444
FXUS06 KWBC 141902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Wed May 14 2025

6-10 DAY OUTLOOK FOR MAY 20 - 24 2025

Today`s model solutions are in good agreement on the predicted 500-hPa
circulation pattern across North America and surrounding regions during the
6-10 day period. The manual 500-hPa height blend is based primarily on the
ensemble means from the GEFS, ECMWF and Canadian models due to recent model
skill. The resultant manual blend features above-normal heights over the
Eastern Pacific extending eastward to the west coast of the Contiguous United
States (CONUS). A mid-level trough is forecast over the north-central CONUS,
while a ridge and above-normal 500-hPa heights are predicted across the
southeastern CONUS. Weak troughing is also forecast across Mainland Alaska,
extending into Southeast Alaska, while an amplified ridge and above-normal
500-hPa heights are forecast upstream over the Bering Sea, the Aleutians and
southwestern Mainland Alaska. Slightly below-normal  500-hPa heights are
predicted across Hawaii.

Below-normal temperatures are favored over most of the northern CONUS with
below-normal heights stretched across most of the Northern Tier. Probabilities
of below-normal temperatures exceed 60% for portions of the Northeast.
Above-normal temperatures are favored over parts of the southwestern CONUS and
for the southern CONUS east of the Rockies, under positive 500-hPa height
anomalies. Chances of above-normal temperatures increase from north to south,
exceeding 70% in southern Texas and portions of the Florida Peninsula. Under
predicted negative 500-hPa height anomalies, below-normal temperatures are
likely over northern Alaska and Southeast Alaska, while slightly enhanced
above-normal temperature probabilities are favored for parts of the
southwestern Mainland Alaska, consistent with the reforecast consolidation
temperature tool. Above-normal temperatures are likely for Hawaii, with
positive sea surface temperature anomalies surrounding the Islands.

Above-normal precipitation is slightly favored for much of the central and
eastern CONUS, ahead of predicted troughing and due to enhanced Gulf moisture
inflow. Near- to below-normal precipitation is favored across much of the
western CONUS with amplified ridging upstream over the Eastern Pacific, as well
as the Florida Peninsula where surface high pressure is favored. Above-normal
precipitation is favored for most of Alaska, with a predicted trough, supported
by most of the dynamical precipitation forecast tools. Precipitation
consolidation tool forecasts favor above-normal precipitation 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. Good
agreement among the dynamical and statistical tools is offset by a progressive
pattern.


8-14 DAY OUTLOOK FOR MAY 22 - 28 2025

Ensemble mean solutions for the 8-14 day period predict a fairly consistent
500-hPa circulation pattern relative to the 6-10 day period across North
America and the surrounding regions. Ensemble mean solutions for the 8-14 day
period predict mid-level ridging and above-normal 500-hPa heights over the
western and central CONUS, while a mid-level trough and below-normal 500-hPa
heights are forecast over the eastern CONUS. Weak troughing continues over
northern Mainland Alaska and Southeast Alaska, with an amplified ridge upstream
over the Bering Sea, the Aleutians, and parts of southwestern Mainland Alaska.
Generally near- to slightly below-normal 500-hPa heights are forecast for
Hawaii, well to the south of a mean ridge forecast across the eastern Pacific.

Above-normal temperatures continue to be favored across most of the western
CONUS, parts of the Southern Plains, and the Florida Peninsula in the week-2
period, under ridging and positive 500-hPa height anomalies. Probabilities of
above-normal temperatures exceed 60% for portions of the southwestern CONUS,
where positive height anomalies are greatest. Below-normal temperatures are
favored for most of the eastern CONUS under persistent troughing. Above-normal
temperatures are favored for portions of southern Alaska, while enhanced
below-normal temperature probabilities are indicated over much of northern
Alaska and Southeast Alaska, consistent with most of the dynamical temperature
forecast tools. Above-normal temperatures are favored to persist across Hawaii
during week-2 by dynamical models.

Near- to above-normal precipitation is slightly favored for much of the
Northeast and Mid-Atlantic and parts of the Southern Plains and southern
Rockies, supported by most dynamical model precipitation forecast tools. Near-
to below-normal precipitation is slightly favored over the western CONUS
extending eastward to the Upper and Middle Mississippi Valley as well as the
Florida Peninsula, under mean positive 500-hPa height anomalies. Above-normal
precipitation is favored for most Alaska under persistent troughing, while
near-normal precipitation is favored over the western Aleutians. Above-normal
precipitation is favored for Hawaii during the week-2 period, consistent with
skill weighted calibrated precipitation amounts calculated from the GEFS and
ECMWF ensembles.

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: Above average, 4 out of 5. Good
agreement among the temperature and precipitation dynamical and statistical
tools is offset by differences in ensemble mean 500-hPa height anomalies.


FORECASTER: Luke H

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 May
15.


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:
19570424 - 19910527 - 19590507 - 19720517 - 19880503


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:
19570423 - 19910526 - 19620514 - 19590506 - 19740423


6-10 DAY OUTLOOK TABLE
Outlook for May 20 - 24 2025

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



8-14 DAY OUTLOOK TABLE
Outlook for May 22 - 28 2025

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

$$