Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
000
FOUS30 KWBC 250057
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
857 PM EDT FRI MAR 24 2017

...VALID 01Z SAT MAR 25 2017 - 12Z SAT MAR 25 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
35 SE MLU 10 SSE DRI 20 NE IAH 10 ENE JSO VBT 50 S SZL JEF
30 S SUS 20 SE JBR 45 SW UTA 35 SE MLU.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 E UKL 25 NE WLD 10 ESE IAB 30 N EWK 20 N MHK 45 NE MHK
25 WSW STJ 10 SW MCI 20 E UKL.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 WNW HRO 40 ENE SGF 35 ESE TBN 15 NW ARG 20 NNE SGT 15 SW LLQ
15 W IER 15 SSE OCH 25 NNE GGG 30 NW MWT 15 WNW HRO.


...SOUTHERN PLAINS / LOWER MISSISSIPPI VALLEY...

THE HI-RES MODELS CONTINUE TO INDICATE WIDESPREAD HEAVY RAIN OVER
CENTRAL TO NORTHERN LOUISIANA LATER TONIGHT...BUT AT 00Z SHARPLY
DEFINED LINEAR CONVECTION WAS EVOLVING FARTHER NORTH IN THE AREA
OF STRONG HEIGHT FALLS OVER EXTREME EASTERN OKLAHOMA INTO MUCH OF
WESTERN ARKANSAS. THE COMBINATION OF LOWER LEVEL CONFLUENCE...DEEP
LAYER HEIGHT FALLS...AND MODERATE INSTABILITY MAY STILL YIELD A
FOCUSED HEAVY RAIN EVENT OVER NORTHERN LOUISIANA WITH TIME...BUT
THE GLOBAL MODEL FORECASTS WERE CERTAINLY BETTER EMPHASIZING THE
STRONG CONVECTION FARTHER NORTH AT 00Z PER THE LOCATION OF THE
BETTER SYNOPTIC FORCING. GIVEN THIS FACT AND THE VERY HIGH FLASH
FLOOD GUIDANCE NUMBERS...REQUIRING EXCEPTIONALLY HEAVY RAIN TO
PRODUCE BANKFUL CONDITIONS OVER EAST TX AND PARTS OF LA...WE MADE
SOME ADJUSTMENT NORTHWARD WITH THE SLIGHT RISK AREA...AND NOW
INCLUDE MORE OF NORTHWEST ARKANSAS AND SOUTHERN MISSOURI. RAINFALL
OF JUST OVER ONE INCH IN AN HOUR WAS MEASURED AT THE WISTER OK
STATION OF THE OKLAHOMA MESONET...AND RADAR-BASED ESTIMATES ALL UP
AND DOWN THE CONVECTIVE LINE WERE RUNNING UP TO 1.25 INCHES IN AN
HOUR...WHICH WILL AT LEAST APPROACH FFG VALUES...AND MAY BE OF
CONCERN PARTICULARLY IN THE MORE HILLY TERRAIN OF AR/MO.

WITH THIS ACTIVITY AND OTHER CONVECTION EXPECTED TO CONGEAL LATER
TONIGHT FARTHER TO THE SOUTH AND EAST...EXPECT LOCAL RATES OF 1 TO
2 INCHES IN AN HOUR...WITH STORM TOTAL AMOUNTS IN EXCESS OF 3
INCHES POSSIBLY LEADING TO RAPID RUNOFF / FLASH FLOODING.


...EASTERN KANSAS...

A SMALL SCALE FOCUS FOR HEAVY RAINFALL AND POTENTIALLY SOME
ISOLATED FLASH FLOODING HAD COME TOGETHER IN THE DIFLUENT UPPER
FLOW REGION ON THE NORTH SIDE OF THE WOUND-UP CYCLONE OVER THE
SOUTHERN PLAINS. PARTIAL HEATING HAD CONTRIBUTED TO MIXED LAYER
CAPE VALUES AROUND 1000 J/KG...FUELING SLOW MOVING CONVECTION
WITHIN AN AREA OF STRONG UPWARD VERTICAL VELOCITIES AND BROAD
SCALE LOWER LEVEL CONVERGENCE BUT OTHERWISE LITTLE MEAN LAYER
STEERING FLOW. VERY SMALL SCALE RADAR-BASED ESTIMATES OF NEAR 5
INCHES OF RAIN NEAR COUNCIL GROVE KS MAY BE A LITTLE OVERDONE WITH
HAIL INVOLVED...BUT THIS WAS THE AREA OF GREATEST THREAT...WITH
SHALLOW BUT EFFICIENT CONVECTIVE CELLS AWAITING BEING OVERTAKEN BY
THE BROADER SCALE EVOLUTION OF THE CYCLONE. AT
00Z...HOWEVER...RADAR TRENDS INDICATED A GREATER AMOUNT OF
OUTFLOW...AND WITH LOSS OF DAYTIME HEATING THE RAINFALL INTENSITY
SHOULD DECREASE GRADUALLY THIS EVENING...WITH THE FLASH FLOOD
THREAT WANING THROUGH TIME.

BURKE
$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.