880
FXUS06 KWBC 041903
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Tue June 04 2024

6-10 DAY OUTLOOK FOR JUN 10 - 14 2024

The ECENS, GEFS, and Canadian ensemble mean predicted 500-hPa heights are in
good agreement with each other for a robust mid-level ridge and trough across
the western and eastern contiguous U.S. (CONUS) respectively. A weak shortwave
trough is forecast to undercut the ridging in the West. In Alaska, near-normal
heights are forecast across much of the state but negative 500-hPa height
anomalies shifted east relative to yesterday and are likely to bring more
substantial changes to the height pattern over the CONUS during week-2. For
Hawaii, slightly above-normal mid-level heights are forecast.

During the 6-10 day period, a cold front is forecast to be progressing across
the eastern CONUS. This will help to maintain below-normal temperature chances
across much of the eastern CONUS. However, the frontal system may not reach the
Gulf Coast region where dynamical tools continue to bring strong chances for
above-normal temperatures, particularly to South Texas and southern Florida.
The GEFS has come into better agreement with the ECENS for the western extent
of the below-normal temperature chances across the Plains, bringing it a shade
further west relative to prior forecasts. In the West, above-normal
temperatures are strongly favored across most of the region. There are slightly
reduced temperature chances across Southern California and the Desert Southwest
where an undercutting trough may reduce above-normal temperatures. For Alaska,
below-normal temperatures remain forecast for southern Alaska. The rest of the
Mainland is favored to have near- to above-normal temperatures during the
period. In Hawaii, the consolidation tool is less warm than prior forecasts and
coming into better agreement with a cooler blend of models forecast, therefore,
below-normal temperatures are favored for much of Hawaii.

The precipitation forecast across the southeastern CONUS is rather uncertain
with fairly different solutions among the model tools. The GEFS based tools are
forecasting drier than normal conditions across much of the eastern CONUS.
While the ECENS based tools are forecasting above-normal precipitation across
the southeastern CONUS along a frontal boundary that is likely to be in the
region. The wetter ECENS reforecast tool has been performing better across the
Southeast in recent weeks and a slight tilt towards above-normal precipitation
is favored. Across the northern tier of the CONUS from the West Coast to the
Great Lakes, below-normal precipitation is forecast. A shortwave trough,
undercutting the ridge aloft, favors above-normal precipitation from the
central Rockies southeastward to the central and southern Great Plains. In the
Northeast and Mid-Atlantic, a departing low-pressure system and associated
frontal region is likely to bring above-normal precipitation. Above-normal
precipitation is favored across much of Alaska, with the best chances of
above-normal precipitation favored for parts of southeastern Mainland Alaska.
Above-normal precipitation is favored for Hawaii with the consolidation tool
forecasting less dry conditions relative to yesterday.

The official 6-10 day 500-hPa height blend consists of 40% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 40% of Today`s 0z European Ensemble Mean
centered on Day 8, and 20% 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 height and temperatures tools is offset by
reduced agreement in the precipitation outlook.

8-14 DAY OUTLOOK FOR JUN 12 - 18 2024

The mid-level height pattern for week-2 is transitioning away from a ridge and
trough pattern across the western and eastern CONUS, respectively, towards
ridging across the Plains and troughing along the coasts. The GEFS is faster in
establishing the new regime with troughing along the West Coast by around day
10. The ECENS is a day or two slower relative to the GEFS but there is good
agreement for a transition to occur. As a result, the 500-hPa manual blend has
a deeper trough along the West Coast and more enhanced ridging across the
Plains relative to yesterday. In Alaska, near to above-normal 500-hPa height
are forecast with ridging trying to develop across the Gulf of Alaska. In
Hawaii, near-normal heights are forecast.

Below-normal temperature chances across the eastern CONUS are substantially
lower relative to yesterday with above-normal chances developing across the
upper Midwest and Northeast. Above-normal temperatures remain forecast during
the week-2 period across much of the western CONUS, Rio-Grande Valley, and Gulf
Coast. Mid-level ridging looks likely to persist through much of the period
across the interior-West. However, along the immediate West Coast,
probabilities for above-normal temperature are substantially reduced relative
to prior forecasts and the mid-level trough becomes more established by the
middle to end of the period. The sub-tropical mid-level high pressure looks
likely to remain fairly well established. One concern further east, across
Florida, is the potential for a heavy rain event that may limit above-normal
temperatures. This reduces confidence in above-normal temperatures relative to
what some of the dynamical tools would support. In Alaska, above-normal
temperatures are favored in the northern third of the Mainland with near- to
below-normal temperatures favored across the southern Mainland, Aleutians and
Southeast Alaska. Tools are generally a little warmer across the southern
Mainland relative to prior days as some ridging may try to become established
across parts of Alaska by the end of the period. In Hawaii, a slight tilt
towards below-normal temperatures is favored. There continues to be a large
amount of disagreement among the dynamical model tools.

The precipitation forecast is quite uncertain across most of the CONUS during
week-2 with limited support for above or below-normal precipitation across the
country. Above-normal precipitation is favored ahead and at the base of the
trough forecast across the eastern CONUS. The region with strongest chances for
above-normal is across parts of Florida where a wave of tropical moisture may
enhance precipitation amounts. Behind the trough, below-normal precipitation is
favored. Across the interior West, above-normal precipitation is slightly
favored with good agreement among the tools for a slight tilt among the model
tools. However, there is broad disagreement in the raw tools for precipitation
in the Pacific Northwest, where near-normal precipitation is favored. In
Alaska, a slight tilt towards above-normal precipitation is favored beneath
near-normal heights and weak troughing. In Hawaii, above-normal precipitation,
consistent with a blend of models forecast.

The official 8-14 day 500-hPa height blend consists of: 10% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 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 20%
of Today`s 0z Canadian Ensemble Mean centered on Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below-Average, 2 out of 5, Fair
agreement among the dynamical height and temperatures tools is offset by
reduced agreement in the precipitation outlook and lower mid-level height
anomalies as a pattern transition occurs during the period.

FORECASTER: Ryan Bolt

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:
20030515 - 19880528 - 19550526 - 19730521 - 20010516


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:
20030515 - 19550527 - 19880529 - 19730522 - 19520529


6-10 DAY OUTLOOK TABLE
Outlook for Jun 10 - 14 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    A
UTAH        A    N     ARIZONA     A    N     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    N
NEBRASKA    B    N     KANSAS      B    A     OKLAHOMA    B    A
N TEXAS     N    A     S TEXAS     A    A     W TEXAS     A    A
MINNESOTA   B    B     IOWA        B    B     MISSOURI    B    N
ARKANSAS    B    N     LOUISIANA   N    A     WISCONSIN   B    N
ILLINOIS    B    B     MISSISSIPPI B    N     MICHIGAN    B    N
INDIANA     B    N     OHIO        B    N     KENTUCKY    B    B
TENNESSEE   B    B     ALABAMA     B    N     NEW YORK    B    A
VERMONT     N    A     NEW HAMP    N    A     MAINE       N    A
MASS        N    A     CONN        B    A     RHODE IS    N    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  N    N     GEORGIA     N    N
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  N    N
AK ALEUTIAN B    N     AK WESTERN  N    N     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 12 - 18 2024

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

$$