Quantitative Precipitation Forecast
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FOUS30 KWBC 271343
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
942 AM EDT WED MAY 27 2015

...VALID 15Z WED MAY 27 2015 - 12Z THU MAY 28 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...



...CENTRAL INTO THE SOUTHERN HIGH PLAINS...

GUIDANCE SHOWS AN AMPLIFYING LOW LEVEL JET ACROSS WEST TX THROUGH
THE PANHANDLE REGION INTO THE CENTRAL PLAINS.  INCREASING
MOISTURE/INSTABILITY ALONG THIS AXIS OF STRONG SOUTHERLY FLOW IS
EXPECTED TO INTERACT WITH WEAK MID LEVEL ENERGY EMERGING FROM A
BROADER SCALE TROUGH CENTERED OVER THE WEST.  EXPECT CONVECTION TO
BEGIN FIRING THIS AFTERNOON-EVENING NEAR A STALLED FRONTAL
BOUNDARY AND ITS CORRESPONDING POOL OF DEEPER MOISTURE EXTENDING
FROM SOUTHERN KS BACK INTO THE HIGH PLAINS.  C-VECTORS SHOW THE
POTENTIAL FOR BACKBUILDING CELLS...WHICH MAY RAISE THE THREAT FOR
LOCAL RUNOFF PROBLEMS.

...CENTRAL GULF COAST REGION/TN VALLEY....

AS THE MORNING CONTINUES...ALREADY MOIST AND UNSTABLE CONDITIONS
ARE EXPECTED TO INCREASE AHEAD OF THE SQUALL LINE NOW PROPAGATING
OUT OF EAST TX THROUGH LA.  THIS IS EXPECTED TO SUPPORT EXPANDING
CONVECTION AHEAD OF THE LINE AS IT BEGINS TO APPROACH AND THEN
MERGE WITH A PAIR OF RESIDUAL MESOSCALE BOUNDARIES LINGERING
ACROSS NORTHERN MS AND ALONG THE CENTRAL GULF COAST.  LOCAL RAIN
RATES MAY APPROACH FLASH FLOOD GUIDANCE VALUES...ESPECIALLY ACROSS
CENTRAL MS INTO WESTERN TN WHERE THEY ARE RELATIVELY LOWER.  REFER
TO WPC MESOSCALE PRECIPITATION DISCUSSION #139 FOR FURTHER DETAILS.

...NORTH/NORTHEAST AND SOUTHEAST TX INTO EAST OK...

GIVEN THE OVERALL POOR HANDLING BY THE MODELS OF THE SQUALL LINE
NOW EXITING REGION...HAVE LIMITED CONFIDENCE IN ANY PARTICULAR
MODEL`S DEPICTION OF THE CONVECTION THAT MAY EVOLVE THIS
AFTERNOON-EVENING.  SOME OF THE LATEST GUIDANCE SHOWS STORMS
REDEVELOPING ALONG A RESIDUAL MESOSCALE BOUNDARY AS IT RETURNS TO
THE NORTH LATER TODAY ALONG WITH DEEPER MOISTURE.  EXPECT THAT THE
SUBSIDENCE AND CAPPING INVERSION IN THE WAKE OF THE SYSTEM NOW
EXITING THE REGION TO HAMPER THE POTENTIAL FOR REDEVELOPMENT FOR
AT LEAST THE FEW HOURS.  ANY HEAVY RAINS THAT DO REDEVELOP MAY
POSE FLASH FLOODING CONCERNS...ESPECIALLY ACROSS N-CENTRAL TX
WHERE FLASH FLOOD GUIDANCE VALUES ARE LOW.

PEREIRA
$$





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