUIDANCE VALUES ARE RELATIVELY LOW FROM
EASTERN TN INTO SW TO NW VA AND EASTERN WV. SLOW MOVING STORMS MAY
CAUSE FLASH FLOODING.

ORAVEC/BURKE




Last Updated: 1030 AM EDT WED JUL 29 2015