387
FXUS06 KWBC 051910
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Thu June 05 2025

6-10 DAY OUTLOOK FOR JUN 11 - 15 2025

Today`s ensemble mean solutions depict a transitional pattern underway across
much of the nation as the 6-10 Day period begins. Moderately strong mid-level
ridging is shifting out of the Northwest and toward the northeastern Contiguous
States (CONUS) at this time, only to retrograde by the end of the period,
establishing a ridge over central North America. This is in response to a
digging mid-level trough pushing toward the northwestern CONUS. This feature is
considerably stronger than depicted by most models yesterday, with the manual
500-hPa blend depicting a mean 500-hPa height anomaly near -60 m just off the
Washington coast (height forecasts were near to slightly above normal
yesterday). 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 +180 m) just south of the eastern Aleutians. Other changes from
yesterday include higher 500-hPa heights expected across central Canada, and
less of a mean mid-level trough between the positive height anomaly centered
over the north-central CONUS and another in the northwestern North Atlantic.
However, both the location and strength of these last two features oscillate as
the central North American mid-level ridge retrogrades, and lack of consensus
on the details of these transitions increase forecast uncertainty.

Above normal temperatures are favored from the Intermountain West eastward
across the central and northern Plains, the Great Lakes, and the Northeast in
association with mid-level ridging affecting these areas for at least part of
the 6-10 day period. With a weaker mean mid-level trough over the Great Lakes
and Ohio Valley, enhanced chances for warmer than normal conditions stretch
across these areas today, in contrast to yesterdays forecast. The greatest
odds for above-normal temperatures (over 60 percent) stretch from the central
Rockies into the northern Plains, near the maximum positive 500-hPa height
anomalies. Meanwhile, a preponderance of the temperature tools derived from the
ensembles somewhat favors above-normal temperatures along the East Coast and
over most of the Gulf Coast. Meanwhile, the mid-level trough digging into or
just west of the Northwest implies a forecast favoring below-normal
temperatures along portions of the West Coast, especially the Pacific
Northwest. This signal is stronger and farther east than depicted yesterday due
to the stronger-looking mid-level trough encroaching on the region, and the
downstream above-normal mid-level heights starting the period slightly farther
east. Across Alaska, there are considerable discrepancies between the raw and
bias-corrected ensemble temperature output favoring subnormal temperatures over
most of the state, and the reforecast and calibrated tools showing a much
warmer solution. Based on the mid-level height pattern and recent trends,
near-normal temperatures seem most likely across much of the state. Unusually
warm weather is favored over part of the southwestern Mainland and the
Aleutians (near the largest positive mean 500-hPa height anomalies) while
subnormal temperatures seem most likely in west-central sections (upstream from
the mid-level ridge axis).  Above normal temperatures are favored for Hawaii
associated with warmer than normal sea surface temperatures in the adjacent
Pacific.

An active pattern is anticipated across much of the CONUS in conjunction with
mid-level features progressing eastward, then retrograding somewhat. Unusually
wet weather is favored over a large part of the Northwest, Rockies and
Intermountain West, Plains, and southeastern CONUS. Low-level flow should bring
tropical moisture into the south-central and southeastern CONUS. The best odds
for wetter than normal weather cover the Lower Mississippi Valley and western
half of the Gulf Coast region, where the general tool consensus places the best
chances for interaction between the tropical moisture inflow and a weak,
wavering frontal system. Meanwhile, downstream from the mean mid-level ridge
position, near- or below-normal precipitation is favored under anticyclonic
mid-level flow across portions of the Ohio Valley and the Northeast.
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 22% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 20% of Today`s 0z European Ensemble Mean
centered on Day 8, 40% of Today`s operational 0z ECMWF centered on Day 8, and
18% of Today`s 0z Canadian Ensemble Mean centered on Day 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Average, 3 out of 5, with decent
agreement among the tools on the mean mid-level pattern, tempered by less
consensus in the day-to-day evolution of individual features and areas of
disagreement among the disparate temperature and precipitation tools derived
from the ensembles.

8-14 DAY OUTLOOK FOR JUN 13 - 19 2025

The week-2 500-hPa pattern features a less transitional pattern, with the
mid-level features settling into more stationary positions. There is decent
agreement on the locations of the main mid-level features. A mid-level ridge
south of Alaska should persist with a ridge 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 over the northern Plains. The
eastward extent of this mean ridge is uncertain, with the Canadian ensemble
mean stretching above-normal heights robustly into the northeastern CONUS while
the GEFS and European ensemble mean keep heights a bit lower in this region,
though still a little above normal. The majority solution is favored, but the
solution from the Canadian ensemble mean cant be discounted. The manual
500-hPa height blend favored the GEFS and European ensemble mean, but some
weight was also given to the Canadian ensemble mean.

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 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 and northern Rockies into portions of the northern
Plains. Enhanced chances for subnormal temperatures in the CONUS are limited to
the West Coast region, near the axis of the persistent but weakening 500-hPa
trough. Upstream, temperature tools are still inconsistent across Alaska, but a
preponderance of the guidance and the location of mid-level features would
favor warmer than normal weather slightly in southern and eastern parts of the
state while below-normal temperatures hang on along the western tier. Increased
sea surface temperatures and the consolidation forecast both favor 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. 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 the mid-Atlantic region. Above-normal precipitation is also
favored from the Northwest into portions of the northern Plains, downstream
from the moderating mid-level trough along the West Coast. Over the rest of the
CONUS, the precipitation tools from the ensembles exhibit a lot of uncertainty,
which is reflected in the near-normal forecasts there. Southeastern Alaska
remains upstream from the persistent 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: 35% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 40% of Today`s 0z European Ensemble Mean
centered on Day 11, and 25% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Average, 3 out of 5, with good
agreement on the mean mid-level pattern west of the Appalachians tempered by
the inherent uncertainty associated with weak surface features, along with
disparity 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:
19980612 - 19990530 - 19510617 - 19780616 - 20000616


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:
19990530 - 19980612 - 20000617 - 19510617 - 19780618


6-10 DAY OUTLOOK TABLE
Outlook for Jun 11 - 15 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Jun 13 - 19 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    N
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    N
UTAH        A    N     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     A    A     W TEXAS     A    N
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    N
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    N
ILLINOIS    A    N     MISSISSIPPI A    A     MICHIGAN    A    N
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    N
VERMONT     N    N     NEW HAMP    N    N     MAINE       N    N
MASS        N    N     CONN        N    N     RHODE IS    N    N
PENN        A    N     NEW JERSEY  A    N     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  N    A
AK ALEUTIAN A    N     AK WESTERN  N    A     AK INT BSN  N    N
AK S INT    A    N     AK SO COAST A    N     AK PNHDL    N    B

                           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.

$$