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000
FXUS06 KWBC 221913
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Mon April 22 2024

6-10 DAY OUTLOOK FOR APR 28 - MAY 02, 2024

A variable 500-hPa circulation pattern is forecast over the region of North
America during the 6-10 day period. At the start of the period a trough is
forecast near the coast of the Alaska Panhandle and British Columbia, and a
weak trough is forecast over the central contiguous U.S. (CONUS). A weak trough
is forecast over Mainland Alaska during the period. A ridge is generally
predicted over the eastern CONUS by ensemble mean forecasts at the start of the
period, retrogressing into the central CONUS over time, as a predicted trough
moves into the West.

Above normal temperatures are favored for the Aleutians and southern half of
Mainland Alaska during the 6-10 day period under southerly mid-level flow.
Below normal temperatures are favored for northern Mainland Alaska, under a
predicted trough. Below normal temperatures are favored for the Pacific
Northwest, under a predicted trough during the period. Above normal
temperatures are likely across most of the remainder of the CONUS with a ridge
predicted over the eastern and central CONUS. Above normal temperatures are
slightly favored for northwestern islands of Hawaii supported by the Auto
forecast.

Above normal precipitation is favored for interior areas of central Mainland
Alaska and the Alaska Panhandle, consistent with most dynamical model
forecasts, and under a predicted trough. Near normal precipitation is favored
for much of the southwestern CONUS, where little or no precipitation is
expected during the period for these climatologically relatively dry regions.
Above normal precipitation is favored across much of the northern CONUS from
the Pacific Northwest, ahead of a predicted trough, and for the Great Plains
and Mississippi Valley with southerly surface moisture transport, as well as
far northern areas of the Northeast, as predicted by the consolidation of
calibrated dynamical model precipitation forecasts. Above normal precipitation
is slightly favored across Hawaii supported by the Auto forecast.

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, with
good agreement in the overall circulation pattern for the period, offset by
weaker signals and some disagreement among precipitation and temperature tools.


8-14 DAY OUTLOOK FOR APR 30 - MAY 06, 2024

The overall 500-hPa circulation pattern predicted for the 6-10 day period
mostly persists into the 8-14 day period. Weak anomalies with slightly below
average 500-hPa heights continue to be predicted over northern Mainland Alaska,
while positive 500-hPa height anomalies are predicted over the Aleutians and
south coast. A weak trough is predicted over the western CONUS for the 8-14 day
period, while positive 500-hPa height anomalies are predicted over the eastern
two-thirds of the CONUS. Overall, predicted 500-hPa anomalies have weakened in
the 8-14 day period with increased uncertainty.

Above normal temperatures continue to be favored for Alaska, outside of
northern and western Mainland Alaska, where near normal temperatures are
favored, supported by the consolidation of calibrated dynamical model
forecasts. Near to below normal temperatures are slightly favored for the West,
under a weak trough. Above normal temperatures continue to be likely over the
remainder of the CONUS, under predicted positive 500-hPa height anomalies. Near
normal temperatures are forecast for Hawaii.

Broad troughing to the west of Alaska leads to a slight tilt towards above
normal precipitation across most of the state, excluding far northwestern
climatologically dry areas of the Mainland and the southern Alaska Panhandle.
Above normal precipitation is slightly favored for the northwestern and
north-central CONUS ahead of the predicted weak trough over the west coast.
Above normal precipitation is also slightly favored for the Great Plains and
upper Mississippi Valley with southerly surface moisture transport into this
region. Near normal precipitation is favored for most of the eastern CONUS as
there is uncertainty among model forecasts, while below normal precipitation is
slightly favored for the eastern Gulf Coast under high pressure. Above normal
precipitation is slightly favored across Hawaii supported by the Auto forecast.

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: Slightly below average, 2 out of
5, with general agreement in the overall circulation pattern for the period,
offset by weaker 500-hPa height anomalies and weaker signals and some
disagreement among precipitation and temperature 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 May
16.


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:
19510402 - 19520402 - 19530402 - 19540402 - 19550402


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:
19510401 - 19520401 - 19530401 - 19540401 - 19550401


6-10 DAY OUTLOOK TABLE
Outlook for Apr 28 - May 02, 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      N    N
W MONTANA   N    A     E MONTANA   A    A     WYOMING     A    A
UTAH        A    N     ARIZONA     A    N     COLORADO    A    N
NEW MEXICO  A    A     N DAKOTA    A    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    A
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    A     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    A
VERMONT     A    A     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    B     VIRGINIA    A    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    N
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  B    N
AK ALEUTIAN A    N     AK WESTERN  A    N     AK INT BSN  N    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    N



8-14 DAY OUTLOOK TABLE
Outlook for Apr 30 - May 06, 2024

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   A    N     IDAHO       N    A     NEVADA      N    N
W MONTANA   N    A     E MONTANA   A    A     WYOMING     A    A
UTAH        A    N     ARIZONA     A    N     COLORADO    A    N
NEW MEXICO  A    A     N DAKOTA    A    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    A
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   A    A
ILLINOIS    A    N     MISSISSIPPI A    N     MICHIGAN    A    N
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     A    N     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    N
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  N    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     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.

$$