561
FXUS06 KWBC 061901
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Fri June 06 2025

6-10 DAY OUTLOOK FOR JUN 12 - 16 2025

Today`s ensemble mean solutions are similar to yesterday, with a transitional
pattern underway early in the period that settles into a stable pattern for the
last half of the period. Moderate mid-level ridging with an axis extending from
the Upper Midwest into the northeastern Contiguous States (CONUS) retrograding
by the middle of the period, establishing a ridge axis over central North
America with peak mean 500-hPa height anomalies (above +60 m) reaching from the
northern Great Plains and Upper Mississippi Valley into the central
Appalachians. The mid-level ridge retrogression is in response to a digging
mid-level trough dropping slowly from southeastern Alaska toward the
northwestern CONUS. Models are slightly weaker with this feature than
yesterday, but placement of the trough axis is nearly identical, and the
location of a closed 558 dam contour at 500 hPa is essentially unchanged from
yesterday, over far southeastern Alaska and adjacent Canada. Upstream, a strong
mid-level ridge is expected to persist across the central North Pacific and
Mainland Alaska, with a mean height anomaly maximum (near +150 m) just south of
the eastern Aleutians. Todays manual 500-hPa height field is very similar to
yesterday, with some subtle differences in the magnitude of individual
features, but almost identical placement.

Above normal temperatures are favored from the Intermountain West eastward
across the central and northern Plains, the Great Lakes, the lower Northeast,
and the mid-Atlantic region in association with the mid-level ridging affecting
these areas. With positive 500-hPa height anomalies stretching a bit farther
east than yesterday, the greatest odds for above-normal temperatures (over 60
percent) similarly stretch from the central Rockies into portions of the
central and northern Plains and the Middle and Upper Mississippi Valley. Odds
exceeding 50 percent reach farther east across much of the Great Lakes, Ohio
Valley, and mid-Atlantic region. Meanwhile, a preponderance of the temperature
tools derived from the ensembles somewhat favors above-normal temperatures for
most other locations along the Atlantic Seaboard in addition to the Southeast,
the Gulf Coast region, and the Lower Mississippi Valley. However, confidence
here is tempered because constructed analogs based on the various ensemble mean
solutions are much cooler in the Southeast and Gulf Coast region. Farther west,
the mid-level trough digging toward the northwestern CONUS favors below-normal
temperatures along portions of the West Coast, especially western sections of
the Pacific Northwest. Across Alaska, considerable discrepancies continue among
the various raw and derived temperature tools based on the ensembles, with raw
and bias-corrected output much cooler than the reforecast and calibrated tools.
The official outlook is more in concert with the above-normal 500-hPa heights
across the southern tier of the state, favoring above-normal temperatures
across most of the Mainland, with near-normal temperatures favored near the
Bering Sea. Above-normal temperatures are favored for Hawaii associated with
warmer than normal sea surface temperatures in the adjacent Pacific, and
nominal increases in 500-hPa heights.

An active pattern is anticipated across much of the CONUS in conjunction with
mid-level features progressing eastward slightly, then retrograding. Unusually
wet weather is favored over a large part of the Northwest, Rockies and
Intermountain West, Plains, and eastern CONUS. Low-level flow should bring
tropical moisture into the south-central and southeastern CONUS, which will
interact at times with a wavering but persistent quasi-stationary front draped
from southern Texas into the Southeast. This significantly enhances the
likelihood of above-normal precipitation to over 50 percent from the western
Gulf Coast region to the Lower Mississippi Valley. Meanwhile, downstream from
the mean mid-level ridge position, precipitation should be closer to normal
across New England under anticyclonic mid-level flow. Near-normal precipitation
is also favored for much of California and the Southwest where this is a
climatologically dry time of year. Across Alaska, southeastern areas just
upstream from the mid-level trough should average drier than normal while
portions of the western and northern Mainland - north and west of the ridge
axis - should experience wetter than normal conditions under
cyclonically-curved mid-level flow. Above normal precipitation is slightly
favored for Hawaii with a weak trough potentially impacting the state.

The official 6-10 day 500-hPa height blend consists of 26% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 37% of Today`s 0z European Ensemble Mean
centered on Day 8, 22% of Today`s operational 0z ECMWF centered on Day 8, and
15% of Today`s 0z Canadian Ensemble Mean centered on Day 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, with
decent agreement among the tools on the mean mid-level pattern and in the
day-to-day evolution of individual features, tempered by areas of significant
disagreement among the disparate temperature and precipitation tools derived
from the ensembles.

8-14 DAY OUTLOOK FOR JUN 14 - 20 2025

The week-2 500-hPa pattern keeps the mid-level features in approximately the
same locations as during the 6-10 day period while slowly deamplifying with
time. In addition to good agreement on the locations of the main mid-level
features, there is decent agreement on the evolution of these features until
late in the period, when uncertainty increases as the ensemble mean forecasts
all flatten out the height field. The positive 500-hPa height anomaly center
south of Alaska should persist with an axis extending northward into the
Mainland. Downstream, week-2 starts with a strong mid-level trough centered
near the northwestern CONUS which is expected to slowly weaken over the course
of the period. The central North American mid-level ridge is expected to move
little, with maximum 500-hPa anomalies centered approximately over the northern
Plains until late week-2, when the tools begin to diverge. The manual 500-hPa
height blend favored the GEFS and European ensemble mean again today, with less
weight given to the Canadian ensemble mean, which is slightly out of step with
the GEFS and European ensemble mean, especially late in the period.

With above-normal 500-hPa heights forecast for most locations from the Rockies
eastward, above-normal temperatures continue to be broadly favored. The only
exceptions are in central and southwestern Texas (consistent with the
consolidation forecast) and in the Northeast (closer to lower mid-level heights
in southeastern Canada). Odds for warmer than normal weather remain above 60
percent from the central Rockies and adjacent areas of the Plains. Enhanced
chances for subnormal temperatures in the CONUS are limited to the West Coast
region near the persistent but weakening 500-hPa trough, and to northern New
England near anomalously low mid-level heights centered near Atlantic Canada.
Upstream, temperature tools are still very inconsistent across Alaska, but a
preponderance of the guidance and the location of mid-level features would
favor warmer than normal weather across most of the state outside the western
and southeastern fringes, where mid-level heights are closer to normal.
Slightly elevated 500-hPa heights and warmer than normal sea surface
temperatures both enhance chances of warmer than normal conditions across
Hawaii.

The flow of low-level tropical moisture into the south-central and southeastern
CONUS is expected to continue through much of week-2, but may weaken later in
the period. Periodically this inflow is expected to interact with a weak but
persistent quasi-stationary frontal boundary, keeping enhanced odds for surplus
precipitation across these areas, as far north as southern New England.
Above-normal precipitation is also favored in the Northwest, downstream from
the moderating mid-level trough just off the West Coast. Over most other parts
of the CONUS,  the precipitation tools from the ensembles exhibit a lot of
uncertainty, which is reflected by forecasts for near-normal conditions or
slightly favoring above-normal amounts. The odds slightly favor drier than
normal conditions in the central Great Basin and adjacent Rockies, consistent
with the consolidation and a preponderance of the raw and adjusted output from
the ensembles. Southeastern Alaska remains upstream from the dissipating West
Coast mid-level trough, resulting in anticyclonic mid-level flow that should
inhibit precipitation. Farther west, upstream from a mid-level ridge axis,
cyclonic mid-level flow enhances the odds for above-normal precipitation over
western and northern Alaska. Enhanced above-normal precipitation probabilities
persist across Hawaii, consistent with the consolidation of calibrated
precipitation amounts from the GEFS and the European ensemble.

The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 7% of Today`s operational 6z GFS centered on
Day 11, 40% of Today`s 0z European Ensemble Mean centered on Day 11, and 23% of
Today`s 0z Canadian Ensemble Mean centered on Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Above average, 4 out of 5, with
good agreement on the mean mid-level pattern and broad deamplification tempered
by the inherent uncertainty associated with weak surface features, and
disparities among the temperature and precipitation tools derived from the
ensembles.

FORECASTER: Rich Tinker

Notes:


Automated forecasts are issued on Saturday and Sunday. Occasionally manual
intervention is necessary to address quality control and consistency issues. In
these cases, forecasts are manually drawn but a full discussion is not issued.


The notation for the categorical forecast indicated on the maps is the same as
that in the tables: A-above   N-near normal   B-below


The temperature map shows regions with > 33% chance of being warmer (orange,
"A"), colder (blue, "B"), or close to (unshaded, "N"). Historical average
values for the calendar period of the forecast (dashes, "f").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


The precipitation map shows regions with > 33% chance of being wetter (green,
"A"), drier (tan, "B"), or close to (unshaded, "n"). Historical median values
for the calendar period of the forecast (dashes, "inches").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


In the southwest and other climatologically dry regions - there will be a
greater than 33.3% chance of no precipitation and occasionally even a normal
(i.e. Median) value of zero - especially during the dry seasons.  In such cases
a forecast of near normal is effectively a forecast of little or no
precipitation.


The climate prediction center uses 1991-2020 base period means as reference in
the climate outlooks.

The next set of long-lead monthly and seasonal outlooks will be released on
June 19.


Analogs to the 5 day mean observed pattern centered 3 days ago (D-3)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 5 day periods centered on the following dates:
19990530 - 19980612 - 19510617 - 19800530 - 19780617


Analogs to the 7 day mean observed pattern centered 4 days ago (D-4)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 7 day periods centered on the following dates:
19990531 - 20000617 - 19900616 - 19780618 - 19980612


6-10 DAY OUTLOOK TABLE
Outlook for Jun 12 - 16 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    N     NRN CALIF   B    N
SRN CALIF   N    N     IDAHO       A    A     NEVADA      A    N
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A
UTAH        A    A     ARIZONA     A    N     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    N    A
N TEXAS     N    A     S TEXAS     A    A     W TEXAS     N    A
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  N    A     AK INT BSN  A    N
AK S INT    A    B     AK SO COAST A    B     AK PNHDL    B    N



8-14 DAY OUTLOOK TABLE
Outlook for Jun 14 - 20 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    N
SRN CALIF   A    N     IDAHO       A    N     NEVADA      A    B
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    N
UTAH        A    B     ARIZONA     A    N     COLORADO    A    N
NEW MEXICO  A    N     N DAKOTA    A    A     S DAKOTA    A    N
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    A     S TEXAS     N    A     W TEXAS     A    N
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    N    A
VERMONT     N    N     NEW HAMP    N    N     MAINE       B    N
MASS        N    A     CONN        N    A     RHODE IS    N    A
PENN        A    A     NEW JERSEY  N    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    N     AK N SLOPE  A    A
AK ALEUTIAN N    A     AK WESTERN  A    A     AK INT BSN  A    N
AK S INT    A    N     AK SO COAST A    B     AK PNHDL    N    N

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$