591
FXUS02 KWBC 011849
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
249 PM EDT SUN JUN 1 2025
VALID 12Z WED JUN 04 2025 - 12Z SUN JUN 08 2025
..OVERVIEW
STRONG UPPER RIDGING OVER THE NORTHEASTERN PACIFIC BENEATH AN
UPPER LOW/TROUGHING OVER ALASKA WILL PROMOTE A STRONG JET INTO
WESTERN CANADA AND SPLIT FLOW OVER THE CONUS LATER THIS WEEK INTO
NEXT WEEKEND. OVER THE EAST, UPPER RIDGING WILL BE SPLIT BETWEEN
ATLANTIC CANADA AND SOUTHWEST OF BERMUDA WITH ADDITIONAL RIDGING
ACROSS MEXICO. THE PATTERN WILL FAVOR A WARMING TREND FOR MUCH OF
THE COUNTRY WITH THE HIGHEST RAIN CHANCES OF THE CENTRAL/SOUTHERN
PLAINS INTO THE MIDWEST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MUCH OF THE 00Z/06Z GUIDANCE SHOWED REASONABLE AGREEMENT WITH THE
PATTERN OVER THE CONUS THROUGH ABOUT FRIDAY, BEFORE THE 06Z
GFS/GEFS BECAME MUCH FASTER WITH A SYSTEM EXITING THE GULF OF
ALASKA THAN THE 00Z ECMWF/CANADIAN AND THEIR ENSEMBLE MEANS (AS
WELL AS THE ECMWF-AIFS AND AIFS-ENSEMBLE MEAN). UTILIZED A BLEND OF
THAT MUCH LARGER CONSENSUS TO ROUND OUT THE FORECAST. THE NBM WAS
A REASONABLE STARTING POINT AS WELL FOR THE SENSIBLE WEATHER GRIDS.
PRECIPITATION WILL BE MOST UNCERTAIN DUE TO DIFFERENCES IN DAY-TO-
DAY CONVECTION.
..WEATHER/HAZARDS HIGHLIGHTS
FOR WED/THU, A SLOWLY-MOVING FRONTAL BOUNDARY STRETCHED FROM THE
GREAT LAKES BACK TO TEXAS WILL BE THE FOCUS FOR BOUTS OF
THUNDERSTORMS AND LOCALLY HEAVY RAINFALL. GULF MOISTURE WILL FLOW
INTO THE SOUTHERN PLAINS WHERE IT HAS BEEN RATHER WET THE PAST
WEEK. WE HAVE MAINTAINED A BROAD MARGINAL RISK OF EXCESSIVE
RAINFALL AND FLASH FLOODING FOR THIS REGION WITH A SMALLER (AND
LESS CERTAIN) SLIGHT RISK WHERE HEAVIER RAINFALL IS MORE LIKELY AT
THIS POINT. HOWEVER, THIS WILL LIKELY BE SUBJECT TO CHANGE AS LEAD
TIME DECREASES.
THE NORTHERN PART OF THE FRONT WILL CONTINUE EASTWARD INTO THE
WEEKEND, BRINGING SOME RAIN TO THE NORTHEAST (ON YET ANOTHER
WEEKEND). THE SOUTHERN PART WILL SLOWLY LIFT NORTHWARD AS A WARM
FRONT AS HEIGHTS RISE OVER MEXICO/SOUTHERN TEXAS, ALLOWING THE
HEAVIER RAIN POTENTIAL TO MOVE BOTH NORTHWARD (INTO THE CENTRAL
PLAINS) BUT ALSO SPILL EASTWARD INTO THE MID-SOUTH.
ANOTHER POTENTIAL AREA OF RAINFALL WILL BE ALONG THE NORTHEASTERN
FL AND SOUTHEAST COAST AS A LINGERING/WEAKENING FRONTAL BOUNDARY
LIFTS NORTHWARD BENEATH A WEAKNESS ALOFT. MOISTURE MAY STAY
OFFSHORE AND UNCERTAINTY IS HIGH, BUT THERE IS A SMALL CHANCE OF
SOME HEAVIER RAINFALL ALONG THE COAST (AND A MARGINAL RISK OF
EXCESSIVE RAINFALL WAS INTRODUCED).
TEMPERATURES WILL BE BELOW NORMAL TO START ALONG AND EAST OF THE
ROCKIES TO THE PLAINS BEHIND THE COLD FRONT, BUT THEY WILL MODERATE
BY LATER IN THE WEEK INTO THE WEEKEND. MUCH ABOVE NORMAL
TEMPERATURES FOR THE EAST (WARMEST SO FAR THIS YEAR FOR MANY INTO
THE UPPER 80S TO LOW 90S) WILL PUSH HEATRISK VALUES TO THE MODERATE
CATEGORY -- TAKE CARE OUTSIDE DURING THE HOTTEST PART OF THE DAY.
AREAS OF SOUTH TEXAS WILL SEE RISING TEMPERATURES THROUGH THE LATE
WEEK INTO THE WEEKEND, CRESTING 105F BY NEXT WEEKEND ALONG THE RIO
GRANDE. THIS MAY PUSH HEAT INDEX VALUES OVER 110F.
HEAT SAFETY -- TAKE PRECAUTIONS SUCH AS INCREASED WATER INTAKE AND
MORE TIME IN AIR CONDITIONED AREAS TO AVOID HEAT EXHAUSTION AND
HEAT STROKE. SEE WEATHER.GOV/HEAT FOR MORE INFORMATION ON SAFETY
TIPS AND RESOURCES.
FRACASSO
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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page