674
FXUS06 KWBC 272012
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EST Thu February 27 2025

6-10 DAY OUTLOOK FOR MAR 05 - 09 2025

There is better agreement today among the GEFS, ECMWF, and CMCE depictions of
500-hPa height anomalies during the extended range forecast period, with less
spread regarding to the amplitude, location, and phase speed of shortwave
troughs imbedded in the larger flow. The mean 500-hPa manual height blend
consists of the ensemble means from the ECMWF, GEFS, and Canadian model. The
resultant pattern depicts below normal heights across most of the CONUS and
western Alaska. An amplified ridge is favored over the Alaska/Canada border and
above normal heights are forecast over Hawaii while near normal heights are
depicted for the Gulf Coast Region. A notable change toward increased below
normal heights is noted across the eastern CONUS and western Alaska relative to
yesterdays manual blend.

Above normal temperatures are likely across most of Alaska, due to anomalous
ridging forecast over the eastern Mainland. Conversely, shortwave troughs
associated with an active southern stream enhances probabilities of below
normal temperatures across California, as well as portions of the southern
Great Basin and Central Rockies. Above normal temperatures are favored for much
of the Great Plains due to predicted transient ridging. A significant swing
from positive to negative temperature anomalies is depicted east of the
Mississippi River during the 6-10 day period, mostly cancelling each other out
over the whole period, resulting in near normal temperature favored for the
eastern CONUS. Predicted above normal mid-level heights and anticipated above
normal Sea Surface Temperatures (SSTs) lead to elevated probabilities of above
normal temperatures across Hawaii.

An active pattern is anticipated across much of the country as multiple low
pressure systems are expected at various locations during the period. Above
normal precipitation is favored for most of Alaska, especially across the Kenai
Peninsula and adjacent areas, due to predicted onshore flow ahead of a mean
trough centered over the Alaska Peninsula. An active period is expected for
much of the western CONUS as one southern stream trough exits the Southwest
early in the period only to be replaced by another trough approaching the West
Coast later. Due to this anticipated active pattern, above normal precipitation
is favored for most of the western half of the CONUS, particularly for
California and adjacent areas of Nevada. The initial southern stream trough is
forecast to progress eastward across the country, drawing ample Gulf moisture
northward, leading to increased probabilities for above normal precipitation
for the eastern quarter of the CONUS as well. Confidence for increased
precipitation amounts is highest over portions of New England as surface low
pressure shifts over the northeastern CONUS. A tilt toward below normal
precipitation is indicated for much of the Great Plains due to potential
mid-level ridge development later in the period. Hawaii tilts slightly towards
above normal precipitation, consistent with the Hawaii CON.

The official 6-10 day 500-hPa height blend consists of 33% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 34% of Today`s 0z European Ensemble Mean
centered on Day 8, and 33% of Today`s 0z Canadian Ensemble Mean centered on Day
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: About average, 3 out of 5, due to
good agreement among the forecast tools with regard to temperature and
precipitation, offset by a very progressive synoptic pattern.

8-14 DAY OUTLOOK FOR MAR 07 - 13 2025

Similar to the 6-10 day period models have come into better agreement on the
overall synoptic pattern and evolutions, and once again an active pattern with
a series of disturbances moving over the CONUS results in a large swing in
temperatures and a couple rounds of precipitation for the eastern CONUS during
the 8-14 day period. Some transient ridging is favored over the central CONUS
during the middle of the period but overall the mean pattern features below
normal heights across most of the country. Ridging east of Alaska is also
favored to give way to negative height anomalies while ridging builds over the
North Pacific and well off the East Coast.

Due to the complex transitional pattern expected, near normal temperatures are
favored for most of the eastern CONUS, with the exception of New England where
a slight tilt towards below normal temperatures is indicated, located near the
center of the favored troughing. With the ridging over western Canada during
the 6-10 day period subsiding and giving way to negative 500-hPa height
anomalies, a significant shift is featured for Alaska with below normal
temperatures favored for northern and western portions of the state, while near
normal temperatures are favored for the rest of the state. Below normal
temperatures are also favored for much of the western third of the CONUS as a
trough overspreads the area during the middle and latter parts of the period.
Enhanced probabilities of above normal temperatures are indicated across much
of the Great Plains and Mississippi Valley due to predicted transient ridging
near the middle of the period, with probabilities increasing from north to
south. Above normal temperatures are likely for Hawaii due in large part to
anticipated above normal SSTs across adjacent waters.

An active pattern is anticipated to continue across much of the country during
week-2. As a trough approaches and eventually overspreads the West Coast of the
CONUS, increased onshore flow and instability are likely. Therefore, chances of
above normal precipitation are elevated for most of the western third of the
CONUS. Probabilities of above normal precipitation exceed 50 percent across
most of the West Coast and adjacent areas where advection of Pacific moisture
may be most pronounced. A tilt toward above normal precipitation is also
indicated for the eastern third of the CONUS due primarily to a departing
surface low early in the period and the potential for an additional round of
precipitation toward the end of the period. Below normal precipitation is
slightly favored for parts of the Southern Plains. Onshore flow is expected to
weaken over much of Alaska during the second half of the week-2 period,
resulting in only modestly enhanced probabilities of above normal precipitation
for southeastern Alaska, and near normal precipitation favored for the rest of
the state. Above normal precipitation is slightly favored for most of western
Hawaii, with near normal precipitation favored for the Big Island and most of
Maui , consistent with a consolidation of calibrated precipitation output from
the ECMWF and GEFS ensembles.

The official 8-14 day 500-hPa height blend consists of: 33% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 34% of Today`s 0z European Ensemble Mean
centered on Day 11, and 33% 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 forecast tools with regard to temperature and
precipitation, offset by a very progressive synoptic pattern.

FORECASTER: Daniel Barandiaran

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:
20040217 - 19580223 - 19700217 - 19860307 - 19970215


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:
20040216 - 19860307 - 19700218 - 19800223 - 19580223


6-10 DAY OUTLOOK TABLE
Outlook for Mar 05 - 09 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for Mar 07 - 13 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   N    N     WYOMING     B    A
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A
NEW MEXICO  A    A     N DAKOTA    A    N     S DAKOTA    A    N
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    N     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    N
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   N    N
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    N    A
INDIANA     N    A     OHIO        N    A     KENTUCKY    N    A
TENNESSEE   N    A     ALABAMA     N    A     NEW YORK    N    A
VERMONT     B    A     NEW HAMP    B    A     MAINE       B    A
MASS        N    A     CONN        N    A     RHODE IS    N    A
PENN        N    A     NEW JERSEY  N    A     W VIRGINIA  N    A
MARYLAND    N    A     DELAWARE    N    A     VIRGINIA    N    A
N CAROLINA  N    A     S CAROLINA  N    A     GEORGIA     N    A
FL PNHDL    N    A     FL PENIN    N    A     AK N SLOPE  B    N
AK ALEUTIAN N    A     AK WESTERN  B    N     AK INT BSN  N    N
AK S INT    N    A     AK SO COAST N    A     AK PNHDL    N    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.

$$