478
FXUS02 KWBC 161848
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
248 PM EDT TUE JUN 16 2026
VALID 12Z FRI JUN 19 2026 - 12Z TUE JUN 23 2026
...SIGNIFICANT EXCESSIVE RAINFALL/FLOODING THREAT TO PERSIST FOR
THE GULF COAST STATES AND SOUTHEAST INTO FRIDAY/SATURDAY...
...WEEKEND TO EARLY NEXT WEEK HEAVY RAINS EMERGE FROM THE CENTRAL
PLAINS/MIDWEST/OHIO VALLEY TO THE NORTHEAST/MID-ATLANTIC...
..PATTERN OVERVIEW AND GUIDANCE/PREDICTABILITY ASSESSMENT
THE LEFTOVER MOISTURE ASSOCIATED WITH CURRENT POTENTIAL TROPICAL
CYCLONE ONE WILL STILL BE ENTANGLED WITH A FRONTAL BOUNDARY OVER
THE SOUTHEAST AT THE START OF THE PERIOD, CONTINUING A
HEAVY/EXCESSIVE RAINFALL AND FLASH FLOODING THREAT AT THE END OF
THE WEEK.
ELSEWHERE, HOT WEST/SOUTHWEST UPPER RIDGING WILL TEND TO FLATTEN
AND BECOME EAST-WEST ORIENTED OVER THE SOUTHERN TIER THIS PERIOD AS
AN EAST PACIFIC UPPER TROUGH PROGRESSES OVER THE NORTHERN TWO-
THIRDS OF THE CONUS. UPPER RIDGING MAY START TO INCREASE OVER TEXAS
BY NEXT TUESDAY AND BEYOND. OTHERWISE, QUASI-ZONAL FLOW WILL
DOMINATE WHICH LEADS TO DECREASED CONFIDENCE IN SYSTEM TIMING.
GUIDANCE FORECAST SPREAD REMAINS GENERALLY BETTER THAN AVERAGE FOR
THE FRI-SUN PERIOD THEN INCREASES NEXT WEEK WITH FLOW TRANSITION.
ACCORDINGLY, MOSTLY FAVOR A COMPATIBLE MULTI-MODEL AND ENSEMBLE
MEAN AND MACHINE LEARNING GUIDANCE BLEND FOR THE PERIOD WHICH DOES
NOT FAVOR ANY SPECIFIC DETERMINISTIC SOLUTION. THIS ALSO ACTS TO
MAINTAIN BEST WPC PRODUCT CONTINUITY.
..WEATHER/HAZARDS HIGHLIGHTS
POTENTIAL TROPICAL CYCLONE ONE WILL LIKELY BE ABSORBED INTO A
FRONT OVER THE SOUTHEAST BY THE START OF THIS PERIOD, BUT THE
INFUSION OF DEEP TROPICAL MOISTURE AND INSTABILITY WILL MAINTAIN
THE EXCESSIVE RAINFALL/FLASH FLOODING THREAT. PLEASE ALSO SEE THE
WPC EXCESSIVE RAINFALL DISCUSSION (ERD) AND HAZARDS OUTLOOK CHART
(LINKED BELOW) FOR ADDITIONAL RISK DETAILS.
THIS WEEKEND, A COLORADO LOW LOOKS TO FORM AND TRACK OVER THE
CENTRAL PLAINS TO THE GREAT LAKES THEN THE NORTHEAST. DEEPENING
MOISTURE LIFTING INTO THIS SYSTEM AND ASSOCIATED FRONTAL SYSTEM
GENESIS SHOULD LEAD TO SIZABLE AREAS OF HEAVY CONVECTIVE RAIN WITH
WEEKEND FOCUS ACROSS THE CENTRAL PLAINS/MIDWEST/OHIO VALLEY STATES
EXPANDING TO THE NORTHEAST/MID-ATLANTIC EARLY NEXT WEEK.
WEST COAST UPPER RIDGING KEEPS TEMPERATURES 10-20 DEGREES ABOVE
NORMAL OVER THE NORTHWEST/NORTHERN INTERMOUNTAIN WEST ON FRIDAY
WITH A NORTHERN STREAM LOW OVER BC BREAKING DOWN THE RIDGE INTO THE
WEEKEND, KNOCKING DOWN TEMPERATURES BACK TOWARD NORMAL. SOME
RIDGING LOOKS TO RETURN TO THE WEST COAST EARLY NEXT WEEK WITH
WARMER TEMPERATURES AGAIN FOR THE PAC NW AND NORTHERN GREAT BASIN.
OTHERWISE, CLOSER TO NORMAL SUMMER TEMPERATURES ARE EXPECTED ACROSS
THE LOWER 48, THOUGH THE TROPICAL MOISTURE ALONG THE GULF COAST
WILL MAINTAIN HIGH NIGHTTIME TEMPERATURES THAT, ALONG WITH SOUTHERN
TIER UPPER RIDGING, MAY SUPPORT HAZARDOUS HEAT AND HIGH HUMIDITY
LEVELS OVER PORTIONS OF THE FLORIDA PENINSULA AND THE GULF COAST.
HEATRISK LEVELS MAY EXCEED MODERATE TO MAJOR LEVELS FROM PARTS OF
TEXAS EASTWARD TO THE SOUTHEAST/FLORIDA NEXT WEEK.
FRACASSO/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, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY MESSAGES
ARE AT:
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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