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 26
000
FOUS30 KWBC 160002
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
801 PM EDT FRI SEP 15 2017

...VALID 01Z SAT SEP 16 2017 - 12Z SAT SEP 16 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
MSP 10 S OWA MCW 10 WSW CAV 25 W FOD 25 NW SLB 25 SSE PQN BKX
15 E ATY 8D3 10 E K2D5 20 N K2D5 35 NE KBAC 20 NW CWTX
10 NNE CWCH 35 N CKC 10 N CKC 10 WNW TWM COQ 10 WSW COQ MSP.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
45 SE FIR 25 NE VEL VEL 55 W VEL 30 E PVU 40 E U24 30 SSW PVU
PVU 10 SE SLC 10 NE SLC 15 E HIF 25 W EVW 15 NW EVW 25 N EVW
50 SE U78 25 SW BPI 45 SSW BPI 25 ENE FIR 45 SE FIR.


16/0100 UTC UPDATE...

REMOVED MARGINAL RISK AREA ACROSS UT WITH CONTINUED EWD
PROGRESSION OF ACTIVITY OUT OF THE AREA.
OTHERWISE...STRENGTHENING LOW LEVEL JET THROUGH THE UPPER MS
VALLEY WILL CONTINUE TO SUPPORT MAINLY ELEVATED CONVECTION AND
MDTLY HEAVY STRATIFORM PCPN FROM PORTONS OF THE DAKOTAS EWD
THROUGH MN AHEAD OF SFC WAVE THAT IS FCST TO LIFT NEWD TOWARD NRN
MN BY SAT MORNING.  FOR THE MOST PART ACTIVITY HAS BEEN FAIRLY
PROGRESSIVE..AND SHOULD REMAIN SO..BUT WHERE THE MORE SURFACE
BASED CONVECTION DVLPS FARTHER SW THROUGH SE SD INTO ERN NEB AND
TRACKS NEWD..THERE MAY BE A SOME BRIEF TRAINING ELEMENTS THAT
COULD PRODUCE ISOLD HEAVIER RAIN AMOUNTS/BRIEF RUNOFF ISSUES
WITHIN THE MARGINAL RISK AREA.  SULLIVAN

1500 UPDATE

CHANGES TO THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK WERE
RELATIVELY MINOR.  SLIGHT ADJUSTMENTS FOR CURRENT RADAR TRENDS
DONE OVER NORTH CENTRAL IA INTO SOUTH CENTRAL MN---EXTENDING THE
PREVIOUS MARGINAL RISK AREA APPROXIMATELY 100 NM TO THE SOUTHEAST
AND TRIMMING THE AREA OVER FAR SOUTHEAST SD.

ORAVEC


INITIAL DISCUSSION

WPC CONTINUITY BLENDED WELL WITH THE REASONABLY CLUSTERED 00 UTC
ARW/NNMB FOR INCREASED MESOSCALE DETAIL.


...CENTRAL GREAT BASIN AND NRN PLAINS/UPPER MS VALLEY...

THERE IS STILL GOOD MODEL AGREEMENT WITH THE AMPLIFICATION OF THE
GREAT BASIN/NRN ROCKIES UPPER TROUGH AND GOOD DEPICTION OF THE
WIDESPREAD LEAD MODERATE TO HEAVY PRECIP TOTALS ACROSS THESE
AREAS. THE DEVELOPING AREA OF PRECIP STRETCHING FROM THE NRN
ROCKIES/HIGH PLAINS AREA AND SWWD INTO THE GREAT BASIN IS EXPECTED
TO BECOME MORE DEFINED WITH TIME AS THE UPPER TROUGH AMPLIFIES AND
HELPS SPREAD PRECIPITATION ENEWD ACROSS THE NRN PLAINS AND UPPER
MS VALLEY AS UPWARDS TO 2-3 STANDARD DEVIATION ABOVE NORMAL
PRECIPITABLE WATER VALUES INTERACTS WITH WAVY FRONTAL ZONE.
CONFIDENCE IS HIGH THIS PERIOD ON THE PRECIP POTENTIAL WITH THIS
SYSTEM GIVEN THE GOOD GUIDANCE SOLUTION CLUSTERING AND PATTERN
FIT...BUT FFG VALUES ARE HIGH AND MUCH OF THE PREVIOUS AREA DOES
NOT SEEM TO HAVE THOSE ORDER OF RAIN RATES. ACCORDINGLY...ADJUSTED
WPC CONTINUITY TO OFFER A SMALLER SET OF MARGINAL AREAS TO FOCUS
LIMITED EXCESSIVE RAINFALL POTENTIAL TO AREAS OF HIGHEST MOISTURE
AVAILABILITY ALONG/AHEAD OF THE FRONT.

SCHICHTEL



$$





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