583
FXUS06 KWBC 101944
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon March 10 2025

6-10 DAY OUTLOOK FOR MAR 16 - 20 2025

There is good agreement between the latest ECMWF, GEFS, and Canadian ensemble
mean 500-hPa height forecasts on the predicted circulation pattern across North
America for the 6-10 day period. All ensemble models forecast a broad trough
and associated negative 500-hPa height anomalies that extend from eastern
Siberia across Alaska. Negative 500-hPa height anomalies are also forecast
across most of western and central Canada and the western and central
Contiguous U.S. (CONUS) by all ensemble models. Troughs are predicted to
progress eastward into the Pacific coast and over the Midwest, early in the
period. A ridge and associated positive 500-hPa height anomalies are predicted
over the southeastern and eastern CONUS into eastern Quebec and Atlantic
Canada. The GEFS ensemble mean predicts negative 500-hPa height anomalies
further east into the Central Plains, relative to the ECMWF ensemble mean
solution.

The 6-10 day temperature outlook favors above normal temperatures for the
Alaska Peninsula and southern Mainland Alaska, consistent with a consensus of
dynamical model forecasts. Below normal temperatures are very likely for much
of the western CONUS, under a predicted trough and anomalous northerly flow.
Below normal temperatures are favored for parts of the Northern Plains,
associated with anomalous northerly flow behind a predicted trough axis over
Canada. Above normal temperatures are likely across the south-central and
eastern CONUS, under positive 500-hPa height anomalies. There is increased
uncertainty on the temperature forecast for the Central Plains, where the GEFS
and ECMWF temperature forecasts disagree. High probabilities for above normal
temperatures are forecast for Hawaii, in part due to positive sea surface
temperature anomalies surrounding the islands.

The 6-10 day precipitation outlook favors above normal precipitation for the
eastern Aleutians, southern Mainland Alaska, and Southeast Alaska, ahead of a
predicted trough and consistent with dynamical model forecasts. Above normal
precipitation is likely for much of the western CONUS, ahead of a predicted
trough. Above normal precipitation is favored across much of the remainder of
the CONUS, excluding the Southern Plains, consistent with dynamical model
tools. Across the eastern CONUS, above normal precipitation is most likely from
the Tennessee Valley into the eastern Great Lakes region, as significant
precipitation is forecast early in the 6-10 day period. Below normal
precipitation is favored for the Southern Plains, consistent with the dynamical
model precipitation tools. Above normal precipitation is favored for the
islands of Hawaii, partly due to above average sea surface temperatures.

The official 6-10 day 500-hPa height blend consists of 35% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 35% of Today`s 0z European Ensemble Mean
centered on Day 8, and 30% 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, due to
good agreement among the dynamical model height forecasts and among the
precipitation and temperature forecast tools, offset by some areas of
disagreement and evolution of the pattern during the period.

8-14 DAY OUTLOOK FOR MAR 18 - 24 2025

Dynamical model 500-hPa height forecasts from the ECMWF, GEFS, and Canadian
ensemble means continue to be in fairly good agreement on the week-2
circulation pattern, with increasing uncertainty as large-scale anomalies
deamplify in week-2. An area of positive 500-hPa height anomalies shifts
eastward into the west coast of the CONUS during the week-2 period. A broad
trough and negative 500-hPa height anomalies continue to the west of and over
Mainland Alaska. A trough and negative 500-hPa height anomalies are predicted
over most of Canada in the week-2 period, with an extension southwestward into
the Northern Plains and the interior West. Positive 500-hPa height anomalies
are predicted from the south-central CONUS across the eastern CONUS in week-2,
by all ensemble mean forecasts.

Below normal temperatures are favored for parts of western Mainland Alaska,
under the stronger negative 500-hPa height anomalies. Above normal temperatures
are favored for most of eastern Mainland Alaska and northern areas of the
Alaska Panhandle, under anomalous southerly flow. Below normal temperatures
continue to be favored for the western CONUS in the 8-14 day period, under a
trough and negative 500-hPa height anomalies. However, probabilities for below
normal temperatures decrease substantially from the 6-10 day period forecast,
as the trough deamplifies over the West. Above normal temperatures are favored
from the Southern Plains extending northeastward into the Great Lakes region
and over the remainder of the eastern CONUS, under anomalous southerly flow and
consistent with most dynamical model tools. Above normal temperatures are
slightly favored over a small area in eastern Montana, consistent with most
dynamical model forecasts and rising mid-level heights. High probabilities for
above normal temperatures continue to be forecast for Hawaii in week-2,
consistent with the temperature consolidation.

Above normal precipitation is favored across southern Mainland Alaska and
Southeast Alaska, consistent with dynamical model forecasts. Uncertainty
increases in the week-2 precipitation forecast over the CONUS, as the pattern
becomes less amplified during the period. Above normal precipitation continues
to be favored for parts of the Pacific Northwest, consistent with most
dynamical model forecast tools, and across a large area of the southwestern
CONUS northeastward to the Central Rockies and Central High Plains, under a
predicted trough and negative 500-hPa height anomalies. Below normal
precipitation is slightly favored over parts of the Southern Plains, consistent
with dynamical model forecast tools. Above normal precipitation is slightly
favored over most of the eastern CONUS in week-2, consistent with most
dynamical model tools including the precipitation consolidation. However, below
normal precipitation is slightly favored for the southern Florida Peninsula,
consistent with the precipitation consolidation. Above normal precipitation is
slightly favored for northwestern islands of Hawaii, consistent with the
precipitation consolidation.

The official 8-14 day 500-hPa height blend consists of: 35% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 35% of Today`s 0z European Ensemble Mean
centered on Day 11, and 30% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5, due to
good agreement among the mean dynamical model height forecasts and surface
tools for most areas, offset by weaker signals and an evolving pattern.

FORECASTER: D Collins

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
March 20.


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:
20070218 - 19560228 - 19530226 - 19770322 - 19640226


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:
20070219 - 19670227 - 19590222 - 19530308 - 19760220


6-10 DAY OUTLOOK TABLE
Outlook for Mar 16 - 20 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   B    A     IDAHO       B    A     NEVADA      B    A
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    N    A     KANSAS      N    N     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   B    A     IOWA        N    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    N     WISCONSIN   N    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    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    A
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    N     AK N SLOPE  N    N
AK ALEUTIAN N    A     AK WESTERN  N    A     AK INT BSN  N    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    N    A



8-14 DAY OUTLOOK TABLE
Outlook for Mar 18 - 24 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    N
SRN CALIF   B    A     IDAHO       B    N     NEVADA      B    N
W MONTANA   N    N     E MONTANA   A    N     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    N    N     S DAKOTA    N    N
NEBRASKA    N    N     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    N     W TEXAS     N    N
MINNESOTA   N    N     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    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    A
MASS        A    A     CONN        A    A     RHODE IS    A    N
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    N     VIRGINIA    A    A
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    A
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  B    N
AK ALEUTIAN N    A     AK WESTERN  B    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A

                           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.

$$