EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
411 AM EDT TUE SEP 19 2017

...VALID 12Z TUE SEP 19 2017 - 12Z WED SEP 20 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 NNW K46D 20 SE CWZE 35 NNE CWOJ 20 ENE CWEA 10 ENE CWTX
10 NNE PKD 15 S ETH 25 WSW ATY 25 SSE ABR 45 W K2D5 10 NNW K46D.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
120 ESE ACY 65 ESE ACY 45 SE MJX 25 E BLM FRG BDR MMK
10 SSE FIT 25 SE PSM 70 NE PVC 100 ENE CQX.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
75 SSE HTO 40 SSE FOK FOK 15 SE IJD SFZ 10 WNW PVC 35 ENE CQX
60 E ACK.


...HURRICANE JOSE CONTINUES TO LIFT NORTHWARD OVER THE WRN
ATLANTIC...


...SRN/SERN NEW ENGLAND...

WITH THE CONTINUED OFFSHORE APPROACH OF JOSE...WAA
PATTERN/WRAPPING TROPICAL MOISTURE WILL INCREASE RAINS ALONG
COASTAL SECTIONS OF SRN NEW ENGLAND SWWD BACK INTO PORTIONS OF THE
COASTAL NRN MID-ATLANTIC...WITH THE STRONGER ONSHORE FLOW
ESPECIALLY FAVORING AREAS FROM ERN LONG ISLAND INTO SE MA AS
RAINFALL EFFICIENCY/AMOUNTS INCREASE. A SLIGHT EWD SHIFT OF THE
NHC TRACK OF JOSE AND SATELLITE IMAGERY FAVORS TIGHTER
MOISTURE/PCPN GRADIENT ON ITS WRN PERIPHERY. THIS ALSO SEEMS TO BE
SUPPORTED BY GENERAL OFFSHORE MODEL TRENDS OF THE LAST FEW MODEL
CYCLES. EVEN SO...THERE REMAINS A SLIGHT RISK OF RUNOFF ISSUES
WITH EXCESSIVE RAINFALL OVER SERN NEW ENGLAND.


...NRN PLAINS/UPPER MIDWEST...

GUIDANCE REASONABLY AGREES THAT AN AMPLIFIED MID-UPPER TROUGH WILL
EJECT NEWD OVER THE N-CENTRAL US AS KICKER UPSTREAM S/WV ENERGY
AND POWERFUL JET DIGS FROM THE NE PACIFIC TO THE PACIFIC NW. A
LEAD FRONTAL SYSTEM WILL PUSH ACROSS THE N-CENTRAL US AS AMPLE
ENERGY ALOFT WORKS OVER THE REGION. MODELS SHOW STRONG RETURN SRLY
FLOW DEVELOPING IN RESPONSE INTO THE DAKOTAS/MN WHERE A NARROW
AXIS OF 1.5-1.75" PWS POOL INTO A REGION UNDER A COUPLED UPPER
JET. INCREASING LIFT AND INSTABILITY SHOULD COMBINE WITH TRIPLE
POINT ENHANCED FRONTAL CONVERGENCE TO SUPPORT SOME STRONG
CONVECTION AND A QUICK FEW INCHES OF RAIN THAT OFFERS A MARGINAL
RISK OF EXCESSIVE RAINFALL AND ASSOCIATED LOCAL RUNOFF ISSUES.

SCHICHTEL