807
FXUS06 KWBC 281903
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Tue May 28 2024

6-10 DAY OUTLOOK FOR JUN 03 - 07 2024

Today`s model solutions are in good agreement on a moderately amplified 500-hPa
circulation pattern across North America and surrounding regions during the
6-10 day period. The manual 500-hPa height blend is based on the ensemble means
from the GEFS, ECMWF, and Canadian models due to recent model skill. The
resultant manual blend features strong troughing and negative 500-hPa height
anomalies over Alaska and the Gulf of Alaska. Ridging and positive height
anomalies are forecast over the western and central contiguous U.S. (CONUS),
while another trough is depicted over the Southeast and western Atlantic. Near-
to slightly above-normal 500-hPa heights are forecast over the Hawaiian Islands.

Enhanced chances for above-normal temperatures are predicted over most of the
CONUS due to the anticipated mid-level ridging, generally above-normal 500-hPa
height anomalies, and increased southwesterly surface flow, supported by most
of the dynamical temperature forecast tools. Probabilities favoring above
normal temperatures exceed 80% for parts of the Central Great Basin.
Below-normal temperature probabilities are increased over Alaska, including the
Aleutians and Southeast Alaska, closer to the mid-level trough and surface
storminess. In Hawaii, above-normal temperature probabilities are slightly
favored underneath near- to weak positive height anomalies.

Anomalous mid-level ridging favors below-normal precipitation over parts of the
Northern and Central Great Basin extending eastward to portions of the western
Upper Mississippi Valley. Above-normal precipitation is likely over the Pacific
Northwest and parts of northern California in association with a trough
predicted over the Gulf of Alaska. Above-normal precipitation probabilities are
also increased over much of the eastern and the south-central CONUS due to
southerly return flow associated with mean surface high pressure over the
Southeast and the mid-level trough expected to linger in the region through
much of the period, and supported by most of the dynamical precipitation
forecast tools. In Alaska, above-normal precipitation chances are elevated over
much of Alaska due to the trend toward increased troughing to the south and
southwest of the state later in the period, consistent with most temperature
guidance. In Hawaii, below-normal precipitation probabilities are slightly
elevated across Hawaii Islands, consistent with the consolidation precipitation
forecast tool.

The official 6-10 day 500-hPa height blend consists of 30% of Today`s GFS
Superensemble 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 model solutions and forecast temperature and precipitation
tools.

8-14 DAY OUTLOOK FOR JUN 05 - 11 2024

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.The GEFS and ECMWF are in good agreement
regarding a ridge with above-normal 500-hPa heights over the western and
central CONUS during the week-2 period. Weak anomalous troughing is forecast
over the eastern CONUS. Strong troughing and negative 500-hPa height anomalies
are persistent over much of Alaska and the Gulf of Alaska. Near- to slightly
above-normal 500-hPa heights are still predicted over the Hawaiian Islands.

The subtropical ridge and broadly above-normal 500-hPa heights as well as
increased southwesterly surface flow over the south-central CONUS favor
elevated probabilities for near- to above-normal temperatures for much of the
CONUS, with the highest probabilities persisting across portions of Northern
and Central Great Basin. One exception is over parts of the Ohio and Tennessee
Valleys as well as portions of the southern Upper Great Lakes favoring slightly
below-normal temperatures due to lingering influence from a trough and negative
500-hPa anomalies predicted over the region. In Alaska, below-normal
temperature chances are increased over southern portions of the state, while
above-normal temperatures are likely over northern parts of the state. In
Hawaii, above-normal temperatures are slightly favored over the State,
consistent with the consolidation temperature forecast tool.

Increased probabilities for above-normal precipitation are favored across much
of the southwestern and northeastern CONUS, supported by most of the
precipitation forecast tools. There is a tilt toward elevated below-normal
precipitation probabilities across the Pacific Northwest extending eastward to
the western Upper Great Lakes, under a ridge and positive 500-hPa anomalies
predicted over the region. There are enhanced chances for above-normal
precipitation over much of Alaska, under a moist Pacific air mass and some
potential influence from the strong troughing centered near southern Alaska.
Slightly drier than normal weather is likely across the Hawaii islands,
consistent with the consolidation precipitation forecast tool.

The official 8-14 day 500-hPa height blend consists of: 30% of Today`s GFS
Superensemble 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, with
good run-to-run continuity among forecast models, offset by differences between
models regarding strength and position of various synoptic features.


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
June 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:
19660514 - 19660519 - 20040529 - 19620601 - 19890519


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:
19660515 - 20040529 - 19620530 - 19660520 - 19890520


6-10 DAY OUTLOOK TABLE
Outlook for Jun 03 - 07 2024

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    A     OREGON      A    A     NRN CALIF   A    N
SRN CALIF   A    N     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    B
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      A    N     OKLAHOMA    A    A
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     A    A
MINNESOTA   A    N     IOWA        A    B     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    N
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    N     FL PENIN    A    N     AK N SLOPE  B    A
AK ALEUTIAN B    N     AK WESTERN  B    A     AK INT BSN  B    A
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    A



8-14 DAY OUTLOOK TABLE
Outlook for Jun 05 - 11 2024

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

$$