Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
094
FXUS06 KWBC 301911
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Thu May 30 2024
6-10 DAY OUTLOOK FOR JUN 05 - 09 2024
Today`s model solutions are in good agreement on a moderately amplified 500-hPa
circulation pattern across North America during the 6-10 day period. The manual
500-hPa height blend is based on the 0Z ensemble means from the GEFS, ECMWF,
and Canadian ensemble models. A trough predicted over western Mainland Alaska,
the Aleutians, and the North Pacific at the start of the period progresses
southeastward as mid-level heights rise over Mainland Alaska during the period
in the GEFS and ECMWF ensemble means. The manual blend predicts an amplified
trough and negative 500-hPa height anomalies over southwestern Alaska and the
North Pacific. A ridge and positive 500-hPa height anomalies are predicted over
the western contiguous U.S. (CONUS). Ensemble mean model forecasts from the
GEFS and ECMWF predict positive 500-hPa height anomalies over the northeastern
CONUS at the start of the 6-10 day period and negative 500-hPa height
anomalies, associated with a developing trough, later in the period. Slightly
below zero 500-hPa height anomalies are predicted over the eastern CONUS in the
6-10 day mean manual blend, while positive anomalies are predicted over New
England.
Enhanced chances for above-normal temperatures are predicted over the western
CONUS due to the predicted mid-level ridge and positive 500-hPa height
anomalies, and supported by most dynamical model temperature forecast tools.
Probabilities favoring above-normal temperatures exceed 80% for parts of the
central Great Basin. Above-normal temperatures are also favored for the Gulf
Coast states and much of the eastern CONUS, supported by the temperature
consolidation. Near- to below-normal temperatures are slightly favored for
parts of the Central and Upper Mississippi Valley region, under the predicted
trough. Probabilities for below-normal temperatures are enhanced over western
and southern Alaska, including the Aleutians and Southeast Alaska, under the
predicted trough and enhanced precipitation, while near- to above-normal
temperatures are slightly favored for northeastern Mainland Alaska, as a ridge
pushes into the region later in the period. Near-normal temperatures are
favored for Hawaii, where temperature forecast tools are in disagreement.
Above-normal precipitation is favored for most of Mainland Alaska and Southeast
Alaska, with southerly flow ahead of a predicted trough over the North Pacific.
A predicted anomalous mid-level ridge favors below-normal precipitation from
the Pacific Northwest across the Northern Rockies into parts of the Upper
Mississippi Valley. Above normal precipitation is slightly favored from eastern
New Mexico and much of Texas into parts of the Southern Plains and Central
Mississippi Valley, consistent with most dynamical model precipitation
forecasts. Median precipitation accumulation predictions by the precipitation
consolidation tool are as little as one or two millimeters during the 6-10 day
period in semi-arid regions of the Southwest. However, any precipitation in
arid regions would be considered above-normal. Above-normal precipitation is
also favored for the northeastern CONUS, consistent with most dynamical model
precipitation tools. Near- to below-normal precipitation is favored for the
Southeast, consistent with the precipitation consolidation. Probabilities of
below-normal precipitation are slightly enhanced across Hawaii, consistent with
the consolidation precipitation forecast tool.
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: About average, 3 out of 5, due to
good agreement among model solutions on the mean circulation pattern, offset by
an evolving pattern and some differences among forecast temperature and
precipitation tools.
8-14 DAY OUTLOOK FOR JUN 07 - 13 2024
Ensemble mean solutions for the 8-14 day period 500-hPa height forecast are
consistent with the overall mid-level circulation pattern across North America
in the 6-10 day period forecast. Positive 500-hPa height anomalies are
predicted over Mainland Alaska during the 8-14 day period, with the center of
negative 500-hPa height anomalies shifting southward into the North Pacific. An
amplified ridge and associated positive 500-hPa height anomalies are predicted
over the western half of the CONUS in the manual blend, while a trough and
negative 500-hPa height anomalies are predicted over the eastern CONUS during
week 2.
Below-normal temperatures continue to be favored for southern areas of Alaska,
including the Aleutians and Southeast Alaska, associated with the predicted
trough over the Gulf of Alaska at the start of the period. Above normal
temperatures are slightly favored for northern Mainland Alaska, consistent with
most temperature tools including the consolidation. A predicted ridge over the
western CONUS and positive 500-hPa height anomalies favor above-normal
temperatures for the western CONUS, with probabilities exceeding 70 percent
over parts of the Northwest. Below-normal temperatures are favored over most of
the eastern CONUS, under a predicted trough during the period. Above-normal
temperatures continue to be likely for much of the Gulf Coast and southern
Atlantic Coast, consistent with dynamical model forecast tools. Near-normal
temperatures are slightly favored for New England, where temperature forecast
tools are inconsistent. Near-normal temperatures continue to be favored for
Hawaii, where temperature forecast tools are in disagreement.
Above-normal precipitation continues to be very slightly favored for most of
Alaska, consistent with most dynamical model forecast tools, and under
southerly flow. Below-normal precipitation is favored for the northern tier of
the CONUS from Washington and northern Oregon to the Northern Plains, under a
predicted ridge. Above normal precipitation continues to be slightly favored
from eastern New Mexico and much of Texas into parts of the Central Plains,
consistent with most dynamical model precipitation forecasts. Above-normal
precipitation is favored for much of the northeastern CONUS, ahead of a
predicted trough. Near-normal precipitation is favored for the Southeast,
consistent with the precipitation consolidation. Below-normal precipitation is
favored across Hawaii, consistent with the consolidation precipitation forecast
tool.
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
consistent evolution of the forecast pattern among ensemble mean model
forecasts, offset by increasing differences among precipitation forecast tools.
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
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:
20030514 - 19660514 - 19660520 - 20040530 - 19840529
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:
20030513 - 19660513 - 19550527 - 20040529 - 19840529
6-10 DAY OUTLOOK TABLE
Outlook for Jun 05 - 09 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A N ARIZONA A N COLORADO A A
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 N W TEXAS A A
MINNESOTA N B IOWA N B MISSOURI N N
ARKANSAS A A LOUISIANA A N WISCONSIN N N
ILLINOIS N N MISSISSIPPI A N MICHIGAN N A
INDIANA N N OHIO A A KENTUCKY N N
TENNESSEE A N ALABAMA A 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 A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A B FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B N AK WESTERN B A AK INT BSN N A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
Outlook for Jun 07 - 13 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A A
UTAH A N ARIZONA A N COLORADO A A
NEW MEXICO A A N DAKOTA N B S DAKOTA B B
NEBRASKA B N KANSAS B A OKLAHOMA N A
N TEXAS A A S TEXAS A N W TEXAS A A
MINNESOTA B B IOWA B N MISSOURI B N
ARKANSAS B A LOUISIANA A N WISCONSIN B N
ILLINOIS B N MISSISSIPPI A N MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B N ALABAMA A N NEW YORK B A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN B N NEW JERSEY B A W VIRGINIA B N
MARYLAND B A DELAWARE N A VIRGINIA B 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 A A
AK S INT B A AK SO COAST B A 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.
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