MESOSCALE PRECIPITATION DISCUSSION 0426
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
406 PM EDT THU OCT 16 2014
 
AREAS AFFECTED...RI...MA...VT...NH...ME 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 162005Z - 170205Z
 
SUMMARY...SIGNIFICANT AND LOCALLY FLASH FLOOD PRODUCING RAINS ARE
EXPECTED THROUGH THE EVENING OVER PORTIONS OF NEW ENGLAND.

DISCUSSION...THE LATEST IR/WV SAT IMAGERY CONTINUES TO SHOW A DEEP
PLUME OF MOISTURE WITH A RATHER WELL-DEFINED TROPICAL CONNECTION
ORIENTED NW/SE THAT EXTENDS FROM SOUTHERN NEW ENGLAND TO WELL
OFFSHORE THE EAST COAST. NUMEROUS CLUSTERS OF COLD-TOPPED
CONVECTION ALONG WITH SOME LINEAR INTENSE BANDS ARE IN EMBEDDED
WITHIN THE PLUME ITSELF...AND ALL OF THIS IS ALONG AND JUST AHEAD
OF A STRONG COLD FRONT AND DEEP LAYER TROUGH MOVING INTO THE
NORTHEASTERN U.S. ATTM.

THIS ATMOSPHERIC RIVER OF MOISTURE CONTAINS PWAT VALUES OF 1.8 TO
2.0 INCHES BASED ON THE LATEST GOES-SOUNDER IMAGERY AND IT IS
EXPECTED THAT DEEP MOISTURE/CONVECTIVE PLUME WILL AIM AND ORIENT
ITSELF FOR A NUMBER OF HOURS INTO SOUTHERN NEW ENGLAND...WHILE
GRADUALLY PIVOTING NORTHEAST UP INTO PORTIONS OF NORTHERN AND
EASTERN NEW ENGLAND THROUGH THE LATE AFTERNOON AND EVENING HOURS.
THE MOISTURE TRANSPORT WILL BE AIDED BY A ROBUST LOW LVL JET OF 40
TO 50 KTS.

THE LATEST GLOBAL MODELS INDICATE SOME POTENTIAL FOR ADDITIONAL
MOISTURE ENHANCEMENT...ESPECIALLY LATER THIS EVENING FROM THE
INTERACTION OF THIS DEEP TROUGH AND HURRICANE GONZALO WHICH IS 460
MILES SSW OF BERMUDA AS PER THE 2PM AST NHC ADVISORY. ALBEIT
INDIRECT...ANY ADDITIONAL MOISTURE CONTRIBUTION IN OFF THE
ATLANTIC OCEAN WILL ONLY CONTRIBUTE TO HEAVIER RAINFALL RATES.
GIVEN THE DEEP LAYER UNIDIRECTIONAL FLOW AND SLOW MOVEMENT OF THE
FRONT THROUGH NEW ENGLAND...ADDITIONAL HEAVY TRAINING RAINFALL IS
EXPECTED AND THEREFORE FLASH FLOODING WILL BE LIKELY. RAINFALL
RATES OF 1 TO 2 INCHES/HR CAN BE EXPECTED AND WILL BE ENHANCED
FURTHER BY OROGRAPHICS. 

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE EXPECTED...AT
LEAST LOCALLY...ALONG WITH ISOLD HEAVIER TOTALS.

ORRISON

ATTN...WFO...BOX...BTV...CAR...GYX...

ATTN...RFC...NERFC...

LAT...LON   46027075 45466972 44306927 43246923 42336932 
            41076973 40527038 40607113 41007146 41877157 
            43117199 44217226 45507225