192  
FXUS02 KWBC 301900  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT SAT MAR 30 2024  
 
VALID 12Z TUE APR 02 2024 - 12Z SAT APR 06 2024  
 
...HEAVY RAIN THREAT FROM PENNSYLVANIA TO NEW JERSEY ALONG WITH  
STRONG TO POSSIBLY SEVERE THUNDERSTORMS DOWN THE SPINE OF THE  
APPALACHIANS ON TUESDAY...  
 
...NEW ENGLAND COASTAL STORM WITH MARITIME HAZARDS/HIGH  
WIND/COASTAL FLOODING ALONG WITH HEAVY SNOW THREAT WEDNESDAY-  
THURSDAY...  
   
..WIDESPREAD PRECIPITATION/COOLING FOR THE WEST MID-LATE WEEK  
 
...PATTERN OVERVIEW, GUIDANCE/PREDICTABILITY ASSESSMENT, AND  
WEATHER/HAZARDS HIGHLIGHTS...  
 
THE MEDIUM-RANGE PERIOD WILL BEGIN WITH A LOW PRESSURE SYSTEM  
DEVELOPING FROM ACROSS THE MID-MISSISSIPPI TO THE OHIO VALLEY.  
MODEL GUIDANCE CONTINUES WITH THE ONGOING TREND OF SLOWING DOWN THE  
UPPER TROUGH THAT IS FORECAST TO LIFT NORTHEASTWARD ACROSS THE  
CENTRAL PLAINS. THIS TREND HAS HELPED STRENGTHEN A LOW PRESSURE  
WAVE FARTHER BACK OVER THE MID-MISSISSIPPI VALLEY ON TUESDAY WHILE  
KEEPING ANOTHER WAVE FARTHER DOWNSTREAM NEAR THE UPPER OHIO VALLEY.  
THE BEST DYNAMICS WILL SUPPORT HEAVY RAIN LIKELY FROM PENNSYLVANIA  
TO NEW JERSEY ON TUESDAY WHILE AN AXIS OF MODERATE TO HEAVY RAIN  
EXTENDS SOUTHWESTWARD DOWN THE SPINE OF THE APPALACHIANS WELL  
AHEAD OF A COLD FRONT WHERE MINOR ADJUSTMENTS TO THE MARGINAL  
EXCESSIVE RAINFALL RISK AREA WAS NECESSARY. SOME STRONG TO POSSIBLY  
SEVERE THUNDERSTORMS ARE EXPECTED TO ACCOMPANY THIS AXIS OF  
ENHANCED RAINFALL.  
 
WEDNESDAY WILL LIKELY FEATURE CYCLOGENESIS OVER THE EASTERN U.S.,  
WITH NEW ENGLAND LIKLEY BEING IMPACTED BY A SIGNIFICANT  
NOR'EASTER BY THURSDAY. THERE ARE TWO IMPORTANT CONTRIBUTORS TO  
THE CYCLOGENESIS. AN UPPER TROUGH ASSOCIATED WITH A SURGE OF COLD  
AIR FROM CENTRAL CANADA IS FORECAST TO DIVE TOWARD THE UPPER GREAT  
LAKES ON TUESDAY. GIVEN THE ONGOING SLOWING TREND OF THE UPPER  
TROUGH LIFTING ACROSS THE CENTRAL PLAINS, MODELS ARE TRENDING  
TOWARD HAVING AN DOUBLE-BARREL LOW PRESSURE SYSTEM AS IT TRACKS  
TOWARD THE NEW ENGLAND COAST. THE SLOWER LIFTING OF THE TROUGH  
OVER THE CENTRAL PLAINS WILL ALSO HELP KEEP A STRONGER LOW BACK  
ACROSS THE GREAT LAKES WHILE KEEPING THE COLD AIR IN PLACE OVER NEW  
ENGLAND. AS A RESULT, THE CHANCE OF HEAVY SNOW, INSTEAD OF HEAVY  
RAIN, HAS CONTINUED TO INCREASE FROM CENTRAL NEW ENGLAND THROUGH  
ALL OF MAINE ON THURSDAY.  
 
MEANWHILE AND SIGNIFICANTLY ON THE COLDER NORTHERN SIDE OF STORM  
SYSTEM, THERE WILL BE A SIGNIFICANT THREAT FOR LAKE-EFFECT SNOW  
BANDS AND SNOW SQUALLS OUT FROM THE GREAT LAKES AND THROUGH THE  
INTERIOR NORTHEAST TUESDAY TO THURSDAY AS DEPICTED BY ENHANCED WPC  
WINTER WEATHER OUTLOOK PROBABILITIES.  
 
TOWARD THE END OF NEXT WEEK, MODELS SHOW VERY GOOD AGREEMENT ON A  
HIGHLY AMPLIPIED UPPER PATTERN ACROSS THE U.S. WITH RIDGE BUILDING  
OVER THE CENTRAL U.S. AS THE DEEP LOW SLOWLY PULLING OUT OF THE  
NORTHEAST AND THE NEXT UPPER TROUGH DIGGING JUST OFF THE WEST  
COAST. A STRONGLY AMPLIFYING UPPER TROUGH/CLOSED LOW AND LEADING  
AND WAVY COLD FRONT/SECONDARY CANADIAN COLD SURGE DIGGING INTO THE  
WEST SHOULD ACT TO COOL TEMPERATURES AND SPREAD ENHANCED  
PRECIPITATION AND WINDY/UNSETTLED FLOW TO INCLUDE COASTAL RAINS  
DOWN THROUGH CALIFORNIA ALONG WITH A PROLONGED PERIOD WITH INTERIOR  
AND TERRAIN/MOUNTAIN SNOWS INCREASINGLY INLAND ACROSS MUCH OF THE  
WEST MIDWEEK INTO NEXT WEEKEND. DEPICTED AREAS OF PRECIPITATION ARE  
CURRENTLY ON THE MODEST TO MODERATE SIDE GIVEN TRACK/MOISTURE, BUT  
AMPLE UPPER SUPPORT AND FAVORED TERRAIN LIFT MAY LEAD TO LOCALLY  
HEAVIER FOCUS AND ACTIVITY TO MONITOR. THE WPC WINTER WEATHER  
OUTLOOK SHOWS THE GREATEST SNOW PROBABILITIES OVER NORTHWEST TO  
NORTHERN INTERMOUNTAIN/ROCKIES TERRAIN/MOUNTAINS.  
 
KONG/SCHICHTEL  
 
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL  
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT  
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:  
 
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW  
 
 
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