Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
302 PM EDT Mon Jun 2 2025

Valid 12Z Thu Jun 05 2025 - 12Z Mon Jun 09 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. Much of the country will see warming temperatures
along with greatest chances for heavy rain for the Central/Southern
Plains and Midwest into the Northeast and NHC is monitoring sub-
tropical low development potential off the Southeast.

...Guidance/Predictability Assessment...

Guidance offers a reasonably similar larger scale pattern evolution
and broad threat messaging hazars potential for the upcoming medium
range period, but run to run guidance cycle variances remain less
than stellar through the period. Accordingly, the WPC medium range
product suite was broadly constructed from a composite blend of
latest guidance from the GFS/ECMWF/Canadian and best clustered
ECMWF/Canadian ensemble guidance along with favorably supporting
guidance from the 13 UTC National Blend of Models.

...Weather/Hazards Highlights...

Heavy rainfall may impact portions of the Southeast Coast thanks
to a compact low under a closed weakness aloft. NHC is monitorring
development sub-tropical potential of this feature. Deepest
moisture
may stay offshore and uncertainty is high, but there is a chance
of some heavier rainfall along the coast. Accordingly, a Marginal
Risk of excessive rainfall shifts Thursday into Friday from far
northern Florida up through the coastal Carolinas as the low lifts
slowly up the coast in warm and moist Gulf Stream waters.

Numerous Showers and thunderstorms will focus along a slow-moving
and wavy front that will stretch from the Northeast and Ohio Valley
states down to the southern Plains. Gulf moisture pooling over the
region and shortwave/jet support will help prime the environment
for embedded heavy rain potential. Slow translation and deep
moisture could lead into some locally quite heavy totals, but local
focus details are proving quite varied in guidance from run to
run. Accordingly, a Day4/Thursday and Day 5/Friday WPC Marginal
Risk area for excessive rainfall and flash flooding remains
depicted for this region, with a smaller and less certain Slight
Risk area focused over Oklahoma for Friday. The southern trailing
tail of the elongated boundary will stall over the southern Plains,
eventually with baroclinicity rejuvenated more broadly again over
the central U.S. by ample northern stream system reinforcement that
may also act to spread main heavy rainfall focus across the Mid-
South and Tennessee Valley.

Meanwhile, enhanced rain and thuinderstorms will also spread
across the Northeast late week and the weekend as the northern
portion of the front advances, eventually shifting southward
through the Mid-Atlantic toward the Southeast later weekend into
next Monday.

Initially, below normal temperatures will be in place across the
Rockies and Plains on the backside of the frontal boundary. As the
frontal progresses, temperatures will begin to moderate by the end
of the week and into the weekend. Some of the warmest year to date
temperatures will be across much of the Eastern U.S. With daily
readings climbing into the upper 80s to lower 90s there will be a
Moderate level of HeatRisk. Care should be taken to protect
yourself from 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.

Schichtel/Campbell


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