800
FXUS06 KWBC 111902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Tue March 11 2025

6-10 DAY OUTLOOK FOR MAR 17 - 21 2025

Dynamical model forecasts from the 0z ECENS, GEFS, and CMCE are in good
agreement regarding the 500-hPa height pattern across North America during the
6-10 day period. Troughing and an associated robust surface cyclone are
forecast to be exiting the East Coast at the outset of the period, with
transient ridging building in behind this system. Troughing is forecast over
Alaska, with another shortwave trough forecast to progress across the CONUS
during the 6-10 day period, reaching the eastern U.S. by the end of the period,
and displacing the aforementioned ridge. The 0z GEFS depicts troughing
reloading near the West Coast at the end of the period, with the 0z ECENS and
CMCE keeping the trough further north across Alaska, and depicting above-normal
heights building near the West Coast by day-10. The manual height blend depicts
below-normal 500-hPa heights across Alaska and much of the western and
north-central CONUS. Above-normal heights are favored across the south-central
and eastern CONUS.

Elevated probabilities of above-normal temperatures are forecast across much of
the central and eastern CONUS, with the highest chances across the Northeast
(greater than 70 percent). A brief period of near- to below-normal temperatures
are possible in the East behind the departing storm system at the outset of the
period, with above-normal temperatures likely returning later in the period.
Parts of the Southeast are forecast to flip between weakly positive and
negative temperature anomalies throughout the period supporting near-normal
temperatures for the period as a whole. Troughing progressing through the West
favors increased probabilities for below-normal temperatures across the region.
As this feature moves further to the East, increasing downslope flow favors a
tilt toward elevated above-normal temperatures chances across the Northern
Rockies and Northern High Plains supported by the GEFS and ECENS reforecast
tools. Enhanced southerly flow across eastern Alaska favors increased
probabilities of near- to above-normal temperatures across eastern Mainland and
Southeast Alaska. Below-normal temperature chances are increased over western
and northern Alaska underneath stronger negative mid-level height anomalies.
Above-normal temperatures are forecast across Hawaii, supported by the
temperature consolidation tool.

Above-normal precipitation probabilities are increased for much of the western
CONUS tied to troughing forecast to move through the region. As this trough
shifts farther east, a surface low is forecast to eject out to the Rockies.
While this system is not expected to be as strong as the preceding system in
week-1, chances of above-normal precipitation are increased across northern and
eastern parts of the CONUS. Below-normal precipitation probabilities are
increased across portions of the south-central states and Gulf Coast which are
forecast to be far enough displaced from the system. Above-normal precipitation
is forecast for much of Mainland and Southeast Alaska due to enhanced southerly
flow and consistent with the GEFS and ECENS reforecast tools. Above-normal
precipitation is favored for Hawaii.

The official 6-10 day 500-hPa height blend consists of 30% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 40% 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 models, offset by some uncertainty in the
mid-level height pattern toward the end of the period across the West

8-14 DAY OUTLOOK FOR MAR 19 - 25 2025

The 500-hPa height forecasts from the 0z ECENS, GEFS, and CMCE depict troughing
across the interior western and central CONUS, with ridging on either side of
this trough. There is some uncertainty regarding the progression and placement
of these features as the 0z ECENS and CMCE depict a weaker trough moving into
the Midwest, allowing heights to increase across the West Coast but decrease in
the East. On the other hand, the 0z GEFS depicts a slower and stronger trough
across the west-central CONUS, resulting in lower heights across the West, but
with a stronger ridge axis downstream of the trough near the Eastern Seaboard.
The manual height blend for week-2 depicts below-normal heights continuing
across Alaska. Near- to slightly above-normal heights are forecast near the
West Coast of the CONUS. Below-normal heights are forecast across the interior
western and much of the central CONUS, with above-normal heights favored over
the eastern third of the CONUS and along the Gulf Coast.

Uncertainty in the mid-level height pattern evolution translates to the
surface, particularly over the western CONUS where the ECENS reforecast tool
persists higher probabilities of below-normal temperatures, but with
near-normal temperatures depicted in the GEFS reforeast tool. Below-normal
temperature probabilities remain elevated across the West in todays forecast
to maintain some continuity with yesterday and supported by the colder
uncalibrated guidance, although probabilities are reduced below 50 percent.
Above-normal temperature chances are increased over much of the central and
eastern CONUS, although probabilities are slightly reduced compared to the 6-10
day period. While transient cooling episodes are possible, especially early,
MJO propagation across the Indian Ocean supports warming temperatures in the
East later in week-2 and into week-3. Above-normal temperature chances are
increased for most of eastern Mainland and Southeast Alaska underneath
anomalous southerly flow. Below-normal temperatures are favored for parts of
western Mainland Alaska, underneath the stronger negative 500-hPa height
anomalies. High probabilities for above-normal temperatures continue to be
forecast for Hawaii in week-2, consistent with the temperature consolidation
tool.

There is less confidence in the week-2 precipitation forecast across the
western CONUS due to the aforementioned model differences regarding the
evolution of troughing. The best agreement is across the Pacific Northwest
where above-normal precipitation probabilities continue to be elevated. The
ECENS and CMCE are notably drier across the Southwest compared to the GEFS due
to the more expansive ridge, with the discrepancy favoring a near-normal
forecast. Above-normal precipitation chances are enhanced over most of the
eastern CONUS in week-2, tied to surface low pressure across the Great Plains
and Midwest early in the period followed by another potential system across the
Southeast later in the period. Above-normal precipitation is favored across
southern Mainland Alaska and Southeast Alaska, consistent with the GEFS and
ECENS reforecast tools. Near-normal precipitation is favored across Hawaii.

The official 8-14 day 500-hPa height blend consists of: 30% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 40% 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: Average, 3 out of 5, due to fair
agreement among the dynamical models, with uncertainty in the exact placement
of mid-level features and decreasing amplification.

FORECASTER: Thomas Collow

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:
19560228 - 20070219 - 19800310 - 19760221 - 19770322


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:
19560228 - 19760220 - 20070219 - 19800309 - 19640227


6-10 DAY OUTLOOK TABLE
Outlook for Mar 17 - 21 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   N    A     E MONTANA   N    A     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A
NEW MEXICO  B    A     N DAKOTA    N    N     S DAKOTA    A    A
NEBRASKA    A    A     KANSAS      A    N     OKLAHOMA    A    B
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   N    A     IOWA        A    A     MISSOURI    A    N
ARKANSAS    A    B     LOUISIANA   N    B     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI N    B     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     N    N     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    N
MARYLAND    A    N     DELAWARE    A    A     VIRGINIA    A    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     N    N
FL PNHDL    N    B     FL PENIN    N    N     AK N SLOPE  B    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 19 - 25 2025

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   B    N     IDAHO       B    A     NEVADA      B    A
W MONTANA   A    A     E MONTANA   A    N     WYOMING     N    A
UTAH        B    A     ARIZONA     B    N     COLORADO    B    A
NEW MEXICO  B    N     N DAKOTA    A    N     S DAKOTA    A    A
NEBRASKA    N    A     KANSAS      N    N     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    B     W TEXAS     N    B
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    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  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.

$$