883
FXUS02 KWBC 290700
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EDT FRI MAR 29 2024
VALID 12Z MON APR 01 2024 - 12Z FRI APR 05 2024
...A LOW PRESSURE/FRONTAL SYSTEM WILL SPREAD POTENTIALLY HEAVY
RAIN AND MOUNTAIN/NORTHERN TIER SNOW ACROSS THE CENTRAL TO EASTERN
U.S. NEXT WEEK AS AN ACTIVE NEW STORM DIGS INTO A COOLING WEST...
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE FROM YESTERDAYS 12 UTC CYCLE AND LATEST 00 UTC CYCLE
ECMWF/UKMET/CANADIAN AND ECMWF ENSEMBLES SEEM BEST CLUSTERED FOR
NEXT WEEK AND A COMPOSITE SEEMS TO REASONABLY REPRESENT RECENT
GUIDANCE TRENDS FOR A MORE AMPLIFIED AND LESS PROGRESSIVE NORTHERN
STREAM, ASSOCIATED ENTRAINMENT OF ASPECTS OF AMBIENT ENERGY FROM A
SOUTHWEST CLOSED UPPER TROUGH/LOW POSITION AND SUBSEQUENT UPSTREAM
UPPER TROUGH AMPLIFICATION INTO THE WEST FROM THE GULF OF ALASKA.
THE 12 UTC AND NOW 00 UTC RUNS OF THE GFS/GEFS ARE MORE IN LINE
WITH THIS PREFERRED CLUSTER THAN A SEEMINGLY OUTLIER 18 UTC
GFS/GEFS THAT WERE OVERALL LESS AMPLIFIED.
..PATTERN OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
CLOSED UPPER TROUGHING WITH SEVERAL EMBEDDED LOWS WILL WORK INTO
THE FOUR CORNERS STATES AND NORTHWEST MEXICO INTO EARLY NEXT WEEK.
THIS FEATURE AND ITS SURFACE LOW PRESSURE SYSTEM WILL DIRECT
LINGERING MOISTURE INTO THE SOUTHWEST AND INTO THE ROCKIES INTO
MONDAY AND PRODUCE TERRAIN ENHANCED RAIN AND HIGHER ELEVATION SNOW.
ASPECTS OF THESE UPPER/SURFACE FEATURES WILL EJECT DOWNSTREAM TO
INTERACT WITH INCREASINGLY DIGGING NORTHERN STREAM TROUGHING INTO
THE NORTH-CENTRAL U.S.. THIS SHOULD ACT TO CONSOLIDATE A MAIN
SURFACE LOW THAT SHOULD DEEPEN AND MOVE FROM THE CENTRAL PLAINS TO
THE NORTHEAST DURING THE WORKWEEK. EXPANSIVE PRECIPITATION COVERAGE
IS LIKELY WITH THIS LARGE SYSTEM, WITH SNOW AND FREEZING RAIN
POSSIBLE ON ITS NORTH SIDE, AND A HEAVY RAIN AND STRONG TO SEVERE
THUNDERSTORM FOCUS WITHIN AN UNSTABLE WARM SECTOR AND INTO THE LOW
AS MOISTURE POOLS ALONG THE SURFACE LOW'S FRONTS.
WELL BEHIND THIS SYSTEM, A STRONGLY AMPLIFYING UPPER TROUGH AND
LEADING AND WAVY COLD FRONT DIGGING INTO THE WEST SHOULD ACT TO
COOL TEMPERATURES AND SPREAD ENHANCED PRECIPITATION TO INCLUDE
INTERIOR AND TERRAIN/MOUNTAIN SNOWS SOUTHEASTWARD ACROSS THE WEST
INTO NEXT WEDNESDAY-FRIDAY IN INCREASINGLY UNSETTLED FLOW. 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.
MEANWHILE, THE OHIO VALLEY WILL BE ONE AREA OF FOCUS FOR
POTENTIALLY HEAVY RAINFALL. SOME RAIN IS LIKELY THERE ON SUNDAY,
BUT AMOUNTS ARE FORECAST TO INCREASE BY MONDAY. A MARGINAL RISK
REMAINS IN PLACE FROM THE MIDDLE MISSISSIPPI VALLEY INTO THE OHIO
VALLEY ON MONDAY FOR THE WPC DAY 4 EXCESSIVE RAINFALL OUTLOOK
(ERO). MOISTURE AND INSTABILITY ARE ANOMALOUSLY HIGH FOR THIS TIME
OF YEAR, AND SHOWERS COULD TRAIN ALONG THE WEST TO EAST ORIENTED
WARM FRONT NEARBY. BY TUESDAY THE COLD FRONT AND LOW SHOULD
CONTINUE TO PUSH EAST AND THE HEAVIEST RAINFALL AT THAT POINT MAY
FOCUS OUT FROM THE TENNESSEE VALLEY AND INTO THE APPALACHIANS WHERE
A MARGINAL RISK ERO HAS ALSO BEEN INTRODUCED, WITH LOWERED FLASH
FLOOD GUIDANCE (FFG) VALUES ON THE NORTHERN END AND GREATER
INSTABILITY OVER SOUTHERN PORTIONS. ACCORDINGLY, THE STORM
PREDICTION CENTER IS MONITORING SEVERE POTENTIAL IN THE WARM SECTOR
FROM THE PLAINS TO JUST WEST OF THE APPALACHIANS FOR EARLY NEXT
WEEK TO MONITOR.
ON THE NORTHERN SIDE OF THE STORM SYSTEM, SNOW AND FREEZING RAIN
ARE POTENTIAL THREATS FROM THE UPPER MIDWEST AND GREAT LAKES
REGION MONDAY AND INTERIOR/HIGHER ELEVATIONS OF THE NORTHEAST BY
TUESDAY-WEDNESDAY AND LINGERING INTO THURSDAY WITH CONTINUED WRAP-
AROUND FLOW INTO THE MAIN/WINDY LOW. HOWEVER, THERE IS STILL
CONSIDERABLE UNCERTAINTY IN THE PLACEMENT AND AMOUNTS OF SNOW AND
ICE, SO CONTINUE TO MONITOR FORECASTS. THE INTERIOR NORTHEAST MAY
SEE THE HEAVIEST SNOW AMOUNTS OVERALL BECAUSE OF THE DURATION OF
THE POTENTIAL SNOW EVENT THERE COMPARED TO THE NORTH-CENTRAL
U.S./MIDWEST/GREAT LAKES.
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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