MESOSCALE PRECIPITATION DISCUSSION 0029
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1140 AM EST WED FEB 03 2016
 
AREAS AFFECTED...EASTERN WV...SOUTH-CENTRAL PA...MD...VA...DC... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 031639Z - 032239Z
 
SUMMARY...UPSTREAM BAND OF LIGHT/MODERATE PRECIPITATION HAS A
HISTORY OF PRODUCING 3-HOUR RAINFALL AMOUNTS OF OVER 0.50 INCHES.
WHILE MEAGER IN NATURE...THIS WOULD BE ENOUGH TO EXCEED MANY OF
THE LOCAL FFG VALUES. FLASH FLOODING IS POSSIBLE GIVEN THIS
COMBINATION OF SATURATED SOILS COUPLED WITH SNOW MELT GIVEN ANY
REMAINING SNOWPACK OVER THE REGION.

DISCUSSION...THE 16Z FRONTAL ANALYSIS INDICATED A COMPLEX SURFACE
PATTERN WITH A WELL-DEFINED COLD-AIR DAMMING EVENT ANCHORING A
VAST MAJORITY OF THE MID-ATLANTIC. EXTENSIVE CLOUD COVER COMBINED
WITH FALLING PRECIPITATION SHOULD ENCOURAGE THE WEDGE TO REMAIN IN
PLACE INTO THE AFTERNOON HOURS. THE AIR MASS OVER THE REGION IS
QUITE SATURATED PER LOCAL RAOBS WITH A PWAT OF 1.24 INCHES AT IAD
THIS MORNING. BASED ON THE SPC SOUNDING CLIMATOLOGY...THIS
GENERALLY RANKS ABOVE THE DAILY MOVING MAXIMA FOR EARLY FEB. IN
SPITE OF A LACK OF INSTABILITY...THE HIGHLY ANOMALOUS MOISTURE
CONTENT WILL SUPPORT 1-HOUR/3-HOUR RAINFALL TOTALS CAPABLE OF
EXCEEDING LOCAL FFG VALUES. THE SATURATED AIR MASS OVER THE
DIMINISHING SNOWPACK WILL SUPPORT FURTHER MELTING WHICH COULD LEAD
TO ADDITIONAL HYDROLOGIC ISSUES.

MANY OF THE HIGH-RESOLUTION MODELS HAVE BEEN SLOW TO SLIDE THE
ONGOING PRECIPITATION EASTWARD. THE CURRENT 15Z HRRR REMAINS THE
ONLY RELIABLE SOLUTION AT THIS TIME. FOLLOWING ITS OUTPUT
FORWARD...IT DEPICTS A BAND OF RAINFALL TRACKING THROUGH THE DC
METRO AREA BETWEEN 20-22Z WITH HOURLY RATES IN THE 0.25 TO 0.50
INCH RANGE. THIS COULD LEAD TO SOME LOCAL FLOOD ISSUES IF THIS
COMES TO FRUITION.


RUBIN-OSTER

ATTN...WFO...AKQ...CTP...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...SERFC...

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            39817624 39427621 39017636 38397652 38207688 
            37977706 37437725 37267764 37267839 37397878 
            37397906 37467934 37507967 37398001 37328031 
            37578050 37888018 38537979 39187955 39837924