Quantitative Precipitation Forecast
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FOUS30 KWBC 181431
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1030 AM EDT SUN JUN 18 2017

...VALID 15Z SUN JUN 18 2017 - 12Z MON JUN 19 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
CWFQ 10 NE MPV 15 NE GFL 20 SE BGM 10 S HGR 25 W CJR 15 NNW INT
15 SSE AVL 25 SSW AVL 10 WNW WDR OPN 10 ESE LSF 25 N DHN
25 NNE CEW 25 WSW GZH 50 W GZH 25 S HBG 15 NNW HSA MSY 15 SE 7R3
20 W P92 20 W LFT ESF 20 ESE BAD 20 E GGG 10 ESE LNC 15 E MWL
20 NNE RPH 25 S DUC 15 SSE ADH 20 SSE OKM 20 SE TQH 30 SSW FLP
25 NNE BVX 25 SSW POF 10 ESE CIR 25 SSE HSB 20 W EHR 15 E BMG
10 NNE BAK 20 WSW MNN 20 N BKL 10 W CWNC 15 W CYTR 10 N CTWN
CWFQ.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 S CYGK 10 NW GTB 20 SE SLK 30 WNW GFL FIG 20 ENE CRW
35 SSE JKL 10 NW CSV 25 WNW 1M4 30 SW TUP 10 ENE ELD 10 W ELD
40 ESE OSA 3T1 10 W TKI 10 ENE DTO 15 SSE GLE 15 ESE GLE
15 WSW DUA 20 E AQR RKR 30 ENE FSM 30 WNW SRC 20 SSW JBR
15 SSE DYR 15 NNE BWG SDF 30 NNE LOU 10 SW HAO AKR HZY BUF
20 S CYGK.


1500 UTC UPDATE

CHANGES TO THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK WERE
TO CONNECT THE TWO SLIGHT RISK AREAS TO COVER CURRENT ORGANIZED
ACTIVITY PUSHING SOUTHEASTWARD INTO ARKANSAS AND POTENTIAL FOR
ADDITIONAL ACTIVITY ACROSS THIS AREA LATE SUNDAY NIGHT INTO MONDAY
MORNING.

THE SLIGHT RISK AREA WAS ALSO BUMPED BACK TO THE NORTHWEST ACROSS
CENTRAL KY INTO SOUTHWEST OH TO COVER SOME OF THE MODEL SPREAD FOR
POTENTIALLY HEAVY AMOUNTS.

THE MARGINAL RISK AREA WAS EXTENDED SLIGHTLY FARTHER TO THE EAST
IN THE VICINITY OF THE SOUTHERN TO CENTRAL APPALACHIANS TO COVER
POTENTIAL FOR SCATTERED CONVECTION THIS AFTERNOON THAT MAY PRODUCE
LOCALLY HEAVY RAINFALL AMOUNTS OVER THE LOWER FFG VALUES FROM
WESTERN NC INTO NORTHWEST VA.

ORAVEC

INITIAL DISCUSSION


...GT LAKES/NE SWWD THROUGH THE OH/TN VALLEYS..LOWER MS
VALLEY..AND SRN PLAINS...

...SLIGHT RISK OF EXCESSIVE RAINS EXPECTED FROM WRN NY SWWD
THROUGH PORTIONS OF THE ERN OH VALLEY..THE TN VALLEY..AND NORTHER
PORTIONS OF THE LOWER MS VALLEY.   A SLIGHT RISK OF EXCESSIVE
RAINS IS ALSO EXPECTED OVER PORTIONS OF NE TX/SE OK...

THE MID TO UPPER LEVEL FLOW IS EXPECTED TO CONTINUE TO STRENGTHEN
ACRS THE NRN/MID MS VALLEY AS STG JET HELPS CARVE OUT AN
AMPLIFYING UPPER TROF ACRS THIS REGION THROUGH THE GT LAKES
THROUGH MON MORNING.  BACKING MID/UPPER FLOW AHEAD OF THE TROF
WILL ALLOW DEEP MSTR WITH PWS APCHG 2 INCHES TO STREAM NEWD AHEAD
OF ASSOCD COLD FRONT THAT WILL CONTINUE TO PRESS EWD INTO NY STATE
SUN NIGHT WHILE TRAILING PORTION SLOWS ALONG THE SRN EDGE OF THE
STRONGER WLYS NEAR THE RED RIVER ACRS THE SRN PLAINS.  THE BACKING
FLOW AND AMPLIFYING RT ENTRANCE REGION OF AN ASSOCD UPPER JET EAST
OF THE TROF WILL GRADUALLY ENHANCE BROADER SCALE ASCENT ALONG THE
FRONT FROM THE TN/OH VALLEY NEWD INTO ERN PORTIONS OF NEW
ENGLAND..WHICH ALONG WITH EXPECTED DECENT WARM SECTOR INSTABILITY
WILL SUPPORT FAIRLY WIDESPREAD MDT TO HEAVY RAIN RATES ALONG THE
FRONT AS IT MAKES ITS WAY SLOWLY EWD SUN/SUN NIGHT..ESPECIALLY
DURING PEAK HEATING.  WITH THE MID/UPR FLOW BECOMING MORE ALIGNED
WITH THE FRONT/PREFRONTAL CONVECTION...POTNL WILL EXIST FOR SOME
TRAINING ELEMENTS THAT COULD LEAD TO FLASH FLOODING IN SPOTS.
HOURLY RAIN RATES OF 1 TO 2 INCHES PER HOUR WITH SOME ISOLD RAIN
AMOUNTS IN EXCESS OF 3 INCHES WILL BE PSBL.  WITH EVEN HIER
INSTABILITIES AND DEEPER MSTR FOCUSED FARTHER SOUTH THROUGH
NORTHERN PARTS OF THE LOWER MS VALLEY AHEAD OF POTNL MCVS TRACKING
ESEWD FROM SAT NIGHT CONVECTION OVER PARTS OF ERN KS/MO..EXPECT
STORMS TO REFIRE AHEAD OF THESE FEATURES ON SUN LEADING TO MDT TO
HEAVY RAIN AMOUNTS.  SOME OF THE HIER CAM GUIDANCE SHOW LOCAL
RAINFALL AMOUNTS IN EXCESS OF 5 INCHES OVER PORTIONS OF NORTHER
MS/TN..THOUGH THERE IS NOT SUFFICIENT CLUSTERING OF MODELS TO
SUPPORT MORE THAN A SLIGHT RISK OVER THOSE AREAS AT THIS TIME.
FARTHER WEST ALONG THE TRAILING PORTION OF THE FRONT...HEAVIER
CONVECTIVE RAINS ARE ALSO LIKELY TO REFIRE ALONG THE BNDRY LATE
SUN/SUN NIGHT AS SUFFICIENT HEATING/INSTABILITY AND POOLING OF
MSTR HELPS BREAK CAP ACRS PORTIONS OF NE TX/SE OK.  PATRN HERE IS
SUGGESTIVE OF POTNL BACK BUILDING OF CONVECTION SUN NIGHT ALONG
THE FRONT ALONG WITH PSBL MCS DVLPMENT AS ACTIVITY WILL LIKELY
FORM UNDER ANTICYCLONIC EWD EXTENSION OF UPPER RIDGE AXIS.  WHILE
THERE IS SOME DECENT SPREAD IN THE 00Z HI RES GUIDANCE AS TO THE
PLACEMENT OF THE HEAVIER RAINS ACRS NE TX/SE OK...ALL SHOW A STG
SIGNAL FOR POTNL HEAVY RAIN THREAT ACRS THAT AREA SUN NIGHT WITH
LOCAL RAINFALL AMOUNTS IN EXCESS OF 3 INCHES.

SULLIVAN

$$





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