502
FXUS02 KWBC 010820
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
320 AM EST SUN MAR 1 2026
VALID 12Z WED MAR 04 2026 - 12Z SUN MAR 08 2026
..EMERGING EAST-CENTRAL U.S. HEAVY RAINFALL PATTERN THIS WEEK
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE UNCERTAINTY IN THE UPCOMING MEDIUM-RANGE PERIOD BEGINS
PRIMARILY FOCUSED ACROSS THE PLAINS AND VICINITY MID-LATER WEEK.
RECENT GFS/GEFS RUNS SWING A SHORTWAVE ALOFT AND THEN BRINGS AN
AMPLIFIED FRONTAL WAVE NORTHEASTWARD INTO THE MIDWEST. THIS
SOLUTION STILL SEEMS TOO AMPLIFIED COMPARED WITH THE REST OF THE
DYNAMICAL GUIDANCE THAT DIG ENERGY MORE SHARPLY THROUGH THE WEST.
THE AI MODELS ALSO FAVOR A DELAYED AMPLIFICATION RELATIVE TO THE
GFS/GEFS. THEREAFTER, ANOTHER UPPER-LEVEL TROUGH/WAVE IS NOW MORE
UNIFORMLY FORECAST IN GUIDANCE WITH 00 UTC CANADIAN MODEL FAVORABLE
TREND TOWARD THE REST OF GUIDANCE TO DIG MORE THROUGH THE WEST TO
THE SOUTHWEST/BAJA NEXT WEEKEND, BUT ALSO ALLOW FOR RENEWED GULF
RETURN FLOW DOWNSTREAM IN CHANNELED FLOW ON THE WESTERN TO NORTHERN
PERIPHERY OF A BUILDING/WARMING SOUTHWEST U.S./ATLANTIC UPPER
TROUGH. THIS WILL SET ANOTHER STAGE FOR THE NEXT BOUT OF HIGH QPF
INTO NEXT WEEKEND FROM THE SOUTH- CENTRAL PLAINS TO THE MIDWEST IN
A REGION HAVING JUST EXPERIENCED WIDESPREAD RAINFALL/CONVECTION.
..WEATHER/HAZARDS HIGHLIGHTS
A PRONOUNCED SPLIT UPPER FLOW PATTERN WILL DOMINATE THE NATION THIS
WEEK. A LEADING SOUTHERN STREAM UPPER TROUGH AND SURFACE SYSTEM
WILL EJECT FROM THE SOUTH-CENTRAL U.S. THROUGH THE MIDWEST THEN
NORTHEAST MID-LATE WEEK AND RETURN INFLOW WILL FUEL AN EMERGING
AREA OF MODERATE TO HEAVY RAINS/CONVECTION UNDER A FAVORABLE UPPER
JET. ELONGATED DAY 4/5 (WEDNESDAY/THURSDAY) WPC EXCESSIVE RAINFALL
MARGINAL THREAT AREAS ARE IN PLACE FROM THE SOUTHERN PLAINS
THROUGH THE MID-MS AND CENTRAL OHIO VALLEY STATES GIVEN POOLING
MOISTURE AND REPEAT POTENTIAL. MOISTURE OVERRUN INTO COLD CANADIAN
HIGH PRESSURE SKIMMING INTO THE U.S. NORTHERN TIER AS DRIVEN BY
MORE PROGRESSIVE NORTHERN STREAM ENERGIES SHOULD ALSO SUPPORT A
SWATH OF SNOW FROM NORTHERN PORTIONS OF THE UPPER MIDWEST/GREAT
LAKES TO THE INTERIOR NORTHEAST WHERE CONDITIONS MAY ALSO SUPPORT
AN ICY TRANSITION ZONE TO MONITOR.
MEANWHILE UPSTREAM, AN AMPLIFIED UPPER TROUGH WILL DIG SHARPLY
SOUTHEASTWARD INTO THE WEST FROM THE PACIFIC NORTHWEST TO THE
SOUTHWEST/ROCKIES WEDNESDAY-FRIDAY AND BRING UNSETTLED AND COOLING
FLOW ALONG WITH A WIDESPREAD MODERATE PRECIPITATION FOCUS FROM THE
PACIFIC NORTHWEST THROUGH THE NORTH-CENTRAL INTERMOUNTAIN/ROCKIES
TO INCLUDE TERRAIN ENHANCED SNOWS. WHILE RECENT GUIDANCE TRENDS DIG
AN INCREASING SOUTHERN STREAM DETATCHED UPPER LOW/TROUGH THROUGH
THE SOUTHWEST INTO BAJA NEXT WEEKEND, DOWNSTREAM ENERGY TRANSLATION
SHOULD ALSO ACT TO RENEW THE WET/CONVECTIVE FLOW PATTERN NEXT
WEEKEND AGAIN OVER THE SOUTH-CENTRAL U.S. TO MIDWEST TO MONITOR
FOR RUNOFF ISSUES GIVEN AMPLE EARLIER RAINFALL TO MOISTEN SOILS.
ADDITIONAL FLOW FROM THE NORTHEAST PACIFIC MAY ALSO WORK BACK INTO
THE NORTHWEST TO RENEW MODERATE PRECIPITATION NEXT WEEKEND AND
CONTINUED NORTHERN STREAM ENERGY TRANSLATION INTO CYCLONIC UPPER
FLOW DOWNSTREAM INTO THE NORTHERN TIER COULD ALSO ALLOW FOR SOME
COOLER AIRMASS INTRUSIONS TO INTERACT WITH THE NORTHERN FRINGE OF
THE AFOREMENTIONED EXPANDING SOUTHERN STREAM PRECIPITATION AREA.
IN THIS PATTERN, AMPLIFIED SOUTHEAST/ATLANTIC UPPER RIDGING AND
SIGNIFICANT SPRINGTIME WARMING WILL BUILD AND LINGER UP THE EAST
COAST THROUGH LATER NEXT WEEK/WEEKEND AS LEAD COLD DAMNED HIGH
PRESSURE LOSES SOUTHWARD INFLUENCE.
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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