MESOSCALE PRECIPITATION DISCUSSION 0006
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
137 PM EST SUN JAN 10 2016
 
AREAS AFFECTED...EASTERN NH/WESTERN ME... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 101837Z - 102337Z
 
SUMMARY...IN SPITE OF RELATIVELY HIGH FLASH GUIDANCE
VALUES...EXPECT A BRIEF THREAT FOR ISOLATED EPISODES OF FLASH
FLOODING AS THE LOW-LEVEL JET STRENGTHENS THIS AFTERNOON AND
EVENING. LOCALIZED HEAVY RAINFALL COUPLED WITH SNOW MELT MAY LEAD
TO SOME RUNOFF ISSUES.

DISCUSSION...THE 18Z SURFACE ANALYSIS SHOWED A STRONG CYCLONE
DEEPENING IN THE VICINITY OF LAKE ONTARIO WHILE A WARM FRONT
STRETCHED FROM SOUTHEASTERN NY ACROSS CENTRAL MA AND INTO THE
OFFSHORE WATERS. STRONG ASCENT ALONG AND NORTH OF THIS BOUNDARY
HAS HELPED SPREAD MODERATE RAINFALL OVER MUCH OF NEW ENGLAND.
HOURLY RAINFALL RATES HAVE NOT BEEN TREMENDOUS GENERALLY PEAKING
AT AROUND 0.25 TO 0.50 INCHES PER MESONET DATA. EXPECT THESE RATES
TO INCREASE A BIT AS BETTER MOISTURE AND STRONGER LOW-LEVEL INFLOW
TAKES SHAPE. RECENT RUNS OF THE RAP SHOW THE 850-MB WINDS PEAKING
IN THE 80 TO 90 KNOT RANGE LATER THIS EVENING. SOUTH TO
SOUTH-SOUTHEAST FACING SLOPES WILL SEE STRONG OROGRAPHIC LIFT
WHICH COULD LEAD TO PERIODS OF RATHER INTENSE RAINFALL. THIS IS
PARTICULARLY THE CASE OVER THE WHITE MOUNTAINS ALONG WITH THE
MAHOOSUCS. RECENT CAMS SUGGEST 6-HOUR TOTALS APPROACHING 2 TO 2.50
INCHES THROUGH 00Z. MILD MARITIME AIR WORKING ITS WAY INLAND WILL
AID IN SOME SNOW MELT WHICH WOULD AID IN LOCAL RUNOFF ISSUES.

THERE ARE MANY ASPECTS OF THE FORECAST WHICH WILL LIMIT THE THREAT
FOR FLASH FLOODING. THIS INCLUDES THE HIGHER GUIDANCE
VALUES...LACK OF INSTABILITY...AND PROGRESSIVE NATURE OF THE
SYSTEM. HOWEVER...GIVEN HOW DYNAMIC THIS SYSTEM HAS PROVEN TO
BE...FEEL THERE REMAINS AT LEAST A LOCALIZED THREAT FOR FLASH
FLOODING...ESPECIALLY OVER THE COMPLEX TERRAIN.


RUBIN-OSTER

ATTN...WFO...GYX...

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

LAT...LON   45207050 45206990 44666966 44216967 43716980 
            43307008 42847027 42897075 43607119 43777166 
            44137180 44677115