951
FXUS06 KWBC 101902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon June 10 2024

6-10 DAY OUTLOOK FOR JUN 16 - 20 2024

The GEFS, ECENS, and CMCE are in good agreement on an amplified longwave
pattern for mid-June with a 500-hPa trough over the western contiguous U.S.
(CONUS) and a broad ridge centered across the Midwest. This amplified 500-hPa
trough and negative height anomalies favors below-normal temperatures across
the Pacific Northwest, northern Rockies, Great Basin, and northern California.
Strong ridging and its associated positive height anomalies increase
above-normal temperature probabilities throughout the eastern and central
CONUS. The largest probabilities (above 80 percent) are forecast across the
Midwest where 5-day temperatures are forecast to average near 10 degrees F
above normal. Model solutions depict the anomalous mid-level ridging expanding
westward during the 6-10 day period with 500-hPa heights increasing to 588 dam
over the Upper Mississippi Valley and Great Lakes by day 10, June 20.

The troughing aloft favors above-normal precipitation from the Pacific
Northwest east to the northern Rockies. Downstream of the amplified trough over
the western CONUS and to the north of the 500-hPa ridge axis, above-normal
precipitation is favored for the northern Great Plains, Upper Mississippi
Valley, and Great Lakes. Model guidance has trended wetter across the central
to southern Great Plains and Middle to Lower Mississippi Valley in recent days
as enhanced tropical moisture from the Gulf of Mexico overspreads these areas.
Shortwave troughs, emerging from the longwave trough over the West, are
expected to promote daily convective rainfall throughout the Great Plains and
Mississippi Valley. Although tropical cyclone development remains highly
uncertain across the Gulf of Mexico through mid-June, easterly waves and
anomalous low to mid-level moisture are likely to increase above-normal
precipitation probabilities along and near the Gulf Coast. The GEFS, ECENS, and
CMCE agree with a 5-day precipitation maximum of more than 2 inches across
southern Louisiana. Precipitation amounts vary for Florida with the ECENS model
much wetter than the GEFS.

Multi-model ensemble mean solutions depict a 500-hPa ridge over western
Mainland Alaska with positive height anomalies throughout the state. Therefore,
increased above-normal temperature probabilities are forecast for nearly all of
Alaska except for the Aleutian Islands. Along with the favored warmth,
below-normal precipitation is most likely for a majority of Alaska due to the
ridging aloft. The GEFS and ECMWF reforecast tools and analog tool derived from
the manual 500-hPa height blend tilt slightly wet for northeastern Mainland
Alaska.

Based on the GEFS and ECMWF reforecast tools, near to above-normal temperature
and precipitation are favored for Hawaii.

The official 6-10 day 500-hPa height blend consists of 35% of Today`s 6z GFS
Ensemble Mean centered on Day 8, 40% of Today`s 0z European Ensemble Mean
centered on Day 8, and 25% of Today`s 0z Canadian Ensemble Mean centered on Day
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Forecast confidence: Above
average, 4 out of 5, due to an amplified longwave pattern and good agreement
among the temperature and precipitation tools.

8-14 DAY OUTLOOK FOR JUN 18 - 24 2024

Model solutions are in good agreement and consistent that the amplified 500-hPa
trough weakens over the western CONUS, while the anomalous mid-level ridge
expands throughout the lower 48 states. The ECENS has the strongest ridging,
but all the ensemble means depict 500-hPa heights of 588 dam or greater north
of the 40th parallel during week-2 with heights peaking close to 594 dam over
the Southwest, southern Great Plains, and Lower Mississippi Valley. Based on
the predicted longwave pattern, above-normal temperatures are favored for
nearly all of the CONUS. The largest probabilities (above 70 percent) are
forecast for the Midwest and Mid-Atlantic where the greatest 500-hPa height
departures are predicted.  Above-normal temperature probabilities are slightly
lower across parts of Texas where moist topsoil in northeastern parts of the
state could provide a slight cooling effect and also enhanced rainfall and
cloudiness are expected. Lingering cooler-than-normal temperatures early in
week-2 and the uncalibrated GEFS and ECENS tools support a slight tilt towards
below-normal temperatures across the Pacific Northwest and northern Rockies.

Easterly waves and enhanced low-level moisture from the Gulf of Mexico increase
chances for above-normal precipitation across parts of the Southeast, Gulf
Coast States, and southern Great Plains. This favored wet area extends west to
parts of New Mexico and Arizona as the enhanced moisture is likely to spread
northwest from the Rio Grande Valley. Arizona and western New Mexico remain
quite dry climatologically through mid to late June so only low amounts of
precipitation could be in the upper tercile.  Shortwave troughs tracking from
the Pacific Northwest and to the north of the expanding ridge axis favor a
swath of increased above-normal precipitation probabilities from the Pacific
Northwest east to the northern Great Plains and Upper Mississippi Valley. In
between the favored wet areas of the CONUS, precipitation tools depict weak
signals and near normal precipitation is favored at this time. According to the
GEFS reforecast and uncalibrated model output, below-normal precipitation is
most likely across the Great Basin, central Rockies, and central high Plains.

Increased above-normal temperature probabilities are forecast for Mainland
Alaska due to positive 500-hPa height anomalies. Reforecast tools are in good
agreement for below-normal temperatures favored for the Aleutian Islands.
Precipitation tools offer weak signals with below (above)-normal precipitation
probabilities slightly elevated across northeastern (western) Mainland Alaska.

Based on the GEFS and ECMWF models, near to below-normal temperatures are
favored for Hawaii. Increased above-normal precipitation probabilities are
forecast throughout Hawaii.

The official 8-14 day 500-hPa height blend consists of: 35% of Today`s 6z GFS
Ensemble Mean centered on Day 11, 40% of Today`s 0z European Ensemble Mean
centered on Day 11, and 25% of Today`s 0z Canadian Ensemble Mean centered on
Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Forecast confidence: Average, 3
out of 5, due to good agreement among the temperature tools offset by less
agreement among the precipitation tools along with lower predictability
associated with convective rainfall.


FORECASTER: Brad Pugh

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:
20050528 - 19920620 - 20030530 - 19870624 - 19770618


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:
20050528 - 19770617 - 20060612 - 20030530 - 19920620


6-10 DAY OUTLOOK TABLE
Outlook for Jun 16 - 20 2024

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



8-14 DAY OUTLOOK TABLE
Outlook for Jun 18 - 24 2024

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

$$